MAJ des dépendances

vendor/github.com/Jille/raft-grpc-transport/LICENSE

@@ -0,0 +1,25 @@
+BSD 2-Clause License
+
+Copyright (c) 2020, Jille Timmermans
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/Jille/raft-grpc-transport/README.md

@@ -0,0 +1,20 @@
+# raft-grpc-transport
+
+[![Godoc](https://godoc.org/github.com/Jille/raft-grpc-transport?status.svg)](https://godoc.org/github.com/Jille/raft-grpc-transport)
+
+This library provides a [Transport](https://godoc.org/github.com/hashicorp/raft#Transport) for https://github.com/hashicorp/raft over gRPC.
+
+One benefit of this is that gRPC is easy to multiplex over a single port.
+
+## Usage
+
+```go
+// ...
+tm := transport.New(raft.ServerAddress(myAddress), []grpc.DialOption{grpc.WithInsecure()})
+s := grpc.NewServer()
+tm.Register(s)
+r, err := raft.NewRaft(..., tm.Transport())
+// ...
+```
+
+Want more example code? Check out main.go at https://github.com/Jille/raft-grpc-example

vendor/github.com/Jille/raft-grpc-transport/fromproto.go

@@ -0,0 +1,146 @@
+package transport
+
+import (
+	pb "github.com/Jille/raft-grpc-transport/proto"
+	"github.com/hashicorp/raft"
+)
+
+func decodeAppendEntriesRequest(m *pb.AppendEntriesRequest) *raft.AppendEntriesRequest {
+	return &raft.AppendEntriesRequest{
+		RPCHeader:         decodeRPCHeader(m.RpcHeader),
+		Term:              m.Term,
+		Leader:            m.Leader,
+		PrevLogEntry:      m.PrevLogEntry,
+		PrevLogTerm:       m.PrevLogTerm,
+		Entries:           decodeLogs(m.Entries),
+		LeaderCommitIndex: m.LeaderCommitIndex,
+	}
+}
+
+func decodeRPCHeader(m *pb.RPCHeader) raft.RPCHeader {
+	return raft.RPCHeader{
+		ProtocolVersion: raft.ProtocolVersion(m.ProtocolVersion),
+		ID:              m.Id,
+		Addr:            m.Addr,
+	}
+}
+
+func decodeLogs(m []*pb.Log) []*raft.Log {
+	ret := make([]*raft.Log, len(m))
+	for i, l := range m {
+		ret[i] = decodeLog(l)
+	}
+	return ret
+}
+
+func decodeLog(m *pb.Log) *raft.Log {
+	return &raft.Log{
+		Index:      m.Index,
+		Term:       m.Term,
+		Type:       decodeLogType(m.Type),
+		Data:       m.Data,
+		Extensions: m.Extensions,
+		AppendedAt: m.AppendedAt.AsTime(),
+	}
+}
+
+func decodeLogType(m pb.Log_LogType) raft.LogType {
+	switch m {
+	case pb.Log_LOG_COMMAND:
+		return raft.LogCommand
+	case pb.Log_LOG_NOOP:
+		return raft.LogNoop
+	case pb.Log_LOG_ADD_PEER_DEPRECATED:
+		return raft.LogAddPeerDeprecated
+	case pb.Log_LOG_REMOVE_PEER_DEPRECATED:
+		return raft.LogRemovePeerDeprecated
+	case pb.Log_LOG_BARRIER:
+		return raft.LogBarrier
+	case pb.Log_LOG_CONFIGURATION:
+		return raft.LogConfiguration
+	default:
+		panic("invalid LogType")
+	}
+}
+
+func decodeAppendEntriesResponse(m *pb.AppendEntriesResponse) *raft.AppendEntriesResponse {
+	return &raft.AppendEntriesResponse{
+		RPCHeader:      decodeRPCHeader(m.RpcHeader),
+		Term:           m.Term,
+		LastLog:        m.LastLog,
+		Success:        m.Success,
+		NoRetryBackoff: m.NoRetryBackoff,
+	}
+}
+
+func decodeRequestVoteRequest(m *pb.RequestVoteRequest) *raft.RequestVoteRequest {
+	return &raft.RequestVoteRequest{
+		RPCHeader:          decodeRPCHeader(m.RpcHeader),
+		Term:               m.Term,
+		Candidate:          m.Candidate,
+		LastLogIndex:       m.LastLogIndex,
+		LastLogTerm:        m.LastLogTerm,
+		LeadershipTransfer: m.LeadershipTransfer,
+	}
+}
+
+func decodeRequestVoteResponse(m *pb.RequestVoteResponse) *raft.RequestVoteResponse {
+	return &raft.RequestVoteResponse{
+		RPCHeader: decodeRPCHeader(m.RpcHeader),
+		Term:      m.Term,
+		Peers:     m.Peers,
+		Granted:   m.Granted,
+	}
+}
+
+func decodeInstallSnapshotRequest(m *pb.InstallSnapshotRequest) *raft.InstallSnapshotRequest {
+	return &raft.InstallSnapshotRequest{
+		RPCHeader:          decodeRPCHeader(m.RpcHeader),
+		SnapshotVersion:    raft.SnapshotVersion(m.SnapshotVersion),
+		Term:               m.Term,
+		Leader:             m.Leader,
+		LastLogIndex:       m.LastLogIndex,
+		LastLogTerm:        m.LastLogTerm,
+		Peers:              m.Peers,
+		Configuration:      m.Configuration,
+		ConfigurationIndex: m.ConfigurationIndex,
+		Size:               m.Size,
+	}
+}
+
+func decodeInstallSnapshotResponse(m *pb.InstallSnapshotResponse) *raft.InstallSnapshotResponse {
+	return &raft.InstallSnapshotResponse{
+		RPCHeader: decodeRPCHeader(m.RpcHeader),
+		Term:      m.Term,
+		Success:   m.Success,
+	}
+}
+
+func decodeTimeoutNowRequest(m *pb.TimeoutNowRequest) *raft.TimeoutNowRequest {
+	return &raft.TimeoutNowRequest{
+		RPCHeader: decodeRPCHeader(m.RpcHeader),
+	}
+}
+
+func decodeTimeoutNowResponse(m *pb.TimeoutNowResponse) *raft.TimeoutNowResponse {
+	return &raft.TimeoutNowResponse{
+		RPCHeader: decodeRPCHeader(m.RpcHeader),
+	}
+}
+
+func decodeRequestPreVoteRequest(m *pb.RequestPreVoteRequest) *raft.RequestPreVoteRequest {
+	return &raft.RequestPreVoteRequest{
+		RPCHeader:    decodeRPCHeader(m.RpcHeader),
+		Term:         m.Term,
+		LastLogIndex: m.LastLogIndex,
+		LastLogTerm:  m.LastLogTerm,
+	}
+}
+
+func decodeRequestPreVoteResponse(m *pb.RequestPreVoteResponse) *raft.RequestPreVoteResponse {
+	return &raft.RequestPreVoteResponse{
+		RPCHeader: decodeRPCHeader(m.RpcHeader),
+		Term:      m.Term,
+		Granted:   m.Granted,
+	}
+}

vendor/github.com/Jille/raft-grpc-transport/grpcapi.go

@@ -0,0 +1,146 @@
+package transport
+
+import (
+	"context"
+	"io"
+
+	pb "github.com/Jille/raft-grpc-transport/proto"
+	"github.com/hashicorp/raft"
+)
+
+// These are requests incoming over gRPC that we need to relay to the Raft engine.
+
+type gRPCAPI struct {
+	manager *Manager
+
+	// "Unsafe" to ensure compilation fails if new methods are added but not implemented
+	pb.UnsafeRaftTransportServer
+}
+
+func (g gRPCAPI) handleRPC(command interface{}, data io.Reader) (interface{}, error) {
+	ch := make(chan raft.RPCResponse, 1)
+	rpc := raft.RPC{
+		Command:  command,
+		RespChan: ch,
+		Reader:   data,
+	}
+	if isHeartbeat(command) {
+		// We can take the fast path and use the heartbeat callback and skip the queue in g.manager.rpcChan.
+		g.manager.heartbeatFuncMtx.Lock()
+		fn := g.manager.heartbeatFunc
+		g.manager.heartbeatFuncMtx.Unlock()
+		if fn != nil {
+			fn(rpc)
+			goto wait
+		}
+	}
+	select {
+	case g.manager.rpcChan <- rpc:
+	case <-g.manager.shutdownCh:
+		return nil, raft.ErrTransportShutdown
+	}
+
+wait:
+	select {
+	case resp := <-ch:
+		if resp.Error != nil {
+			return nil, resp.Error
+		}
+		return resp.Response, nil
+	case <-g.manager.shutdownCh:
+		return nil, raft.ErrTransportShutdown
+	}
+}
+
+func (g gRPCAPI) AppendEntries(ctx context.Context, req *pb.AppendEntriesRequest) (*pb.AppendEntriesResponse, error) {
+	resp, err := g.handleRPC(decodeAppendEntriesRequest(req), nil)
+	if err != nil {
+		return nil, err
+	}
+	return encodeAppendEntriesResponse(resp.(*raft.AppendEntriesResponse)), nil
+}
+
+func (g gRPCAPI) RequestVote(ctx context.Context, req *pb.RequestVoteRequest) (*pb.RequestVoteResponse, error) {
+	resp, err := g.handleRPC(decodeRequestVoteRequest(req), nil)
+	if err != nil {
+		return nil, err
+	}
+	return encodeRequestVoteResponse(resp.(*raft.RequestVoteResponse)), nil
+}
+
+func (g gRPCAPI) TimeoutNow(ctx context.Context, req *pb.TimeoutNowRequest) (*pb.TimeoutNowResponse, error) {
+	resp, err := g.handleRPC(decodeTimeoutNowRequest(req), nil)
+	if err != nil {
+		return nil, err
+	}
+	return encodeTimeoutNowResponse(resp.(*raft.TimeoutNowResponse)), nil
+}
+
+func (g gRPCAPI) RequestPreVote(ctx context.Context, req *pb.RequestPreVoteRequest) (*pb.RequestPreVoteResponse, error) {
+	resp, err := g.handleRPC(decodeRequestPreVoteRequest(req), nil)
+	if err != nil {
+		return nil, err
+	}
+	return encodeRequestPreVoteResponse(resp.(*raft.RequestPreVoteResponse)), nil
+}
+
+func (g gRPCAPI) InstallSnapshot(s pb.RaftTransport_InstallSnapshotServer) error {
+	isr, err := s.Recv()
+	if err != nil {
+		return err
+	}
+	resp, err := g.handleRPC(decodeInstallSnapshotRequest(isr), &snapshotStream{s, isr.GetData()})
+	if err != nil {
+		return err
+	}
+	return s.SendAndClose(encodeInstallSnapshotResponse(resp.(*raft.InstallSnapshotResponse)))
+}
+
+type snapshotStream struct {
+	s pb.RaftTransport_InstallSnapshotServer
+
+	buf []byte
+}
+
+func (s *snapshotStream) Read(b []byte) (int, error) {
+	if len(s.buf) > 0 {
+		n := copy(b, s.buf)
+		s.buf = s.buf[n:]
+		return n, nil
+	}
+	m, err := s.s.Recv()
+	if err != nil {
+		return 0, err
+	}
+	n := copy(b, m.GetData())
+	if n < len(m.GetData()) {
+		s.buf = m.GetData()[n:]
+	}
+	return n, nil
+}
+
+func (g gRPCAPI) AppendEntriesPipeline(s pb.RaftTransport_AppendEntriesPipelineServer) error {
+	for {
+		msg, err := s.Recv()
+		if err != nil {
+			return err
+		}
+		resp, err := g.handleRPC(decodeAppendEntriesRequest(msg), nil)
+		if err != nil {
+			// TODO(quis): One failure doesn't have to break the entire stream?
+			// Or does it all go wrong when it's out of order anyway?
+			return err
+		}
+		if err := s.Send(encodeAppendEntriesResponse(resp.(*raft.AppendEntriesResponse))); err != nil {
+			return err
+		}
+	}
+}
+
+func isHeartbeat(command interface{}) bool {
+	req, ok := command.(*raft.AppendEntriesRequest)
+	if !ok {
+		return false
+	}
+	return req.Term != 0 && len(req.Leader) != 0 && req.PrevLogEntry == 0 && req.PrevLogTerm == 0 && len(req.Entries) == 0 && req.LeaderCommitIndex == 0
+}

vendor/github.com/Jille/raft-grpc-transport/options.go

@@ -0,0 +1,13 @@
+package transport
+
+import "time"
+
+type Option func(m *Manager)
+
+// WithHeartbeatTimeout configures the transport to not wait for more than d
+// for a heartbeat to be executed by a remote peer.
+func WithHeartbeatTimeout(d time.Duration) Option {
+	return func(m *Manager) {
+		m.heartbeatTimeout = d
+	}
+}

vendor/github.com/Jille/raft-grpc-transport/proto/Makefile

@@ -0,0 +1,6 @@
+transport.pb.go: transport.proto
+	protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative transport.proto
+
+force:
+	rm -f transport.pb.go
+	make transport.pb.go

vendor/github.com/Jille/raft-grpc-transport/proto/transport.proto

@@ -0,0 +1,122 @@
+syntax = "proto3";
+
+option go_package = "github.com/Jille/raft-grpc-transport/proto";
+
+import "google/protobuf/timestamp.proto";
+
+service RaftTransport {
+  // AppendEntriesPipeline opens an AppendEntries message stream.
+  rpc AppendEntriesPipeline(stream AppendEntriesRequest) returns (stream AppendEntriesResponse) {}
+
+  // AppendEntries performs a single append entries request / response.
+  rpc AppendEntries(AppendEntriesRequest) returns (AppendEntriesResponse) {}
+  // RequestVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+  rpc RequestVote(RequestVoteRequest) returns (RequestVoteResponse) {}
+  // TimeoutNow is used to start a leadership transfer to the target node.
+  rpc TimeoutNow(TimeoutNowRequest) returns (TimeoutNowResponse) {}
+  // InstallSnapshot is the command sent to a Raft peer to bootstrap its log (and state machine) from a snapshot on another peer.
+  rpc InstallSnapshot(stream InstallSnapshotRequest) returns (InstallSnapshotResponse) {}
+  // RequestPreVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+  rpc RequestPreVote(RequestPreVoteRequest) returns (RequestPreVoteResponse) {}
+}
+
+message RPCHeader {
+	int64 protocol_version = 1;
+	bytes id = 2;
+	bytes addr = 3;
+}
+
+message Log {
+	enum LogType {
+		LOG_COMMAND = 0;
+		LOG_NOOP = 1;
+		LOG_ADD_PEER_DEPRECATED = 2;
+		LOG_REMOVE_PEER_DEPRECATED = 3;
+		LOG_BARRIER = 4;
+		LOG_CONFIGURATION = 5;
+	}
+	uint64 index = 1;
+	uint64 term = 2;
+	LogType type = 3;
+	bytes data = 4;
+	bytes extensions = 5;
+	google.protobuf.Timestamp appended_at = 6;
+}
+
+message AppendEntriesRequest {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	bytes leader = 3;
+	uint64 prev_log_entry = 4;
+	uint64 prev_log_term = 5;
+	repeated Log entries = 6;
+	uint64 leader_commit_index = 7;
+}
+
+message AppendEntriesResponse {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	uint64 last_log = 3;
+	bool success = 4;
+	bool no_retry_backoff = 5;
+}
+
+message RequestVoteRequest {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	bytes candidate = 3;
+	uint64 last_log_index = 4;
+	uint64 last_log_term = 5;
+	bool leadership_transfer = 6;
+}
+
+message RequestVoteResponse {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	bytes peers = 3;
+	bool granted = 4;
+}
+
+message TimeoutNowRequest {
+	RPCHeader rpc_header = 1;
+}
+
+message TimeoutNowResponse {
+	RPCHeader rpc_header = 1;
+}
+
+// The first InstallSnapshotRequest on the stream contains all the metadata.
+// All further messages contain only data.
+message InstallSnapshotRequest {
+	RPCHeader rpc_header = 1;
+	int64 snapshot_version = 11;
+	uint64 term = 2;
+	bytes leader = 3;
+	uint64 last_log_index = 4;
+	uint64 last_log_term = 5;
+	bytes peers = 6;
+	bytes configuration = 7;
+	uint64 configuration_index = 8;
+	int64 size = 9;
+
+	bytes data = 10;
+}
+
+message InstallSnapshotResponse {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	bool success = 3;
+}
+
+message RequestPreVoteRequest {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	uint64 last_log_index = 3;
+	uint64 last_log_term = 4;
+}
+
+message RequestPreVoteResponse {
+	RPCHeader rpc_header = 1;
+	uint64 term = 2;
+	bool granted = 3;
+}

vendor/github.com/Jille/raft-grpc-transport/proto/transport_grpc.pb.go

@@ -0,0 +1,364 @@
+// Code generated by protoc-gen-go-grpc. DO NOT EDIT.
+// versions:
+// - protoc-gen-go-grpc v1.2.0
+// - protoc             v3.21.3
+// source: transport.proto
+
+package proto
+
+import (
+	context "context"
+	grpc "google.golang.org/grpc"
+	codes "google.golang.org/grpc/codes"
+	status "google.golang.org/grpc/status"
+)
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+// Requires gRPC-Go v1.32.0 or later.
+const _ = grpc.SupportPackageIsVersion7
+
+// RaftTransportClient is the client API for RaftTransport service.
+//
+// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.
+type RaftTransportClient interface {
+	// AppendEntriesPipeline opens an AppendEntries message stream.
+	AppendEntriesPipeline(ctx context.Context, opts ...grpc.CallOption) (RaftTransport_AppendEntriesPipelineClient, error)
+	// AppendEntries performs a single append entries request / response.
+	AppendEntries(ctx context.Context, in *AppendEntriesRequest, opts ...grpc.CallOption) (*AppendEntriesResponse, error)
+	// RequestVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+	RequestVote(ctx context.Context, in *RequestVoteRequest, opts ...grpc.CallOption) (*RequestVoteResponse, error)
+	// TimeoutNow is used to start a leadership transfer to the target node.
+	TimeoutNow(ctx context.Context, in *TimeoutNowRequest, opts ...grpc.CallOption) (*TimeoutNowResponse, error)
+	// InstallSnapshot is the command sent to a Raft peer to bootstrap its log (and state machine) from a snapshot on another peer.
+	InstallSnapshot(ctx context.Context, opts ...grpc.CallOption) (RaftTransport_InstallSnapshotClient, error)
+	// RequestPreVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+	RequestPreVote(ctx context.Context, in *RequestPreVoteRequest, opts ...grpc.CallOption) (*RequestPreVoteResponse, error)
+}
+
+type raftTransportClient struct {
+	cc grpc.ClientConnInterface
+}
+
+func NewRaftTransportClient(cc grpc.ClientConnInterface) RaftTransportClient {
+	return &raftTransportClient{cc}
+}
+
+func (c *raftTransportClient) AppendEntriesPipeline(ctx context.Context, opts ...grpc.CallOption) (RaftTransport_AppendEntriesPipelineClient, error) {
+	stream, err := c.cc.NewStream(ctx, &RaftTransport_ServiceDesc.Streams[0], "/RaftTransport/AppendEntriesPipeline", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &raftTransportAppendEntriesPipelineClient{stream}
+	return x, nil
+}
+
+type RaftTransport_AppendEntriesPipelineClient interface {
+	Send(*AppendEntriesRequest) error
+	Recv() (*AppendEntriesResponse, error)
+	grpc.ClientStream
+}
+
+type raftTransportAppendEntriesPipelineClient struct {
+	grpc.ClientStream
+}
+
+func (x *raftTransportAppendEntriesPipelineClient) Send(m *AppendEntriesRequest) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *raftTransportAppendEntriesPipelineClient) Recv() (*AppendEntriesResponse, error) {
+	m := new(AppendEntriesResponse)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func (c *raftTransportClient) AppendEntries(ctx context.Context, in *AppendEntriesRequest, opts ...grpc.CallOption) (*AppendEntriesResponse, error) {
+	out := new(AppendEntriesResponse)
+	err := c.cc.Invoke(ctx, "/RaftTransport/AppendEntries", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *raftTransportClient) RequestVote(ctx context.Context, in *RequestVoteRequest, opts ...grpc.CallOption) (*RequestVoteResponse, error) {
+	out := new(RequestVoteResponse)
+	err := c.cc.Invoke(ctx, "/RaftTransport/RequestVote", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *raftTransportClient) TimeoutNow(ctx context.Context, in *TimeoutNowRequest, opts ...grpc.CallOption) (*TimeoutNowResponse, error) {
+	out := new(TimeoutNowResponse)
+	err := c.cc.Invoke(ctx, "/RaftTransport/TimeoutNow", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *raftTransportClient) InstallSnapshot(ctx context.Context, opts ...grpc.CallOption) (RaftTransport_InstallSnapshotClient, error) {
+	stream, err := c.cc.NewStream(ctx, &RaftTransport_ServiceDesc.Streams[1], "/RaftTransport/InstallSnapshot", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &raftTransportInstallSnapshotClient{stream}
+	return x, nil
+}
+
+type RaftTransport_InstallSnapshotClient interface {
+	Send(*InstallSnapshotRequest) error
+	CloseAndRecv() (*InstallSnapshotResponse, error)
+	grpc.ClientStream
+}
+
+type raftTransportInstallSnapshotClient struct {
+	grpc.ClientStream
+}
+
+func (x *raftTransportInstallSnapshotClient) Send(m *InstallSnapshotRequest) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *raftTransportInstallSnapshotClient) CloseAndRecv() (*InstallSnapshotResponse, error) {
+	if err := x.ClientStream.CloseSend(); err != nil {
+		return nil, err
+	}
+	m := new(InstallSnapshotResponse)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func (c *raftTransportClient) RequestPreVote(ctx context.Context, in *RequestPreVoteRequest, opts ...grpc.CallOption) (*RequestPreVoteResponse, error) {
+	out := new(RequestPreVoteResponse)
+	err := c.cc.Invoke(ctx, "/RaftTransport/RequestPreVote", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// RaftTransportServer is the server API for RaftTransport service.
+// All implementations must embed UnimplementedRaftTransportServer
+// for forward compatibility
+type RaftTransportServer interface {
+	// AppendEntriesPipeline opens an AppendEntries message stream.
+	AppendEntriesPipeline(RaftTransport_AppendEntriesPipelineServer) error
+	// AppendEntries performs a single append entries request / response.
+	AppendEntries(context.Context, *AppendEntriesRequest) (*AppendEntriesResponse, error)
+	// RequestVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+	RequestVote(context.Context, *RequestVoteRequest) (*RequestVoteResponse, error)
+	// TimeoutNow is used to start a leadership transfer to the target node.
+	TimeoutNow(context.Context, *TimeoutNowRequest) (*TimeoutNowResponse, error)
+	// InstallSnapshot is the command sent to a Raft peer to bootstrap its log (and state machine) from a snapshot on another peer.
+	InstallSnapshot(RaftTransport_InstallSnapshotServer) error
+	// RequestPreVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+	RequestPreVote(context.Context, *RequestPreVoteRequest) (*RequestPreVoteResponse, error)
+	mustEmbedUnimplementedRaftTransportServer()
+}
+
+// UnimplementedRaftTransportServer must be embedded to have forward compatible implementations.
+type UnimplementedRaftTransportServer struct {
+}
+
+func (UnimplementedRaftTransportServer) AppendEntriesPipeline(RaftTransport_AppendEntriesPipelineServer) error {
+	return status.Errorf(codes.Unimplemented, "method AppendEntriesPipeline not implemented")
+}
+func (UnimplementedRaftTransportServer) AppendEntries(context.Context, *AppendEntriesRequest) (*AppendEntriesResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method AppendEntries not implemented")
+}
+func (UnimplementedRaftTransportServer) RequestVote(context.Context, *RequestVoteRequest) (*RequestVoteResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method RequestVote not implemented")
+}
+func (UnimplementedRaftTransportServer) TimeoutNow(context.Context, *TimeoutNowRequest) (*TimeoutNowResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method TimeoutNow not implemented")
+}
+func (UnimplementedRaftTransportServer) InstallSnapshot(RaftTransport_InstallSnapshotServer) error {
+	return status.Errorf(codes.Unimplemented, "method InstallSnapshot not implemented")
+}
+func (UnimplementedRaftTransportServer) RequestPreVote(context.Context, *RequestPreVoteRequest) (*RequestPreVoteResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method RequestPreVote not implemented")
+}
+func (UnimplementedRaftTransportServer) mustEmbedUnimplementedRaftTransportServer() {}
+
+// UnsafeRaftTransportServer may be embedded to opt out of forward compatibility for this service.
+// Use of this interface is not recommended, as added methods to RaftTransportServer will
+// result in compilation errors.
+type UnsafeRaftTransportServer interface {
+	mustEmbedUnimplementedRaftTransportServer()
+}
+
+func RegisterRaftTransportServer(s grpc.ServiceRegistrar, srv RaftTransportServer) {
+	s.RegisterService(&RaftTransport_ServiceDesc, srv)
+}
+
+func _RaftTransport_AppendEntriesPipeline_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(RaftTransportServer).AppendEntriesPipeline(&raftTransportAppendEntriesPipelineServer{stream})
+}
+
+type RaftTransport_AppendEntriesPipelineServer interface {
+	Send(*AppendEntriesResponse) error
+	Recv() (*AppendEntriesRequest, error)
+	grpc.ServerStream
+}
+
+type raftTransportAppendEntriesPipelineServer struct {
+	grpc.ServerStream
+}
+
+func (x *raftTransportAppendEntriesPipelineServer) Send(m *AppendEntriesResponse) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *raftTransportAppendEntriesPipelineServer) Recv() (*AppendEntriesRequest, error) {
+	m := new(AppendEntriesRequest)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func _RaftTransport_AppendEntries_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(AppendEntriesRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(RaftTransportServer).AppendEntries(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/RaftTransport/AppendEntries",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(RaftTransportServer).AppendEntries(ctx, req.(*AppendEntriesRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _RaftTransport_RequestVote_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(RequestVoteRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(RaftTransportServer).RequestVote(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/RaftTransport/RequestVote",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(RaftTransportServer).RequestVote(ctx, req.(*RequestVoteRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _RaftTransport_TimeoutNow_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(TimeoutNowRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(RaftTransportServer).TimeoutNow(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/RaftTransport/TimeoutNow",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(RaftTransportServer).TimeoutNow(ctx, req.(*TimeoutNowRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _RaftTransport_InstallSnapshot_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(RaftTransportServer).InstallSnapshot(&raftTransportInstallSnapshotServer{stream})
+}
+
+type RaftTransport_InstallSnapshotServer interface {
+	SendAndClose(*InstallSnapshotResponse) error
+	Recv() (*InstallSnapshotRequest, error)
+	grpc.ServerStream
+}
+
+type raftTransportInstallSnapshotServer struct {
+	grpc.ServerStream
+}
+
+func (x *raftTransportInstallSnapshotServer) SendAndClose(m *InstallSnapshotResponse) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *raftTransportInstallSnapshotServer) Recv() (*InstallSnapshotRequest, error) {
+	m := new(InstallSnapshotRequest)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func _RaftTransport_RequestPreVote_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(RequestPreVoteRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(RaftTransportServer).RequestPreVote(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/RaftTransport/RequestPreVote",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(RaftTransportServer).RequestPreVote(ctx, req.(*RequestPreVoteRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+// RaftTransport_ServiceDesc is the grpc.ServiceDesc for RaftTransport service.
+// It's only intended for direct use with grpc.RegisterService,
+// and not to be introspected or modified (even as a copy)
+var RaftTransport_ServiceDesc = grpc.ServiceDesc{
+	ServiceName: "RaftTransport",
+	HandlerType: (*RaftTransportServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "AppendEntries",
+			Handler:    _RaftTransport_AppendEntries_Handler,
+		},
+		{
+			MethodName: "RequestVote",
+			Handler:    _RaftTransport_RequestVote_Handler,
+		},
+		{
+			MethodName: "TimeoutNow",
+			Handler:    _RaftTransport_TimeoutNow_Handler,
+		},
+		{
+			MethodName: "RequestPreVote",
+			Handler:    _RaftTransport_RequestPreVote_Handler,
+		},
+	},
+	Streams: []grpc.StreamDesc{
+		{
+			StreamName:    "AppendEntriesPipeline",
+			Handler:       _RaftTransport_AppendEntriesPipeline_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
+		{
+			StreamName:    "InstallSnapshot",
+			Handler:       _RaftTransport_InstallSnapshot_Handler,
+			ClientStreams: true,
+		},
+	},
+	Metadata: "transport.proto",
+}

vendor/github.com/Jille/raft-grpc-transport/raftapi.go

@@ -0,0 +1,329 @@
+package transport
+
+import (
+	"context"
+	"io"
+	"sync"
+	"time"
+
+	pb "github.com/Jille/raft-grpc-transport/proto"
+	"github.com/hashicorp/raft"
+	"google.golang.org/grpc"
+)
+
+// These are calls from the Raft engine that we need to send out over gRPC.
+
+type raftAPI struct {
+	manager *Manager
+}
+
+var _ raft.Transport = raftAPI{}
+var _ raft.WithClose = raftAPI{}
+var _ raft.WithPeers = raftAPI{}
+var _ raft.WithPreVote = raftAPI{}
+
+type conn struct {
+	clientConn *grpc.ClientConn
+	client     pb.RaftTransportClient
+	mtx        sync.Mutex
+}
+
+// Consumer returns a channel that can be used to consume and respond to RPC requests.
+func (r raftAPI) Consumer() <-chan raft.RPC {
+	return r.manager.rpcChan
+}
+
+// LocalAddr is used to return our local address to distinguish from our peers.
+func (r raftAPI) LocalAddr() raft.ServerAddress {
+	return r.manager.localAddress
+}
+
+func (r raftAPI) getPeer(target raft.ServerAddress) (pb.RaftTransportClient, error) {
+	r.manager.connectionsMtx.Lock()
+	c, ok := r.manager.connections[target]
+	if !ok {
+		c = &conn{}
+		c.mtx.Lock()
+		r.manager.connections[target] = c
+	}
+	r.manager.connectionsMtx.Unlock()
+	if ok {
+		c.mtx.Lock()
+	}
+	defer c.mtx.Unlock()
+	if c.clientConn == nil {
+		conn, err := grpc.Dial(string(target), r.manager.dialOptions...)
+		if err != nil {
+			return nil, err
+		}
+		c.clientConn = conn
+		c.client = pb.NewRaftTransportClient(conn)
+	}
+	return c.client, nil
+}
+
+// AppendEntries sends the appropriate RPC to the target node.
+func (r raftAPI) AppendEntries(id raft.ServerID, target raft.ServerAddress, args *raft.AppendEntriesRequest, resp *raft.AppendEntriesResponse) error {
+	c, err := r.getPeer(target)
+	if err != nil {
+		return err
+	}
+	ctx := context.TODO()
+	if r.manager.heartbeatTimeout > 0 && isHeartbeat(args) {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, r.manager.heartbeatTimeout)
+		defer cancel()
+	}
+	ret, err := c.AppendEntries(ctx, encodeAppendEntriesRequest(args))
+	if err != nil {
+		return err
+	}
+	*resp = *decodeAppendEntriesResponse(ret)
+	return nil
+}
+
+// RequestVote sends the appropriate RPC to the target node.
+func (r raftAPI) RequestVote(id raft.ServerID, target raft.ServerAddress, args *raft.RequestVoteRequest, resp *raft.RequestVoteResponse) error {
+	c, err := r.getPeer(target)
+	if err != nil {
+		return err
+	}
+	ret, err := c.RequestVote(context.TODO(), encodeRequestVoteRequest(args))
+	if err != nil {
+		return err
+	}
+	*resp = *decodeRequestVoteResponse(ret)
+	return nil
+}
+
+// TimeoutNow is used to start a leadership transfer to the target node.
+func (r raftAPI) TimeoutNow(id raft.ServerID, target raft.ServerAddress, args *raft.TimeoutNowRequest, resp *raft.TimeoutNowResponse) error {
+	c, err := r.getPeer(target)
+	if err != nil {
+		return err
+	}
+	ret, err := c.TimeoutNow(context.TODO(), encodeTimeoutNowRequest(args))
+	if err != nil {
+		return err
+	}
+	*resp = *decodeTimeoutNowResponse(ret)
+	return nil
+}
+
+// RequestPreVote is the command used by a candidate to ask a Raft peer for a vote in an election.
+func (r raftAPI) RequestPreVote(id raft.ServerID, target raft.ServerAddress, args *raft.RequestPreVoteRequest, resp *raft.RequestPreVoteResponse) error {
+	c, err := r.getPeer(target)
+	if err != nil {
+		return err
+	}
+	ret, err := c.RequestPreVote(context.TODO(), encodeRequestPreVoteRequest(args))
+	if err != nil {
+		return err
+	}
+	*resp = *decodeRequestPreVoteResponse(ret)
+	return nil
+}
+
+// InstallSnapshot is used to push a snapshot down to a follower. The data is read from
+// the ReadCloser and streamed to the client.
+func (r raftAPI) InstallSnapshot(id raft.ServerID, target raft.ServerAddress, req *raft.InstallSnapshotRequest, resp *raft.InstallSnapshotResponse, data io.Reader) error {
+	c, err := r.getPeer(target)
+	if err != nil {
+		return err
+	}
+	stream, err := c.InstallSnapshot(context.TODO())
+	if err != nil {
+		return err
+	}
+	if err := stream.Send(encodeInstallSnapshotRequest(req)); err != nil {
+		return err
+	}
+	var buf [16384]byte
+	for {
+		n, err := data.Read(buf[:])
+		if err == io.EOF || (err == nil && n == 0) {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		if err := stream.Send(&pb.InstallSnapshotRequest{
+			Data: buf[:n],
+		}); err != nil {
+			return err
+		}
+	}
+	ret, err := stream.CloseAndRecv()
+	if err != nil {
+		return err
+	}
+	*resp = *decodeInstallSnapshotResponse(ret)
+	return nil
+}
+
+// AppendEntriesPipeline returns an interface that can be used to pipeline
+// AppendEntries requests.
+func (r raftAPI) AppendEntriesPipeline(id raft.ServerID, target raft.ServerAddress) (raft.AppendPipeline, error) {
+	c, err := r.getPeer(target)
+	if err != nil {
+		return nil, err
+	}
+	ctx := context.TODO()
+	ctx, cancel := context.WithCancel(ctx)
+	stream, err := c.AppendEntriesPipeline(ctx)
+	if err != nil {
+		cancel()
+		return nil, err
+	}
+	rpa := raftPipelineAPI{
+		stream:     stream,
+		cancel:     cancel,
+		inflightCh: make(chan *appendFuture, 20),
+		doneCh:     make(chan raft.AppendFuture, 20),
+	}
+	go rpa.receiver()
+	return rpa, nil
+}
+
+type raftPipelineAPI struct {
+	stream        pb.RaftTransport_AppendEntriesPipelineClient
+	cancel        func()
+	inflightChMtx sync.Mutex
+	inflightCh    chan *appendFuture
+	doneCh        chan raft.AppendFuture
+}
+
+// AppendEntries is used to add another request to the pipeline.
+// The send may block which is an effective form of back-pressure.
+func (r raftPipelineAPI) AppendEntries(req *raft.AppendEntriesRequest, resp *raft.AppendEntriesResponse) (raft.AppendFuture, error) {
+	af := &appendFuture{
+		start:   time.Now(),
+		request: req,
+		done:    make(chan struct{}),
+	}
+	if err := r.stream.Send(encodeAppendEntriesRequest(req)); err != nil {
+		return nil, err
+	}
+	r.inflightChMtx.Lock()
+	select {
+	case <-r.stream.Context().Done():
+	default:
+		r.inflightCh <- af
+	}
+	r.inflightChMtx.Unlock()
+	return af, nil
+}
+
+// Consumer returns a channel that can be used to consume
+// response futures when they are ready.
+func (r raftPipelineAPI) Consumer() <-chan raft.AppendFuture {
+	return r.doneCh
+}
+
+// Close closes the pipeline and cancels all inflight RPCs
+func (r raftPipelineAPI) Close() error {
+	r.cancel()
+	r.inflightChMtx.Lock()
+	close(r.inflightCh)
+	r.inflightChMtx.Unlock()
+	return nil
+}
+
+func (r raftPipelineAPI) receiver() {
+	for af := range r.inflightCh {
+		msg, err := r.stream.Recv()
+		if err != nil {
+			af.err = err
+		} else {
+			af.response = *decodeAppendEntriesResponse(msg)
+		}
+		close(af.done)
+		r.doneCh <- af
+	}
+}
+
+type appendFuture struct {
+	raft.AppendFuture
+
+	start    time.Time
+	request  *raft.AppendEntriesRequest
+	response raft.AppendEntriesResponse
+	err      error
+	done     chan struct{}
+}
+
+// Error blocks until the future arrives and then
+// returns the error status of the future.
+// This may be called any number of times - all
+// calls will return the same value.
+// Note that it is not OK to call this method
+// twice concurrently on the same Future instance.
+func (f *appendFuture) Error() error {
+	<-f.done
+	return f.err
+}
+
+// Start returns the time that the append request was started.
+// It is always OK to call this method.
+func (f *appendFuture) Start() time.Time {
+	return f.start
+}
+
+// Request holds the parameters of the AppendEntries call.
+// It is always OK to call this method.
+func (f *appendFuture) Request() *raft.AppendEntriesRequest {
+	return f.request
+}
+
+// Response holds the results of the AppendEntries call.
+// This method must only be called after the Error
+// method returns, and will only be valid on success.
+func (f *appendFuture) Response() *raft.AppendEntriesResponse {
+	return &f.response
+}
+
+// EncodePeer is used to serialize a peer's address.
+func (r raftAPI) EncodePeer(id raft.ServerID, addr raft.ServerAddress) []byte {
+	return []byte(addr)
+}
+
+// DecodePeer is used to deserialize a peer's address.
+func (r raftAPI) DecodePeer(p []byte) raft.ServerAddress {
+	return raft.ServerAddress(p)
+}
+
+// SetHeartbeatHandler is used to setup a heartbeat handler
+// as a fast-pass. This is to avoid head-of-line blocking from
+// disk IO. If a Transport does not support this, it can simply
+// ignore the call, and push the heartbeat onto the Consumer channel.
+func (r raftAPI) SetHeartbeatHandler(cb func(rpc raft.RPC)) {
+	r.manager.heartbeatFuncMtx.Lock()
+	r.manager.heartbeatFunc = cb
+	r.manager.heartbeatFuncMtx.Unlock()
+}
+
+func (r raftAPI) Close() error {
+	return r.manager.Close()
+}
+
+func (r raftAPI) Connect(target raft.ServerAddress, t raft.Transport) {
+	_, _ = r.getPeer(target)
+}
+
+func (r raftAPI) Disconnect(target raft.ServerAddress) {
+	r.manager.connectionsMtx.Lock()
+	c, ok := r.manager.connections[target]
+	if !ok {
+		delete(r.manager.connections, target)
+	}
+	r.manager.connectionsMtx.Unlock()
+	if ok {
+		c.mtx.Lock()
+		c.mtx.Unlock()
+		_ = c.clientConn.Close()
+	}
+}
+
+func (r raftAPI) DisconnectAll() {
+	_ = r.manager.disconnectAll()
+}

vendor/github.com/Jille/raft-grpc-transport/toproto.go

@@ -0,0 +1,147 @@
+package transport
+
+import (
+	pb "github.com/Jille/raft-grpc-transport/proto"
+	"github.com/hashicorp/raft"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+func encodeAppendEntriesRequest(s *raft.AppendEntriesRequest) *pb.AppendEntriesRequest {
+	return &pb.AppendEntriesRequest{
+		RpcHeader:         encodeRPCHeader(s.RPCHeader),
+		Term:              s.Term,
+		Leader:            s.Leader,
+		PrevLogEntry:      s.PrevLogEntry,
+		PrevLogTerm:       s.PrevLogTerm,
+		Entries:           encodeLogs(s.Entries),
+		LeaderCommitIndex: s.LeaderCommitIndex,
+	}
+}
+
+func encodeRPCHeader(s raft.RPCHeader) *pb.RPCHeader {
+	return &pb.RPCHeader{
+		ProtocolVersion: int64(s.ProtocolVersion),
+		Id:              s.ID,
+		Addr:            s.Addr,
+	}
+}
+
+func encodeLogs(s []*raft.Log) []*pb.Log {
+	ret := make([]*pb.Log, len(s))
+	for i, l := range s {
+		ret[i] = encodeLog(l)
+	}
+	return ret
+}
+
+func encodeLog(s *raft.Log) *pb.Log {
+	return &pb.Log{
+		Index:      s.Index,
+		Term:       s.Term,
+		Type:       encodeLogType(s.Type),
+		Data:       s.Data,
+		Extensions: s.Extensions,
+		AppendedAt: timestamppb.New(s.AppendedAt),
+	}
+}
+
+func encodeLogType(s raft.LogType) pb.Log_LogType {
+	switch s {
+	case raft.LogCommand:
+		return pb.Log_LOG_COMMAND
+	case raft.LogNoop:
+		return pb.Log_LOG_NOOP
+	case raft.LogAddPeerDeprecated:
+		return pb.Log_LOG_ADD_PEER_DEPRECATED
+	case raft.LogRemovePeerDeprecated:
+		return pb.Log_LOG_REMOVE_PEER_DEPRECATED
+	case raft.LogBarrier:
+		return pb.Log_LOG_BARRIER
+	case raft.LogConfiguration:
+		return pb.Log_LOG_CONFIGURATION
+	default:
+		panic("invalid LogType")
+	}
+}
+
+func encodeAppendEntriesResponse(s *raft.AppendEntriesResponse) *pb.AppendEntriesResponse {
+	return &pb.AppendEntriesResponse{
+		RpcHeader:      encodeRPCHeader(s.RPCHeader),
+		Term:           s.Term,
+		LastLog:        s.LastLog,
+		Success:        s.Success,
+		NoRetryBackoff: s.NoRetryBackoff,
+	}
+}
+
+func encodeRequestVoteRequest(s *raft.RequestVoteRequest) *pb.RequestVoteRequest {
+	return &pb.RequestVoteRequest{
+		RpcHeader:          encodeRPCHeader(s.RPCHeader),
+		Term:               s.Term,
+		Candidate:          s.Candidate,
+		LastLogIndex:       s.LastLogIndex,
+		LastLogTerm:        s.LastLogTerm,
+		LeadershipTransfer: s.LeadershipTransfer,
+	}
+}
+
+func encodeRequestVoteResponse(s *raft.RequestVoteResponse) *pb.RequestVoteResponse {
+	return &pb.RequestVoteResponse{
+		RpcHeader: encodeRPCHeader(s.RPCHeader),
+		Term:      s.Term,
+		Peers:     s.Peers,
+		Granted:   s.Granted,
+	}
+}
+
+func encodeInstallSnapshotRequest(s *raft.InstallSnapshotRequest) *pb.InstallSnapshotRequest {
+	return &pb.InstallSnapshotRequest{
+		RpcHeader:          encodeRPCHeader(s.RPCHeader),
+		SnapshotVersion:    int64(s.SnapshotVersion),
+		Term:               s.Term,
+		Leader:             s.Leader,
+		LastLogIndex:       s.LastLogIndex,
+		LastLogTerm:        s.LastLogTerm,
+		Peers:              s.Peers,
+		Configuration:      s.Configuration,
+		ConfigurationIndex: s.ConfigurationIndex,
+		Size:               s.Size,
+	}
+}
+
+func encodeInstallSnapshotResponse(s *raft.InstallSnapshotResponse) *pb.InstallSnapshotResponse {
+	return &pb.InstallSnapshotResponse{
+		RpcHeader: encodeRPCHeader(s.RPCHeader),
+		Term:      s.Term,
+		Success:   s.Success,
+	}
+}
+
+func encodeTimeoutNowRequest(s *raft.TimeoutNowRequest) *pb.TimeoutNowRequest {
+	return &pb.TimeoutNowRequest{
+		RpcHeader: encodeRPCHeader(s.RPCHeader),
+	}
+}
+
+func encodeTimeoutNowResponse(s *raft.TimeoutNowResponse) *pb.TimeoutNowResponse {
+	return &pb.TimeoutNowResponse{
+		RpcHeader: encodeRPCHeader(s.RPCHeader),
+	}
+}
+
+func encodeRequestPreVoteRequest(s *raft.RequestPreVoteRequest) *pb.RequestPreVoteRequest {
+	return &pb.RequestPreVoteRequest{
+		RpcHeader:    encodeRPCHeader(s.RPCHeader),
+		Term:         s.Term,
+		LastLogIndex: s.LastLogIndex,
+		LastLogTerm:  s.LastLogTerm,
+	}
+}
+
+func encodeRequestPreVoteResponse(s *raft.RequestPreVoteResponse) *pb.RequestPreVoteResponse {
+	return &pb.RequestPreVoteResponse{
+		RpcHeader: encodeRPCHeader(s.RPCHeader),
+		Term:      s.Term,
+		Granted:   s.Granted,
+	}
+}

vendor/github.com/Jille/raft-grpc-transport/transport.go

@@ -0,0 +1,97 @@
+// Package transport provides a Transport for github.com/hashicorp/raft over gRPC.
+package transport
+
+import (
+	"sync"
+	"time"
+
+	pb "github.com/Jille/raft-grpc-transport/proto"
+	"github.com/hashicorp/go-multierror"
+	"github.com/hashicorp/raft"
+	"github.com/pkg/errors"
+	"google.golang.org/grpc"
+)
+
+var (
+	errCloseErr = errors.New("error closing connections")
+)
+
+type Manager struct {
+	localAddress raft.ServerAddress
+	dialOptions  []grpc.DialOption
+
+	rpcChan          chan raft.RPC
+	heartbeatFunc    func(raft.RPC)
+	heartbeatFuncMtx sync.Mutex
+	heartbeatTimeout time.Duration
+
+	connectionsMtx sync.Mutex
+	connections    map[raft.ServerAddress]*conn
+
+	shutdown     bool
+	shutdownCh   chan struct{}
+	shutdownLock sync.Mutex
+}
+
+// New creates both components of raft-grpc-transport: a gRPC service and a Raft Transport.
+func New(localAddress raft.ServerAddress, dialOptions []grpc.DialOption, options ...Option) *Manager {
+	m := &Manager{
+		localAddress: localAddress,
+		dialOptions:  dialOptions,
+
+		rpcChan:     make(chan raft.RPC),
+		connections: map[raft.ServerAddress]*conn{},
+
+		shutdownCh: make(chan struct{}),
+	}
+	for _, opt := range options {
+		opt(m)
+	}
+	return m
+}
+
+// Register the RaftTransport gRPC service on a gRPC server.
+func (m *Manager) Register(s grpc.ServiceRegistrar) {
+	pb.RegisterRaftTransportServer(s, gRPCAPI{manager: m})
+}
+
+// Transport returns a raft.Transport that communicates over gRPC.
+func (m *Manager) Transport() raft.Transport {
+	return raftAPI{m}
+}
+
+func (m *Manager) Close() error {
+	m.shutdownLock.Lock()
+	defer m.shutdownLock.Unlock()
+
+	if m.shutdown {
+		return nil
+	}
+
+	close(m.shutdownCh)
+	m.shutdown = true
+	return m.disconnectAll()
+}
+
+func (m *Manager) disconnectAll() error {
+	m.connectionsMtx.Lock()
+	defer m.connectionsMtx.Unlock()
+
+	err := errCloseErr
+	for k, conn := range m.connections {
+		// Lock conn.mtx to ensure Dial() is complete
+		conn.mtx.Lock()
+		conn.mtx.Unlock()
+		closeErr := conn.clientConn.Close()
+		if closeErr != nil {
+			err = multierror.Append(err, closeErr)
+		}
+		delete(m.connections, k)
+	}
+
+	if err != errCloseErr {
+		return err
+	}
+
+	return nil
+}

vendor/github.com/armon/go-metrics/LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Armon Dadgar
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/armon/go-metrics/README.md

@@ -0,0 +1,91 @@
+go-metrics
+==========
+
+This library provides a `metrics` package which can be used to instrument code,
+expose application metrics, and profile runtime performance in a flexible manner.
+
+Current API: [![GoDoc](https://godoc.org/github.com/armon/go-metrics?status.svg)](https://godoc.org/github.com/armon/go-metrics)
+
+Sinks
+-----
+
+The `metrics` package makes use of a `MetricSink` interface to support delivery
+to any type of backend. Currently the following sinks are provided:
+
+* StatsiteSink : Sinks to a [statsite](https://github.com/armon/statsite/) instance (TCP)
+* StatsdSink: Sinks to a [StatsD](https://github.com/etsy/statsd/) / statsite instance (UDP)
+* PrometheusSink: Sinks to a [Prometheus](http://prometheus.io/) metrics endpoint (exposed via HTTP for scrapes)
+* InmemSink : Provides in-memory aggregation, can be used to export stats
+* FanoutSink : Sinks to multiple sinks. Enables writing to multiple statsite instances for example.
+* BlackholeSink : Sinks to nowhere
+
+In addition to the sinks, the `InmemSignal` can be used to catch a signal,
+and dump a formatted output of recent metrics. For example, when a process gets
+a SIGUSR1, it can dump to stderr recent performance metrics for debugging.
+
+Labels
+------
+
+Most metrics do have an equivalent ending with `WithLabels`, such methods
+allow to push metrics with labels and use some features of underlying Sinks
+(ex: translated into Prometheus labels).
+
+Since some of these labels may increase greatly cardinality of metrics, the
+library allow to filter labels using a blacklist/whitelist filtering system
+which is global to all metrics.
+
+* If `Config.AllowedLabels` is not nil, then only labels specified in this value will be sent to underlying Sink, otherwise, all labels are sent by default.
+* If `Config.BlockedLabels` is not nil, any label specified in this value will not be sent to underlying Sinks.
+
+By default, both `Config.AllowedLabels` and `Config.BlockedLabels` are nil, meaning that
+no tags are filetered at all, but it allow to a user to globally block some tags with high
+cardinality at application level.
+
+Examples
+--------
+
+Here is an example of using the package:
+
+```go
+func SlowMethod() {
+    // Profiling the runtime of a method
+    defer metrics.MeasureSince([]string{"SlowMethod"}, time.Now())
+}
+
+// Configure a statsite sink as the global metrics sink
+sink, _ := metrics.NewStatsiteSink("statsite:8125")
+metrics.NewGlobal(metrics.DefaultConfig("service-name"), sink)
+
+// Emit a Key/Value pair
+metrics.EmitKey([]string{"questions", "meaning of life"}, 42)
+```
+
+Here is an example of setting up a signal handler:
+
+```go
+// Setup the inmem sink and signal handler
+inm := metrics.NewInmemSink(10*time.Second, time.Minute)
+sig := metrics.DefaultInmemSignal(inm)
+metrics.NewGlobal(metrics.DefaultConfig("service-name"), inm)
+
+// Run some code
+inm.SetGauge([]string{"foo"}, 42)
+inm.EmitKey([]string{"bar"}, 30)
+
+inm.IncrCounter([]string{"baz"}, 42)
+inm.IncrCounter([]string{"baz"}, 1)
+inm.IncrCounter([]string{"baz"}, 80)
+
+inm.AddSample([]string{"method", "wow"}, 42)
+inm.AddSample([]string{"method", "wow"}, 100)
+inm.AddSample([]string{"method", "wow"}, 22)
+
+....
+```
+
+When a signal comes in, output like the following will be dumped to stderr:
+
+    [2014-01-28 14:57:33.04 -0800 PST][G] 'foo': 42.000
+    [2014-01-28 14:57:33.04 -0800 PST][P] 'bar': 30.000
+    [2014-01-28 14:57:33.04 -0800 PST][C] 'baz': Count: 3 Min: 1.000 Mean: 41.000 Max: 80.000 Stddev: 39.509
+    [2014-01-28 14:57:33.04 -0800 PST][S] 'method.wow': Count: 3 Min: 22.000 Mean: 54.667 Max: 100.000 Stddev: 40.513

vendor/github.com/armon/go-metrics/const_unix.go

@@ -0,0 +1,12 @@
+// +build !windows
+
+package metrics
+
+import (
+	"syscall"
+)
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	DefaultSignal = syscall.SIGUSR1
+)

vendor/github.com/armon/go-metrics/const_windows.go

@@ -0,0 +1,13 @@
+// +build windows
+
+package metrics
+
+import (
+	"syscall"
+)
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	// Windows has no SIGUSR1, use SIGBREAK
+	DefaultSignal = syscall.Signal(21)
+)

vendor/github.com/armon/go-metrics/inmem.go

@@ -0,0 +1,339 @@
+package metrics
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+var spaceReplacer = strings.NewReplacer(" ", "_")
+
+// InmemSink provides a MetricSink that does in-memory aggregation
+// without sending metrics over a network. It can be embedded within
+// an application to provide profiling information.
+type InmemSink struct {
+	// How long is each aggregation interval
+	interval time.Duration
+
+	// Retain controls how many metrics interval we keep
+	retain time.Duration
+
+	// maxIntervals is the maximum length of intervals.
+	// It is retain / interval.
+	maxIntervals int
+
+	// intervals is a slice of the retained intervals
+	intervals    []*IntervalMetrics
+	intervalLock sync.RWMutex
+
+	rateDenom float64
+}
+
+// IntervalMetrics stores the aggregated metrics
+// for a specific interval
+type IntervalMetrics struct {
+	sync.RWMutex
+
+	// The start time of the interval
+	Interval time.Time
+
+	// Gauges maps the key to the last set value
+	Gauges map[string]GaugeValue
+
+	// Points maps the string to the list of emitted values
+	// from EmitKey
+	Points map[string][]float32
+
+	// Counters maps the string key to a sum of the counter
+	// values
+	Counters map[string]SampledValue
+
+	// Samples maps the key to an AggregateSample,
+	// which has the rolled up view of a sample
+	Samples map[string]SampledValue
+
+	// done is closed when this interval has ended, and a new IntervalMetrics
+	// has been created to receive any future metrics.
+	done chan struct{}
+}
+
+// NewIntervalMetrics creates a new IntervalMetrics for a given interval
+func NewIntervalMetrics(intv time.Time) *IntervalMetrics {
+	return &IntervalMetrics{
+		Interval: intv,
+		Gauges:   make(map[string]GaugeValue),
+		Points:   make(map[string][]float32),
+		Counters: make(map[string]SampledValue),
+		Samples:  make(map[string]SampledValue),
+		done:     make(chan struct{}),
+	}
+}
+
+// AggregateSample is used to hold aggregate metrics
+// about a sample
+type AggregateSample struct {
+	Count       int       // The count of emitted pairs
+	Rate        float64   // The values rate per time unit (usually 1 second)
+	Sum         float64   // The sum of values
+	SumSq       float64   `json:"-"` // The sum of squared values
+	Min         float64   // Minimum value
+	Max         float64   // Maximum value
+	LastUpdated time.Time `json:"-"` // When value was last updated
+}
+
+// Computes a Stddev of the values
+func (a *AggregateSample) Stddev() float64 {
+	num := (float64(a.Count) * a.SumSq) - math.Pow(a.Sum, 2)
+	div := float64(a.Count * (a.Count - 1))
+	if div == 0 {
+		return 0
+	}
+	return math.Sqrt(num / div)
+}
+
+// Computes a mean of the values
+func (a *AggregateSample) Mean() float64 {
+	if a.Count == 0 {
+		return 0
+	}
+	return a.Sum / float64(a.Count)
+}
+
+// Ingest is used to update a sample
+func (a *AggregateSample) Ingest(v float64, rateDenom float64) {
+	a.Count++
+	a.Sum += v
+	a.SumSq += (v * v)
+	if v < a.Min || a.Count == 1 {
+		a.Min = v
+	}
+	if v > a.Max || a.Count == 1 {
+		a.Max = v
+	}
+	a.Rate = float64(a.Sum) / rateDenom
+	a.LastUpdated = time.Now()
+}
+
+func (a *AggregateSample) String() string {
+	if a.Count == 0 {
+		return "Count: 0"
+	} else if a.Stddev() == 0 {
+		return fmt.Sprintf("Count: %d Sum: %0.3f LastUpdated: %s", a.Count, a.Sum, a.LastUpdated)
+	} else {
+		return fmt.Sprintf("Count: %d Min: %0.3f Mean: %0.3f Max: %0.3f Stddev: %0.3f Sum: %0.3f LastUpdated: %s",
+			a.Count, a.Min, a.Mean(), a.Max, a.Stddev(), a.Sum, a.LastUpdated)
+	}
+}
+
+// NewInmemSinkFromURL creates an InmemSink from a URL. It is used
+// (and tested) from NewMetricSinkFromURL.
+func NewInmemSinkFromURL(u *url.URL) (MetricSink, error) {
+	params := u.Query()
+
+	interval, err := time.ParseDuration(params.Get("interval"))
+	if err != nil {
+		return nil, fmt.Errorf("Bad 'interval' param: %s", err)
+	}
+
+	retain, err := time.ParseDuration(params.Get("retain"))
+	if err != nil {
+		return nil, fmt.Errorf("Bad 'retain' param: %s", err)
+	}
+
+	return NewInmemSink(interval, retain), nil
+}
+
+// NewInmemSink is used to construct a new in-memory sink.
+// Uses an aggregation interval and maximum retention period.
+func NewInmemSink(interval, retain time.Duration) *InmemSink {
+	rateTimeUnit := time.Second
+	i := &InmemSink{
+		interval:     interval,
+		retain:       retain,
+		maxIntervals: int(retain / interval),
+		rateDenom:    float64(interval.Nanoseconds()) / float64(rateTimeUnit.Nanoseconds()),
+	}
+	i.intervals = make([]*IntervalMetrics, 0, i.maxIntervals)
+	return i
+}
+
+func (i *InmemSink) SetGauge(key []string, val float32) {
+	i.SetGaugeWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+	intv.Gauges[k] = GaugeValue{Name: name, Value: val, Labels: labels}
+}
+
+func (i *InmemSink) EmitKey(key []string, val float32) {
+	k := i.flattenKey(key)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+	vals := intv.Points[k]
+	intv.Points[k] = append(vals, val)
+}
+
+func (i *InmemSink) IncrCounter(key []string, val float32) {
+	i.IncrCounterWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+
+	agg, ok := intv.Counters[k]
+	if !ok {
+		agg = SampledValue{
+			Name:            name,
+			AggregateSample: &AggregateSample{},
+			Labels:          labels,
+		}
+		intv.Counters[k] = agg
+	}
+	agg.Ingest(float64(val), i.rateDenom)
+}
+
+func (i *InmemSink) AddSample(key []string, val float32) {
+	i.AddSampleWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+
+	agg, ok := intv.Samples[k]
+	if !ok {
+		agg = SampledValue{
+			Name:            name,
+			AggregateSample: &AggregateSample{},
+			Labels:          labels,
+		}
+		intv.Samples[k] = agg
+	}
+	agg.Ingest(float64(val), i.rateDenom)
+}
+
+// Data is used to retrieve all the aggregated metrics
+// Intervals may be in use, and a read lock should be acquired
+func (i *InmemSink) Data() []*IntervalMetrics {
+	// Get the current interval, forces creation
+	i.getInterval()
+
+	i.intervalLock.RLock()
+	defer i.intervalLock.RUnlock()
+
+	n := len(i.intervals)
+	intervals := make([]*IntervalMetrics, n)
+
+	copy(intervals[:n-1], i.intervals[:n-1])
+	current := i.intervals[n-1]
+
+	// make its own copy for current interval
+	intervals[n-1] = &IntervalMetrics{}
+	copyCurrent := intervals[n-1]
+	current.RLock()
+	*copyCurrent = *current
+	// RWMutex is not safe to copy, so create a new instance on the copy
+	copyCurrent.RWMutex = sync.RWMutex{}
+
+	copyCurrent.Gauges = make(map[string]GaugeValue, len(current.Gauges))
+	for k, v := range current.Gauges {
+		copyCurrent.Gauges[k] = v
+	}
+	// saved values will be not change, just copy its link
+	copyCurrent.Points = make(map[string][]float32, len(current.Points))
+	for k, v := range current.Points {
+		copyCurrent.Points[k] = v
+	}
+	copyCurrent.Counters = make(map[string]SampledValue, len(current.Counters))
+	for k, v := range current.Counters {
+		copyCurrent.Counters[k] = v.deepCopy()
+	}
+	copyCurrent.Samples = make(map[string]SampledValue, len(current.Samples))
+	for k, v := range current.Samples {
+		copyCurrent.Samples[k] = v.deepCopy()
+	}
+	current.RUnlock()
+
+	return intervals
+}
+
+// getInterval returns the current interval. A new interval is created if no
+// previous interval exists, or if the current time is beyond the window for the
+// current interval.
+func (i *InmemSink) getInterval() *IntervalMetrics {
+	intv := time.Now().Truncate(i.interval)
+
+	// Attempt to return the existing interval first, because it only requires
+	// a read lock.
+	i.intervalLock.RLock()
+	n := len(i.intervals)
+	if n > 0 && i.intervals[n-1].Interval == intv {
+		defer i.intervalLock.RUnlock()
+		return i.intervals[n-1]
+	}
+	i.intervalLock.RUnlock()
+
+	i.intervalLock.Lock()
+	defer i.intervalLock.Unlock()
+
+	// Re-check for an existing interval now that the lock is re-acquired.
+	n = len(i.intervals)
+	if n > 0 && i.intervals[n-1].Interval == intv {
+		return i.intervals[n-1]
+	}
+
+	current := NewIntervalMetrics(intv)
+	i.intervals = append(i.intervals, current)
+	if n > 0 {
+		close(i.intervals[n-1].done)
+	}
+
+	n++
+	// Prune old intervals if the count exceeds the max.
+	if n >= i.maxIntervals {
+		copy(i.intervals[0:], i.intervals[n-i.maxIntervals:])
+		i.intervals = i.intervals[:i.maxIntervals]
+	}
+	return current
+}
+
+// Flattens the key for formatting, removes spaces
+func (i *InmemSink) flattenKey(parts []string) string {
+	buf := &bytes.Buffer{}
+
+	joined := strings.Join(parts, ".")
+
+	spaceReplacer.WriteString(buf, joined)
+
+	return buf.String()
+}
+
+// Flattens the key for formatting along with its labels, removes spaces
+func (i *InmemSink) flattenKeyLabels(parts []string, labels []Label) (string, string) {
+	key := i.flattenKey(parts)
+	buf := bytes.NewBufferString(key)
+
+	for _, label := range labels {
+		spaceReplacer.WriteString(buf, fmt.Sprintf(";%s=%s", label.Name, label.Value))
+	}
+
+	return buf.String(), key
+}

vendor/github.com/armon/go-metrics/inmem_endpoint.go

@@ -0,0 +1,162 @@
+package metrics
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"sort"
+	"time"
+)
+
+// MetricsSummary holds a roll-up of metrics info for a given interval
+type MetricsSummary struct {
+	Timestamp string
+	Gauges    []GaugeValue
+	Points    []PointValue
+	Counters  []SampledValue
+	Samples   []SampledValue
+}
+
+type GaugeValue struct {
+	Name  string
+	Hash  string `json:"-"`
+	Value float32
+
+	Labels        []Label           `json:"-"`
+	DisplayLabels map[string]string `json:"Labels"`
+}
+
+type PointValue struct {
+	Name   string
+	Points []float32
+}
+
+type SampledValue struct {
+	Name string
+	Hash string `json:"-"`
+	*AggregateSample
+	Mean   float64
+	Stddev float64
+
+	Labels        []Label           `json:"-"`
+	DisplayLabels map[string]string `json:"Labels"`
+}
+
+// deepCopy allocates a new instance of AggregateSample
+func (source *SampledValue) deepCopy() SampledValue {
+	dest := *source
+	if source.AggregateSample != nil {
+		dest.AggregateSample = &AggregateSample{}
+		*dest.AggregateSample = *source.AggregateSample
+	}
+	return dest
+}
+
+// DisplayMetrics returns a summary of the metrics from the most recent finished interval.
+func (i *InmemSink) DisplayMetrics(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	data := i.Data()
+
+	var interval *IntervalMetrics
+	n := len(data)
+	switch {
+	case n == 0:
+		return nil, fmt.Errorf("no metric intervals have been initialized yet")
+	case n == 1:
+		// Show the current interval if it's all we have
+		interval = data[0]
+	default:
+		// Show the most recent finished interval if we have one
+		interval = data[n-2]
+	}
+
+	return newMetricSummaryFromInterval(interval), nil
+}
+
+func newMetricSummaryFromInterval(interval *IntervalMetrics) MetricsSummary {
+	interval.RLock()
+	defer interval.RUnlock()
+
+	summary := MetricsSummary{
+		Timestamp: interval.Interval.Round(time.Second).UTC().String(),
+		Gauges:    make([]GaugeValue, 0, len(interval.Gauges)),
+		Points:    make([]PointValue, 0, len(interval.Points)),
+	}
+
+	// Format and sort the output of each metric type, so it gets displayed in a
+	// deterministic order.
+	for name, points := range interval.Points {
+		summary.Points = append(summary.Points, PointValue{name, points})
+	}
+	sort.Slice(summary.Points, func(i, j int) bool {
+		return summary.Points[i].Name < summary.Points[j].Name
+	})
+
+	for hash, value := range interval.Gauges {
+		value.Hash = hash
+		value.DisplayLabels = make(map[string]string)
+		for _, label := range value.Labels {
+			value.DisplayLabels[label.Name] = label.Value
+		}
+		value.Labels = nil
+
+		summary.Gauges = append(summary.Gauges, value)
+	}
+	sort.Slice(summary.Gauges, func(i, j int) bool {
+		return summary.Gauges[i].Hash < summary.Gauges[j].Hash
+	})
+
+	summary.Counters = formatSamples(interval.Counters)
+	summary.Samples = formatSamples(interval.Samples)
+
+	return summary
+}
+
+func formatSamples(source map[string]SampledValue) []SampledValue {
+	output := make([]SampledValue, 0, len(source))
+	for hash, sample := range source {
+		displayLabels := make(map[string]string)
+		for _, label := range sample.Labels {
+			displayLabels[label.Name] = label.Value
+		}
+
+		output = append(output, SampledValue{
+			Name:            sample.Name,
+			Hash:            hash,
+			AggregateSample: sample.AggregateSample,
+			Mean:            sample.AggregateSample.Mean(),
+			Stddev:          sample.AggregateSample.Stddev(),
+			DisplayLabels:   displayLabels,
+		})
+	}
+	sort.Slice(output, func(i, j int) bool {
+		return output[i].Hash < output[j].Hash
+	})
+
+	return output
+}
+
+type Encoder interface {
+	Encode(interface{}) error
+}
+
+// Stream writes metrics using encoder.Encode each time an interval ends. Runs
+// until the request context is cancelled, or the encoder returns an error.
+// The caller is responsible for logging any errors from encoder.
+func (i *InmemSink) Stream(ctx context.Context, encoder Encoder) {
+	interval := i.getInterval()
+
+	for {
+		select {
+		case <-interval.done:
+			summary := newMetricSummaryFromInterval(interval)
+			if err := encoder.Encode(summary); err != nil {
+				return
+			}
+
+			// update interval to the next one
+			interval = i.getInterval()
+		case <-ctx.Done():
+			return
+		}
+	}
+}

vendor/github.com/armon/go-metrics/inmem_signal.go

@@ -0,0 +1,117 @@
+package metrics
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"os/signal"
+	"strings"
+	"sync"
+	"syscall"
+)
+
+// InmemSignal is used to listen for a given signal, and when received,
+// to dump the current metrics from the InmemSink to an io.Writer
+type InmemSignal struct {
+	signal syscall.Signal
+	inm    *InmemSink
+	w      io.Writer
+	sigCh  chan os.Signal
+
+	stop     bool
+	stopCh   chan struct{}
+	stopLock sync.Mutex
+}
+
+// NewInmemSignal creates a new InmemSignal which listens for a given signal,
+// and dumps the current metrics out to a writer
+func NewInmemSignal(inmem *InmemSink, sig syscall.Signal, w io.Writer) *InmemSignal {
+	i := &InmemSignal{
+		signal: sig,
+		inm:    inmem,
+		w:      w,
+		sigCh:  make(chan os.Signal, 1),
+		stopCh: make(chan struct{}),
+	}
+	signal.Notify(i.sigCh, sig)
+	go i.run()
+	return i
+}
+
+// DefaultInmemSignal returns a new InmemSignal that responds to SIGUSR1
+// and writes output to stderr. Windows uses SIGBREAK
+func DefaultInmemSignal(inmem *InmemSink) *InmemSignal {
+	return NewInmemSignal(inmem, DefaultSignal, os.Stderr)
+}
+
+// Stop is used to stop the InmemSignal from listening
+func (i *InmemSignal) Stop() {
+	i.stopLock.Lock()
+	defer i.stopLock.Unlock()
+
+	if i.stop {
+		return
+	}
+	i.stop = true
+	close(i.stopCh)
+	signal.Stop(i.sigCh)
+}
+
+// run is a long running routine that handles signals
+func (i *InmemSignal) run() {
+	for {
+		select {
+		case <-i.sigCh:
+			i.dumpStats()
+		case <-i.stopCh:
+			return
+		}
+	}
+}
+
+// dumpStats is used to dump the data to output writer
+func (i *InmemSignal) dumpStats() {
+	buf := bytes.NewBuffer(nil)
+
+	data := i.inm.Data()
+	// Skip the last period which is still being aggregated
+	for j := 0; j < len(data)-1; j++ {
+		intv := data[j]
+		intv.RLock()
+		for _, val := range intv.Gauges {
+			name := i.flattenLabels(val.Name, val.Labels)
+			fmt.Fprintf(buf, "[%v][G] '%s': %0.3f\n", intv.Interval, name, val.Value)
+		}
+		for name, vals := range intv.Points {
+			for _, val := range vals {
+				fmt.Fprintf(buf, "[%v][P] '%s': %0.3f\n", intv.Interval, name, val)
+			}
+		}
+		for _, agg := range intv.Counters {
+			name := i.flattenLabels(agg.Name, agg.Labels)
+			fmt.Fprintf(buf, "[%v][C] '%s': %s\n", intv.Interval, name, agg.AggregateSample)
+		}
+		for _, agg := range intv.Samples {
+			name := i.flattenLabels(agg.Name, agg.Labels)
+			fmt.Fprintf(buf, "[%v][S] '%s': %s\n", intv.Interval, name, agg.AggregateSample)
+		}
+		intv.RUnlock()
+	}
+
+	// Write out the bytes
+	i.w.Write(buf.Bytes())
+}
+
+// Flattens the key for formatting along with its labels, removes spaces
+func (i *InmemSignal) flattenLabels(name string, labels []Label) string {
+	buf := bytes.NewBufferString(name)
+	replacer := strings.NewReplacer(" ", "_", ":", "_")
+
+	for _, label := range labels {
+		replacer.WriteString(buf, ".")
+		replacer.WriteString(buf, label.Value)
+	}
+
+	return buf.String()
+}

vendor/github.com/armon/go-metrics/metrics.go

@@ -0,0 +1,299 @@
+package metrics
+
+import (
+	"runtime"
+	"strings"
+	"time"
+
+	iradix "github.com/hashicorp/go-immutable-radix"
+)
+
+type Label struct {
+	Name  string
+	Value string
+}
+
+func (m *Metrics) SetGauge(key []string, val float32) {
+	m.SetGaugeWithLabels(key, val, nil)
+}
+
+func (m *Metrics) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" {
+		if m.EnableHostnameLabel {
+			labels = append(labels, Label{"host", m.HostName})
+		} else if m.EnableHostname {
+			key = insert(0, m.HostName, key)
+		}
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "gauge", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.SetGaugeWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) EmitKey(key []string, val float32) {
+	if m.EnableTypePrefix {
+		key = insert(0, "kv", key)
+	}
+	if m.ServiceName != "" {
+		key = insert(0, m.ServiceName, key)
+	}
+	allowed, _ := m.allowMetric(key, nil)
+	if !allowed {
+		return
+	}
+	m.sink.EmitKey(key, val)
+}
+
+func (m *Metrics) IncrCounter(key []string, val float32) {
+	m.IncrCounterWithLabels(key, val, nil)
+}
+
+func (m *Metrics) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "counter", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.IncrCounterWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) AddSample(key []string, val float32) {
+	m.AddSampleWithLabels(key, val, nil)
+}
+
+func (m *Metrics) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "sample", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.AddSampleWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) MeasureSince(key []string, start time.Time) {
+	m.MeasureSinceWithLabels(key, start, nil)
+}
+
+func (m *Metrics) MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "timer", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	now := time.Now()
+	elapsed := now.Sub(start)
+	msec := float32(elapsed.Nanoseconds()) / float32(m.TimerGranularity)
+	m.sink.AddSampleWithLabels(key, msec, labelsFiltered)
+}
+
+// UpdateFilter overwrites the existing filter with the given rules.
+func (m *Metrics) UpdateFilter(allow, block []string) {
+	m.UpdateFilterAndLabels(allow, block, m.AllowedLabels, m.BlockedLabels)
+}
+
+// UpdateFilterAndLabels overwrites the existing filter with the given rules.
+func (m *Metrics) UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	m.filterLock.Lock()
+	defer m.filterLock.Unlock()
+
+	m.AllowedPrefixes = allow
+	m.BlockedPrefixes = block
+
+	if allowedLabels == nil {
+		// Having a white list means we take only elements from it
+		m.allowedLabels = nil
+	} else {
+		m.allowedLabels = make(map[string]bool)
+		for _, v := range allowedLabels {
+			m.allowedLabels[v] = true
+		}
+	}
+	m.blockedLabels = make(map[string]bool)
+	for _, v := range blockedLabels {
+		m.blockedLabels[v] = true
+	}
+	m.AllowedLabels = allowedLabels
+	m.BlockedLabels = blockedLabels
+
+	m.filter = iradix.New()
+	for _, prefix := range m.AllowedPrefixes {
+		m.filter, _, _ = m.filter.Insert([]byte(prefix), true)
+	}
+	for _, prefix := range m.BlockedPrefixes {
+		m.filter, _, _ = m.filter.Insert([]byte(prefix), false)
+	}
+}
+
+func (m *Metrics) Shutdown() {
+	if ss, ok := m.sink.(ShutdownSink); ok {
+		ss.Shutdown()
+	}
+}
+
+// labelIsAllowed return true if a should be included in metric
+// the caller should lock m.filterLock while calling this method
+func (m *Metrics) labelIsAllowed(label *Label) bool {
+	labelName := (*label).Name
+	if m.blockedLabels != nil {
+		_, ok := m.blockedLabels[labelName]
+		if ok {
+			// If present, let's remove this label
+			return false
+		}
+	}
+	if m.allowedLabels != nil {
+		_, ok := m.allowedLabels[labelName]
+		return ok
+	}
+	// Allow by default
+	return true
+}
+
+// filterLabels return only allowed labels
+// the caller should lock m.filterLock while calling this method
+func (m *Metrics) filterLabels(labels []Label) []Label {
+	if labels == nil {
+		return nil
+	}
+	toReturn := []Label{}
+	for _, label := range labels {
+		if m.labelIsAllowed(&label) {
+			toReturn = append(toReturn, label)
+		}
+	}
+	return toReturn
+}
+
+// Returns whether the metric should be allowed based on configured prefix filters
+// Also return the applicable labels
+func (m *Metrics) allowMetric(key []string, labels []Label) (bool, []Label) {
+	m.filterLock.RLock()
+	defer m.filterLock.RUnlock()
+
+	if m.filter == nil || m.filter.Len() == 0 {
+		return m.Config.FilterDefault, m.filterLabels(labels)
+	}
+
+	_, allowed, ok := m.filter.Root().LongestPrefix([]byte(strings.Join(key, ".")))
+	if !ok {
+		return m.Config.FilterDefault, m.filterLabels(labels)
+	}
+
+	return allowed.(bool), m.filterLabels(labels)
+}
+
+// Periodically collects runtime stats to publish
+func (m *Metrics) collectStats() {
+	for {
+		time.Sleep(m.ProfileInterval)
+		m.EmitRuntimeStats()
+	}
+}
+
+// Emits various runtime statsitics
+func (m *Metrics) EmitRuntimeStats() {
+	// Export number of Goroutines
+	numRoutines := runtime.NumGoroutine()
+	m.SetGauge([]string{"runtime", "num_goroutines"}, float32(numRoutines))
+
+	// Export memory stats
+	var stats runtime.MemStats
+	runtime.ReadMemStats(&stats)
+	m.SetGauge([]string{"runtime", "alloc_bytes"}, float32(stats.Alloc))
+	m.SetGauge([]string{"runtime", "sys_bytes"}, float32(stats.Sys))
+	m.SetGauge([]string{"runtime", "malloc_count"}, float32(stats.Mallocs))
+	m.SetGauge([]string{"runtime", "free_count"}, float32(stats.Frees))
+	m.SetGauge([]string{"runtime", "heap_objects"}, float32(stats.HeapObjects))
+	m.SetGauge([]string{"runtime", "total_gc_pause_ns"}, float32(stats.PauseTotalNs))
+	m.SetGauge([]string{"runtime", "total_gc_runs"}, float32(stats.NumGC))
+
+	// Export info about the last few GC runs
+	num := stats.NumGC
+
+	// Handle wrap around
+	if num < m.lastNumGC {
+		m.lastNumGC = 0
+	}
+
+	// Ensure we don't scan more than 256
+	if num-m.lastNumGC >= 256 {
+		m.lastNumGC = num - 255
+	}
+
+	for i := m.lastNumGC; i < num; i++ {
+		pause := stats.PauseNs[i%256]
+		m.AddSample([]string{"runtime", "gc_pause_ns"}, float32(pause))
+	}
+	m.lastNumGC = num
+}
+
+// Creates a new slice with the provided string value as the first element
+// and the provided slice values as the remaining values.
+// Ordering of the values in the provided input slice is kept in tact in the output slice.
+func insert(i int, v string, s []string) []string {
+	// Allocate new slice to avoid modifying the input slice
+	newS := make([]string, len(s)+1)
+
+	// Copy s[0, i-1] into newS
+	for j := 0; j < i; j++ {
+		newS[j] = s[j]
+	}
+
+	// Insert provided element at index i
+	newS[i] = v
+
+	// Copy s[i, len(s)-1] into newS starting at newS[i+1]
+	for j := i; j < len(s); j++ {
+		newS[j+1] = s[j]
+	}
+
+	return newS
+}

vendor/github.com/armon/go-metrics/sink.go

@@ -0,0 +1,132 @@
+package metrics
+
+import (
+	"fmt"
+	"net/url"
+)
+
+// The MetricSink interface is used to transmit metrics information
+// to an external system
+type MetricSink interface {
+	// A Gauge should retain the last value it is set to
+	SetGauge(key []string, val float32)
+	SetGaugeWithLabels(key []string, val float32, labels []Label)
+
+	// Should emit a Key/Value pair for each call
+	EmitKey(key []string, val float32)
+
+	// Counters should accumulate values
+	IncrCounter(key []string, val float32)
+	IncrCounterWithLabels(key []string, val float32, labels []Label)
+
+	// Samples are for timing information, where quantiles are used
+	AddSample(key []string, val float32)
+	AddSampleWithLabels(key []string, val float32, labels []Label)
+}
+
+type ShutdownSink interface {
+	MetricSink
+
+	// Shutdown the metric sink, flush metrics to storage, and cleanup resources.
+	// Called immediately prior to application exit. Implementations must block
+	// until metrics are flushed to storage.
+	Shutdown()
+}
+
+// BlackholeSink is used to just blackhole messages
+type BlackholeSink struct{}
+
+func (*BlackholeSink) SetGauge(key []string, val float32)                              {}
+func (*BlackholeSink) SetGaugeWithLabels(key []string, val float32, labels []Label)    {}
+func (*BlackholeSink) EmitKey(key []string, val float32)                               {}
+func (*BlackholeSink) IncrCounter(key []string, val float32)                           {}
+func (*BlackholeSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {}
+func (*BlackholeSink) AddSample(key []string, val float32)                             {}
+func (*BlackholeSink) AddSampleWithLabels(key []string, val float32, labels []Label)   {}
+
+// FanoutSink is used to sink to fanout values to multiple sinks
+type FanoutSink []MetricSink
+
+func (fh FanoutSink) SetGauge(key []string, val float32) {
+	fh.SetGaugeWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	for _, s := range fh {
+		s.SetGaugeWithLabels(key, val, labels)
+	}
+}
+
+func (fh FanoutSink) EmitKey(key []string, val float32) {
+	for _, s := range fh {
+		s.EmitKey(key, val)
+	}
+}
+
+func (fh FanoutSink) IncrCounter(key []string, val float32) {
+	fh.IncrCounterWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	for _, s := range fh {
+		s.IncrCounterWithLabels(key, val, labels)
+	}
+}
+
+func (fh FanoutSink) AddSample(key []string, val float32) {
+	fh.AddSampleWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	for _, s := range fh {
+		s.AddSampleWithLabels(key, val, labels)
+	}
+}
+
+func (fh FanoutSink) Shutdown() {
+	for _, s := range fh {
+		if ss, ok := s.(ShutdownSink); ok {
+			ss.Shutdown()
+		}
+	}
+}
+
+// sinkURLFactoryFunc is an generic interface around the *SinkFromURL() function provided
+// by each sink type
+type sinkURLFactoryFunc func(*url.URL) (MetricSink, error)
+
+// sinkRegistry supports the generic NewMetricSink function by mapping URL
+// schemes to metric sink factory functions
+var sinkRegistry = map[string]sinkURLFactoryFunc{
+	"statsd":   NewStatsdSinkFromURL,
+	"statsite": NewStatsiteSinkFromURL,
+	"inmem":    NewInmemSinkFromURL,
+}
+
+// NewMetricSinkFromURL allows a generic URL input to configure any of the
+// supported sinks. The scheme of the URL identifies the type of the sink, the
+// and query parameters are used to set options.
+//
+// "statsd://" - Initializes a StatsdSink. The host and port are passed through
+// as the "addr" of the sink
+//
+// "statsite://" - Initializes a StatsiteSink. The host and port become the
+// "addr" of the sink
+//
+// "inmem://" - Initializes an InmemSink. The host and port are ignored. The
+// "interval" and "duration" query parameters must be specified with valid
+// durations, see NewInmemSink for details.
+func NewMetricSinkFromURL(urlStr string) (MetricSink, error) {
+	u, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, err
+	}
+
+	sinkURLFactoryFunc := sinkRegistry[u.Scheme]
+	if sinkURLFactoryFunc == nil {
+		return nil, fmt.Errorf(
+			"cannot create metric sink, unrecognized sink name: %q", u.Scheme)
+	}
+
+	return sinkURLFactoryFunc(u)
+}

vendor/github.com/armon/go-metrics/start.go

@@ -0,0 +1,158 @@
+package metrics
+
+import (
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	iradix "github.com/hashicorp/go-immutable-radix"
+)
+
+// Config is used to configure metrics settings
+type Config struct {
+	ServiceName          string        // Prefixed with keys to separate services
+	HostName             string        // Hostname to use. If not provided and EnableHostname, it will be os.Hostname
+	EnableHostname       bool          // Enable prefixing gauge values with hostname
+	EnableHostnameLabel  bool          // Enable adding hostname to labels
+	EnableServiceLabel   bool          // Enable adding service to labels
+	EnableRuntimeMetrics bool          // Enables profiling of runtime metrics (GC, Goroutines, Memory)
+	EnableTypePrefix     bool          // Prefixes key with a type ("counter", "gauge", "timer")
+	TimerGranularity     time.Duration // Granularity of timers.
+	ProfileInterval      time.Duration // Interval to profile runtime metrics
+
+	AllowedPrefixes []string // A list of metric prefixes to allow, with '.' as the separator
+	BlockedPrefixes []string // A list of metric prefixes to block, with '.' as the separator
+	AllowedLabels   []string // A list of metric labels to allow, with '.' as the separator
+	BlockedLabels   []string // A list of metric labels to block, with '.' as the separator
+	FilterDefault   bool     // Whether to allow metrics by default
+}
+
+// Metrics represents an instance of a metrics sink that can
+// be used to emit
+type Metrics struct {
+	Config
+	lastNumGC     uint32
+	sink          MetricSink
+	filter        *iradix.Tree
+	allowedLabels map[string]bool
+	blockedLabels map[string]bool
+	filterLock    sync.RWMutex // Lock filters and allowedLabels/blockedLabels access
+}
+
+// Shared global metrics instance
+var globalMetrics atomic.Value // *Metrics
+
+func init() {
+	// Initialize to a blackhole sink to avoid errors
+	globalMetrics.Store(&Metrics{sink: &BlackholeSink{}})
+}
+
+// Default returns the shared global metrics instance.
+func Default() *Metrics {
+	return globalMetrics.Load().(*Metrics)
+}
+
+// DefaultConfig provides a sane default configuration
+func DefaultConfig(serviceName string) *Config {
+	c := &Config{
+		ServiceName:          serviceName, // Use client provided service
+		HostName:             "",
+		EnableHostname:       true,             // Enable hostname prefix
+		EnableRuntimeMetrics: true,             // Enable runtime profiling
+		EnableTypePrefix:     false,            // Disable type prefix
+		TimerGranularity:     time.Millisecond, // Timers are in milliseconds
+		ProfileInterval:      time.Second,      // Poll runtime every second
+		FilterDefault:        true,             // Don't filter metrics by default
+	}
+
+	// Try to get the hostname
+	name, _ := os.Hostname()
+	c.HostName = name
+	return c
+}
+
+// New is used to create a new instance of Metrics
+func New(conf *Config, sink MetricSink) (*Metrics, error) {
+	met := &Metrics{}
+	met.Config = *conf
+	met.sink = sink
+	met.UpdateFilterAndLabels(conf.AllowedPrefixes, conf.BlockedPrefixes, conf.AllowedLabels, conf.BlockedLabels)
+
+	// Start the runtime collector
+	if conf.EnableRuntimeMetrics {
+		go met.collectStats()
+	}
+	return met, nil
+}
+
+// NewGlobal is the same as New, but it assigns the metrics object to be
+// used globally as well as returning it.
+func NewGlobal(conf *Config, sink MetricSink) (*Metrics, error) {
+	metrics, err := New(conf, sink)
+	if err == nil {
+		globalMetrics.Store(metrics)
+	}
+	return metrics, err
+}
+
+// Proxy all the methods to the globalMetrics instance
+func SetGauge(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).SetGauge(key, val)
+}
+
+func SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	globalMetrics.Load().(*Metrics).SetGaugeWithLabels(key, val, labels)
+}
+
+func EmitKey(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).EmitKey(key, val)
+}
+
+func IncrCounter(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).IncrCounter(key, val)
+}
+
+func IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	globalMetrics.Load().(*Metrics).IncrCounterWithLabels(key, val, labels)
+}
+
+func AddSample(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).AddSample(key, val)
+}
+
+func AddSampleWithLabels(key []string, val float32, labels []Label) {
+	globalMetrics.Load().(*Metrics).AddSampleWithLabels(key, val, labels)
+}
+
+func MeasureSince(key []string, start time.Time) {
+	globalMetrics.Load().(*Metrics).MeasureSince(key, start)
+}
+
+func MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	globalMetrics.Load().(*Metrics).MeasureSinceWithLabels(key, start, labels)
+}
+
+func UpdateFilter(allow, block []string) {
+	globalMetrics.Load().(*Metrics).UpdateFilter(allow, block)
+}
+
+// UpdateFilterAndLabels set allow/block prefixes of metrics while allowedLabels
+// and blockedLabels - when not nil - allow filtering of labels in order to
+// block/allow globally labels (especially useful when having large number of
+// values for a given label). See README.md for more information about usage.
+func UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	globalMetrics.Load().(*Metrics).UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels)
+}
+
+// Shutdown disables metric collection, then blocks while attempting to flush metrics to storage.
+// WARNING: Not all MetricSink backends support this functionality, and calling this will cause them to leak resources.
+// This is intended for use immediately prior to application exit.
+func Shutdown() {
+	m := globalMetrics.Load().(*Metrics)
+	// Swap whatever MetricSink is currently active with a BlackholeSink. Callers must not have a
+	// reason to expect that calls to the library will successfully collect metrics after Shutdown
+	// has been called.
+	globalMetrics.Store(&Metrics{sink: &BlackholeSink{}})
+	m.Shutdown()
+}

vendor/github.com/armon/go-metrics/statsd.go

@@ -0,0 +1,184 @@
+package metrics
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"net"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const (
+	// statsdMaxLen is the maximum size of a packet
+	// to send to statsd
+	statsdMaxLen = 1400
+)
+
+// StatsdSink provides a MetricSink that can be used
+// with a statsite or statsd metrics server. It uses
+// only UDP packets, while StatsiteSink uses TCP.
+type StatsdSink struct {
+	addr        string
+	metricQueue chan string
+}
+
+// NewStatsdSinkFromURL creates an StatsdSink from a URL. It is used
+// (and tested) from NewMetricSinkFromURL.
+func NewStatsdSinkFromURL(u *url.URL) (MetricSink, error) {
+	return NewStatsdSink(u.Host)
+}
+
+// NewStatsdSink is used to create a new StatsdSink
+func NewStatsdSink(addr string) (*StatsdSink, error) {
+	s := &StatsdSink{
+		addr:        addr,
+		metricQueue: make(chan string, 4096),
+	}
+	go s.flushMetrics()
+	return s, nil
+}
+
+// Close is used to stop flushing to statsd
+func (s *StatsdSink) Shutdown() {
+	close(s.metricQueue)
+}
+
+func (s *StatsdSink) SetGauge(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsdSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsdSink) EmitKey(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|kv\n", flatKey, val))
+}
+
+func (s *StatsdSink) IncrCounter(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsdSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsdSink) AddSample(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+func (s *StatsdSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+// Flattens the key for formatting, removes spaces
+func (s *StatsdSink) flattenKey(parts []string) string {
+	joined := strings.Join(parts, ".")
+	return strings.Map(func(r rune) rune {
+		switch r {
+		case ':':
+			fallthrough
+		case ' ':
+			return '_'
+		default:
+			return r
+		}
+	}, joined)
+}
+
+// Flattens the key along with labels for formatting, removes spaces
+func (s *StatsdSink) flattenKeyLabels(parts []string, labels []Label) string {
+	for _, label := range labels {
+		parts = append(parts, label.Value)
+	}
+	return s.flattenKey(parts)
+}
+
+// Does a non-blocking push to the metrics queue
+func (s *StatsdSink) pushMetric(m string) {
+	select {
+	case s.metricQueue <- m:
+	default:
+	}
+}
+
+// Flushes metrics
+func (s *StatsdSink) flushMetrics() {
+	var sock net.Conn
+	var err error
+	var wait <-chan time.Time
+	ticker := time.NewTicker(flushInterval)
+	defer ticker.Stop()
+
+CONNECT:
+	// Create a buffer
+	buf := bytes.NewBuffer(nil)
+
+	// Attempt to connect
+	sock, err = net.Dial("udp", s.addr)
+	if err != nil {
+		log.Printf("[ERR] Error connecting to statsd! Err: %s", err)
+		goto WAIT
+	}
+
+	for {
+		select {
+		case metric, ok := <-s.metricQueue:
+			// Get a metric from the queue
+			if !ok {
+				goto QUIT
+			}
+
+			// Check if this would overflow the packet size
+			if len(metric)+buf.Len() > statsdMaxLen {
+				_, err := sock.Write(buf.Bytes())
+				buf.Reset()
+				if err != nil {
+					log.Printf("[ERR] Error writing to statsd! Err: %s", err)
+					goto WAIT
+				}
+			}
+
+			// Append to the buffer
+			buf.WriteString(metric)
+
+		case <-ticker.C:
+			if buf.Len() == 0 {
+				continue
+			}
+
+			_, err := sock.Write(buf.Bytes())
+			buf.Reset()
+			if err != nil {
+				log.Printf("[ERR] Error flushing to statsd! Err: %s", err)
+				goto WAIT
+			}
+		}
+	}
+
+WAIT:
+	// Wait for a while
+	wait = time.After(time.Duration(5) * time.Second)
+	for {
+		select {
+		// Dequeue the messages to avoid backlog
+		case _, ok := <-s.metricQueue:
+			if !ok {
+				goto QUIT
+			}
+		case <-wait:
+			goto CONNECT
+		}
+	}
+QUIT:
+	s.metricQueue = nil
+}

vendor/github.com/armon/go-metrics/statsite.go

@@ -0,0 +1,172 @@
+package metrics
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"net"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const (
+	// We force flush the statsite metrics after this period of
+	// inactivity. Prevents stats from getting stuck in a buffer
+	// forever.
+	flushInterval = 100 * time.Millisecond
+)
+
+// NewStatsiteSinkFromURL creates an StatsiteSink from a URL. It is used
+// (and tested) from NewMetricSinkFromURL.
+func NewStatsiteSinkFromURL(u *url.URL) (MetricSink, error) {
+	return NewStatsiteSink(u.Host)
+}
+
+// StatsiteSink provides a MetricSink that can be used with a
+// statsite metrics server
+type StatsiteSink struct {
+	addr        string
+	metricQueue chan string
+}
+
+// NewStatsiteSink is used to create a new StatsiteSink
+func NewStatsiteSink(addr string) (*StatsiteSink, error) {
+	s := &StatsiteSink{
+		addr:        addr,
+		metricQueue: make(chan string, 4096),
+	}
+	go s.flushMetrics()
+	return s, nil
+}
+
+// Close is used to stop flushing to statsite
+func (s *StatsiteSink) Shutdown() {
+	close(s.metricQueue)
+}
+
+func (s *StatsiteSink) SetGauge(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsiteSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsiteSink) EmitKey(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|kv\n", flatKey, val))
+}
+
+func (s *StatsiteSink) IncrCounter(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsiteSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsiteSink) AddSample(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+func (s *StatsiteSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+// Flattens the key for formatting, removes spaces
+func (s *StatsiteSink) flattenKey(parts []string) string {
+	joined := strings.Join(parts, ".")
+	return strings.Map(func(r rune) rune {
+		switch r {
+		case ':':
+			fallthrough
+		case ' ':
+			return '_'
+		default:
+			return r
+		}
+	}, joined)
+}
+
+// Flattens the key along with labels for formatting, removes spaces
+func (s *StatsiteSink) flattenKeyLabels(parts []string, labels []Label) string {
+	for _, label := range labels {
+		parts = append(parts, label.Value)
+	}
+	return s.flattenKey(parts)
+}
+
+// Does a non-blocking push to the metrics queue
+func (s *StatsiteSink) pushMetric(m string) {
+	select {
+	case s.metricQueue <- m:
+	default:
+	}
+}
+
+// Flushes metrics
+func (s *StatsiteSink) flushMetrics() {
+	var sock net.Conn
+	var err error
+	var wait <-chan time.Time
+	var buffered *bufio.Writer
+	ticker := time.NewTicker(flushInterval)
+	defer ticker.Stop()
+
+CONNECT:
+	// Attempt to connect
+	sock, err = net.Dial("tcp", s.addr)
+	if err != nil {
+		log.Printf("[ERR] Error connecting to statsite! Err: %s", err)
+		goto WAIT
+	}
+
+	// Create a buffered writer
+	buffered = bufio.NewWriter(sock)
+
+	for {
+		select {
+		case metric, ok := <-s.metricQueue:
+			// Get a metric from the queue
+			if !ok {
+				goto QUIT
+			}
+
+			// Try to send to statsite
+			_, err := buffered.Write([]byte(metric))
+			if err != nil {
+				log.Printf("[ERR] Error writing to statsite! Err: %s", err)
+				goto WAIT
+			}
+		case <-ticker.C:
+			if err := buffered.Flush(); err != nil {
+				log.Printf("[ERR] Error flushing to statsite! Err: %s", err)
+				goto WAIT
+			}
+		}
+	}
+
+WAIT:
+	// Wait for a while
+	wait = time.After(time.Duration(5) * time.Second)
+	for {
+		select {
+		// Dequeue the messages to avoid backlog
+		case _, ok := <-s.metricQueue:
+			if !ok {
+				goto QUIT
+			}
+		case <-wait:
+			goto CONNECT
+		}
+	}
+QUIT:
+	s.metricQueue = nil
+}

vendor/github.com/boltdb/bolt/LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Ben Johnson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/boltdb/bolt/Makefile

@@ -0,0 +1,18 @@
+BRANCH=`git rev-parse --abbrev-ref HEAD`
+COMMIT=`git rev-parse --short HEAD`
+GOLDFLAGS="-X main.branch $(BRANCH) -X main.commit $(COMMIT)"
+
+default: build
+
+race:
+	@go test -v -race -test.run="TestSimulate_(100op|1000op)"
+
+# go get github.com/kisielk/errcheck
+errcheck:
+	@errcheck -ignorepkg=bytes -ignore=os:Remove github.com/boltdb/bolt
+
+test: 
+	@go test -v -cover .
+	@go test -v ./cmd/bolt
+
+.PHONY: fmt test

vendor/github.com/boltdb/bolt/README.md

@@ -0,0 +1,916 @@
+Bolt [![Coverage Status](https://coveralls.io/repos/boltdb/bolt/badge.svg?branch=master)](https://coveralls.io/r/boltdb/bolt?branch=master) [![GoDoc](https://godoc.org/github.com/boltdb/bolt?status.svg)](https://godoc.org/github.com/boltdb/bolt) ![Version](https://img.shields.io/badge/version-1.2.1-green.svg)
+====
+
+Bolt is a pure Go key/value store inspired by [Howard Chu's][hyc_symas]
+[LMDB project][lmdb]. The goal of the project is to provide a simple,
+fast, and reliable database for projects that don't require a full database
+server such as Postgres or MySQL.
+
+Since Bolt is meant to be used as such a low-level piece of functionality,
+simplicity is key. The API will be small and only focus on getting values
+and setting values. That's it.
+
+[hyc_symas]: https://twitter.com/hyc_symas
+[lmdb]: http://symas.com/mdb/
+
+## Project Status
+
+Bolt is stable, the API is fixed, and the file format is fixed. Full unit
+test coverage and randomized black box testing are used to ensure database
+consistency and thread safety. Bolt is currently used in high-load production
+environments serving databases as large as 1TB. Many companies such as
+Shopify and Heroku use Bolt-backed services every day.
+
+## Table of Contents
+
+- [Getting Started](#getting-started)
+  - [Installing](#installing)
+  - [Opening a database](#opening-a-database)
+  - [Transactions](#transactions)
+    - [Read-write transactions](#read-write-transactions)
+    - [Read-only transactions](#read-only-transactions)
+    - [Batch read-write transactions](#batch-read-write-transactions)
+    - [Managing transactions manually](#managing-transactions-manually)
+  - [Using buckets](#using-buckets)
+  - [Using key/value pairs](#using-keyvalue-pairs)
+  - [Autoincrementing integer for the bucket](#autoincrementing-integer-for-the-bucket)
+  - [Iterating over keys](#iterating-over-keys)
+    - [Prefix scans](#prefix-scans)
+    - [Range scans](#range-scans)
+    - [ForEach()](#foreach)
+  - [Nested buckets](#nested-buckets)
+  - [Database backups](#database-backups)
+  - [Statistics](#statistics)
+  - [Read-Only Mode](#read-only-mode)
+  - [Mobile Use (iOS/Android)](#mobile-use-iosandroid)
+- [Resources](#resources)
+- [Comparison with other databases](#comparison-with-other-databases)
+  - [Postgres, MySQL, & other relational databases](#postgres-mysql--other-relational-databases)
+  - [LevelDB, RocksDB](#leveldb-rocksdb)
+  - [LMDB](#lmdb)
+- [Caveats & Limitations](#caveats--limitations)
+- [Reading the Source](#reading-the-source)
+- [Other Projects Using Bolt](#other-projects-using-bolt)
+
+## Getting Started
+
+### Installing
+
+To start using Bolt, install Go and run `go get`:
+
+```sh
+$ go get github.com/boltdb/bolt/...
+```
+
+This will retrieve the library and install the `bolt` command line utility into
+your `$GOBIN` path.
+
+
+### Opening a database
+
+The top-level object in Bolt is a `DB`. It is represented as a single file on
+your disk and represents a consistent snapshot of your data.
+
+To open your database, simply use the `bolt.Open()` function:
+
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/boltdb/bolt"
+)
+
+func main() {
+	// Open the my.db data file in your current directory.
+	// It will be created if it doesn't exist.
+	db, err := bolt.Open("my.db", 0600, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	...
+}
+```
+
+Please note that Bolt obtains a file lock on the data file so multiple processes
+cannot open the same database at the same time. Opening an already open Bolt
+database will cause it to hang until the other process closes it. To prevent
+an indefinite wait you can pass a timeout option to the `Open()` function:
+
+```go
+db, err := bolt.Open("my.db", 0600, &bolt.Options{Timeout: 1 * time.Second})
+```
+
+
+### Transactions
+
+Bolt allows only one read-write transaction at a time but allows as many
+read-only transactions as you want at a time. Each transaction has a consistent
+view of the data as it existed when the transaction started.
+
+Individual transactions and all objects created from them (e.g. buckets, keys)
+are not thread safe. To work with data in multiple goroutines you must start
+a transaction for each one or use locking to ensure only one goroutine accesses
+a transaction at a time. Creating transaction from the `DB` is thread safe.
+
+Read-only transactions and read-write transactions should not depend on one
+another and generally shouldn't be opened simultaneously in the same goroutine.
+This can cause a deadlock as the read-write transaction needs to periodically
+re-map the data file but it cannot do so while a read-only transaction is open.
+
+
+#### Read-write transactions
+
+To start a read-write transaction, you can use the `DB.Update()` function:
+
+```go
+err := db.Update(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+Inside the closure, you have a consistent view of the database. You commit the
+transaction by returning `nil` at the end. You can also rollback the transaction
+at any point by returning an error. All database operations are allowed inside
+a read-write transaction.
+
+Always check the return error as it will report any disk failures that can cause
+your transaction to not complete. If you return an error within your closure
+it will be passed through.
+
+
+#### Read-only transactions
+
+To start a read-only transaction, you can use the `DB.View()` function:
+
+```go
+err := db.View(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+You also get a consistent view of the database within this closure, however,
+no mutating operations are allowed within a read-only transaction. You can only
+retrieve buckets, retrieve values, and copy the database within a read-only
+transaction.
+
+
+#### Batch read-write transactions
+
+Each `DB.Update()` waits for disk to commit the writes. This overhead
+can be minimized by combining multiple updates with the `DB.Batch()`
+function:
+
+```go
+err := db.Batch(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+Concurrent Batch calls are opportunistically combined into larger
+transactions. Batch is only useful when there are multiple goroutines
+calling it.
+
+The trade-off is that `Batch` can call the given
+function multiple times, if parts of the transaction fail. The
+function must be idempotent and side effects must take effect only
+after a successful return from `DB.Batch()`.
+
+For example: don't display messages from inside the function, instead
+set variables in the enclosing scope:
+
+```go
+var id uint64
+err := db.Batch(func(tx *bolt.Tx) error {
+	// Find last key in bucket, decode as bigendian uint64, increment
+	// by one, encode back to []byte, and add new key.
+	...
+	id = newValue
+	return nil
+})
+if err != nil {
+	return ...
+}
+fmt.Println("Allocated ID %d", id)
+```
+
+
+#### Managing transactions manually
+
+The `DB.View()` and `DB.Update()` functions are wrappers around the `DB.Begin()`
+function. These helper functions will start the transaction, execute a function,
+and then safely close your transaction if an error is returned. This is the
+recommended way to use Bolt transactions.
+
+However, sometimes you may want to manually start and end your transactions.
+You can use the `DB.Begin()` function directly but **please** be sure to close
+the transaction.
+
+```go
+// Start a writable transaction.
+tx, err := db.Begin(true)
+if err != nil {
+    return err
+}
+defer tx.Rollback()
+
+// Use the transaction...
+_, err := tx.CreateBucket([]byte("MyBucket"))
+if err != nil {
+    return err
+}
+
+// Commit the transaction and check for error.
+if err := tx.Commit(); err != nil {
+    return err
+}
+```
+
+The first argument to `DB.Begin()` is a boolean stating if the transaction
+should be writable.
+
+
+### Using buckets
+
+Buckets are collections of key/value pairs within the database. All keys in a
+bucket must be unique. You can create a bucket using the `DB.CreateBucket()`
+function:
+
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b, err := tx.CreateBucket([]byte("MyBucket"))
+	if err != nil {
+		return fmt.Errorf("create bucket: %s", err)
+	}
+	return nil
+})
+```
+
+You can also create a bucket only if it doesn't exist by using the
+`Tx.CreateBucketIfNotExists()` function. It's a common pattern to call this
+function for all your top-level buckets after you open your database so you can
+guarantee that they exist for future transactions.
+
+To delete a bucket, simply call the `Tx.DeleteBucket()` function.
+
+
+### Using key/value pairs
+
+To save a key/value pair to a bucket, use the `Bucket.Put()` function:
+
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	err := b.Put([]byte("answer"), []byte("42"))
+	return err
+})
+```
+
+This will set the value of the `"answer"` key to `"42"` in the `MyBucket`
+bucket. To retrieve this value, we can use the `Bucket.Get()` function:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	v := b.Get([]byte("answer"))
+	fmt.Printf("The answer is: %s\n", v)
+	return nil
+})
+```
+
+The `Get()` function does not return an error because its operation is
+guaranteed to work (unless there is some kind of system failure). If the key
+exists then it will return its byte slice value. If it doesn't exist then it
+will return `nil`. It's important to note that you can have a zero-length value
+set to a key which is different than the key not existing.
+
+Use the `Bucket.Delete()` function to delete a key from the bucket.
+
+Please note that values returned from `Get()` are only valid while the
+transaction is open. If you need to use a value outside of the transaction
+then you must use `copy()` to copy it to another byte slice.
+
+
+### Autoincrementing integer for the bucket
+By using the `NextSequence()` function, you can let Bolt determine a sequence
+which can be used as the unique identifier for your key/value pairs. See the
+example below.
+
+```go
+// CreateUser saves u to the store. The new user ID is set on u once the data is persisted.
+func (s *Store) CreateUser(u *User) error {
+    return s.db.Update(func(tx *bolt.Tx) error {
+        // Retrieve the users bucket.
+        // This should be created when the DB is first opened.
+        b := tx.Bucket([]byte("users"))
+
+        // Generate ID for the user.
+        // This returns an error only if the Tx is closed or not writeable.
+        // That can't happen in an Update() call so I ignore the error check.
+        id, _ := b.NextSequence()
+        u.ID = int(id)
+
+        // Marshal user data into bytes.
+        buf, err := json.Marshal(u)
+        if err != nil {
+            return err
+        }
+
+        // Persist bytes to users bucket.
+        return b.Put(itob(u.ID), buf)
+    })
+}
+
+// itob returns an 8-byte big endian representation of v.
+func itob(v int) []byte {
+    b := make([]byte, 8)
+    binary.BigEndian.PutUint64(b, uint64(v))
+    return b
+}
+
+type User struct {
+    ID int
+    ...
+}
+```
+
+### Iterating over keys
+
+Bolt stores its keys in byte-sorted order within a bucket. This makes sequential
+iteration over these keys extremely fast. To iterate over keys we'll use a
+`Cursor`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	b := tx.Bucket([]byte("MyBucket"))
+
+	c := b.Cursor()
+
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+The cursor allows you to move to a specific point in the list of keys and move
+forward or backward through the keys one at a time.
+
+The following functions are available on the cursor:
+
+```
+First()  Move to the first key.
+Last()   Move to the last key.
+Seek()   Move to a specific key.
+Next()   Move to the next key.
+Prev()   Move to the previous key.
+```
+
+Each of those functions has a return signature of `(key []byte, value []byte)`.
+When you have iterated to the end of the cursor then `Next()` will return a
+`nil` key.  You must seek to a position using `First()`, `Last()`, or `Seek()`
+before calling `Next()` or `Prev()`. If you do not seek to a position then
+these functions will return a `nil` key.
+
+During iteration, if the key is non-`nil` but the value is `nil`, that means
+the key refers to a bucket rather than a value.  Use `Bucket.Bucket()` to
+access the sub-bucket.
+
+
+#### Prefix scans
+
+To iterate over a key prefix, you can combine `Seek()` and `bytes.HasPrefix()`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	c := tx.Bucket([]byte("MyBucket")).Cursor()
+
+	prefix := []byte("1234")
+	for k, v := c.Seek(prefix); k != nil && bytes.HasPrefix(k, prefix); k, v = c.Next() {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+#### Range scans
+
+Another common use case is scanning over a range such as a time range. If you
+use a sortable time encoding such as RFC3339 then you can query a specific
+date range like this:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume our events bucket exists and has RFC3339 encoded time keys.
+	c := tx.Bucket([]byte("Events")).Cursor()
+
+	// Our time range spans the 90's decade.
+	min := []byte("1990-01-01T00:00:00Z")
+	max := []byte("2000-01-01T00:00:00Z")
+
+	// Iterate over the 90's.
+	for k, v := c.Seek(min); k != nil && bytes.Compare(k, max) <= 0; k, v = c.Next() {
+		fmt.Printf("%s: %s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+Note that, while RFC3339 is sortable, the Golang implementation of RFC3339Nano does not use a fixed number of digits after the decimal point and is therefore not sortable.
+
+
+#### ForEach()
+
+You can also use the function `ForEach()` if you know you'll be iterating over
+all the keys in a bucket:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	b := tx.Bucket([]byte("MyBucket"))
+
+	b.ForEach(func(k, v []byte) error {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+		return nil
+	})
+	return nil
+})
+```
+
+Please note that keys and values in `ForEach()` are only valid while
+the transaction is open. If you need to use a key or value outside of
+the transaction, you must use `copy()` to copy it to another byte
+slice.
+
+### Nested buckets
+
+You can also store a bucket in a key to create nested buckets. The API is the
+same as the bucket management API on the `DB` object:
+
+```go
+func (*Bucket) CreateBucket(key []byte) (*Bucket, error)
+func (*Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error)
+func (*Bucket) DeleteBucket(key []byte) error
+```
+
+Say you had a multi-tenant application where the root level bucket was the account bucket. Inside of this bucket was a sequence of accounts which themselves are buckets. And inside the sequence bucket you could have many buckets pertaining to the Account itself (Users, Notes, etc) isolating the information into logical groupings.
+
+```go
+
+// createUser creates a new user in the given account.
+func createUser(accountID int, u *User) error {
+    // Start the transaction.
+    tx, err := db.Begin(true)
+    if err != nil {
+        return err
+    }
+    defer tx.Rollback()
+
+    // Retrieve the root bucket for the account.
+    // Assume this has already been created when the account was set up.
+    root := tx.Bucket([]byte(strconv.FormatUint(accountID, 10)))
+
+    // Setup the users bucket.
+    bkt, err := root.CreateBucketIfNotExists([]byte("USERS"))
+    if err != nil {
+        return err
+    }
+
+    // Generate an ID for the new user.
+    userID, err := bkt.NextSequence()
+    if err != nil {
+        return err
+    }
+    u.ID = userID
+
+    // Marshal and save the encoded user.
+    if buf, err := json.Marshal(u); err != nil {
+        return err
+    } else if err := bkt.Put([]byte(strconv.FormatUint(u.ID, 10)), buf); err != nil {
+        return err
+    }
+
+    // Commit the transaction.
+    if err := tx.Commit(); err != nil {
+        return err
+    }
+
+    return nil
+}
+
+```
+
+
+
+
+### Database backups
+
+Bolt is a single file so it's easy to backup. You can use the `Tx.WriteTo()`
+function to write a consistent view of the database to a writer. If you call
+this from a read-only transaction, it will perform a hot backup and not block
+your other database reads and writes.
+
+By default, it will use a regular file handle which will utilize the operating
+system's page cache. See the [`Tx`](https://godoc.org/github.com/boltdb/bolt#Tx)
+documentation for information about optimizing for larger-than-RAM datasets.
+
+One common use case is to backup over HTTP so you can use tools like `cURL` to
+do database backups:
+
+```go
+func BackupHandleFunc(w http.ResponseWriter, req *http.Request) {
+	err := db.View(func(tx *bolt.Tx) error {
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Disposition", `attachment; filename="my.db"`)
+		w.Header().Set("Content-Length", strconv.Itoa(int(tx.Size())))
+		_, err := tx.WriteTo(w)
+		return err
+	})
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}
+```
+
+Then you can backup using this command:
+
+```sh
+$ curl http://localhost/backup > my.db
+```
+
+Or you can open your browser to `http://localhost/backup` and it will download
+automatically.
+
+If you want to backup to another file you can use the `Tx.CopyFile()` helper
+function.
+
+
+### Statistics
+
+The database keeps a running count of many of the internal operations it
+performs so you can better understand what's going on. By grabbing a snapshot
+of these stats at two points in time we can see what operations were performed
+in that time range.
+
+For example, we could start a goroutine to log stats every 10 seconds:
+
+```go
+go func() {
+	// Grab the initial stats.
+	prev := db.Stats()
+
+	for {
+		// Wait for 10s.
+		time.Sleep(10 * time.Second)
+
+		// Grab the current stats and diff them.
+		stats := db.Stats()
+		diff := stats.Sub(&prev)
+
+		// Encode stats to JSON and print to STDERR.
+		json.NewEncoder(os.Stderr).Encode(diff)
+
+		// Save stats for the next loop.
+		prev = stats
+	}
+}()
+```
+
+It's also useful to pipe these stats to a service such as statsd for monitoring
+or to provide an HTTP endpoint that will perform a fixed-length sample.
+
+
+### Read-Only Mode
+
+Sometimes it is useful to create a shared, read-only Bolt database. To this,
+set the `Options.ReadOnly` flag when opening your database. Read-only mode
+uses a shared lock to allow multiple processes to read from the database but
+it will block any processes from opening the database in read-write mode.
+
+```go
+db, err := bolt.Open("my.db", 0666, &bolt.Options{ReadOnly: true})
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+### Mobile Use (iOS/Android)
+
+Bolt is able to run on mobile devices by leveraging the binding feature of the
+[gomobile](https://github.com/golang/mobile) tool. Create a struct that will
+contain your database logic and a reference to a `*bolt.DB` with a initializing
+constructor that takes in a filepath where the database file will be stored.
+Neither Android nor iOS require extra permissions or cleanup from using this method.
+
+```go
+func NewBoltDB(filepath string) *BoltDB {
+	db, err := bolt.Open(filepath+"/demo.db", 0600, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return &BoltDB{db}
+}
+
+type BoltDB struct {
+	db *bolt.DB
+	...
+}
+
+func (b *BoltDB) Path() string {
+	return b.db.Path()
+}
+
+func (b *BoltDB) Close() {
+	b.db.Close()
+}
+```
+
+Database logic should be defined as methods on this wrapper struct.
+
+To initialize this struct from the native language (both platforms now sync
+their local storage to the cloud. These snippets disable that functionality for the
+database file):
+
+#### Android
+
+```java
+String path;
+if (android.os.Build.VERSION.SDK_INT >=android.os.Build.VERSION_CODES.LOLLIPOP){
+    path = getNoBackupFilesDir().getAbsolutePath();
+} else{
+    path = getFilesDir().getAbsolutePath();
+}
+Boltmobiledemo.BoltDB boltDB = Boltmobiledemo.NewBoltDB(path)
+```
+
+#### iOS
+
+```objc
+- (void)demo {
+    NSString* path = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,
+                                                          NSUserDomainMask,
+                                                          YES) objectAtIndex:0];
+	GoBoltmobiledemoBoltDB * demo = GoBoltmobiledemoNewBoltDB(path);
+	[self addSkipBackupAttributeToItemAtPath:demo.path];
+	//Some DB Logic would go here
+	[demo close];
+}
+
+- (BOOL)addSkipBackupAttributeToItemAtPath:(NSString *) filePathString
+{
+    NSURL* URL= [NSURL fileURLWithPath: filePathString];
+    assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);
+
+    NSError *error = nil;
+    BOOL success = [URL setResourceValue: [NSNumber numberWithBool: YES]
+                                  forKey: NSURLIsExcludedFromBackupKey error: &error];
+    if(!success){
+        NSLog(@"Error excluding %@ from backup %@", [URL lastPathComponent], error);
+    }
+    return success;
+}
+
+```
+
+## Resources
+
+For more information on getting started with Bolt, check out the following articles:
+
+* [Intro to BoltDB: Painless Performant Persistence](http://npf.io/2014/07/intro-to-boltdb-painless-performant-persistence/) by [Nate Finch](https://github.com/natefinch).
+* [Bolt -- an embedded key/value database for Go](https://www.progville.com/go/bolt-embedded-db-golang/) by Progville
+
+
+## Comparison with other databases
+
+### Postgres, MySQL, & other relational databases
+
+Relational databases structure data into rows and are only accessible through
+the use of SQL. This approach provides flexibility in how you store and query
+your data but also incurs overhead in parsing and planning SQL statements. Bolt
+accesses all data by a byte slice key. This makes Bolt fast to read and write
+data by key but provides no built-in support for joining values together.
+
+Most relational databases (with the exception of SQLite) are standalone servers
+that run separately from your application. This gives your systems
+flexibility to connect multiple application servers to a single database
+server but also adds overhead in serializing and transporting data over the
+network. Bolt runs as a library included in your application so all data access
+has to go through your application's process. This brings data closer to your
+application but limits multi-process access to the data.
+
+
+### LevelDB, RocksDB
+
+LevelDB and its derivatives (RocksDB, HyperLevelDB) are similar to Bolt in that
+they are libraries bundled into the application, however, their underlying
+structure is a log-structured merge-tree (LSM tree). An LSM tree optimizes
+random writes by using a write ahead log and multi-tiered, sorted files called
+SSTables. Bolt uses a B+tree internally and only a single file. Both approaches
+have trade-offs.
+
+If you require a high random write throughput (>10,000 w/sec) or you need to use
+spinning disks then LevelDB could be a good choice. If your application is
+read-heavy or does a lot of range scans then Bolt could be a good choice.
+
+One other important consideration is that LevelDB does not have transactions.
+It supports batch writing of key/values pairs and it supports read snapshots
+but it will not give you the ability to do a compare-and-swap operation safely.
+Bolt supports fully serializable ACID transactions.
+
+
+### LMDB
+
+Bolt was originally a port of LMDB so it is architecturally similar. Both use
+a B+tree, have ACID semantics with fully serializable transactions, and support
+lock-free MVCC using a single writer and multiple readers.
+
+The two projects have somewhat diverged. LMDB heavily focuses on raw performance
+while Bolt has focused on simplicity and ease of use. For example, LMDB allows
+several unsafe actions such as direct writes for the sake of performance. Bolt
+opts to disallow actions which can leave the database in a corrupted state. The
+only exception to this in Bolt is `DB.NoSync`.
+
+There are also a few differences in API. LMDB requires a maximum mmap size when
+opening an `mdb_env` whereas Bolt will handle incremental mmap resizing
+automatically. LMDB overloads the getter and setter functions with multiple
+flags whereas Bolt splits these specialized cases into their own functions.
+
+
+## Caveats & Limitations
+
+It's important to pick the right tool for the job and Bolt is no exception.
+Here are a few things to note when evaluating and using Bolt:
+
+* Bolt is good for read intensive workloads. Sequential write performance is
+  also fast but random writes can be slow. You can use `DB.Batch()` or add a
+  write-ahead log to help mitigate this issue.
+
+* Bolt uses a B+tree internally so there can be a lot of random page access.
+  SSDs provide a significant performance boost over spinning disks.
+
+* Try to avoid long running read transactions. Bolt uses copy-on-write so
+  old pages cannot be reclaimed while an old transaction is using them.
+
+* Byte slices returned from Bolt are only valid during a transaction. Once the
+  transaction has been committed or rolled back then the memory they point to
+  can be reused by a new page or can be unmapped from virtual memory and you'll
+  see an `unexpected fault address` panic when accessing it.
+
+* Bolt uses an exclusive write lock on the database file so it cannot be
+  shared by multiple processes.
+
+* Be careful when using `Bucket.FillPercent`. Setting a high fill percent for
+  buckets that have random inserts will cause your database to have very poor
+  page utilization.
+
+* Use larger buckets in general. Smaller buckets causes poor page utilization
+  once they become larger than the page size (typically 4KB).
+
+* Bulk loading a lot of random writes into a new bucket can be slow as the
+  page will not split until the transaction is committed. Randomly inserting
+  more than 100,000 key/value pairs into a single new bucket in a single
+  transaction is not advised.
+
+* Bolt uses a memory-mapped file so the underlying operating system handles the
+  caching of the data. Typically, the OS will cache as much of the file as it
+  can in memory and will release memory as needed to other processes. This means
+  that Bolt can show very high memory usage when working with large databases.
+  However, this is expected and the OS will release memory as needed. Bolt can
+  handle databases much larger than the available physical RAM, provided its
+  memory-map fits in the process virtual address space. It may be problematic
+  on 32-bits systems.
+
+* The data structures in the Bolt database are memory mapped so the data file
+  will be endian specific. This means that you cannot copy a Bolt file from a
+  little endian machine to a big endian machine and have it work. For most
+  users this is not a concern since most modern CPUs are little endian.
+
+* Because of the way pages are laid out on disk, Bolt cannot truncate data files
+  and return free pages back to the disk. Instead, Bolt maintains a free list
+  of unused pages within its data file. These free pages can be reused by later
+  transactions. This works well for many use cases as databases generally tend
+  to grow. However, it's important to note that deleting large chunks of data
+  will not allow you to reclaim that space on disk.
+
+  For more information on page allocation, [see this comment][page-allocation].
+
+[page-allocation]: https://github.com/boltdb/bolt/issues/308#issuecomment-74811638
+
+
+## Reading the Source
+
+Bolt is a relatively small code base (<3KLOC) for an embedded, serializable,
+transactional key/value database so it can be a good starting point for people
+interested in how databases work.
+
+The best places to start are the main entry points into Bolt:
+
+- `Open()` - Initializes the reference to the database. It's responsible for
+  creating the database if it doesn't exist, obtaining an exclusive lock on the
+  file, reading the meta pages, & memory-mapping the file.
+
+- `DB.Begin()` - Starts a read-only or read-write transaction depending on the
+  value of the `writable` argument. This requires briefly obtaining the "meta"
+  lock to keep track of open transactions. Only one read-write transaction can
+  exist at a time so the "rwlock" is acquired during the life of a read-write
+  transaction.
+
+- `Bucket.Put()` - Writes a key/value pair into a bucket. After validating the
+  arguments, a cursor is used to traverse the B+tree to the page and position
+  where they key & value will be written. Once the position is found, the bucket
+  materializes the underlying page and the page's parent pages into memory as
+  "nodes". These nodes are where mutations occur during read-write transactions.
+  These changes get flushed to disk during commit.
+
+- `Bucket.Get()` - Retrieves a key/value pair from a bucket. This uses a cursor
+  to move to the page & position of a key/value pair. During a read-only
+  transaction, the key and value data is returned as a direct reference to the
+  underlying mmap file so there's no allocation overhead. For read-write
+  transactions, this data may reference the mmap file or one of the in-memory
+  node values.
+
+- `Cursor` - This object is simply for traversing the B+tree of on-disk pages
+  or in-memory nodes. It can seek to a specific key, move to the first or last
+  value, or it can move forward or backward. The cursor handles the movement up
+  and down the B+tree transparently to the end user.
+
+- `Tx.Commit()` - Converts the in-memory dirty nodes and the list of free pages
+  into pages to be written to disk. Writing to disk then occurs in two phases.
+  First, the dirty pages are written to disk and an `fsync()` occurs. Second, a
+  new meta page with an incremented transaction ID is written and another
+  `fsync()` occurs. This two phase write ensures that partially written data
+  pages are ignored in the event of a crash since the meta page pointing to them
+  is never written. Partially written meta pages are invalidated because they
+  are written with a checksum.
+
+If you have additional notes that could be helpful for others, please submit
+them via pull request.
+
+
+## Other Projects Using Bolt
+
+Below is a list of public, open source projects that use Bolt:
+
+* [BoltDbWeb](https://github.com/evnix/boltdbweb) - A web based GUI for BoltDB files.
+* [Operation Go: A Routine Mission](http://gocode.io) - An online programming game for Golang using Bolt for user accounts and a leaderboard.
+* [Bazil](https://bazil.org/) - A file system that lets your data reside where it is most convenient for it to reside.
+* [DVID](https://github.com/janelia-flyem/dvid) - Added Bolt as optional storage engine and testing it against Basho-tuned leveldb.
+* [Skybox Analytics](https://github.com/skybox/skybox) - A standalone funnel analysis tool for web analytics.
+* [Scuttlebutt](https://github.com/benbjohnson/scuttlebutt) - Uses Bolt to store and process all Twitter mentions of GitHub projects.
+* [Wiki](https://github.com/peterhellberg/wiki) - A tiny wiki using Goji, BoltDB and Blackfriday.
+* [ChainStore](https://github.com/pressly/chainstore) - Simple key-value interface to a variety of storage engines organized as a chain of operations.
+* [MetricBase](https://github.com/msiebuhr/MetricBase) - Single-binary version of Graphite.
+* [Gitchain](https://github.com/gitchain/gitchain) - Decentralized, peer-to-peer Git repositories aka "Git meets Bitcoin".
+* [event-shuttle](https://github.com/sclasen/event-shuttle) - A Unix system service to collect and reliably deliver messages to Kafka.
+* [ipxed](https://github.com/kelseyhightower/ipxed) - Web interface and api for ipxed.
+* [BoltStore](https://github.com/yosssi/boltstore) - Session store using Bolt.
+* [photosite/session](https://godoc.org/bitbucket.org/kardianos/photosite/session) - Sessions for a photo viewing site.
+* [LedisDB](https://github.com/siddontang/ledisdb) - A high performance NoSQL, using Bolt as optional storage.
+* [ipLocator](https://github.com/AndreasBriese/ipLocator) - A fast ip-geo-location-server using bolt with bloom filters.
+* [cayley](https://github.com/google/cayley) - Cayley is an open-source graph database using Bolt as optional backend.
+* [bleve](http://www.blevesearch.com/) - A pure Go search engine similar to ElasticSearch that uses Bolt as the default storage backend.
+* [tentacool](https://github.com/optiflows/tentacool) - REST api server to manage system stuff (IP, DNS, Gateway...) on a linux server.
+* [Seaweed File System](https://github.com/chrislusf/seaweedfs) - Highly scalable distributed key~file system with O(1) disk read.
+* [InfluxDB](https://influxdata.com) - Scalable datastore for metrics, events, and real-time analytics.
+* [Freehold](http://tshannon.bitbucket.org/freehold/) - An open, secure, and lightweight platform for your files and data.
+* [Prometheus Annotation Server](https://github.com/oliver006/prom_annotation_server) - Annotation server for PromDash & Prometheus service monitoring system.
+* [Consul](https://github.com/hashicorp/consul) - Consul is service discovery and configuration made easy. Distributed, highly available, and datacenter-aware.
+* [Kala](https://github.com/ajvb/kala) - Kala is a modern job scheduler optimized to run on a single node. It is persistent, JSON over HTTP API, ISO 8601 duration notation, and dependent jobs.
+* [drive](https://github.com/odeke-em/drive) - drive is an unofficial Google Drive command line client for \*NIX operating systems.
+* [stow](https://github.com/djherbis/stow) -  a persistence manager for objects
+  backed by boltdb.
+* [buckets](https://github.com/joyrexus/buckets) - a bolt wrapper streamlining
+  simple tx and key scans.
+* [mbuckets](https://github.com/abhigupta912/mbuckets) - A Bolt wrapper that allows easy operations on multi level (nested) buckets.
+* [Request Baskets](https://github.com/darklynx/request-baskets) - A web service to collect arbitrary HTTP requests and inspect them via REST API or simple web UI, similar to [RequestBin](http://requestb.in/) service
+* [Go Report Card](https://goreportcard.com/) - Go code quality report cards as a (free and open source) service.
+* [Boltdb Boilerplate](https://github.com/bobintornado/boltdb-boilerplate) - Boilerplate wrapper around bolt aiming to make simple calls one-liners.
+* [lru](https://github.com/crowdriff/lru) - Easy to use Bolt-backed Least-Recently-Used (LRU) read-through cache with chainable remote stores.
+* [Storm](https://github.com/asdine/storm) - Simple and powerful ORM for BoltDB.
+* [GoWebApp](https://github.com/josephspurrier/gowebapp) - A basic MVC web application in Go using BoltDB.
+* [SimpleBolt](https://github.com/xyproto/simplebolt) - A simple way to use BoltDB. Deals mainly with strings.
+* [Algernon](https://github.com/xyproto/algernon) - A HTTP/2 web server with built-in support for Lua. Uses BoltDB as the default database backend.
+* [MuLiFS](https://github.com/dankomiocevic/mulifs) - Music Library Filesystem creates a filesystem to organise your music files.
+* [GoShort](https://github.com/pankajkhairnar/goShort) - GoShort is a URL shortener written in Golang and BoltDB for persistent key/value storage and for routing it's using high performent HTTPRouter.
+* [torrent](https://github.com/anacrolix/torrent) - Full-featured BitTorrent client package and utilities in Go. BoltDB is a storage backend in development.
+* [gopherpit](https://github.com/gopherpit/gopherpit) - A web service to manage Go remote import paths with custom domains
+* [bolter](https://github.com/hasit/bolter) - Command-line app for viewing BoltDB file in your terminal.
+* [btcwallet](https://github.com/btcsuite/btcwallet) - A bitcoin wallet.
+* [dcrwallet](https://github.com/decred/dcrwallet) - A wallet for the Decred cryptocurrency.
+* [Ironsmith](https://github.com/timshannon/ironsmith) - A simple, script-driven continuous integration (build - > test -> release) tool, with no external dependencies
+* [BoltHold](https://github.com/timshannon/bolthold) - An embeddable NoSQL store for Go types built on BoltDB
+* [Ponzu CMS](https://ponzu-cms.org) - Headless CMS + automatic JSON API with auto-HTTPS, HTTP/2 Server Push, and flexible server framework.
+
+If you are using Bolt in a project please send a pull request to add it to the list.

vendor/github.com/boltdb/bolt/bolt_386.go

@@ -0,0 +1,10 @@
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x7FFFFFFF // 2GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false

vendor/github.com/boltdb/bolt/bolt_amd64.go

@@ -0,0 +1,10 @@
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false

vendor/github.com/boltdb/bolt/bolt_arm.go

@@ -0,0 +1,28 @@
+package bolt
+
+import "unsafe"
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x7FFFFFFF // 2GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned bool
+
+func init() {
+	// Simple check to see whether this arch handles unaligned load/stores
+	// correctly.
+
+	// ARM9 and older devices require load/stores to be from/to aligned
+	// addresses. If not, the lower 2 bits are cleared and that address is
+	// read in a jumbled up order.
+
+	// See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15414.html
+
+	raw := [6]byte{0xfe, 0xef, 0x11, 0x22, 0x22, 0x11}
+	val := *(*uint32)(unsafe.Pointer(uintptr(unsafe.Pointer(&raw)) + 2))
+
+	brokenUnaligned = val != 0x11222211
+}

vendor/github.com/boltdb/bolt/bolt_arm64.go

@@ -0,0 +1,12 @@
+// +build arm64
+
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false

vendor/github.com/boltdb/bolt/bolt_linux.go

@@ -0,0 +1,10 @@
+package bolt
+
+import (
+	"syscall"
+)
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return syscall.Fdatasync(int(db.file.Fd()))
+}

vendor/github.com/boltdb/bolt/bolt_openbsd.go

@@ -0,0 +1,27 @@
+package bolt
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const (
+	msAsync      = 1 << iota // perform asynchronous writes
+	msSync                   // perform synchronous writes
+	msInvalidate             // invalidate cached data
+)
+
+func msync(db *DB) error {
+	_, _, errno := syscall.Syscall(syscall.SYS_MSYNC, uintptr(unsafe.Pointer(db.data)), uintptr(db.datasz), msInvalidate)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+func fdatasync(db *DB) error {
+	if db.data != nil {
+		return msync(db)
+	}
+	return db.file.Sync()
+}

vendor/github.com/boltdb/bolt/bolt_ppc.go

@@ -0,0 +1,9 @@
+// +build ppc
+
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x7FFFFFFF // 2GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF

vendor/github.com/boltdb/bolt/bolt_ppc64.go

@@ -0,0 +1,12 @@
+// +build ppc64
+
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false

vendor/github.com/boltdb/bolt/bolt_ppc64le.go

@@ -0,0 +1,12 @@
+// +build ppc64le
+
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false

vendor/github.com/boltdb/bolt/bolt_s390x.go

@@ -0,0 +1,12 @@
+// +build s390x
+
+package bolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false

vendor/github.com/boltdb/bolt/bolt_unix.go

@@ -0,0 +1,89 @@
+// +build !windows,!plan9,!solaris
+
+package bolt
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, mode os.FileMode, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	for {
+		// If we're beyond our timeout then return an error.
+		// This can only occur after we've attempted a flock once.
+		if t.IsZero() {
+			t = time.Now()
+		} else if timeout > 0 && time.Since(t) > timeout {
+			return ErrTimeout
+		}
+		flag := syscall.LOCK_SH
+		if exclusive {
+			flag = syscall.LOCK_EX
+		}
+
+		// Otherwise attempt to obtain an exclusive lock.
+		err := syscall.Flock(int(db.file.Fd()), flag|syscall.LOCK_NB)
+		if err == nil {
+			return nil
+		} else if err != syscall.EWOULDBLOCK {
+			return err
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(50 * time.Millisecond)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	return syscall.Flock(int(db.file.Fd()), syscall.LOCK_UN)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := syscall.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	if err := madvise(b, syscall.MADV_RANDOM); err != nil {
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := syscall.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
+
+// NOTE: This function is copied from stdlib because it is not available on darwin.
+func madvise(b []byte, advice int) (err error) {
+	_, _, e1 := syscall.Syscall(syscall.SYS_MADVISE, uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)), uintptr(advice))
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}

vendor/github.com/boltdb/bolt/bolt_unix_solaris.go

@@ -0,0 +1,90 @@
+package bolt
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, mode os.FileMode, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	for {
+		// If we're beyond our timeout then return an error.
+		// This can only occur after we've attempted a flock once.
+		if t.IsZero() {
+			t = time.Now()
+		} else if timeout > 0 && time.Since(t) > timeout {
+			return ErrTimeout
+		}
+		var lock syscall.Flock_t
+		lock.Start = 0
+		lock.Len = 0
+		lock.Pid = 0
+		lock.Whence = 0
+		lock.Pid = 0
+		if exclusive {
+			lock.Type = syscall.F_WRLCK
+		} else {
+			lock.Type = syscall.F_RDLCK
+		}
+		err := syscall.FcntlFlock(db.file.Fd(), syscall.F_SETLK, &lock)
+		if err == nil {
+			return nil
+		} else if err != syscall.EAGAIN {
+			return err
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(50 * time.Millisecond)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	return syscall.FcntlFlock(uintptr(db.file.Fd()), syscall.F_SETLK, &lock)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}

vendor/github.com/boltdb/bolt/bolt_windows.go

@@ -0,0 +1,144 @@
+package bolt
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// LockFileEx code derived from golang build filemutex_windows.go @ v1.5.1
+var (
+	modkernel32      = syscall.NewLazyDLL("kernel32.dll")
+	procLockFileEx   = modkernel32.NewProc("LockFileEx")
+	procUnlockFileEx = modkernel32.NewProc("UnlockFileEx")
+)
+
+const (
+	lockExt = ".lock"
+
+	// see https://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx
+	flagLockExclusive       = 2
+	flagLockFailImmediately = 1
+
+	// see https://msdn.microsoft.com/en-us/library/windows/desktop/ms681382(v=vs.85).aspx
+	errLockViolation syscall.Errno = 0x21
+)
+
+func lockFileEx(h syscall.Handle, flags, reserved, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
+	r, _, err := procLockFileEx.Call(uintptr(h), uintptr(flags), uintptr(reserved), uintptr(locklow), uintptr(lockhigh), uintptr(unsafe.Pointer(ol)))
+	if r == 0 {
+		return err
+	}
+	return nil
+}
+
+func unlockFileEx(h syscall.Handle, reserved, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
+	r, _, err := procUnlockFileEx.Call(uintptr(h), uintptr(reserved), uintptr(locklow), uintptr(lockhigh), uintptr(unsafe.Pointer(ol)), 0)
+	if r == 0 {
+		return err
+	}
+	return nil
+}
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return db.file.Sync()
+}
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, mode os.FileMode, exclusive bool, timeout time.Duration) error {
+	// Create a separate lock file on windows because a process
+	// cannot share an exclusive lock on the same file. This is
+	// needed during Tx.WriteTo().
+	f, err := os.OpenFile(db.path+lockExt, os.O_CREATE, mode)
+	if err != nil {
+		return err
+	}
+	db.lockfile = f
+
+	var t time.Time
+	for {
+		// If we're beyond our timeout then return an error.
+		// This can only occur after we've attempted a flock once.
+		if t.IsZero() {
+			t = time.Now()
+		} else if timeout > 0 && time.Since(t) > timeout {
+			return ErrTimeout
+		}
+
+		var flag uint32 = flagLockFailImmediately
+		if exclusive {
+			flag |= flagLockExclusive
+		}
+
+		err := lockFileEx(syscall.Handle(db.lockfile.Fd()), flag, 0, 1, 0, &syscall.Overlapped{})
+		if err == nil {
+			return nil
+		} else if err != errLockViolation {
+			return err
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(50 * time.Millisecond)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	err := unlockFileEx(syscall.Handle(db.lockfile.Fd()), 0, 1, 0, &syscall.Overlapped{})
+	db.lockfile.Close()
+	os.Remove(db.path + lockExt)
+	return err
+}
+
+// mmap memory maps a DB's data file.
+// Based on: https://github.com/edsrzf/mmap-go
+func mmap(db *DB, sz int) error {
+	if !db.readOnly {
+		// Truncate the database to the size of the mmap.
+		if err := db.file.Truncate(int64(sz)); err != nil {
+			return fmt.Errorf("truncate: %s", err)
+		}
+	}
+
+	// Open a file mapping handle.
+	sizelo := uint32(sz >> 32)
+	sizehi := uint32(sz) & 0xffffffff
+	h, errno := syscall.CreateFileMapping(syscall.Handle(db.file.Fd()), nil, syscall.PAGE_READONLY, sizelo, sizehi, nil)
+	if h == 0 {
+		return os.NewSyscallError("CreateFileMapping", errno)
+	}
+
+	// Create the memory map.
+	addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz))
+	if addr == 0 {
+		return os.NewSyscallError("MapViewOfFile", errno)
+	}
+
+	// Close mapping handle.
+	if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
+		return os.NewSyscallError("CloseHandle", err)
+	}
+
+	// Convert to a byte array.
+	db.data = ((*[maxMapSize]byte)(unsafe.Pointer(addr)))
+	db.datasz = sz
+
+	return nil
+}
+
+// munmap unmaps a pointer from a file.
+// Based on: https://github.com/edsrzf/mmap-go
+func munmap(db *DB) error {
+	if db.data == nil {
+		return nil
+	}
+
+	addr := (uintptr)(unsafe.Pointer(&db.data[0]))
+	if err := syscall.UnmapViewOfFile(addr); err != nil {
+		return os.NewSyscallError("UnmapViewOfFile", err)
+	}
+	return nil
+}

vendor/github.com/boltdb/bolt/boltsync_unix.go

@@ -0,0 +1,8 @@
+// +build !windows,!plan9,!linux,!openbsd
+
+package bolt
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return db.file.Sync()
+}

vendor/github.com/boltdb/bolt/bucket.go

@@ -0,0 +1,777 @@
+package bolt
+
+import (
+	"bytes"
+	"fmt"
+	"unsafe"
+)
+
+const (
+	// MaxKeySize is the maximum length of a key, in bytes.
+	MaxKeySize = 32768
+
+	// MaxValueSize is the maximum length of a value, in bytes.
+	MaxValueSize = (1 << 31) - 2
+)
+
+const (
+	maxUint = ^uint(0)
+	minUint = 0
+	maxInt  = int(^uint(0) >> 1)
+	minInt  = -maxInt - 1
+)
+
+const bucketHeaderSize = int(unsafe.Sizeof(bucket{}))
+
+const (
+	minFillPercent = 0.1
+	maxFillPercent = 1.0
+)
+
+// DefaultFillPercent is the percentage that split pages are filled.
+// This value can be changed by setting Bucket.FillPercent.
+const DefaultFillPercent = 0.5
+
+// Bucket represents a collection of key/value pairs inside the database.
+type Bucket struct {
+	*bucket
+	tx       *Tx                // the associated transaction
+	buckets  map[string]*Bucket // subbucket cache
+	page     *page              // inline page reference
+	rootNode *node              // materialized node for the root page.
+	nodes    map[pgid]*node     // node cache
+
+	// Sets the threshold for filling nodes when they split. By default,
+	// the bucket will fill to 50% but it can be useful to increase this
+	// amount if you know that your write workloads are mostly append-only.
+	//
+	// This is non-persisted across transactions so it must be set in every Tx.
+	FillPercent float64
+}
+
+// bucket represents the on-file representation of a bucket.
+// This is stored as the "value" of a bucket key. If the bucket is small enough,
+// then its root page can be stored inline in the "value", after the bucket
+// header. In the case of inline buckets, the "root" will be 0.
+type bucket struct {
+	root     pgid   // page id of the bucket's root-level page
+	sequence uint64 // monotonically incrementing, used by NextSequence()
+}
+
+// newBucket returns a new bucket associated with a transaction.
+func newBucket(tx *Tx) Bucket {
+	var b = Bucket{tx: tx, FillPercent: DefaultFillPercent}
+	if tx.writable {
+		b.buckets = make(map[string]*Bucket)
+		b.nodes = make(map[pgid]*node)
+	}
+	return b
+}
+
+// Tx returns the tx of the bucket.
+func (b *Bucket) Tx() *Tx {
+	return b.tx
+}
+
+// Root returns the root of the bucket.
+func (b *Bucket) Root() pgid {
+	return b.root
+}
+
+// Writable returns whether the bucket is writable.
+func (b *Bucket) Writable() bool {
+	return b.tx.writable
+}
+
+// Cursor creates a cursor associated with the bucket.
+// The cursor is only valid as long as the transaction is open.
+// Do not use a cursor after the transaction is closed.
+func (b *Bucket) Cursor() *Cursor {
+	// Update transaction statistics.
+	b.tx.stats.CursorCount++
+
+	// Allocate and return a cursor.
+	return &Cursor{
+		bucket: b,
+		stack:  make([]elemRef, 0),
+	}
+}
+
+// Bucket retrieves a nested bucket by name.
+// Returns nil if the bucket does not exist.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) Bucket(name []byte) *Bucket {
+	if b.buckets != nil {
+		if child := b.buckets[string(name)]; child != nil {
+			return child
+		}
+	}
+
+	// Move cursor to key.
+	c := b.Cursor()
+	k, v, flags := c.seek(name)
+
+	// Return nil if the key doesn't exist or it is not a bucket.
+	if !bytes.Equal(name, k) || (flags&bucketLeafFlag) == 0 {
+		return nil
+	}
+
+	// Otherwise create a bucket and cache it.
+	var child = b.openBucket(v)
+	if b.buckets != nil {
+		b.buckets[string(name)] = child
+	}
+
+	return child
+}
+
+// Helper method that re-interprets a sub-bucket value
+// from a parent into a Bucket
+func (b *Bucket) openBucket(value []byte) *Bucket {
+	var child = newBucket(b.tx)
+
+	// If unaligned load/stores are broken on this arch and value is
+	// unaligned simply clone to an aligned byte array.
+	unaligned := brokenUnaligned && uintptr(unsafe.Pointer(&value[0]))&3 != 0
+
+	if unaligned {
+		value = cloneBytes(value)
+	}
+
+	// If this is a writable transaction then we need to copy the bucket entry.
+	// Read-only transactions can point directly at the mmap entry.
+	if b.tx.writable && !unaligned {
+		child.bucket = &bucket{}
+		*child.bucket = *(*bucket)(unsafe.Pointer(&value[0]))
+	} else {
+		child.bucket = (*bucket)(unsafe.Pointer(&value[0]))
+	}
+
+	// Save a reference to the inline page if the bucket is inline.
+	if child.root == 0 {
+		child.page = (*page)(unsafe.Pointer(&value[bucketHeaderSize]))
+	}
+
+	return &child
+}
+
+// CreateBucket creates a new bucket at the given key and returns the new bucket.
+// Returns an error if the key already exists, if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) CreateBucket(key []byte) (*Bucket, error) {
+	if b.tx.db == nil {
+		return nil, ErrTxClosed
+	} else if !b.tx.writable {
+		return nil, ErrTxNotWritable
+	} else if len(key) == 0 {
+		return nil, ErrBucketNameRequired
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if there is an existing key.
+	if bytes.Equal(key, k) {
+		if (flags & bucketLeafFlag) != 0 {
+			return nil, ErrBucketExists
+		}
+		return nil, ErrIncompatibleValue
+	}
+
+	// Create empty, inline bucket.
+	var bucket = Bucket{
+		bucket:      &bucket{},
+		rootNode:    &node{isLeaf: true},
+		FillPercent: DefaultFillPercent,
+	}
+	var value = bucket.write()
+
+	// Insert into node.
+	key = cloneBytes(key)
+	c.node().put(key, key, value, 0, bucketLeafFlag)
+
+	// Since subbuckets are not allowed on inline buckets, we need to
+	// dereference the inline page, if it exists. This will cause the bucket
+	// to be treated as a regular, non-inline bucket for the rest of the tx.
+	b.page = nil
+
+	return b.Bucket(key), nil
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist and returns a reference to it.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error) {
+	child, err := b.CreateBucket(key)
+	if err == ErrBucketExists {
+		return b.Bucket(key), nil
+	} else if err != nil {
+		return nil, err
+	}
+	return child, nil
+}
+
+// DeleteBucket deletes a bucket at the given key.
+// Returns an error if the bucket does not exists, or if the key represents a non-bucket value.
+func (b *Bucket) DeleteBucket(key []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if bucket doesn't exist or is not a bucket.
+	if !bytes.Equal(key, k) {
+		return ErrBucketNotFound
+	} else if (flags & bucketLeafFlag) == 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Recursively delete all child buckets.
+	child := b.Bucket(key)
+	err := child.ForEach(func(k, v []byte) error {
+		if v == nil {
+			if err := child.DeleteBucket(k); err != nil {
+				return fmt.Errorf("delete bucket: %s", err)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// Remove cached copy.
+	delete(b.buckets, string(key))
+
+	// Release all bucket pages to freelist.
+	child.nodes = nil
+	child.rootNode = nil
+	child.free()
+
+	// Delete the node if we have a matching key.
+	c.node().del(key)
+
+	return nil
+}
+
+// Get retrieves the value for a key in the bucket.
+// Returns a nil value if the key does not exist or if the key is a nested bucket.
+// The returned value is only valid for the life of the transaction.
+func (b *Bucket) Get(key []byte) []byte {
+	k, v, flags := b.Cursor().seek(key)
+
+	// Return nil if this is a bucket.
+	if (flags & bucketLeafFlag) != 0 {
+		return nil
+	}
+
+	// If our target node isn't the same key as what's passed in then return nil.
+	if !bytes.Equal(key, k) {
+		return nil
+	}
+	return v
+}
+
+// Put sets the value for a key in the bucket.
+// If the key exist then its previous value will be overwritten.
+// Supplied value must remain valid for the life of the transaction.
+// Returns an error if the bucket was created from a read-only transaction, if the key is blank, if the key is too large, or if the value is too large.
+func (b *Bucket) Put(key []byte, value []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	} else if len(key) == 0 {
+		return ErrKeyRequired
+	} else if len(key) > MaxKeySize {
+		return ErrKeyTooLarge
+	} else if int64(len(value)) > MaxValueSize {
+		return ErrValueTooLarge
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if there is an existing key with a bucket value.
+	if bytes.Equal(key, k) && (flags&bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Insert into node.
+	key = cloneBytes(key)
+	c.node().put(key, key, value, 0, 0)
+
+	return nil
+}
+
+// Delete removes a key from the bucket.
+// If the key does not exist then nothing is done and a nil error is returned.
+// Returns an error if the bucket was created from a read-only transaction.
+func (b *Bucket) Delete(key []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	_, _, flags := c.seek(key)
+
+	// Return an error if there is already existing bucket value.
+	if (flags & bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Delete the node if we have a matching key.
+	c.node().del(key)
+
+	return nil
+}
+
+// Sequence returns the current integer for the bucket without incrementing it.
+func (b *Bucket) Sequence() uint64 { return b.bucket.sequence }
+
+// SetSequence updates the sequence number for the bucket.
+func (b *Bucket) SetSequence(v uint64) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Materialize the root node if it hasn't been already so that the
+	// bucket will be saved during commit.
+	if b.rootNode == nil {
+		_ = b.node(b.root, nil)
+	}
+
+	// Increment and return the sequence.
+	b.bucket.sequence = v
+	return nil
+}
+
+// NextSequence returns an autoincrementing integer for the bucket.
+func (b *Bucket) NextSequence() (uint64, error) {
+	if b.tx.db == nil {
+		return 0, ErrTxClosed
+	} else if !b.Writable() {
+		return 0, ErrTxNotWritable
+	}
+
+	// Materialize the root node if it hasn't been already so that the
+	// bucket will be saved during commit.
+	if b.rootNode == nil {
+		_ = b.node(b.root, nil)
+	}
+
+	// Increment and return the sequence.
+	b.bucket.sequence++
+	return b.bucket.sequence, nil
+}
+
+// ForEach executes a function for each key/value pair in a bucket.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller. The provided function must not modify
+// the bucket; this will result in undefined behavior.
+func (b *Bucket) ForEach(fn func(k, v []byte) error) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	}
+	c := b.Cursor()
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		if err := fn(k, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Stat returns stats on a bucket.
+func (b *Bucket) Stats() BucketStats {
+	var s, subStats BucketStats
+	pageSize := b.tx.db.pageSize
+	s.BucketN += 1
+	if b.root == 0 {
+		s.InlineBucketN += 1
+	}
+	b.forEachPage(func(p *page, depth int) {
+		if (p.flags & leafPageFlag) != 0 {
+			s.KeyN += int(p.count)
+
+			// used totals the used bytes for the page
+			used := pageHeaderSize
+
+			if p.count != 0 {
+				// If page has any elements, add all element headers.
+				used += leafPageElementSize * int(p.count-1)
+
+				// Add all element key, value sizes.
+				// The computation takes advantage of the fact that the position
+				// of the last element's key/value equals to the total of the sizes
+				// of all previous elements' keys and values.
+				// It also includes the last element's header.
+				lastElement := p.leafPageElement(p.count - 1)
+				used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
+			}
+
+			if b.root == 0 {
+				// For inlined bucket just update the inline stats
+				s.InlineBucketInuse += used
+			} else {
+				// For non-inlined bucket update all the leaf stats
+				s.LeafPageN++
+				s.LeafInuse += used
+				s.LeafOverflowN += int(p.overflow)
+
+				// Collect stats from sub-buckets.
+				// Do that by iterating over all element headers
+				// looking for the ones with the bucketLeafFlag.
+				for i := uint16(0); i < p.count; i++ {
+					e := p.leafPageElement(i)
+					if (e.flags & bucketLeafFlag) != 0 {
+						// For any bucket element, open the element value
+						// and recursively call Stats on the contained bucket.
+						subStats.Add(b.openBucket(e.value()).Stats())
+					}
+				}
+			}
+		} else if (p.flags & branchPageFlag) != 0 {
+			s.BranchPageN++
+			lastElement := p.branchPageElement(p.count - 1)
+
+			// used totals the used bytes for the page
+			// Add header and all element headers.
+			used := pageHeaderSize + (branchPageElementSize * int(p.count-1))
+
+			// Add size of all keys and values.
+			// Again, use the fact that last element's position equals to
+			// the total of key, value sizes of all previous elements.
+			used += int(lastElement.pos + lastElement.ksize)
+			s.BranchInuse += used
+			s.BranchOverflowN += int(p.overflow)
+		}
+
+		// Keep track of maximum page depth.
+		if depth+1 > s.Depth {
+			s.Depth = (depth + 1)
+		}
+	})
+
+	// Alloc stats can be computed from page counts and pageSize.
+	s.BranchAlloc = (s.BranchPageN + s.BranchOverflowN) * pageSize
+	s.LeafAlloc = (s.LeafPageN + s.LeafOverflowN) * pageSize
+
+	// Add the max depth of sub-buckets to get total nested depth.
+	s.Depth += subStats.Depth
+	// Add the stats for all sub-buckets
+	s.Add(subStats)
+	return s
+}
+
+// forEachPage iterates over every page in a bucket, including inline pages.
+func (b *Bucket) forEachPage(fn func(*page, int)) {
+	// If we have an inline page then just use that.
+	if b.page != nil {
+		fn(b.page, 0)
+		return
+	}
+
+	// Otherwise traverse the page hierarchy.
+	b.tx.forEachPage(b.root, 0, fn)
+}
+
+// forEachPageNode iterates over every page (or node) in a bucket.
+// This also includes inline pages.
+func (b *Bucket) forEachPageNode(fn func(*page, *node, int)) {
+	// If we have an inline page or root node then just use that.
+	if b.page != nil {
+		fn(b.page, nil, 0)
+		return
+	}
+	b._forEachPageNode(b.root, 0, fn)
+}
+
+func (b *Bucket) _forEachPageNode(pgid pgid, depth int, fn func(*page, *node, int)) {
+	var p, n = b.pageNode(pgid)
+
+	// Execute function.
+	fn(p, n, depth)
+
+	// Recursively loop over children.
+	if p != nil {
+		if (p.flags & branchPageFlag) != 0 {
+			for i := 0; i < int(p.count); i++ {
+				elem := p.branchPageElement(uint16(i))
+				b._forEachPageNode(elem.pgid, depth+1, fn)
+			}
+		}
+	} else {
+		if !n.isLeaf {
+			for _, inode := range n.inodes {
+				b._forEachPageNode(inode.pgid, depth+1, fn)
+			}
+		}
+	}
+}
+
+// spill writes all the nodes for this bucket to dirty pages.
+func (b *Bucket) spill() error {
+	// Spill all child buckets first.
+	for name, child := range b.buckets {
+		// If the child bucket is small enough and it has no child buckets then
+		// write it inline into the parent bucket's page. Otherwise spill it
+		// like a normal bucket and make the parent value a pointer to the page.
+		var value []byte
+		if child.inlineable() {
+			child.free()
+			value = child.write()
+		} else {
+			if err := child.spill(); err != nil {
+				return err
+			}
+
+			// Update the child bucket header in this bucket.
+			value = make([]byte, unsafe.Sizeof(bucket{}))
+			var bucket = (*bucket)(unsafe.Pointer(&value[0]))
+			*bucket = *child.bucket
+		}
+
+		// Skip writing the bucket if there are no materialized nodes.
+		if child.rootNode == nil {
+			continue
+		}
+
+		// Update parent node.
+		var c = b.Cursor()
+		k, _, flags := c.seek([]byte(name))
+		if !bytes.Equal([]byte(name), k) {
+			panic(fmt.Sprintf("misplaced bucket header: %x -> %x", []byte(name), k))
+		}
+		if flags&bucketLeafFlag == 0 {
+			panic(fmt.Sprintf("unexpected bucket header flag: %x", flags))
+		}
+		c.node().put([]byte(name), []byte(name), value, 0, bucketLeafFlag)
+	}
+
+	// Ignore if there's not a materialized root node.
+	if b.rootNode == nil {
+		return nil
+	}
+
+	// Spill nodes.
+	if err := b.rootNode.spill(); err != nil {
+		return err
+	}
+	b.rootNode = b.rootNode.root()
+
+	// Update the root node for this bucket.
+	if b.rootNode.pgid >= b.tx.meta.pgid {
+		panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", b.rootNode.pgid, b.tx.meta.pgid))
+	}
+	b.root = b.rootNode.pgid
+
+	return nil
+}
+
+// inlineable returns true if a bucket is small enough to be written inline
+// and if it contains no subbuckets. Otherwise returns false.
+func (b *Bucket) inlineable() bool {
+	var n = b.rootNode
+
+	// Bucket must only contain a single leaf node.
+	if n == nil || !n.isLeaf {
+		return false
+	}
+
+	// Bucket is not inlineable if it contains subbuckets or if it goes beyond
+	// our threshold for inline bucket size.
+	var size = pageHeaderSize
+	for _, inode := range n.inodes {
+		size += leafPageElementSize + len(inode.key) + len(inode.value)
+
+		if inode.flags&bucketLeafFlag != 0 {
+			return false
+		} else if size > b.maxInlineBucketSize() {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Returns the maximum total size of a bucket to make it a candidate for inlining.
+func (b *Bucket) maxInlineBucketSize() int {
+	return b.tx.db.pageSize / 4
+}
+
+// write allocates and writes a bucket to a byte slice.
+func (b *Bucket) write() []byte {
+	// Allocate the appropriate size.
+	var n = b.rootNode
+	var value = make([]byte, bucketHeaderSize+n.size())
+
+	// Write a bucket header.
+	var bucket = (*bucket)(unsafe.Pointer(&value[0]))
+	*bucket = *b.bucket
+
+	// Convert byte slice to a fake page and write the root node.
+	var p = (*page)(unsafe.Pointer(&value[bucketHeaderSize]))
+	n.write(p)
+
+	return value
+}
+
+// rebalance attempts to balance all nodes.
+func (b *Bucket) rebalance() {
+	for _, n := range b.nodes {
+		n.rebalance()
+	}
+	for _, child := range b.buckets {
+		child.rebalance()
+	}
+}
+
+// node creates a node from a page and associates it with a given parent.
+func (b *Bucket) node(pgid pgid, parent *node) *node {
+	_assert(b.nodes != nil, "nodes map expected")
+
+	// Retrieve node if it's already been created.
+	if n := b.nodes[pgid]; n != nil {
+		return n
+	}
+
+	// Otherwise create a node and cache it.
+	n := &node{bucket: b, parent: parent}
+	if parent == nil {
+		b.rootNode = n
+	} else {
+		parent.children = append(parent.children, n)
+	}
+
+	// Use the inline page if this is an inline bucket.
+	var p = b.page
+	if p == nil {
+		p = b.tx.page(pgid)
+	}
+
+	// Read the page into the node and cache it.
+	n.read(p)
+	b.nodes[pgid] = n
+
+	// Update statistics.
+	b.tx.stats.NodeCount++
+
+	return n
+}
+
+// free recursively frees all pages in the bucket.
+func (b *Bucket) free() {
+	if b.root == 0 {
+		return
+	}
+
+	var tx = b.tx
+	b.forEachPageNode(func(p *page, n *node, _ int) {
+		if p != nil {
+			tx.db.freelist.free(tx.meta.txid, p)
+		} else {
+			n.free()
+		}
+	})
+	b.root = 0
+}
+
+// dereference removes all references to the old mmap.
+func (b *Bucket) dereference() {
+	if b.rootNode != nil {
+		b.rootNode.root().dereference()
+	}
+
+	for _, child := range b.buckets {
+		child.dereference()
+	}
+}
+
+// pageNode returns the in-memory node, if it exists.
+// Otherwise returns the underlying page.
+func (b *Bucket) pageNode(id pgid) (*page, *node) {
+	// Inline buckets have a fake page embedded in their value so treat them
+	// differently. We'll return the rootNode (if available) or the fake page.
+	if b.root == 0 {
+		if id != 0 {
+			panic(fmt.Sprintf("inline bucket non-zero page access(2): %d != 0", id))
+		}
+		if b.rootNode != nil {
+			return nil, b.rootNode
+		}
+		return b.page, nil
+	}
+
+	// Check the node cache for non-inline buckets.
+	if b.nodes != nil {
+		if n := b.nodes[id]; n != nil {
+			return nil, n
+		}
+	}
+
+	// Finally lookup the page from the transaction if no node is materialized.
+	return b.tx.page(id), nil
+}
+
+// BucketStats records statistics about resources used by a bucket.
+type BucketStats struct {
+	// Page count statistics.
+	BranchPageN     int // number of logical branch pages
+	BranchOverflowN int // number of physical branch overflow pages
+	LeafPageN       int // number of logical leaf pages
+	LeafOverflowN   int // number of physical leaf overflow pages
+
+	// Tree statistics.
+	KeyN  int // number of keys/value pairs
+	Depth int // number of levels in B+tree
+
+	// Page size utilization.
+	BranchAlloc int // bytes allocated for physical branch pages
+	BranchInuse int // bytes actually used for branch data
+	LeafAlloc   int // bytes allocated for physical leaf pages
+	LeafInuse   int // bytes actually used for leaf data
+
+	// Bucket statistics
+	BucketN           int // total number of buckets including the top bucket
+	InlineBucketN     int // total number on inlined buckets
+	InlineBucketInuse int // bytes used for inlined buckets (also accounted for in LeafInuse)
+}
+
+func (s *BucketStats) Add(other BucketStats) {
+	s.BranchPageN += other.BranchPageN
+	s.BranchOverflowN += other.BranchOverflowN
+	s.LeafPageN += other.LeafPageN
+	s.LeafOverflowN += other.LeafOverflowN
+	s.KeyN += other.KeyN
+	if s.Depth < other.Depth {
+		s.Depth = other.Depth
+	}
+	s.BranchAlloc += other.BranchAlloc
+	s.BranchInuse += other.BranchInuse
+	s.LeafAlloc += other.LeafAlloc
+	s.LeafInuse += other.LeafInuse
+
+	s.BucketN += other.BucketN
+	s.InlineBucketN += other.InlineBucketN
+	s.InlineBucketInuse += other.InlineBucketInuse
+}
+
+// cloneBytes returns a copy of a given slice.
+func cloneBytes(v []byte) []byte {
+	var clone = make([]byte, len(v))
+	copy(clone, v)
+	return clone
+}

vendor/github.com/boltdb/bolt/cursor.go

@@ -0,0 +1,400 @@
+package bolt
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+)
+
+// Cursor represents an iterator that can traverse over all key/value pairs in a bucket in sorted order.
+// Cursors see nested buckets with value == nil.
+// Cursors can be obtained from a transaction and are valid as long as the transaction is open.
+//
+// Keys and values returned from the cursor are only valid for the life of the transaction.
+//
+// Changing data while traversing with a cursor may cause it to be invalidated
+// and return unexpected keys and/or values. You must reposition your cursor
+// after mutating data.
+type Cursor struct {
+	bucket *Bucket
+	stack  []elemRef
+}
+
+// Bucket returns the bucket that this cursor was created from.
+func (c *Cursor) Bucket() *Bucket {
+	return c.bucket
+}
+
+// First moves the cursor to the first item in the bucket and returns its key and value.
+// If the bucket is empty then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) First() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+	c.stack = c.stack[:0]
+	p, n := c.bucket.pageNode(c.bucket.root)
+	c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
+	c.first()
+
+	// If we land on an empty page then move to the next value.
+	// https://github.com/boltdb/bolt/issues/450
+	if c.stack[len(c.stack)-1].count() == 0 {
+		c.next()
+	}
+
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+
+}
+
+// Last moves the cursor to the last item in the bucket and returns its key and value.
+// If the bucket is empty then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Last() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+	c.stack = c.stack[:0]
+	p, n := c.bucket.pageNode(c.bucket.root)
+	ref := elemRef{page: p, node: n}
+	ref.index = ref.count() - 1
+	c.stack = append(c.stack, ref)
+	c.last()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Next moves the cursor to the next item in the bucket and returns its key and value.
+// If the cursor is at the end of the bucket then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Next() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+	k, v, flags := c.next()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Prev moves the cursor to the previous item in the bucket and returns its key and value.
+// If the cursor is at the beginning of the bucket then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Prev() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+
+	// Attempt to move back one element until we're successful.
+	// Move up the stack as we hit the beginning of each page in our stack.
+	for i := len(c.stack) - 1; i >= 0; i-- {
+		elem := &c.stack[i]
+		if elem.index > 0 {
+			elem.index--
+			break
+		}
+		c.stack = c.stack[:i]
+	}
+
+	// If we've hit the end then return nil.
+	if len(c.stack) == 0 {
+		return nil, nil
+	}
+
+	// Move down the stack to find the last element of the last leaf under this branch.
+	c.last()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Seek moves the cursor to a given key and returns it.
+// If the key does not exist then the next key is used. If no keys
+// follow, a nil key is returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
+	k, v, flags := c.seek(seek)
+
+	// If we ended up after the last element of a page then move to the next one.
+	if ref := &c.stack[len(c.stack)-1]; ref.index >= ref.count() {
+		k, v, flags = c.next()
+	}
+
+	if k == nil {
+		return nil, nil
+	} else if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Delete removes the current key/value under the cursor from the bucket.
+// Delete fails if current key/value is a bucket or if the transaction is not writable.
+func (c *Cursor) Delete() error {
+	if c.bucket.tx.db == nil {
+		return ErrTxClosed
+	} else if !c.bucket.Writable() {
+		return ErrTxNotWritable
+	}
+
+	key, _, flags := c.keyValue()
+	// Return an error if current value is a bucket.
+	if (flags & bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
+	c.node().del(key)
+
+	return nil
+}
+
+// seek moves the cursor to a given key and returns it.
+// If the key does not exist then the next key is used.
+func (c *Cursor) seek(seek []byte) (key []byte, value []byte, flags uint32) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+
+	// Start from root page/node and traverse to correct page.
+	c.stack = c.stack[:0]
+	c.search(seek, c.bucket.root)
+	ref := &c.stack[len(c.stack)-1]
+
+	// If the cursor is pointing to the end of page/node then return nil.
+	if ref.index >= ref.count() {
+		return nil, nil, 0
+	}
+
+	// If this is a bucket then return a nil value.
+	return c.keyValue()
+}
+
+// first moves the cursor to the first leaf element under the last page in the stack.
+func (c *Cursor) first() {
+	for {
+		// Exit when we hit a leaf page.
+		var ref = &c.stack[len(c.stack)-1]
+		if ref.isLeaf() {
+			break
+		}
+
+		// Keep adding pages pointing to the first element to the stack.
+		var pgid pgid
+		if ref.node != nil {
+			pgid = ref.node.inodes[ref.index].pgid
+		} else {
+			pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
+		}
+		p, n := c.bucket.pageNode(pgid)
+		c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
+	}
+}
+
+// last moves the cursor to the last leaf element under the last page in the stack.
+func (c *Cursor) last() {
+	for {
+		// Exit when we hit a leaf page.
+		ref := &c.stack[len(c.stack)-1]
+		if ref.isLeaf() {
+			break
+		}
+
+		// Keep adding pages pointing to the last element in the stack.
+		var pgid pgid
+		if ref.node != nil {
+			pgid = ref.node.inodes[ref.index].pgid
+		} else {
+			pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
+		}
+		p, n := c.bucket.pageNode(pgid)
+
+		var nextRef = elemRef{page: p, node: n}
+		nextRef.index = nextRef.count() - 1
+		c.stack = append(c.stack, nextRef)
+	}
+}
+
+// next moves to the next leaf element and returns the key and value.
+// If the cursor is at the last leaf element then it stays there and returns nil.
+func (c *Cursor) next() (key []byte, value []byte, flags uint32) {
+	for {
+		// Attempt to move over one element until we're successful.
+		// Move up the stack as we hit the end of each page in our stack.
+		var i int
+		for i = len(c.stack) - 1; i >= 0; i-- {
+			elem := &c.stack[i]
+			if elem.index < elem.count()-1 {
+				elem.index++
+				break
+			}
+		}
+
+		// If we've hit the root page then stop and return. This will leave the
+		// cursor on the last element of the last page.
+		if i == -1 {
+			return nil, nil, 0
+		}
+
+		// Otherwise start from where we left off in the stack and find the
+		// first element of the first leaf page.
+		c.stack = c.stack[:i+1]
+		c.first()
+
+		// If this is an empty page then restart and move back up the stack.
+		// https://github.com/boltdb/bolt/issues/450
+		if c.stack[len(c.stack)-1].count() == 0 {
+			continue
+		}
+
+		return c.keyValue()
+	}
+}
+
+// search recursively performs a binary search against a given page/node until it finds a given key.
+func (c *Cursor) search(key []byte, pgid pgid) {
+	p, n := c.bucket.pageNode(pgid)
+	if p != nil && (p.flags&(branchPageFlag|leafPageFlag)) == 0 {
+		panic(fmt.Sprintf("invalid page type: %d: %x", p.id, p.flags))
+	}
+	e := elemRef{page: p, node: n}
+	c.stack = append(c.stack, e)
+
+	// If we're on a leaf page/node then find the specific node.
+	if e.isLeaf() {
+		c.nsearch(key)
+		return
+	}
+
+	if n != nil {
+		c.searchNode(key, n)
+		return
+	}
+	c.searchPage(key, p)
+}
+
+func (c *Cursor) searchNode(key []byte, n *node) {
+	var exact bool
+	index := sort.Search(len(n.inodes), func(i int) bool {
+		// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
+		// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
+		ret := bytes.Compare(n.inodes[i].key, key)
+		if ret == 0 {
+			exact = true
+		}
+		return ret != -1
+	})
+	if !exact && index > 0 {
+		index--
+	}
+	c.stack[len(c.stack)-1].index = index
+
+	// Recursively search to the next page.
+	c.search(key, n.inodes[index].pgid)
+}
+
+func (c *Cursor) searchPage(key []byte, p *page) {
+	// Binary search for the correct range.
+	inodes := p.branchPageElements()
+
+	var exact bool
+	index := sort.Search(int(p.count), func(i int) bool {
+		// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
+		// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
+		ret := bytes.Compare(inodes[i].key(), key)
+		if ret == 0 {
+			exact = true
+		}
+		return ret != -1
+	})
+	if !exact && index > 0 {
+		index--
+	}
+	c.stack[len(c.stack)-1].index = index
+
+	// Recursively search to the next page.
+	c.search(key, inodes[index].pgid)
+}
+
+// nsearch searches the leaf node on the top of the stack for a key.
+func (c *Cursor) nsearch(key []byte) {
+	e := &c.stack[len(c.stack)-1]
+	p, n := e.page, e.node
+
+	// If we have a node then search its inodes.
+	if n != nil {
+		index := sort.Search(len(n.inodes), func(i int) bool {
+			return bytes.Compare(n.inodes[i].key, key) != -1
+		})
+		e.index = index
+		return
+	}
+
+	// If we have a page then search its leaf elements.
+	inodes := p.leafPageElements()
+	index := sort.Search(int(p.count), func(i int) bool {
+		return bytes.Compare(inodes[i].key(), key) != -1
+	})
+	e.index = index
+}
+
+// keyValue returns the key and value of the current leaf element.
+func (c *Cursor) keyValue() ([]byte, []byte, uint32) {
+	ref := &c.stack[len(c.stack)-1]
+	if ref.count() == 0 || ref.index >= ref.count() {
+		return nil, nil, 0
+	}
+
+	// Retrieve value from node.
+	if ref.node != nil {
+		inode := &ref.node.inodes[ref.index]
+		return inode.key, inode.value, inode.flags
+	}
+
+	// Or retrieve value from page.
+	elem := ref.page.leafPageElement(uint16(ref.index))
+	return elem.key(), elem.value(), elem.flags
+}
+
+// node returns the node that the cursor is currently positioned on.
+func (c *Cursor) node() *node {
+	_assert(len(c.stack) > 0, "accessing a node with a zero-length cursor stack")
+
+	// If the top of the stack is a leaf node then just return it.
+	if ref := &c.stack[len(c.stack)-1]; ref.node != nil && ref.isLeaf() {
+		return ref.node
+	}
+
+	// Start from root and traverse down the hierarchy.
+	var n = c.stack[0].node
+	if n == nil {
+		n = c.bucket.node(c.stack[0].page.id, nil)
+	}
+	for _, ref := range c.stack[:len(c.stack)-1] {
+		_assert(!n.isLeaf, "expected branch node")
+		n = n.childAt(int(ref.index))
+	}
+	_assert(n.isLeaf, "expected leaf node")
+	return n
+}
+
+// elemRef represents a reference to an element on a given page/node.
+type elemRef struct {
+	page  *page
+	node  *node
+	index int
+}
+
+// isLeaf returns whether the ref is pointing at a leaf page/node.
+func (r *elemRef) isLeaf() bool {
+	if r.node != nil {
+		return r.node.isLeaf
+	}
+	return (r.page.flags & leafPageFlag) != 0
+}
+
+// count returns the number of inodes or page elements.
+func (r *elemRef) count() int {
+	if r.node != nil {
+		return len(r.node.inodes)
+	}
+	return int(r.page.count)
+}

vendor/github.com/boltdb/bolt/doc.go

@@ -0,0 +1,44 @@
+/*
+Package bolt implements a low-level key/value store in pure Go. It supports
+fully serializable transactions, ACID semantics, and lock-free MVCC with
+multiple readers and a single writer. Bolt can be used for projects that
+want a simple data store without the need to add large dependencies such as
+Postgres or MySQL.
+
+Bolt is a single-level, zero-copy, B+tree data store. This means that Bolt is
+optimized for fast read access and does not require recovery in the event of a
+system crash. Transactions which have not finished committing will simply be
+rolled back in the event of a crash.
+
+The design of Bolt is based on Howard Chu's LMDB database project.
+
+Bolt currently works on Windows, Mac OS X, and Linux.
+
+
+Basics
+
+There are only a few types in Bolt: DB, Bucket, Tx, and Cursor. The DB is
+a collection of buckets and is represented by a single file on disk. A bucket is
+a collection of unique keys that are associated with values.
+
+Transactions provide either read-only or read-write access to the database.
+Read-only transactions can retrieve key/value pairs and can use Cursors to
+iterate over the dataset sequentially. Read-write transactions can create and
+delete buckets and can insert and remove keys. Only one read-write transaction
+is allowed at a time.
+
+
+Caveats
+
+The database uses a read-only, memory-mapped data file to ensure that
+applications cannot corrupt the database, however, this means that keys and
+values returned from Bolt cannot be changed. Writing to a read-only byte slice
+will cause Go to panic.
+
+Keys and values retrieved from the database are only valid for the life of
+the transaction. When used outside the transaction, these byte slices can
+point to different data or can point to invalid memory which will cause a panic.
+
+
+*/
+package bolt

vendor/github.com/boltdb/bolt/errors.go

@@ -0,0 +1,71 @@
+package bolt
+
+import "errors"
+
+// These errors can be returned when opening or calling methods on a DB.
+var (
+	// ErrDatabaseNotOpen is returned when a DB instance is accessed before it
+	// is opened or after it is closed.
+	ErrDatabaseNotOpen = errors.New("database not open")
+
+	// ErrDatabaseOpen is returned when opening a database that is
+	// already open.
+	ErrDatabaseOpen = errors.New("database already open")
+
+	// ErrInvalid is returned when both meta pages on a database are invalid.
+	// This typically occurs when a file is not a bolt database.
+	ErrInvalid = errors.New("invalid database")
+
+	// ErrVersionMismatch is returned when the data file was created with a
+	// different version of Bolt.
+	ErrVersionMismatch = errors.New("version mismatch")
+
+	// ErrChecksum is returned when either meta page checksum does not match.
+	ErrChecksum = errors.New("checksum error")
+
+	// ErrTimeout is returned when a database cannot obtain an exclusive lock
+	// on the data file after the timeout passed to Open().
+	ErrTimeout = errors.New("timeout")
+)
+
+// These errors can occur when beginning or committing a Tx.
+var (
+	// ErrTxNotWritable is returned when performing a write operation on a
+	// read-only transaction.
+	ErrTxNotWritable = errors.New("tx not writable")
+
+	// ErrTxClosed is returned when committing or rolling back a transaction
+	// that has already been committed or rolled back.
+	ErrTxClosed = errors.New("tx closed")
+
+	// ErrDatabaseReadOnly is returned when a mutating transaction is started on a
+	// read-only database.
+	ErrDatabaseReadOnly = errors.New("database is in read-only mode")
+)
+
+// These errors can occur when putting or deleting a value or a bucket.
+var (
+	// ErrBucketNotFound is returned when trying to access a bucket that has
+	// not been created yet.
+	ErrBucketNotFound = errors.New("bucket not found")
+
+	// ErrBucketExists is returned when creating a bucket that already exists.
+	ErrBucketExists = errors.New("bucket already exists")
+
+	// ErrBucketNameRequired is returned when creating a bucket with a blank name.
+	ErrBucketNameRequired = errors.New("bucket name required")
+
+	// ErrKeyRequired is returned when inserting a zero-length key.
+	ErrKeyRequired = errors.New("key required")
+
+	// ErrKeyTooLarge is returned when inserting a key that is larger than MaxKeySize.
+	ErrKeyTooLarge = errors.New("key too large")
+
+	// ErrValueTooLarge is returned when inserting a value that is larger than MaxValueSize.
+	ErrValueTooLarge = errors.New("value too large")
+
+	// ErrIncompatibleValue is returned when trying create or delete a bucket
+	// on an existing non-bucket key or when trying to create or delete a
+	// non-bucket key on an existing bucket key.
+	ErrIncompatibleValue = errors.New("incompatible value")
+)

vendor/github.com/boltdb/bolt/freelist.go

@@ -0,0 +1,252 @@
+package bolt
+
+import (
+	"fmt"
+	"sort"
+	"unsafe"
+)
+
+// freelist represents a list of all pages that are available for allocation.
+// It also tracks pages that have been freed but are still in use by open transactions.
+type freelist struct {
+	ids     []pgid          // all free and available free page ids.
+	pending map[txid][]pgid // mapping of soon-to-be free page ids by tx.
+	cache   map[pgid]bool   // fast lookup of all free and pending page ids.
+}
+
+// newFreelist returns an empty, initialized freelist.
+func newFreelist() *freelist {
+	return &freelist{
+		pending: make(map[txid][]pgid),
+		cache:   make(map[pgid]bool),
+	}
+}
+
+// size returns the size of the page after serialization.
+func (f *freelist) size() int {
+	n := f.count()
+	if n >= 0xFFFF {
+		// The first element will be used to store the count. See freelist.write.
+		n++
+	}
+	return pageHeaderSize + (int(unsafe.Sizeof(pgid(0))) * n)
+}
+
+// count returns count of pages on the freelist
+func (f *freelist) count() int {
+	return f.free_count() + f.pending_count()
+}
+
+// free_count returns count of free pages
+func (f *freelist) free_count() int {
+	return len(f.ids)
+}
+
+// pending_count returns count of pending pages
+func (f *freelist) pending_count() int {
+	var count int
+	for _, list := range f.pending {
+		count += len(list)
+	}
+	return count
+}
+
+// copyall copies into dst a list of all free ids and all pending ids in one sorted list.
+// f.count returns the minimum length required for dst.
+func (f *freelist) copyall(dst []pgid) {
+	m := make(pgids, 0, f.pending_count())
+	for _, list := range f.pending {
+		m = append(m, list...)
+	}
+	sort.Sort(m)
+	mergepgids(dst, f.ids, m)
+}
+
+// allocate returns the starting page id of a contiguous list of pages of a given size.
+// If a contiguous block cannot be found then 0 is returned.
+func (f *freelist) allocate(n int) pgid {
+	if len(f.ids) == 0 {
+		return 0
+	}
+
+	var initial, previd pgid
+	for i, id := range f.ids {
+		if id <= 1 {
+			panic(fmt.Sprintf("invalid page allocation: %d", id))
+		}
+
+		// Reset initial page if this is not contiguous.
+		if previd == 0 || id-previd != 1 {
+			initial = id
+		}
+
+		// If we found a contiguous block then remove it and return it.
+		if (id-initial)+1 == pgid(n) {
+			// If we're allocating off the beginning then take the fast path
+			// and just adjust the existing slice. This will use extra memory
+			// temporarily but the append() in free() will realloc the slice
+			// as is necessary.
+			if (i + 1) == n {
+				f.ids = f.ids[i+1:]
+			} else {
+				copy(f.ids[i-n+1:], f.ids[i+1:])
+				f.ids = f.ids[:len(f.ids)-n]
+			}
+
+			// Remove from the free cache.
+			for i := pgid(0); i < pgid(n); i++ {
+				delete(f.cache, initial+i)
+			}
+
+			return initial
+		}
+
+		previd = id
+	}
+	return 0
+}
+
+// free releases a page and its overflow for a given transaction id.
+// If the page is already free then a panic will occur.
+func (f *freelist) free(txid txid, p *page) {
+	if p.id <= 1 {
+		panic(fmt.Sprintf("cannot free page 0 or 1: %d", p.id))
+	}
+
+	// Free page and all its overflow pages.
+	var ids = f.pending[txid]
+	for id := p.id; id <= p.id+pgid(p.overflow); id++ {
+		// Verify that page is not already free.
+		if f.cache[id] {
+			panic(fmt.Sprintf("page %d already freed", id))
+		}
+
+		// Add to the freelist and cache.
+		ids = append(ids, id)
+		f.cache[id] = true
+	}
+	f.pending[txid] = ids
+}
+
+// release moves all page ids for a transaction id (or older) to the freelist.
+func (f *freelist) release(txid txid) {
+	m := make(pgids, 0)
+	for tid, ids := range f.pending {
+		if tid <= txid {
+			// Move transaction's pending pages to the available freelist.
+			// Don't remove from the cache since the page is still free.
+			m = append(m, ids...)
+			delete(f.pending, tid)
+		}
+	}
+	sort.Sort(m)
+	f.ids = pgids(f.ids).merge(m)
+}
+
+// rollback removes the pages from a given pending tx.
+func (f *freelist) rollback(txid txid) {
+	// Remove page ids from cache.
+	for _, id := range f.pending[txid] {
+		delete(f.cache, id)
+	}
+
+	// Remove pages from pending list.
+	delete(f.pending, txid)
+}
+
+// freed returns whether a given page is in the free list.
+func (f *freelist) freed(pgid pgid) bool {
+	return f.cache[pgid]
+}
+
+// read initializes the freelist from a freelist page.
+func (f *freelist) read(p *page) {
+	// If the page.count is at the max uint16 value (64k) then it's considered
+	// an overflow and the size of the freelist is stored as the first element.
+	idx, count := 0, int(p.count)
+	if count == 0xFFFF {
+		idx = 1
+		count = int(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[0])
+	}
+
+	// Copy the list of page ids from the freelist.
+	if count == 0 {
+		f.ids = nil
+	} else {
+		ids := ((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[idx:count]
+		f.ids = make([]pgid, len(ids))
+		copy(f.ids, ids)
+
+		// Make sure they're sorted.
+		sort.Sort(pgids(f.ids))
+	}
+
+	// Rebuild the page cache.
+	f.reindex()
+}
+
+// write writes the page ids onto a freelist page. All free and pending ids are
+// saved to disk since in the event of a program crash, all pending ids will
+// become free.
+func (f *freelist) write(p *page) error {
+	// Combine the old free pgids and pgids waiting on an open transaction.
+
+	// Update the header flag.
+	p.flags |= freelistPageFlag
+
+	// The page.count can only hold up to 64k elements so if we overflow that
+	// number then we handle it by putting the size in the first element.
+	lenids := f.count()
+	if lenids == 0 {
+		p.count = uint16(lenids)
+	} else if lenids < 0xFFFF {
+		p.count = uint16(lenids)
+		f.copyall(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[:])
+	} else {
+		p.count = 0xFFFF
+		((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[0] = pgid(lenids)
+		f.copyall(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[1:])
+	}
+
+	return nil
+}
+
+// reload reads the freelist from a page and filters out pending items.
+func (f *freelist) reload(p *page) {
+	f.read(p)
+
+	// Build a cache of only pending pages.
+	pcache := make(map[pgid]bool)
+	for _, pendingIDs := range f.pending {
+		for _, pendingID := range pendingIDs {
+			pcache[pendingID] = true
+		}
+	}
+
+	// Check each page in the freelist and build a new available freelist
+	// with any pages not in the pending lists.
+	var a []pgid
+	for _, id := range f.ids {
+		if !pcache[id] {
+			a = append(a, id)
+		}
+	}
+	f.ids = a
+
+	// Once the available list is rebuilt then rebuild the free cache so that
+	// it includes the available and pending free pages.
+	f.reindex()
+}
+
+// reindex rebuilds the free cache based on available and pending free lists.
+func (f *freelist) reindex() {
+	f.cache = make(map[pgid]bool, len(f.ids))
+	for _, id := range f.ids {
+		f.cache[id] = true
+	}
+	for _, pendingIDs := range f.pending {
+		for _, pendingID := range pendingIDs {
+			f.cache[pendingID] = true
+		}
+	}
+}

vendor/github.com/boltdb/bolt/node.go

@@ -0,0 +1,604 @@
+package bolt
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"unsafe"
+)
+
+// node represents an in-memory, deserialized page.
+type node struct {
+	bucket     *Bucket
+	isLeaf     bool
+	unbalanced bool
+	spilled    bool
+	key        []byte
+	pgid       pgid
+	parent     *node
+	children   nodes
+	inodes     inodes
+}
+
+// root returns the top-level node this node is attached to.
+func (n *node) root() *node {
+	if n.parent == nil {
+		return n
+	}
+	return n.parent.root()
+}
+
+// minKeys returns the minimum number of inodes this node should have.
+func (n *node) minKeys() int {
+	if n.isLeaf {
+		return 1
+	}
+	return 2
+}
+
+// size returns the size of the node after serialization.
+func (n *node) size() int {
+	sz, elsz := pageHeaderSize, n.pageElementSize()
+	for i := 0; i < len(n.inodes); i++ {
+		item := &n.inodes[i]
+		sz += elsz + len(item.key) + len(item.value)
+	}
+	return sz
+}
+
+// sizeLessThan returns true if the node is less than a given size.
+// This is an optimization to avoid calculating a large node when we only need
+// to know if it fits inside a certain page size.
+func (n *node) sizeLessThan(v int) bool {
+	sz, elsz := pageHeaderSize, n.pageElementSize()
+	for i := 0; i < len(n.inodes); i++ {
+		item := &n.inodes[i]
+		sz += elsz + len(item.key) + len(item.value)
+		if sz >= v {
+			return false
+		}
+	}
+	return true
+}
+
+// pageElementSize returns the size of each page element based on the type of node.
+func (n *node) pageElementSize() int {
+	if n.isLeaf {
+		return leafPageElementSize
+	}
+	return branchPageElementSize
+}
+
+// childAt returns the child node at a given index.
+func (n *node) childAt(index int) *node {
+	if n.isLeaf {
+		panic(fmt.Sprintf("invalid childAt(%d) on a leaf node", index))
+	}
+	return n.bucket.node(n.inodes[index].pgid, n)
+}
+
+// childIndex returns the index of a given child node.
+func (n *node) childIndex(child *node) int {
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, child.key) != -1 })
+	return index
+}
+
+// numChildren returns the number of children.
+func (n *node) numChildren() int {
+	return len(n.inodes)
+}
+
+// nextSibling returns the next node with the same parent.
+func (n *node) nextSibling() *node {
+	if n.parent == nil {
+		return nil
+	}
+	index := n.parent.childIndex(n)
+	if index >= n.parent.numChildren()-1 {
+		return nil
+	}
+	return n.parent.childAt(index + 1)
+}
+
+// prevSibling returns the previous node with the same parent.
+func (n *node) prevSibling() *node {
+	if n.parent == nil {
+		return nil
+	}
+	index := n.parent.childIndex(n)
+	if index == 0 {
+		return nil
+	}
+	return n.parent.childAt(index - 1)
+}
+
+// put inserts a key/value.
+func (n *node) put(oldKey, newKey, value []byte, pgid pgid, flags uint32) {
+	if pgid >= n.bucket.tx.meta.pgid {
+		panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", pgid, n.bucket.tx.meta.pgid))
+	} else if len(oldKey) <= 0 {
+		panic("put: zero-length old key")
+	} else if len(newKey) <= 0 {
+		panic("put: zero-length new key")
+	}
+
+	// Find insertion index.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, oldKey) != -1 })
+
+	// Add capacity and shift nodes if we don't have an exact match and need to insert.
+	exact := (len(n.inodes) > 0 && index < len(n.inodes) && bytes.Equal(n.inodes[index].key, oldKey))
+	if !exact {
+		n.inodes = append(n.inodes, inode{})
+		copy(n.inodes[index+1:], n.inodes[index:])
+	}
+
+	inode := &n.inodes[index]
+	inode.flags = flags
+	inode.key = newKey
+	inode.value = value
+	inode.pgid = pgid
+	_assert(len(inode.key) > 0, "put: zero-length inode key")
+}
+
+// del removes a key from the node.
+func (n *node) del(key []byte) {
+	// Find index of key.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, key) != -1 })
+
+	// Exit if the key isn't found.
+	if index >= len(n.inodes) || !bytes.Equal(n.inodes[index].key, key) {
+		return
+	}
+
+	// Delete inode from the node.
+	n.inodes = append(n.inodes[:index], n.inodes[index+1:]...)
+
+	// Mark the node as needing rebalancing.
+	n.unbalanced = true
+}
+
+// read initializes the node from a page.
+func (n *node) read(p *page) {
+	n.pgid = p.id
+	n.isLeaf = ((p.flags & leafPageFlag) != 0)
+	n.inodes = make(inodes, int(p.count))
+
+	for i := 0; i < int(p.count); i++ {
+		inode := &n.inodes[i]
+		if n.isLeaf {
+			elem := p.leafPageElement(uint16(i))
+			inode.flags = elem.flags
+			inode.key = elem.key()
+			inode.value = elem.value()
+		} else {
+			elem := p.branchPageElement(uint16(i))
+			inode.pgid = elem.pgid
+			inode.key = elem.key()
+		}
+		_assert(len(inode.key) > 0, "read: zero-length inode key")
+	}
+
+	// Save first key so we can find the node in the parent when we spill.
+	if len(n.inodes) > 0 {
+		n.key = n.inodes[0].key
+		_assert(len(n.key) > 0, "read: zero-length node key")
+	} else {
+		n.key = nil
+	}
+}
+
+// write writes the items onto one or more pages.
+func (n *node) write(p *page) {
+	// Initialize page.
+	if n.isLeaf {
+		p.flags |= leafPageFlag
+	} else {
+		p.flags |= branchPageFlag
+	}
+
+	if len(n.inodes) >= 0xFFFF {
+		panic(fmt.Sprintf("inode overflow: %d (pgid=%d)", len(n.inodes), p.id))
+	}
+	p.count = uint16(len(n.inodes))
+
+	// Stop here if there are no items to write.
+	if p.count == 0 {
+		return
+	}
+
+	// Loop over each item and write it to the page.
+	b := (*[maxAllocSize]byte)(unsafe.Pointer(&p.ptr))[n.pageElementSize()*len(n.inodes):]
+	for i, item := range n.inodes {
+		_assert(len(item.key) > 0, "write: zero-length inode key")
+
+		// Write the page element.
+		if n.isLeaf {
+			elem := p.leafPageElement(uint16(i))
+			elem.pos = uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem)))
+			elem.flags = item.flags
+			elem.ksize = uint32(len(item.key))
+			elem.vsize = uint32(len(item.value))
+		} else {
+			elem := p.branchPageElement(uint16(i))
+			elem.pos = uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem)))
+			elem.ksize = uint32(len(item.key))
+			elem.pgid = item.pgid
+			_assert(elem.pgid != p.id, "write: circular dependency occurred")
+		}
+
+		// If the length of key+value is larger than the max allocation size
+		// then we need to reallocate the byte array pointer.
+		//
+		// See: https://github.com/boltdb/bolt/pull/335
+		klen, vlen := len(item.key), len(item.value)
+		if len(b) < klen+vlen {
+			b = (*[maxAllocSize]byte)(unsafe.Pointer(&b[0]))[:]
+		}
+
+		// Write data for the element to the end of the page.
+		copy(b[0:], item.key)
+		b = b[klen:]
+		copy(b[0:], item.value)
+		b = b[vlen:]
+	}
+
+	// DEBUG ONLY: n.dump()
+}
+
+// split breaks up a node into multiple smaller nodes, if appropriate.
+// This should only be called from the spill() function.
+func (n *node) split(pageSize int) []*node {
+	var nodes []*node
+
+	node := n
+	for {
+		// Split node into two.
+		a, b := node.splitTwo(pageSize)
+		nodes = append(nodes, a)
+
+		// If we can't split then exit the loop.
+		if b == nil {
+			break
+		}
+
+		// Set node to b so it gets split on the next iteration.
+		node = b
+	}
+
+	return nodes
+}
+
+// splitTwo breaks up a node into two smaller nodes, if appropriate.
+// This should only be called from the split() function.
+func (n *node) splitTwo(pageSize int) (*node, *node) {
+	// Ignore the split if the page doesn't have at least enough nodes for
+	// two pages or if the nodes can fit in a single page.
+	if len(n.inodes) <= (minKeysPerPage*2) || n.sizeLessThan(pageSize) {
+		return n, nil
+	}
+
+	// Determine the threshold before starting a new node.
+	var fillPercent = n.bucket.FillPercent
+	if fillPercent < minFillPercent {
+		fillPercent = minFillPercent
+	} else if fillPercent > maxFillPercent {
+		fillPercent = maxFillPercent
+	}
+	threshold := int(float64(pageSize) * fillPercent)
+
+	// Determine split position and sizes of the two pages.
+	splitIndex, _ := n.splitIndex(threshold)
+
+	// Split node into two separate nodes.
+	// If there's no parent then we'll need to create one.
+	if n.parent == nil {
+		n.parent = &node{bucket: n.bucket, children: []*node{n}}
+	}
+
+	// Create a new node and add it to the parent.
+	next := &node{bucket: n.bucket, isLeaf: n.isLeaf, parent: n.parent}
+	n.parent.children = append(n.parent.children, next)
+
+	// Split inodes across two nodes.
+	next.inodes = n.inodes[splitIndex:]
+	n.inodes = n.inodes[:splitIndex]
+
+	// Update the statistics.
+	n.bucket.tx.stats.Split++
+
+	return n, next
+}
+
+// splitIndex finds the position where a page will fill a given threshold.
+// It returns the index as well as the size of the first page.
+// This is only be called from split().
+func (n *node) splitIndex(threshold int) (index, sz int) {
+	sz = pageHeaderSize
+
+	// Loop until we only have the minimum number of keys required for the second page.
+	for i := 0; i < len(n.inodes)-minKeysPerPage; i++ {
+		index = i
+		inode := n.inodes[i]
+		elsize := n.pageElementSize() + len(inode.key) + len(inode.value)
+
+		// If we have at least the minimum number of keys and adding another
+		// node would put us over the threshold then exit and return.
+		if i >= minKeysPerPage && sz+elsize > threshold {
+			break
+		}
+
+		// Add the element size to the total size.
+		sz += elsize
+	}
+
+	return
+}
+
+// spill writes the nodes to dirty pages and splits nodes as it goes.
+// Returns an error if dirty pages cannot be allocated.
+func (n *node) spill() error {
+	var tx = n.bucket.tx
+	if n.spilled {
+		return nil
+	}
+
+	// Spill child nodes first. Child nodes can materialize sibling nodes in
+	// the case of split-merge so we cannot use a range loop. We have to check
+	// the children size on every loop iteration.
+	sort.Sort(n.children)
+	for i := 0; i < len(n.children); i++ {
+		if err := n.children[i].spill(); err != nil {
+			return err
+		}
+	}
+
+	// We no longer need the child list because it's only used for spill tracking.
+	n.children = nil
+
+	// Split nodes into appropriate sizes. The first node will always be n.
+	var nodes = n.split(tx.db.pageSize)
+	for _, node := range nodes {
+		// Add node's page to the freelist if it's not new.
+		if node.pgid > 0 {
+			tx.db.freelist.free(tx.meta.txid, tx.page(node.pgid))
+			node.pgid = 0
+		}
+
+		// Allocate contiguous space for the node.
+		p, err := tx.allocate((node.size() / tx.db.pageSize) + 1)
+		if err != nil {
+			return err
+		}
+
+		// Write the node.
+		if p.id >= tx.meta.pgid {
+			panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", p.id, tx.meta.pgid))
+		}
+		node.pgid = p.id
+		node.write(p)
+		node.spilled = true
+
+		// Insert into parent inodes.
+		if node.parent != nil {
+			var key = node.key
+			if key == nil {
+				key = node.inodes[0].key
+			}
+
+			node.parent.put(key, node.inodes[0].key, nil, node.pgid, 0)
+			node.key = node.inodes[0].key
+			_assert(len(node.key) > 0, "spill: zero-length node key")
+		}
+
+		// Update the statistics.
+		tx.stats.Spill++
+	}
+
+	// If the root node split and created a new root then we need to spill that
+	// as well. We'll clear out the children to make sure it doesn't try to respill.
+	if n.parent != nil && n.parent.pgid == 0 {
+		n.children = nil
+		return n.parent.spill()
+	}
+
+	return nil
+}
+
+// rebalance attempts to combine the node with sibling nodes if the node fill
+// size is below a threshold or if there are not enough keys.
+func (n *node) rebalance() {
+	if !n.unbalanced {
+		return
+	}
+	n.unbalanced = false
+
+	// Update statistics.
+	n.bucket.tx.stats.Rebalance++
+
+	// Ignore if node is above threshold (25%) and has enough keys.
+	var threshold = n.bucket.tx.db.pageSize / 4
+	if n.size() > threshold && len(n.inodes) > n.minKeys() {
+		return
+	}
+
+	// Root node has special handling.
+	if n.parent == nil {
+		// If root node is a branch and only has one node then collapse it.
+		if !n.isLeaf && len(n.inodes) == 1 {
+			// Move root's child up.
+			child := n.bucket.node(n.inodes[0].pgid, n)
+			n.isLeaf = child.isLeaf
+			n.inodes = child.inodes[:]
+			n.children = child.children
+
+			// Reparent all child nodes being moved.
+			for _, inode := range n.inodes {
+				if child, ok := n.bucket.nodes[inode.pgid]; ok {
+					child.parent = n
+				}
+			}
+
+			// Remove old child.
+			child.parent = nil
+			delete(n.bucket.nodes, child.pgid)
+			child.free()
+		}
+
+		return
+	}
+
+	// If node has no keys then just remove it.
+	if n.numChildren() == 0 {
+		n.parent.del(n.key)
+		n.parent.removeChild(n)
+		delete(n.bucket.nodes, n.pgid)
+		n.free()
+		n.parent.rebalance()
+		return
+	}
+
+	_assert(n.parent.numChildren() > 1, "parent must have at least 2 children")
+
+	// Destination node is right sibling if idx == 0, otherwise left sibling.
+	var target *node
+	var useNextSibling = (n.parent.childIndex(n) == 0)
+	if useNextSibling {
+		target = n.nextSibling()
+	} else {
+		target = n.prevSibling()
+	}
+
+	// If both this node and the target node are too small then merge them.
+	if useNextSibling {
+		// Reparent all child nodes being moved.
+		for _, inode := range target.inodes {
+			if child, ok := n.bucket.nodes[inode.pgid]; ok {
+				child.parent.removeChild(child)
+				child.parent = n
+				child.parent.children = append(child.parent.children, child)
+			}
+		}
+
+		// Copy over inodes from target and remove target.
+		n.inodes = append(n.inodes, target.inodes...)
+		n.parent.del(target.key)
+		n.parent.removeChild(target)
+		delete(n.bucket.nodes, target.pgid)
+		target.free()
+	} else {
+		// Reparent all child nodes being moved.
+		for _, inode := range n.inodes {
+			if child, ok := n.bucket.nodes[inode.pgid]; ok {
+				child.parent.removeChild(child)
+				child.parent = target
+				child.parent.children = append(child.parent.children, child)
+			}
+		}
+
+		// Copy over inodes to target and remove node.
+		target.inodes = append(target.inodes, n.inodes...)
+		n.parent.del(n.key)
+		n.parent.removeChild(n)
+		delete(n.bucket.nodes, n.pgid)
+		n.free()
+	}
+
+	// Either this node or the target node was deleted from the parent so rebalance it.
+	n.parent.rebalance()
+}
+
+// removes a node from the list of in-memory children.
+// This does not affect the inodes.
+func (n *node) removeChild(target *node) {
+	for i, child := range n.children {
+		if child == target {
+			n.children = append(n.children[:i], n.children[i+1:]...)
+			return
+		}
+	}
+}
+
+// dereference causes the node to copy all its inode key/value references to heap memory.
+// This is required when the mmap is reallocated so inodes are not pointing to stale data.
+func (n *node) dereference() {
+	if n.key != nil {
+		key := make([]byte, len(n.key))
+		copy(key, n.key)
+		n.key = key
+		_assert(n.pgid == 0 || len(n.key) > 0, "dereference: zero-length node key on existing node")
+	}
+
+	for i := range n.inodes {
+		inode := &n.inodes[i]
+
+		key := make([]byte, len(inode.key))
+		copy(key, inode.key)
+		inode.key = key
+		_assert(len(inode.key) > 0, "dereference: zero-length inode key")
+
+		value := make([]byte, len(inode.value))
+		copy(value, inode.value)
+		inode.value = value
+	}
+
+	// Recursively dereference children.
+	for _, child := range n.children {
+		child.dereference()
+	}
+
+	// Update statistics.
+	n.bucket.tx.stats.NodeDeref++
+}
+
+// free adds the node's underlying page to the freelist.
+func (n *node) free() {
+	if n.pgid != 0 {
+		n.bucket.tx.db.freelist.free(n.bucket.tx.meta.txid, n.bucket.tx.page(n.pgid))
+		n.pgid = 0
+	}
+}
+
+// dump writes the contents of the node to STDERR for debugging purposes.
+/*
+func (n *node) dump() {
+	// Write node header.
+	var typ = "branch"
+	if n.isLeaf {
+		typ = "leaf"
+	}
+	warnf("[NODE %d {type=%s count=%d}]", n.pgid, typ, len(n.inodes))
+
+	// Write out abbreviated version of each item.
+	for _, item := range n.inodes {
+		if n.isLeaf {
+			if item.flags&bucketLeafFlag != 0 {
+				bucket := (*bucket)(unsafe.Pointer(&item.value[0]))
+				warnf("+L %08x -> (bucket root=%d)", trunc(item.key, 4), bucket.root)
+			} else {
+				warnf("+L %08x -> %08x", trunc(item.key, 4), trunc(item.value, 4))
+			}
+		} else {
+			warnf("+B %08x -> pgid=%d", trunc(item.key, 4), item.pgid)
+		}
+	}
+	warn("")
+}
+*/
+
+type nodes []*node
+
+func (s nodes) Len() int           { return len(s) }
+func (s nodes) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s nodes) Less(i, j int) bool { return bytes.Compare(s[i].inodes[0].key, s[j].inodes[0].key) == -1 }
+
+// inode represents an internal node inside of a node.
+// It can be used to point to elements in a page or point
+// to an element which hasn't been added to a page yet.
+type inode struct {
+	flags uint32
+	pgid  pgid
+	key   []byte
+	value []byte
+}
+
+type inodes []inode

vendor/github.com/boltdb/bolt/page.go

@@ -0,0 +1,197 @@
+package bolt
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"unsafe"
+)
+
+const pageHeaderSize = int(unsafe.Offsetof(((*page)(nil)).ptr))
+
+const minKeysPerPage = 2
+
+const branchPageElementSize = int(unsafe.Sizeof(branchPageElement{}))
+const leafPageElementSize = int(unsafe.Sizeof(leafPageElement{}))
+
+const (
+	branchPageFlag   = 0x01
+	leafPageFlag     = 0x02
+	metaPageFlag     = 0x04
+	freelistPageFlag = 0x10
+)
+
+const (
+	bucketLeafFlag = 0x01
+)
+
+type pgid uint64
+
+type page struct {
+	id       pgid
+	flags    uint16
+	count    uint16
+	overflow uint32
+	ptr      uintptr
+}
+
+// typ returns a human readable page type string used for debugging.
+func (p *page) typ() string {
+	if (p.flags & branchPageFlag) != 0 {
+		return "branch"
+	} else if (p.flags & leafPageFlag) != 0 {
+		return "leaf"
+	} else if (p.flags & metaPageFlag) != 0 {
+		return "meta"
+	} else if (p.flags & freelistPageFlag) != 0 {
+		return "freelist"
+	}
+	return fmt.Sprintf("unknown<%02x>", p.flags)
+}
+
+// meta returns a pointer to the metadata section of the page.
+func (p *page) meta() *meta {
+	return (*meta)(unsafe.Pointer(&p.ptr))
+}
+
+// leafPageElement retrieves the leaf node by index
+func (p *page) leafPageElement(index uint16) *leafPageElement {
+	n := &((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[index]
+	return n
+}
+
+// leafPageElements retrieves a list of leaf nodes.
+func (p *page) leafPageElements() []leafPageElement {
+	if p.count == 0 {
+		return nil
+	}
+	return ((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[:]
+}
+
+// branchPageElement retrieves the branch node by index
+func (p *page) branchPageElement(index uint16) *branchPageElement {
+	return &((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[index]
+}
+
+// branchPageElements retrieves a list of branch nodes.
+func (p *page) branchPageElements() []branchPageElement {
+	if p.count == 0 {
+		return nil
+	}
+	return ((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[:]
+}
+
+// dump writes n bytes of the page to STDERR as hex output.
+func (p *page) hexdump(n int) {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:n]
+	fmt.Fprintf(os.Stderr, "%x\n", buf)
+}
+
+type pages []*page
+
+func (s pages) Len() int           { return len(s) }
+func (s pages) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s pages) Less(i, j int) bool { return s[i].id < s[j].id }
+
+// branchPageElement represents a node on a branch page.
+type branchPageElement struct {
+	pos   uint32
+	ksize uint32
+	pgid  pgid
+}
+
+// key returns a byte slice of the node key.
+func (n *branchPageElement) key() []byte {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize]
+}
+
+// leafPageElement represents a node on a leaf page.
+type leafPageElement struct {
+	flags uint32
+	pos   uint32
+	ksize uint32
+	vsize uint32
+}
+
+// key returns a byte slice of the node key.
+func (n *leafPageElement) key() []byte {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize:n.ksize]
+}
+
+// value returns a byte slice of the node value.
+func (n *leafPageElement) value() []byte {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize:n.vsize]
+}
+
+// PageInfo represents human readable information about a page.
+type PageInfo struct {
+	ID            int
+	Type          string
+	Count         int
+	OverflowCount int
+}
+
+type pgids []pgid
+
+func (s pgids) Len() int           { return len(s) }
+func (s pgids) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s pgids) Less(i, j int) bool { return s[i] < s[j] }
+
+// merge returns the sorted union of a and b.
+func (a pgids) merge(b pgids) pgids {
+	// Return the opposite slice if one is nil.
+	if len(a) == 0 {
+		return b
+	}
+	if len(b) == 0 {
+		return a
+	}
+	merged := make(pgids, len(a)+len(b))
+	mergepgids(merged, a, b)
+	return merged
+}
+
+// mergepgids copies the sorted union of a and b into dst.
+// If dst is too small, it panics.
+func mergepgids(dst, a, b pgids) {
+	if len(dst) < len(a)+len(b) {
+		panic(fmt.Errorf("mergepgids bad len %d < %d + %d", len(dst), len(a), len(b)))
+	}
+	// Copy in the opposite slice if one is nil.
+	if len(a) == 0 {
+		copy(dst, b)
+		return
+	}
+	if len(b) == 0 {
+		copy(dst, a)
+		return
+	}
+
+	// Merged will hold all elements from both lists.
+	merged := dst[:0]
+
+	// Assign lead to the slice with a lower starting value, follow to the higher value.
+	lead, follow := a, b
+	if b[0] < a[0] {
+		lead, follow = b, a
+	}
+
+	// Continue while there are elements in the lead.
+	for len(lead) > 0 {
+		// Merge largest prefix of lead that is ahead of follow[0].
+		n := sort.Search(len(lead), func(i int) bool { return lead[i] > follow[0] })
+		merged = append(merged, lead[:n]...)
+		if n >= len(lead) {
+			break
+		}
+
+		// Swap lead and follow.
+		lead, follow = follow, lead[n:]
+	}
+
+	// Append what's left in follow.
+	_ = append(merged, follow...)
+}

vendor/github.com/boltdb/bolt/tx.go

@@ -0,0 +1,684 @@
+package bolt
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"sort"
+	"strings"
+	"time"
+	"unsafe"
+)
+
+// txid represents the internal transaction identifier.
+type txid uint64
+
+// Tx represents a read-only or read/write transaction on the database.
+// Read-only transactions can be used for retrieving values for keys and creating cursors.
+// Read/write transactions can create and remove buckets and create and remove keys.
+//
+// IMPORTANT: You must commit or rollback transactions when you are done with
+// them. Pages can not be reclaimed by the writer until no more transactions
+// are using them. A long running read transaction can cause the database to
+// quickly grow.
+type Tx struct {
+	writable       bool
+	managed        bool
+	db             *DB
+	meta           *meta
+	root           Bucket
+	pages          map[pgid]*page
+	stats          TxStats
+	commitHandlers []func()
+
+	// WriteFlag specifies the flag for write-related methods like WriteTo().
+	// Tx opens the database file with the specified flag to copy the data.
+	//
+	// By default, the flag is unset, which works well for mostly in-memory
+	// workloads. For databases that are much larger than available RAM,
+	// set the flag to syscall.O_DIRECT to avoid trashing the page cache.
+	WriteFlag int
+}
+
+// init initializes the transaction.
+func (tx *Tx) init(db *DB) {
+	tx.db = db
+	tx.pages = nil
+
+	// Copy the meta page since it can be changed by the writer.
+	tx.meta = &meta{}
+	db.meta().copy(tx.meta)
+
+	// Copy over the root bucket.
+	tx.root = newBucket(tx)
+	tx.root.bucket = &bucket{}
+	*tx.root.bucket = tx.meta.root
+
+	// Increment the transaction id and add a page cache for writable transactions.
+	if tx.writable {
+		tx.pages = make(map[pgid]*page)
+		tx.meta.txid += txid(1)
+	}
+}
+
+// ID returns the transaction id.
+func (tx *Tx) ID() int {
+	return int(tx.meta.txid)
+}
+
+// DB returns a reference to the database that created the transaction.
+func (tx *Tx) DB() *DB {
+	return tx.db
+}
+
+// Size returns current database size in bytes as seen by this transaction.
+func (tx *Tx) Size() int64 {
+	return int64(tx.meta.pgid) * int64(tx.db.pageSize)
+}
+
+// Writable returns whether the transaction can perform write operations.
+func (tx *Tx) Writable() bool {
+	return tx.writable
+}
+
+// Cursor creates a cursor associated with the root bucket.
+// All items in the cursor will return a nil value because all root bucket keys point to buckets.
+// The cursor is only valid as long as the transaction is open.
+// Do not use a cursor after the transaction is closed.
+func (tx *Tx) Cursor() *Cursor {
+	return tx.root.Cursor()
+}
+
+// Stats retrieves a copy of the current transaction statistics.
+func (tx *Tx) Stats() TxStats {
+	return tx.stats
+}
+
+// Bucket retrieves a bucket by name.
+// Returns nil if the bucket does not exist.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) Bucket(name []byte) *Bucket {
+	return tx.root.Bucket(name)
+}
+
+// CreateBucket creates a new bucket.
+// Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) CreateBucket(name []byte) (*Bucket, error) {
+	return tx.root.CreateBucket(name)
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) CreateBucketIfNotExists(name []byte) (*Bucket, error) {
+	return tx.root.CreateBucketIfNotExists(name)
+}
+
+// DeleteBucket deletes a bucket.
+// Returns an error if the bucket cannot be found or if the key represents a non-bucket value.
+func (tx *Tx) DeleteBucket(name []byte) error {
+	return tx.root.DeleteBucket(name)
+}
+
+// ForEach executes a function for each bucket in the root.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller.
+func (tx *Tx) ForEach(fn func(name []byte, b *Bucket) error) error {
+	return tx.root.ForEach(func(k, v []byte) error {
+		if err := fn(k, tx.root.Bucket(k)); err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
+// OnCommit adds a handler function to be executed after the transaction successfully commits.
+func (tx *Tx) OnCommit(fn func()) {
+	tx.commitHandlers = append(tx.commitHandlers, fn)
+}
+
+// Commit writes all changes to disk and updates the meta page.
+// Returns an error if a disk write error occurs, or if Commit is
+// called on a read-only transaction.
+func (tx *Tx) Commit() error {
+	_assert(!tx.managed, "managed tx commit not allowed")
+	if tx.db == nil {
+		return ErrTxClosed
+	} else if !tx.writable {
+		return ErrTxNotWritable
+	}
+
+	// TODO(benbjohnson): Use vectorized I/O to write out dirty pages.
+
+	// Rebalance nodes which have had deletions.
+	var startTime = time.Now()
+	tx.root.rebalance()
+	if tx.stats.Rebalance > 0 {
+		tx.stats.RebalanceTime += time.Since(startTime)
+	}
+
+	// spill data onto dirty pages.
+	startTime = time.Now()
+	if err := tx.root.spill(); err != nil {
+		tx.rollback()
+		return err
+	}
+	tx.stats.SpillTime += time.Since(startTime)
+
+	// Free the old root bucket.
+	tx.meta.root.root = tx.root.root
+
+	opgid := tx.meta.pgid
+
+	// Free the freelist and allocate new pages for it. This will overestimate
+	// the size of the freelist but not underestimate the size (which would be bad).
+	tx.db.freelist.free(tx.meta.txid, tx.db.page(tx.meta.freelist))
+	p, err := tx.allocate((tx.db.freelist.size() / tx.db.pageSize) + 1)
+	if err != nil {
+		tx.rollback()
+		return err
+	}
+	if err := tx.db.freelist.write(p); err != nil {
+		tx.rollback()
+		return err
+	}
+	tx.meta.freelist = p.id
+
+	// If the high water mark has moved up then attempt to grow the database.
+	if tx.meta.pgid > opgid {
+		if err := tx.db.grow(int(tx.meta.pgid+1) * tx.db.pageSize); err != nil {
+			tx.rollback()
+			return err
+		}
+	}
+
+	// Write dirty pages to disk.
+	startTime = time.Now()
+	if err := tx.write(); err != nil {
+		tx.rollback()
+		return err
+	}
+
+	// If strict mode is enabled then perform a consistency check.
+	// Only the first consistency error is reported in the panic.
+	if tx.db.StrictMode {
+		ch := tx.Check()
+		var errs []string
+		for {
+			err, ok := <-ch
+			if !ok {
+				break
+			}
+			errs = append(errs, err.Error())
+		}
+		if len(errs) > 0 {
+			panic("check fail: " + strings.Join(errs, "\n"))
+		}
+	}
+
+	// Write meta to disk.
+	if err := tx.writeMeta(); err != nil {
+		tx.rollback()
+		return err
+	}
+	tx.stats.WriteTime += time.Since(startTime)
+
+	// Finalize the transaction.
+	tx.close()
+
+	// Execute commit handlers now that the locks have been removed.
+	for _, fn := range tx.commitHandlers {
+		fn()
+	}
+
+	return nil
+}
+
+// Rollback closes the transaction and ignores all previous updates. Read-only
+// transactions must be rolled back and not committed.
+func (tx *Tx) Rollback() error {
+	_assert(!tx.managed, "managed tx rollback not allowed")
+	if tx.db == nil {
+		return ErrTxClosed
+	}
+	tx.rollback()
+	return nil
+}
+
+func (tx *Tx) rollback() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		tx.db.freelist.rollback(tx.meta.txid)
+		tx.db.freelist.reload(tx.db.page(tx.db.meta().freelist))
+	}
+	tx.close()
+}
+
+func (tx *Tx) close() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		// Grab freelist stats.
+		var freelistFreeN = tx.db.freelist.free_count()
+		var freelistPendingN = tx.db.freelist.pending_count()
+		var freelistAlloc = tx.db.freelist.size()
+
+		// Remove transaction ref & writer lock.
+		tx.db.rwtx = nil
+		tx.db.rwlock.Unlock()
+
+		// Merge statistics.
+		tx.db.statlock.Lock()
+		tx.db.stats.FreePageN = freelistFreeN
+		tx.db.stats.PendingPageN = freelistPendingN
+		tx.db.stats.FreeAlloc = (freelistFreeN + freelistPendingN) * tx.db.pageSize
+		tx.db.stats.FreelistInuse = freelistAlloc
+		tx.db.stats.TxStats.add(&tx.stats)
+		tx.db.statlock.Unlock()
+	} else {
+		tx.db.removeTx(tx)
+	}
+
+	// Clear all references.
+	tx.db = nil
+	tx.meta = nil
+	tx.root = Bucket{tx: tx}
+	tx.pages = nil
+}
+
+// Copy writes the entire database to a writer.
+// This function exists for backwards compatibility. Use WriteTo() instead.
+func (tx *Tx) Copy(w io.Writer) error {
+	_, err := tx.WriteTo(w)
+	return err
+}
+
+// WriteTo writes the entire database to a writer.
+// If err == nil then exactly tx.Size() bytes will be written into the writer.
+func (tx *Tx) WriteTo(w io.Writer) (n int64, err error) {
+	// Attempt to open reader with WriteFlag
+	f, err := os.OpenFile(tx.db.path, os.O_RDONLY|tx.WriteFlag, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer func() { _ = f.Close() }()
+
+	// Generate a meta page. We use the same page data for both meta pages.
+	buf := make([]byte, tx.db.pageSize)
+	page := (*page)(unsafe.Pointer(&buf[0]))
+	page.flags = metaPageFlag
+	*page.meta() = *tx.meta
+
+	// Write meta 0.
+	page.id = 0
+	page.meta().checksum = page.meta().sum64()
+	nn, err := w.Write(buf)
+	n += int64(nn)
+	if err != nil {
+		return n, fmt.Errorf("meta 0 copy: %s", err)
+	}
+
+	// Write meta 1 with a lower transaction id.
+	page.id = 1
+	page.meta().txid -= 1
+	page.meta().checksum = page.meta().sum64()
+	nn, err = w.Write(buf)
+	n += int64(nn)
+	if err != nil {
+		return n, fmt.Errorf("meta 1 copy: %s", err)
+	}
+
+	// Move past the meta pages in the file.
+	if _, err := f.Seek(int64(tx.db.pageSize*2), os.SEEK_SET); err != nil {
+		return n, fmt.Errorf("seek: %s", err)
+	}
+
+	// Copy data pages.
+	wn, err := io.CopyN(w, f, tx.Size()-int64(tx.db.pageSize*2))
+	n += wn
+	if err != nil {
+		return n, err
+	}
+
+	return n, f.Close()
+}
+
+// CopyFile copies the entire database to file at the given path.
+// A reader transaction is maintained during the copy so it is safe to continue
+// using the database while a copy is in progress.
+func (tx *Tx) CopyFile(path string, mode os.FileMode) error {
+	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, mode)
+	if err != nil {
+		return err
+	}
+
+	err = tx.Copy(f)
+	if err != nil {
+		_ = f.Close()
+		return err
+	}
+	return f.Close()
+}
+
+// Check performs several consistency checks on the database for this transaction.
+// An error is returned if any inconsistency is found.
+//
+// It can be safely run concurrently on a writable transaction. However, this
+// incurs a high cost for large databases and databases with a lot of subbuckets
+// because of caching. This overhead can be removed if running on a read-only
+// transaction, however, it is not safe to execute other writer transactions at
+// the same time.
+func (tx *Tx) Check() <-chan error {
+	ch := make(chan error)
+	go tx.check(ch)
+	return ch
+}
+
+func (tx *Tx) check(ch chan error) {
+	// Check if any pages are double freed.
+	freed := make(map[pgid]bool)
+	all := make([]pgid, tx.db.freelist.count())
+	tx.db.freelist.copyall(all)
+	for _, id := range all {
+		if freed[id] {
+			ch <- fmt.Errorf("page %d: already freed", id)
+		}
+		freed[id] = true
+	}
+
+	// Track every reachable page.
+	reachable := make(map[pgid]*page)
+	reachable[0] = tx.page(0) // meta0
+	reachable[1] = tx.page(1) // meta1
+	for i := uint32(0); i <= tx.page(tx.meta.freelist).overflow; i++ {
+		reachable[tx.meta.freelist+pgid(i)] = tx.page(tx.meta.freelist)
+	}
+
+	// Recursively check buckets.
+	tx.checkBucket(&tx.root, reachable, freed, ch)
+
+	// Ensure all pages below high water mark are either reachable or freed.
+	for i := pgid(0); i < tx.meta.pgid; i++ {
+		_, isReachable := reachable[i]
+		if !isReachable && !freed[i] {
+			ch <- fmt.Errorf("page %d: unreachable unfreed", int(i))
+		}
+	}
+
+	// Close the channel to signal completion.
+	close(ch)
+}
+
+func (tx *Tx) checkBucket(b *Bucket, reachable map[pgid]*page, freed map[pgid]bool, ch chan error) {
+	// Ignore inline buckets.
+	if b.root == 0 {
+		return
+	}
+
+	// Check every page used by this bucket.
+	b.tx.forEachPage(b.root, 0, func(p *page, _ int) {
+		if p.id > tx.meta.pgid {
+			ch <- fmt.Errorf("page %d: out of bounds: %d", int(p.id), int(b.tx.meta.pgid))
+		}
+
+		// Ensure each page is only referenced once.
+		for i := pgid(0); i <= pgid(p.overflow); i++ {
+			var id = p.id + i
+			if _, ok := reachable[id]; ok {
+				ch <- fmt.Errorf("page %d: multiple references", int(id))
+			}
+			reachable[id] = p
+		}
+
+		// We should only encounter un-freed leaf and branch pages.
+		if freed[p.id] {
+			ch <- fmt.Errorf("page %d: reachable freed", int(p.id))
+		} else if (p.flags&branchPageFlag) == 0 && (p.flags&leafPageFlag) == 0 {
+			ch <- fmt.Errorf("page %d: invalid type: %s", int(p.id), p.typ())
+		}
+	})
+
+	// Check each bucket within this bucket.
+	_ = b.ForEach(func(k, v []byte) error {
+		if child := b.Bucket(k); child != nil {
+			tx.checkBucket(child, reachable, freed, ch)
+		}
+		return nil
+	})
+}
+
+// allocate returns a contiguous block of memory starting at a given page.
+func (tx *Tx) allocate(count int) (*page, error) {
+	p, err := tx.db.allocate(count)
+	if err != nil {
+		return nil, err
+	}
+
+	// Save to our page cache.
+	tx.pages[p.id] = p
+
+	// Update statistics.
+	tx.stats.PageCount++
+	tx.stats.PageAlloc += count * tx.db.pageSize
+
+	return p, nil
+}
+
+// write writes any dirty pages to disk.
+func (tx *Tx) write() error {
+	// Sort pages by id.
+	pages := make(pages, 0, len(tx.pages))
+	for _, p := range tx.pages {
+		pages = append(pages, p)
+	}
+	// Clear out page cache early.
+	tx.pages = make(map[pgid]*page)
+	sort.Sort(pages)
+
+	// Write pages to disk in order.
+	for _, p := range pages {
+		size := (int(p.overflow) + 1) * tx.db.pageSize
+		offset := int64(p.id) * int64(tx.db.pageSize)
+
+		// Write out page in "max allocation" sized chunks.
+		ptr := (*[maxAllocSize]byte)(unsafe.Pointer(p))
+		for {
+			// Limit our write to our max allocation size.
+			sz := size
+			if sz > maxAllocSize-1 {
+				sz = maxAllocSize - 1
+			}
+
+			// Write chunk to disk.
+			buf := ptr[:sz]
+			if _, err := tx.db.ops.writeAt(buf, offset); err != nil {
+				return err
+			}
+
+			// Update statistics.
+			tx.stats.Write++
+
+			// Exit inner for loop if we've written all the chunks.
+			size -= sz
+			if size == 0 {
+				break
+			}
+
+			// Otherwise move offset forward and move pointer to next chunk.
+			offset += int64(sz)
+			ptr = (*[maxAllocSize]byte)(unsafe.Pointer(&ptr[sz]))
+		}
+	}
+
+	// Ignore file sync if flag is set on DB.
+	if !tx.db.NoSync || IgnoreNoSync {
+		if err := fdatasync(tx.db); err != nil {
+			return err
+		}
+	}
+
+	// Put small pages back to page pool.
+	for _, p := range pages {
+		// Ignore page sizes over 1 page.
+		// These are allocated using make() instead of the page pool.
+		if int(p.overflow) != 0 {
+			continue
+		}
+
+		buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:tx.db.pageSize]
+
+		// See https://go.googlesource.com/go/+/f03c9202c43e0abb130669852082117ca50aa9b1
+		for i := range buf {
+			buf[i] = 0
+		}
+		tx.db.pagePool.Put(buf)
+	}
+
+	return nil
+}
+
+// writeMeta writes the meta to the disk.
+func (tx *Tx) writeMeta() error {
+	// Create a temporary buffer for the meta page.
+	buf := make([]byte, tx.db.pageSize)
+	p := tx.db.pageInBuffer(buf, 0)
+	tx.meta.write(p)
+
+	// Write the meta page to file.
+	if _, err := tx.db.ops.writeAt(buf, int64(p.id)*int64(tx.db.pageSize)); err != nil {
+		return err
+	}
+	if !tx.db.NoSync || IgnoreNoSync {
+		if err := fdatasync(tx.db); err != nil {
+			return err
+		}
+	}
+
+	// Update statistics.
+	tx.stats.Write++
+
+	return nil
+}
+
+// page returns a reference to the page with a given id.
+// If page has been written to then a temporary buffered page is returned.
+func (tx *Tx) page(id pgid) *page {
+	// Check the dirty pages first.
+	if tx.pages != nil {
+		if p, ok := tx.pages[id]; ok {
+			return p
+		}
+	}
+
+	// Otherwise return directly from the mmap.
+	return tx.db.page(id)
+}
+
+// forEachPage iterates over every page within a given page and executes a function.
+func (tx *Tx) forEachPage(pgid pgid, depth int, fn func(*page, int)) {
+	p := tx.page(pgid)
+
+	// Execute function.
+	fn(p, depth)
+
+	// Recursively loop over children.
+	if (p.flags & branchPageFlag) != 0 {
+		for i := 0; i < int(p.count); i++ {
+			elem := p.branchPageElement(uint16(i))
+			tx.forEachPage(elem.pgid, depth+1, fn)
+		}
+	}
+}
+
+// Page returns page information for a given page number.
+// This is only safe for concurrent use when used by a writable transaction.
+func (tx *Tx) Page(id int) (*PageInfo, error) {
+	if tx.db == nil {
+		return nil, ErrTxClosed
+	} else if pgid(id) >= tx.meta.pgid {
+		return nil, nil
+	}
+
+	// Build the page info.
+	p := tx.db.page(pgid(id))
+	info := &PageInfo{
+		ID:            id,
+		Count:         int(p.count),
+		OverflowCount: int(p.overflow),
+	}
+
+	// Determine the type (or if it's free).
+	if tx.db.freelist.freed(pgid(id)) {
+		info.Type = "free"
+	} else {
+		info.Type = p.typ()
+	}
+
+	return info, nil
+}
+
+// TxStats represents statistics about the actions performed by the transaction.
+type TxStats struct {
+	// Page statistics.
+	PageCount int // number of page allocations
+	PageAlloc int // total bytes allocated
+
+	// Cursor statistics.
+	CursorCount int // number of cursors created
+
+	// Node statistics
+	NodeCount int // number of node allocations
+	NodeDeref int // number of node dereferences
+
+	// Rebalance statistics.
+	Rebalance     int           // number of node rebalances
+	RebalanceTime time.Duration // total time spent rebalancing
+
+	// Split/Spill statistics.
+	Split     int           // number of nodes split
+	Spill     int           // number of nodes spilled
+	SpillTime time.Duration // total time spent spilling
+
+	// Write statistics.
+	Write     int           // number of writes performed
+	WriteTime time.Duration // total time spent writing to disk
+}
+
+func (s *TxStats) add(other *TxStats) {
+	s.PageCount += other.PageCount
+	s.PageAlloc += other.PageAlloc
+	s.CursorCount += other.CursorCount
+	s.NodeCount += other.NodeCount
+	s.NodeDeref += other.NodeDeref
+	s.Rebalance += other.Rebalance
+	s.RebalanceTime += other.RebalanceTime
+	s.Split += other.Split
+	s.Spill += other.Spill
+	s.SpillTime += other.SpillTime
+	s.Write += other.Write
+	s.WriteTime += other.WriteTime
+}
+
+// Sub calculates and returns the difference between two sets of transaction stats.
+// This is useful when obtaining stats at two different points and time and
+// you need the performance counters that occurred within that time span.
+func (s *TxStats) Sub(other *TxStats) TxStats {
+	var diff TxStats
+	diff.PageCount = s.PageCount - other.PageCount
+	diff.PageAlloc = s.PageAlloc - other.PageAlloc
+	diff.CursorCount = s.CursorCount - other.CursorCount
+	diff.NodeCount = s.NodeCount - other.NodeCount
+	diff.NodeDeref = s.NodeDeref - other.NodeDeref
+	diff.Rebalance = s.Rebalance - other.Rebalance
+	diff.RebalanceTime = s.RebalanceTime - other.RebalanceTime
+	diff.Split = s.Split - other.Split
+	diff.Spill = s.Spill - other.Spill
+	diff.SpillTime = s.SpillTime - other.SpillTime
+	diff.Write = s.Write - other.Write
+	diff.WriteTime = s.WriteTime - other.WriteTime
+	return diff
+}

vendor/github.com/fatih/color/README.md

@@ -0,0 +1,176 @@
+# color [![](https://github.com/fatih/color/workflows/build/badge.svg)](https://github.com/fatih/color/actions) [![PkgGoDev](https://pkg.go.dev/badge/github.com/fatih/color)](https://pkg.go.dev/github.com/fatih/color)
+
+Color lets you use colorized outputs in terms of [ANSI Escape
+Codes](http://en.wikipedia.org/wiki/ANSI_escape_code#Colors) in Go (Golang). It
+has support for Windows too! The API can be used in several ways, pick one that
+suits you.
+
+![Color](https://user-images.githubusercontent.com/438920/96832689-03b3e000-13f4-11eb-9803-46f4c4de3406.jpg)
+
+## Install
+
+```bash
+go get github.com/fatih/color
+```
+
+## Examples
+
+### Standard colors
+
+```go
+// Print with default helper functions
+color.Cyan("Prints text in cyan.")
+
+// A newline will be appended automatically
+color.Blue("Prints %s in blue.", "text")
+
+// These are using the default foreground colors
+color.Red("We have red")
+color.Magenta("And many others ..")
+
+```
+
+### Mix and reuse colors
+
+```go
+// Create a new color object
+c := color.New(color.FgCyan).Add(color.Underline)
+c.Println("Prints cyan text with an underline.")
+
+// Or just add them to New()
+d := color.New(color.FgCyan, color.Bold)
+d.Printf("This prints bold cyan %s\n", "too!.")
+
+// Mix up foreground and background colors, create new mixes!
+red := color.New(color.FgRed)
+
+boldRed := red.Add(color.Bold)
+boldRed.Println("This will print text in bold red.")
+
+whiteBackground := red.Add(color.BgWhite)
+whiteBackground.Println("Red text with white background.")
+```
+
+### Use your own output (io.Writer)
+
+```go
+// Use your own io.Writer output
+color.New(color.FgBlue).Fprintln(myWriter, "blue color!")
+
+blue := color.New(color.FgBlue)
+blue.Fprint(writer, "This will print text in blue.")
+```
+
+### Custom print functions (PrintFunc)
+
+```go
+// Create a custom print function for convenience
+red := color.New(color.FgRed).PrintfFunc()
+red("Warning")
+red("Error: %s", err)
+
+// Mix up multiple attributes
+notice := color.New(color.Bold, color.FgGreen).PrintlnFunc()
+notice("Don't forget this...")
+```
+
+### Custom fprint functions (FprintFunc)
+
+```go
+blue := color.New(color.FgBlue).FprintfFunc()
+blue(myWriter, "important notice: %s", stars)
+
+// Mix up with multiple attributes
+success := color.New(color.Bold, color.FgGreen).FprintlnFunc()
+success(myWriter, "Don't forget this...")
+```
+
+### Insert into noncolor strings (SprintFunc)
+
+```go
+// Create SprintXxx functions to mix strings with other non-colorized strings:
+yellow := color.New(color.FgYellow).SprintFunc()
+red := color.New(color.FgRed).SprintFunc()
+fmt.Printf("This is a %s and this is %s.\n", yellow("warning"), red("error"))
+
+info := color.New(color.FgWhite, color.BgGreen).SprintFunc()
+fmt.Printf("This %s rocks!\n", info("package"))
+
+// Use helper functions
+fmt.Println("This", color.RedString("warning"), "should be not neglected.")
+fmt.Printf("%v %v\n", color.GreenString("Info:"), "an important message.")
+
+// Windows supported too! Just don't forget to change the output to color.Output
+fmt.Fprintf(color.Output, "Windows support: %s", color.GreenString("PASS"))
+```
+
+### Plug into existing code
+
+```go
+// Use handy standard colors
+color.Set(color.FgYellow)
+
+fmt.Println("Existing text will now be in yellow")
+fmt.Printf("This one %s\n", "too")
+
+color.Unset() // Don't forget to unset
+
+// You can mix up parameters
+color.Set(color.FgMagenta, color.Bold)
+defer color.Unset() // Use it in your function
+
+fmt.Println("All text will now be bold magenta.")
+```
+
+### Disable/Enable color
+
+There might be a case where you want to explicitly disable/enable color output. the 
+`go-isatty` package will automatically disable color output for non-tty output streams 
+(for example if the output were piped directly to `less`).
+
+The `color` package also disables color output if the [`NO_COLOR`](https://no-color.org) environment
+variable is set to a non-empty string.
+
+`Color` has support to disable/enable colors programmatically both globally and
+for single color definitions. For example suppose you have a CLI app and a
+`-no-color` bool flag. You can easily disable the color output with:
+
+```go
+var flagNoColor = flag.Bool("no-color", false, "Disable color output")
+
+if *flagNoColor {
+	color.NoColor = true // disables colorized output
+}
+```
+
+It also has support for single color definitions (local). You can
+disable/enable color output on the fly:
+
+```go
+c := color.New(color.FgCyan)
+c.Println("Prints cyan text")
+
+c.DisableColor()
+c.Println("This is printed without any color")
+
+c.EnableColor()
+c.Println("This prints again cyan...")
+```
+
+## GitHub Actions
+
+To output color in GitHub Actions (or other CI systems that support ANSI colors), make sure to set `color.NoColor = false` so that it bypasses the check for non-tty output streams. 
+
+## Todo
+
+* Save/Return previous values
+* Evaluate fmt.Formatter interface
+
+## Credits
+
+* [Fatih Arslan](https://github.com/fatih)
+* Windows support via @mattn: [colorable](https://github.com/mattn/go-colorable)
+
+## License
+
+The MIT License (MIT) - see [`LICENSE.md`](https://github.com/fatih/color/blob/master/LICENSE.md) for more details

vendor/github.com/fatih/color/color.go

@@ -0,0 +1,616 @@
+package color
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/mattn/go-colorable"
+	"github.com/mattn/go-isatty"
+)
+
+var (
+	// NoColor defines if the output is colorized or not. It's dynamically set to
+	// false or true based on the stdout's file descriptor referring to a terminal
+	// or not. It's also set to true if the NO_COLOR environment variable is
+	// set (regardless of its value). This is a global option and affects all
+	// colors. For more control over each color block use the methods
+	// DisableColor() individually.
+	NoColor = noColorIsSet() || os.Getenv("TERM") == "dumb" ||
+		(!isatty.IsTerminal(os.Stdout.Fd()) && !isatty.IsCygwinTerminal(os.Stdout.Fd()))
+
+	// Output defines the standard output of the print functions. By default,
+	// os.Stdout is used.
+	Output = colorable.NewColorableStdout()
+
+	// Error defines a color supporting writer for os.Stderr.
+	Error = colorable.NewColorableStderr()
+
+	// colorsCache is used to reduce the count of created Color objects and
+	// allows to reuse already created objects with required Attribute.
+	colorsCache   = make(map[Attribute]*Color)
+	colorsCacheMu sync.Mutex // protects colorsCache
+)
+
+// noColorIsSet returns true if the environment variable NO_COLOR is set to a non-empty string.
+func noColorIsSet() bool {
+	return os.Getenv("NO_COLOR") != ""
+}
+
+// Color defines a custom color object which is defined by SGR parameters.
+type Color struct {
+	params  []Attribute
+	noColor *bool
+}
+
+// Attribute defines a single SGR Code
+type Attribute int
+
+const escape = "\x1b"
+
+// Base attributes
+const (
+	Reset Attribute = iota
+	Bold
+	Faint
+	Italic
+	Underline
+	BlinkSlow
+	BlinkRapid
+	ReverseVideo
+	Concealed
+	CrossedOut
+)
+
+// Foreground text colors
+const (
+	FgBlack Attribute = iota + 30
+	FgRed
+	FgGreen
+	FgYellow
+	FgBlue
+	FgMagenta
+	FgCyan
+	FgWhite
+)
+
+// Foreground Hi-Intensity text colors
+const (
+	FgHiBlack Attribute = iota + 90
+	FgHiRed
+	FgHiGreen
+	FgHiYellow
+	FgHiBlue
+	FgHiMagenta
+	FgHiCyan
+	FgHiWhite
+)
+
+// Background text colors
+const (
+	BgBlack Attribute = iota + 40
+	BgRed
+	BgGreen
+	BgYellow
+	BgBlue
+	BgMagenta
+	BgCyan
+	BgWhite
+)
+
+// Background Hi-Intensity text colors
+const (
+	BgHiBlack Attribute = iota + 100
+	BgHiRed
+	BgHiGreen
+	BgHiYellow
+	BgHiBlue
+	BgHiMagenta
+	BgHiCyan
+	BgHiWhite
+)
+
+// New returns a newly created color object.
+func New(value ...Attribute) *Color {
+	c := &Color{
+		params: make([]Attribute, 0),
+	}
+
+	if noColorIsSet() {
+		c.noColor = boolPtr(true)
+	}
+
+	c.Add(value...)
+	return c
+}
+
+// Set sets the given parameters immediately. It will change the color of
+// output with the given SGR parameters until color.Unset() is called.
+func Set(p ...Attribute) *Color {
+	c := New(p...)
+	c.Set()
+	return c
+}
+
+// Unset resets all escape attributes and clears the output. Usually should
+// be called after Set().
+func Unset() {
+	if NoColor {
+		return
+	}
+
+	fmt.Fprintf(Output, "%s[%dm", escape, Reset)
+}
+
+// Set sets the SGR sequence.
+func (c *Color) Set() *Color {
+	if c.isNoColorSet() {
+		return c
+	}
+
+	fmt.Fprint(Output, c.format())
+	return c
+}
+
+func (c *Color) unset() {
+	if c.isNoColorSet() {
+		return
+	}
+
+	Unset()
+}
+
+// SetWriter is used to set the SGR sequence with the given io.Writer. This is
+// a low-level function, and users should use the higher-level functions, such
+// as color.Fprint, color.Print, etc.
+func (c *Color) SetWriter(w io.Writer) *Color {
+	if c.isNoColorSet() {
+		return c
+	}
+
+	fmt.Fprint(w, c.format())
+	return c
+}
+
+// UnsetWriter resets all escape attributes and clears the output with the give
+// io.Writer. Usually should be called after SetWriter().
+func (c *Color) UnsetWriter(w io.Writer) {
+	if c.isNoColorSet() {
+		return
+	}
+
+	if NoColor {
+		return
+	}
+
+	fmt.Fprintf(w, "%s[%dm", escape, Reset)
+}
+
+// Add is used to chain SGR parameters. Use as many as parameters to combine
+// and create custom color objects. Example: Add(color.FgRed, color.Underline).
+func (c *Color) Add(value ...Attribute) *Color {
+	c.params = append(c.params, value...)
+	return c
+}
+
+// Fprint formats using the default formats for its operands and writes to w.
+// Spaces are added between operands when neither is a string.
+// It returns the number of bytes written and any write error encountered.
+// On Windows, users should wrap w with colorable.NewColorable() if w is of
+// type *os.File.
+func (c *Color) Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+	c.SetWriter(w)
+	defer c.UnsetWriter(w)
+
+	return fmt.Fprint(w, a...)
+}
+
+// Print formats using the default formats for its operands and writes to
+// standard output. Spaces are added between operands when neither is a
+// string. It returns the number of bytes written and any write error
+// encountered. This is the standard fmt.Print() method wrapped with the given
+// color.
+func (c *Color) Print(a ...interface{}) (n int, err error) {
+	c.Set()
+	defer c.unset()
+
+	return fmt.Fprint(Output, a...)
+}
+
+// Fprintf formats according to a format specifier and writes to w.
+// It returns the number of bytes written and any write error encountered.
+// On Windows, users should wrap w with colorable.NewColorable() if w is of
+// type *os.File.
+func (c *Color) Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
+	c.SetWriter(w)
+	defer c.UnsetWriter(w)
+
+	return fmt.Fprintf(w, format, a...)
+}
+
+// Printf formats according to a format specifier and writes to standard output.
+// It returns the number of bytes written and any write error encountered.
+// This is the standard fmt.Printf() method wrapped with the given color.
+func (c *Color) Printf(format string, a ...interface{}) (n int, err error) {
+	c.Set()
+	defer c.unset()
+
+	return fmt.Fprintf(Output, format, a...)
+}
+
+// Fprintln formats using the default formats for its operands and writes to w.
+// Spaces are always added between operands and a newline is appended.
+// On Windows, users should wrap w with colorable.NewColorable() if w is of
+// type *os.File.
+func (c *Color) Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+	c.SetWriter(w)
+	defer c.UnsetWriter(w)
+
+	return fmt.Fprintln(w, a...)
+}
+
+// Println formats using the default formats for its operands and writes to
+// standard output. Spaces are always added between operands and a newline is
+// appended. It returns the number of bytes written and any write error
+// encountered. This is the standard fmt.Print() method wrapped with the given
+// color.
+func (c *Color) Println(a ...interface{}) (n int, err error) {
+	c.Set()
+	defer c.unset()
+
+	return fmt.Fprintln(Output, a...)
+}
+
+// Sprint is just like Print, but returns a string instead of printing it.
+func (c *Color) Sprint(a ...interface{}) string {
+	return c.wrap(fmt.Sprint(a...))
+}
+
+// Sprintln is just like Println, but returns a string instead of printing it.
+func (c *Color) Sprintln(a ...interface{}) string {
+	return c.wrap(fmt.Sprintln(a...))
+}
+
+// Sprintf is just like Printf, but returns a string instead of printing it.
+func (c *Color) Sprintf(format string, a ...interface{}) string {
+	return c.wrap(fmt.Sprintf(format, a...))
+}
+
+// FprintFunc returns a new function that prints the passed arguments as
+// colorized with color.Fprint().
+func (c *Color) FprintFunc() func(w io.Writer, a ...interface{}) {
+	return func(w io.Writer, a ...interface{}) {
+		c.Fprint(w, a...)
+	}
+}
+
+// PrintFunc returns a new function that prints the passed arguments as
+// colorized with color.Print().
+func (c *Color) PrintFunc() func(a ...interface{}) {
+	return func(a ...interface{}) {
+		c.Print(a...)
+	}
+}
+
+// FprintfFunc returns a new function that prints the passed arguments as
+// colorized with color.Fprintf().
+func (c *Color) FprintfFunc() func(w io.Writer, format string, a ...interface{}) {
+	return func(w io.Writer, format string, a ...interface{}) {
+		c.Fprintf(w, format, a...)
+	}
+}
+
+// PrintfFunc returns a new function that prints the passed arguments as
+// colorized with color.Printf().
+func (c *Color) PrintfFunc() func(format string, a ...interface{}) {
+	return func(format string, a ...interface{}) {
+		c.Printf(format, a...)
+	}
+}
+
+// FprintlnFunc returns a new function that prints the passed arguments as
+// colorized with color.Fprintln().
+func (c *Color) FprintlnFunc() func(w io.Writer, a ...interface{}) {
+	return func(w io.Writer, a ...interface{}) {
+		c.Fprintln(w, a...)
+	}
+}
+
+// PrintlnFunc returns a new function that prints the passed arguments as
+// colorized with color.Println().
+func (c *Color) PrintlnFunc() func(a ...interface{}) {
+	return func(a ...interface{}) {
+		c.Println(a...)
+	}
+}
+
+// SprintFunc returns a new function that returns colorized strings for the
+// given arguments with fmt.Sprint(). Useful to put into or mix into other
+// string. Windows users should use this in conjunction with color.Output, example:
+//
+//	put := New(FgYellow).SprintFunc()
+//	fmt.Fprintf(color.Output, "This is a %s", put("warning"))
+func (c *Color) SprintFunc() func(a ...interface{}) string {
+	return func(a ...interface{}) string {
+		return c.wrap(fmt.Sprint(a...))
+	}
+}
+
+// SprintfFunc returns a new function that returns colorized strings for the
+// given arguments with fmt.Sprintf(). Useful to put into or mix into other
+// string. Windows users should use this in conjunction with color.Output.
+func (c *Color) SprintfFunc() func(format string, a ...interface{}) string {
+	return func(format string, a ...interface{}) string {
+		return c.wrap(fmt.Sprintf(format, a...))
+	}
+}
+
+// SprintlnFunc returns a new function that returns colorized strings for the
+// given arguments with fmt.Sprintln(). Useful to put into or mix into other
+// string. Windows users should use this in conjunction with color.Output.
+func (c *Color) SprintlnFunc() func(a ...interface{}) string {
+	return func(a ...interface{}) string {
+		return c.wrap(fmt.Sprintln(a...))
+	}
+}
+
+// sequence returns a formatted SGR sequence to be plugged into a "\x1b[...m"
+// an example output might be: "1;36" -> bold cyan
+func (c *Color) sequence() string {
+	format := make([]string, len(c.params))
+	for i, v := range c.params {
+		format[i] = strconv.Itoa(int(v))
+	}
+
+	return strings.Join(format, ";")
+}
+
+// wrap wraps the s string with the colors attributes. The string is ready to
+// be printed.
+func (c *Color) wrap(s string) string {
+	if c.isNoColorSet() {
+		return s
+	}
+
+	return c.format() + s + c.unformat()
+}
+
+func (c *Color) format() string {
+	return fmt.Sprintf("%s[%sm", escape, c.sequence())
+}
+
+func (c *Color) unformat() string {
+	return fmt.Sprintf("%s[%dm", escape, Reset)
+}
+
+// DisableColor disables the color output. Useful to not change any existing
+// code and still being able to output. Can be used for flags like
+// "--no-color". To enable back use EnableColor() method.
+func (c *Color) DisableColor() {
+	c.noColor = boolPtr(true)
+}
+
+// EnableColor enables the color output. Use it in conjunction with
+// DisableColor(). Otherwise, this method has no side effects.
+func (c *Color) EnableColor() {
+	c.noColor = boolPtr(false)
+}
+
+func (c *Color) isNoColorSet() bool {
+	// check first if we have user set action
+	if c.noColor != nil {
+		return *c.noColor
+	}
+
+	// if not return the global option, which is disabled by default
+	return NoColor
+}
+
+// Equals returns a boolean value indicating whether two colors are equal.
+func (c *Color) Equals(c2 *Color) bool {
+	if len(c.params) != len(c2.params) {
+		return false
+	}
+
+	for _, attr := range c.params {
+		if !c2.attrExists(attr) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (c *Color) attrExists(a Attribute) bool {
+	for _, attr := range c.params {
+		if attr == a {
+			return true
+		}
+	}
+
+	return false
+}
+
+func boolPtr(v bool) *bool {
+	return &v
+}
+
+func getCachedColor(p Attribute) *Color {
+	colorsCacheMu.Lock()
+	defer colorsCacheMu.Unlock()
+
+	c, ok := colorsCache[p]
+	if !ok {
+		c = New(p)
+		colorsCache[p] = c
+	}
+
+	return c
+}
+
+func colorPrint(format string, p Attribute, a ...interface{}) {
+	c := getCachedColor(p)
+
+	if !strings.HasSuffix(format, "\n") {
+		format += "\n"
+	}
+
+	if len(a) == 0 {
+		c.Print(format)
+	} else {
+		c.Printf(format, a...)
+	}
+}
+
+func colorString(format string, p Attribute, a ...interface{}) string {
+	c := getCachedColor(p)
+
+	if len(a) == 0 {
+		return c.SprintFunc()(format)
+	}
+
+	return c.SprintfFunc()(format, a...)
+}
+
+// Black is a convenient helper function to print with black foreground. A
+// newline is appended to format by default.
+func Black(format string, a ...interface{}) { colorPrint(format, FgBlack, a...) }
+
+// Red is a convenient helper function to print with red foreground. A
+// newline is appended to format by default.
+func Red(format string, a ...interface{}) { colorPrint(format, FgRed, a...) }
+
+// Green is a convenient helper function to print with green foreground. A
+// newline is appended to format by default.
+func Green(format string, a ...interface{}) { colorPrint(format, FgGreen, a...) }
+
+// Yellow is a convenient helper function to print with yellow foreground.
+// A newline is appended to format by default.
+func Yellow(format string, a ...interface{}) { colorPrint(format, FgYellow, a...) }
+
+// Blue is a convenient helper function to print with blue foreground. A
+// newline is appended to format by default.
+func Blue(format string, a ...interface{}) { colorPrint(format, FgBlue, a...) }
+
+// Magenta is a convenient helper function to print with magenta foreground.
+// A newline is appended to format by default.
+func Magenta(format string, a ...interface{}) { colorPrint(format, FgMagenta, a...) }
+
+// Cyan is a convenient helper function to print with cyan foreground. A
+// newline is appended to format by default.
+func Cyan(format string, a ...interface{}) { colorPrint(format, FgCyan, a...) }
+
+// White is a convenient helper function to print with white foreground. A
+// newline is appended to format by default.
+func White(format string, a ...interface{}) { colorPrint(format, FgWhite, a...) }
+
+// BlackString is a convenient helper function to return a string with black
+// foreground.
+func BlackString(format string, a ...interface{}) string { return colorString(format, FgBlack, a...) }
+
+// RedString is a convenient helper function to return a string with red
+// foreground.
+func RedString(format string, a ...interface{}) string { return colorString(format, FgRed, a...) }
+
+// GreenString is a convenient helper function to return a string with green
+// foreground.
+func GreenString(format string, a ...interface{}) string { return colorString(format, FgGreen, a...) }
+
+// YellowString is a convenient helper function to return a string with yellow
+// foreground.
+func YellowString(format string, a ...interface{}) string { return colorString(format, FgYellow, a...) }
+
+// BlueString is a convenient helper function to return a string with blue
+// foreground.
+func BlueString(format string, a ...interface{}) string { return colorString(format, FgBlue, a...) }
+
+// MagentaString is a convenient helper function to return a string with magenta
+// foreground.
+func MagentaString(format string, a ...interface{}) string {
+	return colorString(format, FgMagenta, a...)
+}
+
+// CyanString is a convenient helper function to return a string with cyan
+// foreground.
+func CyanString(format string, a ...interface{}) string { return colorString(format, FgCyan, a...) }
+
+// WhiteString is a convenient helper function to return a string with white
+// foreground.
+func WhiteString(format string, a ...interface{}) string { return colorString(format, FgWhite, a...) }
+
+// HiBlack is a convenient helper function to print with hi-intensity black foreground. A
+// newline is appended to format by default.
+func HiBlack(format string, a ...interface{}) { colorPrint(format, FgHiBlack, a...) }
+
+// HiRed is a convenient helper function to print with hi-intensity red foreground. A
+// newline is appended to format by default.
+func HiRed(format string, a ...interface{}) { colorPrint(format, FgHiRed, a...) }
+
+// HiGreen is a convenient helper function to print with hi-intensity green foreground. A
+// newline is appended to format by default.
+func HiGreen(format string, a ...interface{}) { colorPrint(format, FgHiGreen, a...) }
+
+// HiYellow is a convenient helper function to print with hi-intensity yellow foreground.
+// A newline is appended to format by default.
+func HiYellow(format string, a ...interface{}) { colorPrint(format, FgHiYellow, a...) }
+
+// HiBlue is a convenient helper function to print with hi-intensity blue foreground. A
+// newline is appended to format by default.
+func HiBlue(format string, a ...interface{}) { colorPrint(format, FgHiBlue, a...) }
+
+// HiMagenta is a convenient helper function to print with hi-intensity magenta foreground.
+// A newline is appended to format by default.
+func HiMagenta(format string, a ...interface{}) { colorPrint(format, FgHiMagenta, a...) }
+
+// HiCyan is a convenient helper function to print with hi-intensity cyan foreground. A
+// newline is appended to format by default.
+func HiCyan(format string, a ...interface{}) { colorPrint(format, FgHiCyan, a...) }
+
+// HiWhite is a convenient helper function to print with hi-intensity white foreground. A
+// newline is appended to format by default.
+func HiWhite(format string, a ...interface{}) { colorPrint(format, FgHiWhite, a...) }
+
+// HiBlackString is a convenient helper function to return a string with hi-intensity black
+// foreground.
+func HiBlackString(format string, a ...interface{}) string {
+	return colorString(format, FgHiBlack, a...)
+}
+
+// HiRedString is a convenient helper function to return a string with hi-intensity red
+// foreground.
+func HiRedString(format string, a ...interface{}) string { return colorString(format, FgHiRed, a...) }
+
+// HiGreenString is a convenient helper function to return a string with hi-intensity green
+// foreground.
+func HiGreenString(format string, a ...interface{}) string {
+	return colorString(format, FgHiGreen, a...)
+}
+
+// HiYellowString is a convenient helper function to return a string with hi-intensity yellow
+// foreground.
+func HiYellowString(format string, a ...interface{}) string {
+	return colorString(format, FgHiYellow, a...)
+}
+
+// HiBlueString is a convenient helper function to return a string with hi-intensity blue
+// foreground.
+func HiBlueString(format string, a ...interface{}) string { return colorString(format, FgHiBlue, a...) }
+
+// HiMagentaString is a convenient helper function to return a string with hi-intensity magenta
+// foreground.
+func HiMagentaString(format string, a ...interface{}) string {
+	return colorString(format, FgHiMagenta, a...)
+}
+
+// HiCyanString is a convenient helper function to return a string with hi-intensity cyan
+// foreground.
+func HiCyanString(format string, a ...interface{}) string { return colorString(format, FgHiCyan, a...) }
+
+// HiWhiteString is a convenient helper function to return a string with hi-intensity white
+// foreground.
+func HiWhiteString(format string, a ...interface{}) string {
+	return colorString(format, FgHiWhite, a...)
+}

vendor/github.com/fatih/color/color_windows.go

@@ -0,0 +1,19 @@
+package color
+
+import (
+	"os"
+
+	"golang.org/x/sys/windows"
+)
+
+func init() {
+	// Opt-in for ansi color support for current process.
+	// https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences#output-sequences
+	var outMode uint32
+	out := windows.Handle(os.Stdout.Fd())
+	if err := windows.GetConsoleMode(out, &outMode); err != nil {
+		return
+	}
+	outMode |= windows.ENABLE_PROCESSED_OUTPUT | windows.ENABLE_VIRTUAL_TERMINAL_PROCESSING
+	_ = windows.SetConsoleMode(out, outMode)
+}

vendor/github.com/fatih/color/doc.go

@@ -0,0 +1,134 @@
+/*
+Package color is an ANSI color package to output colorized or SGR defined
+output to the standard output. The API can be used in several way, pick one
+that suits you.
+
+Use simple and default helper functions with predefined foreground colors:
+
+	color.Cyan("Prints text in cyan.")
+
+	// a newline will be appended automatically
+	color.Blue("Prints %s in blue.", "text")
+
+	// More default foreground colors..
+	color.Red("We have red")
+	color.Yellow("Yellow color too!")
+	color.Magenta("And many others ..")
+
+	// Hi-intensity colors
+	color.HiGreen("Bright green color.")
+	color.HiBlack("Bright black means gray..")
+	color.HiWhite("Shiny white color!")
+
+However, there are times when custom color mixes are required. Below are some
+examples to create custom color objects and use the print functions of each
+separate color object.
+
+	// Create a new color object
+	c := color.New(color.FgCyan).Add(color.Underline)
+	c.Println("Prints cyan text with an underline.")
+
+	// Or just add them to New()
+	d := color.New(color.FgCyan, color.Bold)
+	d.Printf("This prints bold cyan %s\n", "too!.")
+
+
+	// Mix up foreground and background colors, create new mixes!
+	red := color.New(color.FgRed)
+
+	boldRed := red.Add(color.Bold)
+	boldRed.Println("This will print text in bold red.")
+
+	whiteBackground := red.Add(color.BgWhite)
+	whiteBackground.Println("Red text with White background.")
+
+	// Use your own io.Writer output
+	color.New(color.FgBlue).Fprintln(myWriter, "blue color!")
+
+	blue := color.New(color.FgBlue)
+	blue.Fprint(myWriter, "This will print text in blue.")
+
+You can create PrintXxx functions to simplify even more:
+
+	// Create a custom print function for convenient
+	red := color.New(color.FgRed).PrintfFunc()
+	red("warning")
+	red("error: %s", err)
+
+	// Mix up multiple attributes
+	notice := color.New(color.Bold, color.FgGreen).PrintlnFunc()
+	notice("don't forget this...")
+
+You can also FprintXxx functions to pass your own io.Writer:
+
+	blue := color.New(FgBlue).FprintfFunc()
+	blue(myWriter, "important notice: %s", stars)
+
+	// Mix up with multiple attributes
+	success := color.New(color.Bold, color.FgGreen).FprintlnFunc()
+	success(myWriter, don't forget this...")
+
+Or create SprintXxx functions to mix strings with other non-colorized strings:
+
+	yellow := New(FgYellow).SprintFunc()
+	red := New(FgRed).SprintFunc()
+
+	fmt.Printf("this is a %s and this is %s.\n", yellow("warning"), red("error"))
+
+	info := New(FgWhite, BgGreen).SprintFunc()
+	fmt.Printf("this %s rocks!\n", info("package"))
+
+Windows support is enabled by default. All Print functions work as intended.
+However, only for color.SprintXXX functions, user should use fmt.FprintXXX and
+set the output to color.Output:
+
+	fmt.Fprintf(color.Output, "Windows support: %s", color.GreenString("PASS"))
+
+	info := New(FgWhite, BgGreen).SprintFunc()
+	fmt.Fprintf(color.Output, "this %s rocks!\n", info("package"))
+
+Using with existing code is possible. Just use the Set() method to set the
+standard output to the given parameters. That way a rewrite of an existing
+code is not required.
+
+	// Use handy standard colors.
+	color.Set(color.FgYellow)
+
+	fmt.Println("Existing text will be now in Yellow")
+	fmt.Printf("This one %s\n", "too")
+
+	color.Unset() // don't forget to unset
+
+	// You can mix up parameters
+	color.Set(color.FgMagenta, color.Bold)
+	defer color.Unset() // use it in your function
+
+	fmt.Println("All text will be now bold magenta.")
+
+There might be a case where you want to disable color output (for example to
+pipe the standard output of your app to somewhere else). `Color` has support to
+disable colors both globally and for single color definition. For example
+suppose you have a CLI app and a `--no-color` bool flag. You can easily disable
+the color output with:
+
+	var flagNoColor = flag.Bool("no-color", false, "Disable color output")
+
+	if *flagNoColor {
+		color.NoColor = true // disables colorized output
+	}
+
+You can also disable the color by setting the NO_COLOR environment variable to any value.
+
+It also has support for single color definitions (local). You can
+disable/enable color output on the fly:
+
+	c := color.New(color.FgCyan)
+	c.Println("Prints cyan text")
+
+	c.DisableColor()
+	c.Println("This is printed without any color")
+
+	c.EnableColor()
+	c.Println("This prints again cyan...")
+*/
+package color

vendor/github.com/hashicorp/errwrap/LICENSE

@@ -0,0 +1,354 @@
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+1.1. “Contributor”
+
+     means each individual or legal entity that creates, contributes to the
+     creation of, or owns Covered Software.
+
+1.2. “Contributor Version”
+
+     means the combination of the Contributions of others (if any) used by a
+     Contributor and that particular Contributor’s Contribution.
+
+1.3. “Contribution”
+
+     means Covered Software of a particular Contributor.
+
+1.4. “Covered Software”
+
+     means Source Code Form to which the initial Contributor has attached the
+     notice in Exhibit A, the Executable Form of such Source Code Form, and
+     Modifications of such Source Code Form, in each case including portions
+     thereof.
+
+1.5. “Incompatible With Secondary Licenses”
+     means
+
+     a. that the initial Contributor has attached the notice described in
+        Exhibit B to the Covered Software; or
+
+     b. that the Covered Software was made available under the terms of version
+        1.1 or earlier of the License, but not also under the terms of a
+        Secondary License.
+
+1.6. “Executable Form”
+
+     means any form of the work other than Source Code Form.
+
+1.7. “Larger Work”
+
+     means a work that combines Covered Software with other material, in a separate
+     file or files, that is not Covered Software.
+
+1.8. “License”
+
+     means this document.
+
+1.9. “Licensable”
+
+     means having the right to grant, to the maximum extent possible, whether at the
+     time of the initial grant or subsequently, any and all of the rights conveyed by
+     this License.
+
+1.10. “Modifications”
+
+     means any of the following:
+
+     a. any file in Source Code Form that results from an addition to, deletion
+        from, or modification of the contents of Covered Software; or
+
+     b. any new file in Source Code Form that contains any Covered Software.
+
+1.11. “Patent Claims” of a Contributor
+
+      means any patent claim(s), including without limitation, method, process,
+      and apparatus claims, in any patent Licensable by such Contributor that
+      would be infringed, but for the grant of the License, by the making,
+      using, selling, offering for sale, having made, import, or transfer of
+      either its Contributions or its Contributor Version.
+
+1.12. “Secondary License”
+
+      means either the GNU General Public License, Version 2.0, the GNU Lesser
+      General Public License, Version 2.1, the GNU Affero General Public
+      License, Version 3.0, or any later versions of those licenses.
+
+1.13. “Source Code Form”
+
+      means the form of the work preferred for making modifications.
+
+1.14. “You” (or “Your”)
+
+      means an individual or a legal entity exercising rights under this
+      License. For legal entities, “You” includes any entity that controls, is
+      controlled by, or is under common control with You. For purposes of this
+      definition, “control” means (a) the power, direct or indirect, to cause
+      the direction or management of such entity, whether by contract or
+      otherwise, or (b) ownership of more than fifty percent (50%) of the
+      outstanding shares or beneficial ownership of such entity.
+
+
+2. License Grants and Conditions
+
+2.1. Grants
+
+     Each Contributor hereby grants You a world-wide, royalty-free,
+     non-exclusive license:
+
+     a. under intellectual property rights (other than patent or trademark)
+        Licensable by such Contributor to use, reproduce, make available,
+        modify, display, perform, distribute, and otherwise exploit its
+        Contributions, either on an unmodified basis, with Modifications, or as
+        part of a Larger Work; and
+
+     b. under Patent Claims of such Contributor to make, use, sell, offer for
+        sale, have made, import, and otherwise transfer either its Contributions
+        or its Contributor Version.
+
+2.2. Effective Date
+
+     The licenses granted in Section 2.1 with respect to any Contribution become
+     effective for each Contribution on the date the Contributor first distributes
+     such Contribution.
+
+2.3. Limitations on Grant Scope
+
+     The licenses granted in this Section 2 are the only rights granted under this
+     License. No additional rights or licenses will be implied from the distribution
+     or licensing of Covered Software under this License. Notwithstanding Section
+     2.1(b) above, no patent license is granted by a Contributor:
+
+     a. for any code that a Contributor has removed from Covered Software; or
+
+     b. for infringements caused by: (i) Your and any other third party’s
+        modifications of Covered Software, or (ii) the combination of its
+        Contributions with other software (except as part of its Contributor
+        Version); or
+
+     c. under Patent Claims infringed by Covered Software in the absence of its
+        Contributions.
+
+     This License does not grant any rights in the trademarks, service marks, or
+     logos of any Contributor (except as may be necessary to comply with the
+     notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+     No Contributor makes additional grants as a result of Your choice to
+     distribute the Covered Software under a subsequent version of this License
+     (see Section 10.2) or under the terms of a Secondary License (if permitted
+     under the terms of Section 3.3).
+
+2.5. Representation
+
+     Each Contributor represents that the Contributor believes its Contributions
+     are its original creation(s) or it has sufficient rights to grant the
+     rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+     This License is not intended to limit any rights You have under applicable
+     copyright doctrines of fair use, fair dealing, or other equivalents.
+
+2.7. Conditions
+
+     Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
+     Section 2.1.
+
+
+3. Responsibilities
+
+3.1. Distribution of Source Form
+
+     All distribution of Covered Software in Source Code Form, including any
+     Modifications that You create or to which You contribute, must be under the
+     terms of this License. You must inform recipients that the Source Code Form
+     of the Covered Software is governed by the terms of this License, and how
+     they can obtain a copy of this License. You may not attempt to alter or
+     restrict the recipients’ rights in the Source Code Form.
+
+3.2. Distribution of Executable Form
+
+     If You distribute Covered Software in Executable Form then:
+
+     a. such Covered Software must also be made available in Source Code Form,
+        as described in Section 3.1, and You must inform recipients of the
+        Executable Form how they can obtain a copy of such Source Code Form by
+        reasonable means in a timely manner, at a charge no more than the cost
+        of distribution to the recipient; and
+
+     b. You may distribute such Executable Form under the terms of this License,
+        or sublicense it under different terms, provided that the license for
+        the Executable Form does not attempt to limit or alter the recipients’
+        rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+     You may create and distribute a Larger Work under terms of Your choice,
+     provided that You also comply with the requirements of this License for the
+     Covered Software. If the Larger Work is a combination of Covered Software
+     with a work governed by one or more Secondary Licenses, and the Covered
+     Software is not Incompatible With Secondary Licenses, this License permits
+     You to additionally distribute such Covered Software under the terms of
+     such Secondary License(s), so that the recipient of the Larger Work may, at
+     their option, further distribute the Covered Software under the terms of
+     either this License or such Secondary License(s).
+
+3.4. Notices
+
+     You may not remove or alter the substance of any license notices (including
+     copyright notices, patent notices, disclaimers of warranty, or limitations
+     of liability) contained within the Source Code Form of the Covered
+     Software, except that You may alter any license notices to the extent
+     required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+     You may choose to offer, and to charge a fee for, warranty, support,
+     indemnity or liability obligations to one or more recipients of Covered
+     Software. However, You may do so only on Your own behalf, and not on behalf
+     of any Contributor. You must make it absolutely clear that any such
+     warranty, support, indemnity, or liability obligation is offered by You
+     alone, and You hereby agree to indemnify every Contributor for any
+     liability incurred by such Contributor as a result of warranty, support,
+     indemnity or liability terms You offer. You may include additional
+     disclaimers of warranty and limitations of liability specific to any
+     jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+   If it is impossible for You to comply with any of the terms of this License
+   with respect to some or all of the Covered Software due to statute, judicial
+   order, or regulation then You must: (a) comply with the terms of this License
+   to the maximum extent possible; and (b) describe the limitations and the code
+   they affect. Such description must be placed in a text file included with all
+   distributions of the Covered Software under this License. Except to the
+   extent prohibited by statute or regulation, such description must be
+   sufficiently detailed for a recipient of ordinary skill to be able to
+   understand it.
+
+5. Termination
+
+5.1. The rights granted under this License will terminate automatically if You
+     fail to comply with any of its terms. However, if You become compliant,
+     then the rights granted under this License from a particular Contributor
+     are reinstated (a) provisionally, unless and until such Contributor
+     explicitly and finally terminates Your grants, and (b) on an ongoing basis,
+     if such Contributor fails to notify You of the non-compliance by some
+     reasonable means prior to 60 days after You have come back into compliance.
+     Moreover, Your grants from a particular Contributor are reinstated on an
+     ongoing basis if such Contributor notifies You of the non-compliance by
+     some reasonable means, this is the first time You have received notice of
+     non-compliance with this License from such Contributor, and You become
+     compliant prior to 30 days after Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+     infringement claim (excluding declaratory judgment actions, counter-claims,
+     and cross-claims) alleging that a Contributor Version directly or
+     indirectly infringes any patent, then the rights granted to You by any and
+     all Contributors for the Covered Software under Section 2.1 of this License
+     shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
+     license agreements (excluding distributors and resellers) which have been
+     validly granted by You or Your distributors under this License prior to
+     termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+   Covered Software is provided under this License on an “as is” basis, without
+   warranty of any kind, either expressed, implied, or statutory, including,
+   without limitation, warranties that the Covered Software is free of defects,
+   merchantable, fit for a particular purpose or non-infringing. The entire
+   risk as to the quality and performance of the Covered Software is with You.
+   Should any Covered Software prove defective in any respect, You (not any
+   Contributor) assume the cost of any necessary servicing, repair, or
+   correction. This disclaimer of warranty constitutes an essential part of this
+   License. No use of  any Covered Software is authorized under this License
+   except under this disclaimer.
+
+7. Limitation of Liability
+
+   Under no circumstances and under no legal theory, whether tort (including
+   negligence), contract, or otherwise, shall any Contributor, or anyone who
+   distributes Covered Software as permitted above, be liable to You for any
+   direct, indirect, special, incidental, or consequential damages of any
+   character including, without limitation, damages for lost profits, loss of
+   goodwill, work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses, even if such party shall have been
+   informed of the possibility of such damages. This limitation of liability
+   shall not apply to liability for death or personal injury resulting from such
+   party’s negligence to the extent applicable law prohibits such limitation.
+   Some jurisdictions do not allow the exclusion or limitation of incidental or
+   consequential damages, so this exclusion and limitation may not apply to You.
+
+8. Litigation
+
+   Any litigation relating to this License may be brought only in the courts of
+   a jurisdiction where the defendant maintains its principal place of business
+   and such litigation shall be governed by laws of that jurisdiction, without
+   reference to its conflict-of-law provisions. Nothing in this Section shall
+   prevent a party’s ability to bring cross-claims or counter-claims.
+
+9. Miscellaneous
+
+   This License represents the complete agreement concerning the subject matter
+   hereof. If any provision of this License is held to be unenforceable, such
+   provision shall be reformed only to the extent necessary to make it
+   enforceable. Any law or regulation which provides that the language of a
+   contract shall be construed against the drafter shall not be used to construe
+   this License against a Contributor.
+
+
+10. Versions of the License
+
+10.1. New Versions
+
+      Mozilla Foundation is the license steward. Except as provided in Section
+      10.3, no one other than the license steward has the right to modify or
+      publish new versions of this License. Each version will be given a
+      distinguishing version number.
+
+10.2. Effect of New Versions
+
+      You may distribute the Covered Software under the terms of the version of
+      the License under which You originally received the Covered Software, or
+      under the terms of any subsequent version published by the license
+      steward.
+
+10.3. Modified Versions
+
+      If you create software not governed by this License, and you want to
+      create a new license for such software, you may create and use a modified
+      version of this License if you rename the license and remove any
+      references to the name of the license steward (except to note that such
+      modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary Licenses
+      If You choose to distribute Source Code Form that is Incompatible With
+      Secondary Licenses under the terms of this version of the License, the
+      notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+
+      This Source Code Form is subject to the
+      terms of the Mozilla Public License, v.
+      2.0. If a copy of the MPL was not
+      distributed with this file, You can
+      obtain one at
+      http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file, then
+You may include the notice in a location (such as a LICENSE file in a relevant
+directory) where a recipient would be likely to look for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - “Incompatible With Secondary Licenses” Notice
+
+      This Source Code Form is “Incompatible
+      With Secondary Licenses”, as defined by
+      the Mozilla Public License, v. 2.0.
+

vendor/github.com/hashicorp/errwrap/README.md

@@ -0,0 +1,89 @@
+# errwrap
+
+`errwrap` is a package for Go that formalizes the pattern of wrapping errors
+and checking if an error contains another error.
+
+There is a common pattern in Go of taking a returned `error` value and
+then wrapping it (such as with `fmt.Errorf`) before returning it. The problem
+with this pattern is that you completely lose the original `error` structure.
+
+Arguably the _correct_ approach is that you should make a custom structure
+implementing the `error` interface, and have the original error as a field
+on that structure, such [as this example](http://golang.org/pkg/os/#PathError).
+This is a good approach, but you have to know the entire chain of possible
+rewrapping that happens, when you might just care about one.
+
+`errwrap` formalizes this pattern (it doesn't matter what approach you use
+above) by giving a single interface for wrapping errors, checking if a specific
+error is wrapped, and extracting that error.
+
+## Installation and Docs
+
+Install using `go get github.com/hashicorp/errwrap`.
+
+Full documentation is available at
+http://godoc.org/github.com/hashicorp/errwrap
+
+## Usage
+
+#### Basic Usage
+
+Below is a very basic example of its usage:
+
+```go
+// A function that always returns an error, but wraps it, like a real
+// function might.
+func tryOpen() error {
+	_, err := os.Open("/i/dont/exist")
+	if err != nil {
+		return errwrap.Wrapf("Doesn't exist: {{err}}", err)
+	}
+
+	return nil
+}
+
+func main() {
+	err := tryOpen()
+
+	// We can use the Contains helpers to check if an error contains
+	// another error. It is safe to do this with a nil error, or with
+	// an error that doesn't even use the errwrap package.
+	if errwrap.Contains(err, "does not exist") {
+		// Do something
+	}
+	if errwrap.ContainsType(err, new(os.PathError)) {
+		// Do something
+	}
+
+	// Or we can use the associated `Get` functions to just extract
+	// a specific error. This would return nil if that specific error doesn't
+	// exist.
+	perr := errwrap.GetType(err, new(os.PathError))
+}
+```
+
+#### Custom Types
+
+If you're already making custom types that properly wrap errors, then
+you can get all the functionality of `errwraps.Contains` and such by
+implementing the `Wrapper` interface with just one function. Example:
+
+```go
+type AppError {
+  Code ErrorCode
+  Err  error
+}
+
+func (e *AppError) WrappedErrors() []error {
+  return []error{e.Err}
+}
+```
+
+Now this works:
+
+```go
+err := &AppError{Err: fmt.Errorf("an error")}
+if errwrap.ContainsType(err, fmt.Errorf("")) {
+	// This will work!
+}
+```

vendor/github.com/hashicorp/errwrap/errwrap.go

@@ -0,0 +1,178 @@
+// Package errwrap implements methods to formalize error wrapping in Go.
+//
+// All of the top-level functions that take an `error` are built to be able
+// to take any error, not just wrapped errors. This allows you to use errwrap
+// without having to type-check and type-cast everywhere.
+package errwrap
+
+import (
+	"errors"
+	"reflect"
+	"strings"
+)
+
+// WalkFunc is the callback called for Walk.
+type WalkFunc func(error)
+
+// Wrapper is an interface that can be implemented by custom types to
+// have all the Contains, Get, etc. functions in errwrap work.
+//
+// When Walk reaches a Wrapper, it will call the callback for every
+// wrapped error in addition to the wrapper itself. Since all the top-level
+// functions in errwrap use Walk, this means that all those functions work
+// with your custom type.
+type Wrapper interface {
+	WrappedErrors() []error
+}
+
+// Wrap defines that outer wraps inner, returning an error type that
+// can be cleanly used with the other methods in this package, such as
+// Contains, GetAll, etc.
+//
+// This function won't modify the error message at all (the outer message
+// will be used).
+func Wrap(outer, inner error) error {
+	return &wrappedError{
+		Outer: outer,
+		Inner: inner,
+	}
+}
+
+// Wrapf wraps an error with a formatting message. This is similar to using
+// `fmt.Errorf` to wrap an error. If you're using `fmt.Errorf` to wrap
+// errors, you should replace it with this.
+//
+// format is the format of the error message. The string '{{err}}' will
+// be replaced with the original error message.
+//
+// Deprecated: Use fmt.Errorf()
+func Wrapf(format string, err error) error {
+	outerMsg := "<nil>"
+	if err != nil {
+		outerMsg = err.Error()
+	}
+
+	outer := errors.New(strings.Replace(
+		format, "{{err}}", outerMsg, -1))
+
+	return Wrap(outer, err)
+}
+
+// Contains checks if the given error contains an error with the
+// message msg. If err is not a wrapped error, this will always return
+// false unless the error itself happens to match this msg.
+func Contains(err error, msg string) bool {
+	return len(GetAll(err, msg)) > 0
+}
+
+// ContainsType checks if the given error contains an error with
+// the same concrete type as v. If err is not a wrapped error, this will
+// check the err itself.
+func ContainsType(err error, v interface{}) bool {
+	return len(GetAllType(err, v)) > 0
+}
+
+// Get is the same as GetAll but returns the deepest matching error.
+func Get(err error, msg string) error {
+	es := GetAll(err, msg)
+	if len(es) > 0 {
+		return es[len(es)-1]
+	}
+
+	return nil
+}
+
+// GetType is the same as GetAllType but returns the deepest matching error.
+func GetType(err error, v interface{}) error {
+	es := GetAllType(err, v)
+	if len(es) > 0 {
+		return es[len(es)-1]
+	}
+
+	return nil
+}
+
+// GetAll gets all the errors that might be wrapped in err with the
+// given message. The order of the errors is such that the outermost
+// matching error (the most recent wrap) is index zero, and so on.
+func GetAll(err error, msg string) []error {
+	var result []error
+
+	Walk(err, func(err error) {
+		if err.Error() == msg {
+			result = append(result, err)
+		}
+	})
+
+	return result
+}
+
+// GetAllType gets all the errors that are the same type as v.
+//
+// The order of the return value is the same as described in GetAll.
+func GetAllType(err error, v interface{}) []error {
+	var result []error
+
+	var search string
+	if v != nil {
+		search = reflect.TypeOf(v).String()
+	}
+	Walk(err, func(err error) {
+		var needle string
+		if err != nil {
+			needle = reflect.TypeOf(err).String()
+		}
+
+		if needle == search {
+			result = append(result, err)
+		}
+	})
+
+	return result
+}
+
+// Walk walks all the wrapped errors in err and calls the callback. If
+// err isn't a wrapped error, this will be called once for err. If err
+// is a wrapped error, the callback will be called for both the wrapper
+// that implements error as well as the wrapped error itself.
+func Walk(err error, cb WalkFunc) {
+	if err == nil {
+		return
+	}
+
+	switch e := err.(type) {
+	case *wrappedError:
+		cb(e.Outer)
+		Walk(e.Inner, cb)
+	case Wrapper:
+		cb(err)
+
+		for _, err := range e.WrappedErrors() {
+			Walk(err, cb)
+		}
+	case interface{ Unwrap() error }:
+		cb(err)
+		Walk(e.Unwrap(), cb)
+	default:
+		cb(err)
+	}
+}
+
+// wrappedError is an implementation of error that has both the
+// outer and inner errors.
+type wrappedError struct {
+	Outer error
+	Inner error
+}
+
+func (w *wrappedError) Error() string {
+	return w.Outer.Error()
+}
+
+func (w *wrappedError) WrappedErrors() []error {
+	return []error{w.Outer, w.Inner}
+}
+
+func (w *wrappedError) Unwrap() error {
+	return w.Inner
+}

vendor/github.com/hashicorp/go-hclog/LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) 2017 HashiCorp, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/hashicorp/go-hclog/README.md

@@ -0,0 +1,149 @@
+# go-hclog
+
+[![Go Documentation](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)][godocs]
+
+[godocs]: https://godoc.org/github.com/hashicorp/go-hclog
+
+`go-hclog` is a package for Go that provides a simple key/value logging
+interface for use in development and production environments.
+
+It provides logging levels that provide decreased output based upon the
+desired amount of output, unlike the standard library `log` package.
+
+It provides `Printf` style logging of values via `hclog.Fmt()`.
+
+It provides a human readable output mode for use in development as well as
+JSON output mode for production.
+
+## Stability Note
+
+This library has reached 1.0 stability. Its API can be considered solidified
+and promised through future versions.
+
+## Installation and Docs
+
+Install using `go get github.com/hashicorp/go-hclog`.
+
+Full documentation is available at
+http://godoc.org/github.com/hashicorp/go-hclog
+
+## Usage
+
+### Use the global logger
+
+```go
+hclog.Default().Info("hello world")
+```
+
+```text
+2017-07-05T16:15:55.167-0700 [INFO ] hello world
+```
+
+(Note timestamps are removed in future examples for brevity.)
+
+### Create a new logger
+
+```go
+appLogger := hclog.New(&hclog.LoggerOptions{
+	Name:  "my-app",
+	Level: hclog.LevelFromString("DEBUG"),
+})
+```
+
+### Emit an Info level message with 2 key/value pairs
+
+```go
+input := "5.5"
+_, err := strconv.ParseInt(input, 10, 32)
+if err != nil {
+	appLogger.Info("Invalid input for ParseInt", "input", input, "error", err)
+}
+```
+
+```text
+... [INFO ] my-app: Invalid input for ParseInt: input=5.5 error="strconv.ParseInt: parsing "5.5": invalid syntax"
+```
+
+### Create a new Logger for a major subsystem
+
+```go
+subsystemLogger := appLogger.Named("transport")
+subsystemLogger.Info("we are transporting something")
+```
+
+```text
+... [INFO ] my-app.transport: we are transporting something
+```
+
+Notice that logs emitted by `subsystemLogger` contain `my-app.transport`,
+reflecting both the application and subsystem names.
+
+### Create a new Logger with fixed key/value pairs
+
+Using `With()` will include a specific key-value pair in all messages emitted
+by that logger.
+
+```go
+requestID := "5fb446b6-6eba-821d-df1b-cd7501b6a363"
+requestLogger := subsystemLogger.With("request", requestID)
+requestLogger.Info("we are transporting a request")
+```
+
+```text
+... [INFO ] my-app.transport: we are transporting a request: request=5fb446b6-6eba-821d-df1b-cd7501b6a363
+```
+
+This allows sub Loggers to be context specific without having to thread that
+into all the callers.
+
+### Using `hclog.Fmt()`
+
+```go
+totalBandwidth := 200
+appLogger.Info("total bandwidth exceeded", "bandwidth", hclog.Fmt("%d GB/s", totalBandwidth))
+```
+
+```text
+... [INFO ] my-app: total bandwidth exceeded: bandwidth="200 GB/s"
+```
+
+### Use this with code that uses the standard library logger
+
+If you want to use the standard library's `log.Logger` interface you can wrap
+`hclog.Logger` by calling the `StandardLogger()` method. This allows you to use
+it with the familiar `Println()`, `Printf()`, etc. For example:
+
+```go
+stdLogger := appLogger.StandardLogger(&hclog.StandardLoggerOptions{
+	InferLevels: true,
+})
+// Printf() is provided by stdlib log.Logger interface, not hclog.Logger
+stdLogger.Printf("[DEBUG] %+v", stdLogger)
+```
+
+```text
+... [DEBUG] my-app: &{mu:{state:0 sema:0} prefix: flag:0 out:0xc42000a0a0 buf:[]}
+```
+
+Alternatively, you may configure the system-wide logger:
+
+```go
+// log the standard logger from 'import "log"'
+log.SetOutput(appLogger.StandardWriter(&hclog.StandardLoggerOptions{InferLevels: true}))
+log.SetPrefix("")
+log.SetFlags(0)
+
+log.Printf("[DEBUG] %d", 42)
+```
+
+```text
+... [DEBUG] my-app: 42
+```
+
+Notice that if `appLogger` is initialized with the `INFO` log level, _and_ you
+specify `InferLevels: true`, you will not see any output here. You must change
+`appLogger` to `DEBUG` to see output. See the docs for more information.
+
+If the log lines start with a timestamp you can use the
+`InferLevelsWithTimestamp` option to try and ignore them. Please note that in order
+for `InferLevelsWithTimestamp` to be relevant, `InferLevels` must be set to `true`.

vendor/github.com/hashicorp/go-hclog/colorize_unix.go

@@ -0,0 +1,44 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+//go:build !windows
+// +build !windows
+
+package hclog
+
+import (
+	"github.com/mattn/go-isatty"
+)
+
+// hasFD is used to check if the writer has an Fd value to check
+// if it's a terminal.
+type hasFD interface {
+	Fd() uintptr
+}
+
+// setColorization will mutate the values of this logger
+// to appropriately configure colorization options. It provides
+// a wrapper to the output stream on Windows systems.
+func (l *intLogger) setColorization(opts *LoggerOptions) {
+	if opts.Color != AutoColor {
+		return
+	}
+
+	if sc, ok := l.writer.w.(SupportsColor); ok {
+		if !sc.SupportsColor() {
+			l.headerColor = ColorOff
+			l.writer.color = ColorOff
+		}
+		return
+	}
+
+	fi, ok := l.writer.w.(hasFD)
+	if !ok {
+		return
+	}
+
+	if !isatty.IsTerminal(fi.Fd()) {
+		l.headerColor = ColorOff
+		l.writer.color = ColorOff
+	}
+}

vendor/github.com/hashicorp/go-hclog/colorize_windows.go

@@ -0,0 +1,41 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+//go:build windows
+// +build windows
+
+package hclog
+
+import (
+	"os"
+
+	colorable "github.com/mattn/go-colorable"
+)
+
+// setColorization will mutate the values of this logger
+// to appropriately configure colorization options. It provides
+// a wrapper to the output stream on Windows systems.
+func (l *intLogger) setColorization(opts *LoggerOptions) {
+	if opts.Color == ColorOff {
+		return
+	}
+
+	fi, ok := l.writer.w.(*os.File)
+	if !ok {
+		l.writer.color = ColorOff
+		l.headerColor = ColorOff
+		return
+	}
+
+	cfi := colorable.NewColorable(fi)
+
+	// NewColorable detects if color is possible and if it's not, then it
+	// returns the original value. So we can test if we got the original
+	// value back to know if color is possible.
+	if cfi == fi {
+		l.writer.color = ColorOff
+		l.headerColor = ColorOff
+	} else {
+		l.writer.w = cfi
+	}
+}

vendor/github.com/hashicorp/go-hclog/context.go

@@ -0,0 +1,41 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"context"
+)
+
+// WithContext inserts a logger into the context and is retrievable
+// with FromContext. The optional args can be set with the same syntax as
+// Logger.With to set fields on the inserted logger. This will not modify
+// the logger argument in-place.
+func WithContext(ctx context.Context, logger Logger, args ...interface{}) context.Context {
+	// While we could call logger.With even with zero args, we have this
+	// check to avoid unnecessary allocations around creating a copy of a
+	// logger.
+	if len(args) > 0 {
+		logger = logger.With(args...)
+	}
+
+	return context.WithValue(ctx, contextKey, logger)
+}
+
+// FromContext returns a logger from the context. This will return L()
+// (the default logger) if no logger is found in the context. Therefore,
+// this will never return a nil value.
+func FromContext(ctx context.Context) Logger {
+	logger, _ := ctx.Value(contextKey).(Logger)
+	if logger == nil {
+		return L()
+	}
+
+	return logger
+}
+
+// Unexported new type so that our context key never collides with another.
+type contextKeyType struct{}
+
+// contextKey is the key used for the context to store the logger.
+var contextKey = contextKeyType{}

vendor/github.com/hashicorp/go-hclog/exclude.go

@@ -0,0 +1,74 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"regexp"
+	"strings"
+)
+
+// ExcludeByMessage provides a simple way to build a list of log messages that
+// can be queried and matched. This is meant to be used with the Exclude
+// option on Options to suppress log messages. This does not hold any mutexs
+// within itself, so normal usage would be to Add entries at setup and none after
+// Exclude is going to be called. Exclude is called with a mutex held within
+// the Logger, so that doesn't need to use a mutex. Example usage:
+//
+//	f := new(ExcludeByMessage)
+//	f.Add("Noisy log message text")
+//	appLogger.Exclude = f.Exclude
+type ExcludeByMessage struct {
+	messages map[string]struct{}
+}
+
+// Add a message to be filtered. Do not call this after Exclude is to be called
+// due to concurrency issues.
+func (f *ExcludeByMessage) Add(msg string) {
+	if f.messages == nil {
+		f.messages = make(map[string]struct{})
+	}
+
+	f.messages[msg] = struct{}{}
+}
+
+// Return true if the given message should be included
+func (f *ExcludeByMessage) Exclude(level Level, msg string, args ...interface{}) bool {
+	_, ok := f.messages[msg]
+	return ok
+}
+
+// ExcludeByPrefix is a simple type to match a message string that has a common prefix.
+type ExcludeByPrefix string
+
+// Matches an message that starts with the prefix.
+func (p ExcludeByPrefix) Exclude(level Level, msg string, args ...interface{}) bool {
+	return strings.HasPrefix(msg, string(p))
+}
+
+// ExcludeByRegexp takes a regexp and uses it to match a log message string. If it matches
+// the log entry is excluded.
+type ExcludeByRegexp struct {
+	Regexp *regexp.Regexp
+}
+
+// Exclude the log message if the message string matches the regexp
+func (e ExcludeByRegexp) Exclude(level Level, msg string, args ...interface{}) bool {
+	return e.Regexp.MatchString(msg)
+}
+
+// ExcludeFuncs is a slice of functions that will called to see if a log entry
+// should be filtered or not. It stops calling functions once at least one returns
+// true.
+type ExcludeFuncs []func(level Level, msg string, args ...interface{}) bool
+
+// Calls each function until one of them returns true
+func (ff ExcludeFuncs) Exclude(level Level, msg string, args ...interface{}) bool {
+	for _, f := range ff {
+		if f(level, msg, args...) {
+			return true
+		}
+	}
+
+	return false
+}

vendor/github.com/hashicorp/go-hclog/global.go

@@ -0,0 +1,67 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"sync"
+	"time"
+)
+
+var (
+	protect sync.Once
+	def     Logger
+
+	// DefaultOptions is used to create the Default logger. These are read
+	// only when the Default logger is created, so set them as soon as the
+	// process starts.
+	DefaultOptions = &LoggerOptions{
+		Level:  DefaultLevel,
+		Output: DefaultOutput,
+		TimeFn: time.Now,
+	}
+)
+
+// Default returns a globally held logger. This can be a good starting
+// place, and then you can use .With() and .Named() to create sub-loggers
+// to be used in more specific contexts.
+// The value of the Default logger can be set via SetDefault() or by
+// changing the options in DefaultOptions.
+//
+// This method is goroutine safe, returning a global from memory, but
+// care should be used if SetDefault() is called it random times
+// in the program as that may result in race conditions and an unexpected
+// Logger being returned.
+func Default() Logger {
+	protect.Do(func() {
+		// If SetDefault was used before Default() was called, we need to
+		// detect that here.
+		if def == nil {
+			def = New(DefaultOptions)
+		}
+	})
+
+	return def
+}
+
+// L is a short alias for Default().
+func L() Logger {
+	return Default()
+}
+
+// SetDefault changes the logger to be returned by Default()and L()
+// to the one given. This allows packages to use the default logger
+// and have higher level packages change it to match the execution
+// environment. It returns any old default if there is one.
+//
+// NOTE: This is expected to be called early in the program to setup
+// a default logger. As such, it does not attempt to make itself
+// not racy with regard to the value of the default logger. Ergo
+// if it is called in goroutines, you may experience race conditions
+// with other goroutines retrieving the default logger. Basically,
+// don't do that.
+func SetDefault(log Logger) Logger {
+	old := def
+	def = log
+	return old
+}

vendor/github.com/hashicorp/go-hclog/interceptlogger.go

@@ -0,0 +1,207 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"io"
+	"log"
+	"sync"
+	"sync/atomic"
+)
+
+var _ Logger = &interceptLogger{}
+
+type interceptLogger struct {
+	Logger
+
+	mu        *sync.Mutex
+	sinkCount *int32
+	Sinks     map[SinkAdapter]struct{}
+}
+
+func NewInterceptLogger(opts *LoggerOptions) InterceptLogger {
+	l := newLogger(opts)
+	if l.callerOffset > 0 {
+		// extra frames for interceptLogger.{Warn,Info,Log,etc...}, and interceptLogger.log
+		l.callerOffset += 2
+	}
+	intercept := &interceptLogger{
+		Logger:    l,
+		mu:        new(sync.Mutex),
+		sinkCount: new(int32),
+		Sinks:     make(map[SinkAdapter]struct{}),
+	}
+
+	atomic.StoreInt32(intercept.sinkCount, 0)
+
+	return intercept
+}
+
+func (i *interceptLogger) Log(level Level, msg string, args ...interface{}) {
+	i.log(level, msg, args...)
+}
+
+// log is used to make the caller stack frame lookup consistent. If Warn,Info,etc
+// all called Log then direct calls to Log would have a different stack frame
+// depth. By having all the methods call the same helper we ensure the stack
+// frame depth is the same.
+func (i *interceptLogger) log(level Level, msg string, args ...interface{}) {
+	i.Logger.Log(level, msg, args...)
+	if atomic.LoadInt32(i.sinkCount) == 0 {
+		return
+	}
+
+	i.mu.Lock()
+	defer i.mu.Unlock()
+	for s := range i.Sinks {
+		s.Accept(i.Name(), level, msg, i.retrieveImplied(args...)...)
+	}
+}
+
+// Emit the message and args at TRACE level to log and sinks
+func (i *interceptLogger) Trace(msg string, args ...interface{}) {
+	i.log(Trace, msg, args...)
+}
+
+// Emit the message and args at DEBUG level to log and sinks
+func (i *interceptLogger) Debug(msg string, args ...interface{}) {
+	i.log(Debug, msg, args...)
+}
+
+// Emit the message and args at INFO level to log and sinks
+func (i *interceptLogger) Info(msg string, args ...interface{}) {
+	i.log(Info, msg, args...)
+}
+
+// Emit the message and args at WARN level to log and sinks
+func (i *interceptLogger) Warn(msg string, args ...interface{}) {
+	i.log(Warn, msg, args...)
+}
+
+// Emit the message and args at ERROR level to log and sinks
+func (i *interceptLogger) Error(msg string, args ...interface{}) {
+	i.log(Error, msg, args...)
+}
+
+func (i *interceptLogger) retrieveImplied(args ...interface{}) []interface{} {
+	top := i.Logger.ImpliedArgs()
+
+	cp := make([]interface{}, len(top)+len(args))
+	copy(cp, top)
+	copy(cp[len(top):], args)
+
+	return cp
+}
+
+// Create a new sub-Logger that a name descending from the current name.
+// This is used to create a subsystem specific Logger.
+// Registered sinks will subscribe to these messages as well.
+func (i *interceptLogger) Named(name string) Logger {
+	return i.NamedIntercept(name)
+}
+
+// Create a new sub-Logger with an explicit name. This ignores the current
+// name. This is used to create a standalone logger that doesn't fall
+// within the normal hierarchy. Registered sinks will subscribe
+// to these messages as well.
+func (i *interceptLogger) ResetNamed(name string) Logger {
+	return i.ResetNamedIntercept(name)
+}
+
+// Create a new sub-Logger that a name decending from the current name.
+// This is used to create a subsystem specific Logger.
+// Registered sinks will subscribe to these messages as well.
+func (i *interceptLogger) NamedIntercept(name string) InterceptLogger {
+	var sub interceptLogger
+
+	sub = *i
+	sub.Logger = i.Logger.Named(name)
+	return &sub
+}
+
+// Create a new sub-Logger with an explicit name. This ignores the current
+// name. This is used to create a standalone logger that doesn't fall
+// within the normal hierarchy. Registered sinks will subscribe
+// to these messages as well.
+func (i *interceptLogger) ResetNamedIntercept(name string) InterceptLogger {
+	var sub interceptLogger
+
+	sub = *i
+	sub.Logger = i.Logger.ResetNamed(name)
+	return &sub
+}
+
+// Return a sub-Logger for which every emitted log message will contain
+// the given key/value pairs. This is used to create a context specific
+// Logger.
+func (i *interceptLogger) With(args ...interface{}) Logger {
+	var sub interceptLogger
+
+	sub = *i
+
+	sub.Logger = i.Logger.With(args...)
+
+	return &sub
+}
+
+// RegisterSink attaches a SinkAdapter to interceptLoggers sinks.
+func (i *interceptLogger) RegisterSink(sink SinkAdapter) {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	i.Sinks[sink] = struct{}{}
+
+	atomic.AddInt32(i.sinkCount, 1)
+}
+
+// DeregisterSink removes a SinkAdapter from interceptLoggers sinks.
+func (i *interceptLogger) DeregisterSink(sink SinkAdapter) {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	delete(i.Sinks, sink)
+
+	atomic.AddInt32(i.sinkCount, -1)
+}
+
+func (i *interceptLogger) StandardLoggerIntercept(opts *StandardLoggerOptions) *log.Logger {
+	return i.StandardLogger(opts)
+}
+
+func (i *interceptLogger) StandardLogger(opts *StandardLoggerOptions) *log.Logger {
+	if opts == nil {
+		opts = &StandardLoggerOptions{}
+	}
+
+	return log.New(i.StandardWriter(opts), "", 0)
+}
+
+func (i *interceptLogger) StandardWriterIntercept(opts *StandardLoggerOptions) io.Writer {
+	return i.StandardWriter(opts)
+}
+
+func (i *interceptLogger) StandardWriter(opts *StandardLoggerOptions) io.Writer {
+	return &stdlogAdapter{
+		log:                      i,
+		inferLevels:              opts.InferLevels,
+		inferLevelsWithTimestamp: opts.InferLevelsWithTimestamp,
+		forceLevel:               opts.ForceLevel,
+	}
+}
+
+func (i *interceptLogger) ResetOutput(opts *LoggerOptions) error {
+	if or, ok := i.Logger.(OutputResettable); ok {
+		return or.ResetOutput(opts)
+	} else {
+		return nil
+	}
+}
+
+func (i *interceptLogger) ResetOutputWithFlush(opts *LoggerOptions, flushable Flushable) error {
+	if or, ok := i.Logger.(OutputResettable); ok {
+		return or.ResetOutputWithFlush(opts, flushable)
+	} else {
+		return nil
+	}
+}

vendor/github.com/hashicorp/go-hclog/logger.go

@@ -0,0 +1,412 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"io"
+	"log"
+	"os"
+	"strings"
+	"time"
+)
+
+var (
+	// DefaultOutput is used as the default log output.
+	DefaultOutput io.Writer = os.Stderr
+
+	// DefaultLevel is used as the default log level.
+	DefaultLevel = Info
+)
+
+// Level represents a log level.
+type Level int32
+
+const (
+	// NoLevel is a special level used to indicate that no level has been
+	// set and allow for a default to be used.
+	NoLevel Level = 0
+
+	// Trace is the most verbose level. Intended to be used for the tracing
+	// of actions in code, such as function enters/exits, etc.
+	Trace Level = 1
+
+	// Debug information for programmer low-level analysis.
+	Debug Level = 2
+
+	// Info information about steady state operations.
+	Info Level = 3
+
+	// Warn information about rare but handled events.
+	Warn Level = 4
+
+	// Error information about unrecoverable events.
+	Error Level = 5
+
+	// Off disables all logging output.
+	Off Level = 6
+)
+
+// Format is a simple convenience type for when formatting is required. When
+// processing a value of this type, the logger automatically treats the first
+// argument as a Printf formatting string and passes the rest as the values
+// to be formatted. For example: L.Info(Fmt{"%d beans/day", beans}).
+type Format []interface{}
+
+// Fmt returns a Format type. This is a convenience function for creating a Format
+// type.
+func Fmt(str string, args ...interface{}) Format {
+	return append(Format{str}, args...)
+}
+
+// A simple shortcut to format numbers in hex when displayed with the normal
+// text output. For example: L.Info("header value", Hex(17))
+type Hex int
+
+// A simple shortcut to format numbers in octal when displayed with the normal
+// text output. For example: L.Info("perms", Octal(17))
+type Octal int
+
+// A simple shortcut to format numbers in binary when displayed with the normal
+// text output. For example: L.Info("bits", Binary(17))
+type Binary int
+
+// A simple shortcut to format strings with Go quoting. Control and
+// non-printable characters will be escaped with their backslash equivalents in
+// output. Intended for untrusted or multiline strings which should be logged
+// as concisely as possible.
+type Quote string
+
+// ColorOption expresses how the output should be colored, if at all.
+type ColorOption uint8
+
+const (
+	// ColorOff is the default coloration, and does not
+	// inject color codes into the io.Writer.
+	ColorOff ColorOption = iota
+	// AutoColor checks if the io.Writer is a tty,
+	// and if so enables coloring.
+	AutoColor
+	// ForceColor will enable coloring, regardless of whether
+	// the io.Writer is a tty or not.
+	ForceColor
+)
+
+// SupportsColor is an optional interface that can be implemented by the output
+// value. If implemented and SupportsColor() returns true, then AutoColor will
+// enable colorization.
+type SupportsColor interface {
+	SupportsColor() bool
+}
+
+// LevelFromString returns a Level type for the named log level, or "NoLevel" if
+// the level string is invalid. This facilitates setting the log level via
+// config or environment variable by name in a predictable way.
+func LevelFromString(levelStr string) Level {
+	// We don't care about case. Accept both "INFO" and "info".
+	levelStr = strings.ToLower(strings.TrimSpace(levelStr))
+	switch levelStr {
+	case "trace":
+		return Trace
+	case "debug":
+		return Debug
+	case "info":
+		return Info
+	case "warn":
+		return Warn
+	case "error":
+		return Error
+	case "off":
+		return Off
+	default:
+		return NoLevel
+	}
+}
+
+func (l Level) String() string {
+	switch l {
+	case Trace:
+		return "trace"
+	case Debug:
+		return "debug"
+	case Info:
+		return "info"
+	case Warn:
+		return "warn"
+	case Error:
+		return "error"
+	case NoLevel:
+		return "none"
+	case Off:
+		return "off"
+	default:
+		return "unknown"
+	}
+}
+
+// Logger describes the interface that must be implemented by all loggers.
+type Logger interface {
+	// Args are alternating key, val pairs
+	// keys must be strings
+	// vals can be any type, but display is implementation specific
+	// Emit a message and key/value pairs at a provided log level
+	Log(level Level, msg string, args ...interface{})
+
+	// Emit a message and key/value pairs at the TRACE level
+	Trace(msg string, args ...interface{})
+
+	// Emit a message and key/value pairs at the DEBUG level
+	Debug(msg string, args ...interface{})
+
+	// Emit a message and key/value pairs at the INFO level
+	Info(msg string, args ...interface{})
+
+	// Emit a message and key/value pairs at the WARN level
+	Warn(msg string, args ...interface{})
+
+	// Emit a message and key/value pairs at the ERROR level
+	Error(msg string, args ...interface{})
+
+	// Indicate if TRACE logs would be emitted. This and the other Is* guards
+	// are used to elide expensive logging code based on the current level.
+	IsTrace() bool
+
+	// Indicate if DEBUG logs would be emitted. This and the other Is* guards
+	IsDebug() bool
+
+	// Indicate if INFO logs would be emitted. This and the other Is* guards
+	IsInfo() bool
+
+	// Indicate if WARN logs would be emitted. This and the other Is* guards
+	IsWarn() bool
+
+	// Indicate if ERROR logs would be emitted. This and the other Is* guards
+	IsError() bool
+
+	// ImpliedArgs returns With key/value pairs
+	ImpliedArgs() []interface{}
+
+	// Creates a sublogger that will always have the given key/value pairs
+	With(args ...interface{}) Logger
+
+	// Returns the Name of the logger
+	Name() string
+
+	// Create a logger that will prepend the name string on the front of all messages.
+	// If the logger already has a name, the new value will be appended to the current
+	// name. That way, a major subsystem can use this to decorate all it's own logs
+	// without losing context.
+	Named(name string) Logger
+
+	// Create a logger that will prepend the name string on the front of all messages.
+	// This sets the name of the logger to the value directly, unlike Named which honor
+	// the current name as well.
+	ResetNamed(name string) Logger
+
+	// Updates the level. This should affect all related loggers as well,
+	// unless they were created with IndependentLevels. If an
+	// implementation cannot update the level on the fly, it should no-op.
+	SetLevel(level Level)
+
+	// Returns the current level
+	GetLevel() Level
+
+	// Return a value that conforms to the stdlib log.Logger interface
+	StandardLogger(opts *StandardLoggerOptions) *log.Logger
+
+	// Return a value that conforms to io.Writer, which can be passed into log.SetOutput()
+	StandardWriter(opts *StandardLoggerOptions) io.Writer
+}
+
+// StandardLoggerOptions can be used to configure a new standard logger.
+type StandardLoggerOptions struct {
+	// Indicate that some minimal parsing should be done on strings to try
+	// and detect their level and re-emit them.
+	// This supports the strings like [ERROR], [ERR] [TRACE], [WARN], [INFO],
+	// [DEBUG] and strip it off before reapplying it.
+	InferLevels bool
+
+	// Indicate that some minimal parsing should be done on strings to try
+	// and detect their level and re-emit them while ignoring possible
+	// timestamp values in the beginning of the string.
+	// This supports the strings like [ERROR], [ERR] [TRACE], [WARN], [INFO],
+	// [DEBUG] and strip it off before reapplying it.
+	// The timestamp detection may result in false positives and incomplete
+	// string outputs.
+	// InferLevelsWithTimestamp is only relevant if InferLevels is true.
+	InferLevelsWithTimestamp bool
+
+	// ForceLevel is used to force all output from the standard logger to be at
+	// the specified level. Similar to InferLevels, this will strip any level
+	// prefix contained in the logged string before applying the forced level.
+	// If set, this override InferLevels.
+	ForceLevel Level
+}
+
+type TimeFunction = func() time.Time
+
+// LoggerOptions can be used to configure a new logger.
+type LoggerOptions struct {
+	// Name of the subsystem to prefix logs with
+	Name string
+
+	// The threshold for the logger. Anything less severe is suppressed
+	Level Level
+
+	// Where to write the logs to. Defaults to os.Stderr if nil
+	Output io.Writer
+
+	// An optional Locker in case Output is shared. This can be a sync.Mutex or
+	// a NoopLocker if the caller wants control over output, e.g. for batching
+	// log lines.
+	Mutex Locker
+
+	// Control if the output should be in JSON.
+	JSONFormat bool
+
+	// Include file and line information in each log line
+	IncludeLocation bool
+
+	// AdditionalLocationOffset is the number of additional stack levels to skip
+	// when finding the file and line information for the log line
+	AdditionalLocationOffset int
+
+	// The time format to use instead of the default
+	TimeFormat string
+
+	// A function which is called to get the time object that is formatted using `TimeFormat`
+	TimeFn TimeFunction
+
+	// Control whether or not to display the time at all. This is required
+	// because setting TimeFormat to empty assumes the default format.
+	DisableTime bool
+
+	// Color the output. On Windows, colored logs are only available for io.Writers that
+	// are concretely instances of *os.File.
+	Color ColorOption
+
+	// Only color the header, not the body. This can help with readability of long messages.
+	ColorHeaderOnly bool
+
+	// Color the header and message body fields. This can help with readability
+	// of long messages with multiple fields.
+	ColorHeaderAndFields bool
+
+	// A function which is called with the log information and if it returns true the value
+	// should not be logged.
+	// This is useful when interacting with a system that you wish to suppress the log
+	// message for (because it's too noisy, etc)
+	Exclude func(level Level, msg string, args ...interface{}) bool
+
+	// IndependentLevels causes subloggers to be created with an independent
+	// copy of this logger's level. This means that using SetLevel on this
+	// logger will not affect any subloggers, and SetLevel on any subloggers
+	// will not affect the parent or sibling loggers.
+	IndependentLevels bool
+
+	// When set, changing the level of a logger effects only it's direct sub-loggers
+	// rather than all sub-loggers. For example:
+	// a := logger.Named("a")
+	// a.SetLevel(Error)
+	// b := a.Named("b")
+	// c := a.Named("c")
+	// b.GetLevel() => Error
+	// c.GetLevel() => Error
+	// b.SetLevel(Info)
+	// a.GetLevel() => Error
+	// b.GetLevel() => Info
+	// c.GetLevel() => Error
+	// a.SetLevel(Warn)
+	// a.GetLevel() => Warn
+	// b.GetLevel() => Warn
+	// c.GetLevel() => Warn
+	SyncParentLevel bool
+
+	// SubloggerHook registers a function that is called when a sublogger via
+	// Named, With, or ResetNamed is created. If defined, the function is passed
+	// the newly created Logger and the returned Logger is returned from the
+	// original function. This option allows customization via interception and
+	// wrapping of Logger instances.
+	SubloggerHook func(sub Logger) Logger
+}
+
+// InterceptLogger describes the interface for using a logger
+// that can register different output sinks.
+// This is useful for sending lower level log messages
+// to a different output while keeping the root logger
+// at a higher one.
+type InterceptLogger interface {
+	// Logger is the root logger for an InterceptLogger
+	Logger
+
+	// RegisterSink adds a SinkAdapter to the InterceptLogger
+	RegisterSink(sink SinkAdapter)
+
+	// DeregisterSink removes a SinkAdapter from the InterceptLogger
+	DeregisterSink(sink SinkAdapter)
+
+	// Create a interceptlogger that will prepend the name string on the front of all messages.
+	// If the logger already has a name, the new value will be appended to the current
+	// name. That way, a major subsystem can use this to decorate all it's own logs
+	// without losing context.
+	NamedIntercept(name string) InterceptLogger
+
+	// Create a interceptlogger that will prepend the name string on the front of all messages.
+	// This sets the name of the logger to the value directly, unlike Named which honor
+	// the current name as well.
+	ResetNamedIntercept(name string) InterceptLogger
+
+	// Deprecated: use StandardLogger
+	StandardLoggerIntercept(opts *StandardLoggerOptions) *log.Logger
+
+	// Deprecated: use StandardWriter
+	StandardWriterIntercept(opts *StandardLoggerOptions) io.Writer
+}
+
+// SinkAdapter describes the interface that must be implemented
+// in order to Register a new sink to an InterceptLogger
+type SinkAdapter interface {
+	Accept(name string, level Level, msg string, args ...interface{})
+}
+
+// Flushable represents a method for flushing an output buffer. It can be used
+// if Resetting the log to use a new output, in order to flush the writes to
+// the existing output beforehand.
+type Flushable interface {
+	Flush() error
+}
+
+// OutputResettable provides ways to swap the output in use at runtime
+type OutputResettable interface {
+	// ResetOutput swaps the current output writer with the one given in the
+	// opts. Color options given in opts will be used for the new output.
+	ResetOutput(opts *LoggerOptions) error
+
+	// ResetOutputWithFlush swaps the current output writer with the one given
+	// in the opts, first calling Flush on the given Flushable. Color options
+	// given in opts will be used for the new output.
+	ResetOutputWithFlush(opts *LoggerOptions, flushable Flushable) error
+}
+
+// Locker is used for locking output. If not set when creating a logger, a
+// sync.Mutex will be used internally.
+type Locker interface {
+	// Lock is called when the output is going to be changed or written to
+	Lock()
+
+	// Unlock is called when the operation that called Lock() completes
+	Unlock()
+}
+
+// NoopLocker implements locker but does nothing. This is useful if the client
+// wants tight control over locking, in order to provide grouping of log
+// entries or other functionality.
+type NoopLocker struct{}
+
+// Lock does nothing
+func (n NoopLocker) Lock() {}
+
+// Unlock does nothing
+func (n NoopLocker) Unlock() {}
+
+var _ Locker = (*NoopLocker)(nil)

vendor/github.com/hashicorp/go-hclog/nulllogger.go

@@ -0,0 +1,63 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"io"
+	"io/ioutil"
+	"log"
+)
+
+// NewNullLogger instantiates a Logger for which all calls
+// will succeed without doing anything.
+// Useful for testing purposes.
+func NewNullLogger() Logger {
+	return &nullLogger{}
+}
+
+type nullLogger struct{}
+
+func (l *nullLogger) Log(level Level, msg string, args ...interface{}) {}
+
+func (l *nullLogger) Trace(msg string, args ...interface{}) {}
+
+func (l *nullLogger) Debug(msg string, args ...interface{}) {}
+
+func (l *nullLogger) Info(msg string, args ...interface{}) {}
+
+func (l *nullLogger) Warn(msg string, args ...interface{}) {}
+
+func (l *nullLogger) Error(msg string, args ...interface{}) {}
+
+func (l *nullLogger) IsTrace() bool { return false }
+
+func (l *nullLogger) IsDebug() bool { return false }
+
+func (l *nullLogger) IsInfo() bool { return false }
+
+func (l *nullLogger) IsWarn() bool { return false }
+
+func (l *nullLogger) IsError() bool { return false }
+
+func (l *nullLogger) ImpliedArgs() []interface{} { return []interface{}{} }
+
+func (l *nullLogger) With(args ...interface{}) Logger { return l }
+
+func (l *nullLogger) Name() string { return "" }
+
+func (l *nullLogger) Named(name string) Logger { return l }
+
+func (l *nullLogger) ResetNamed(name string) Logger { return l }
+
+func (l *nullLogger) SetLevel(level Level) {}
+
+func (l *nullLogger) GetLevel() Level { return NoLevel }
+
+func (l *nullLogger) StandardLogger(opts *StandardLoggerOptions) *log.Logger {
+	return log.New(l.StandardWriter(opts), "", log.LstdFlags)
+}
+
+func (l *nullLogger) StandardWriter(opts *StandardLoggerOptions) io.Writer {
+	return ioutil.Discard
+}

vendor/github.com/hashicorp/go-hclog/stacktrace.go

@@ -0,0 +1,109 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package hclog
+
+import (
+	"bytes"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+var (
+	_stacktraceIgnorePrefixes = []string{
+		"runtime.goexit",
+		"runtime.main",
+	}
+	_stacktracePool = sync.Pool{
+		New: func() interface{} {
+			return newProgramCounters(64)
+		},
+	}
+)
+
+// CapturedStacktrace represents a stacktrace captured by a previous call
+// to log.Stacktrace. If passed to a logging function, the stacktrace
+// will be appended.
+type CapturedStacktrace string
+
+// Stacktrace captures a stacktrace of the current goroutine and returns
+// it to be passed to a logging function.
+func Stacktrace() CapturedStacktrace {
+	return CapturedStacktrace(takeStacktrace())
+}
+
+func takeStacktrace() string {
+	programCounters := _stacktracePool.Get().(*programCounters)
+	defer _stacktracePool.Put(programCounters)
+
+	var buffer bytes.Buffer
+
+	for {
+		// Skip the call to runtime.Counters and takeStacktrace so that the
+		// program counters start at the caller of takeStacktrace.
+		n := runtime.Callers(2, programCounters.pcs)
+		if n < cap(programCounters.pcs) {
+			programCounters.pcs = programCounters.pcs[:n]
+			break
+		}
+		// Don't put the too-short counter slice back into the pool; this lets
+		// the pool adjust if we consistently take deep stacktraces.
+		programCounters = newProgramCounters(len(programCounters.pcs) * 2)
+	}
+
+	i := 0
+	frames := runtime.CallersFrames(programCounters.pcs)
+	for frame, more := frames.Next(); more; frame, more = frames.Next() {
+		if shouldIgnoreStacktraceFunction(frame.Function) {
+			continue
+		}
+		if i != 0 {
+			buffer.WriteByte('\n')
+		}
+		i++
+		buffer.WriteString(frame.Function)
+		buffer.WriteByte('\n')
+		buffer.WriteByte('\t')
+		buffer.WriteString(frame.File)
+		buffer.WriteByte(':')
+		buffer.WriteString(strconv.Itoa(int(frame.Line)))
+	}
+
+	return buffer.String()
+}
+
+func shouldIgnoreStacktraceFunction(function string) bool {
+	for _, prefix := range _stacktraceIgnorePrefixes {
+		if strings.HasPrefix(function, prefix) {
+			return true
+		}
+	}
+	return false
+}
+
+type programCounters struct {
+	pcs []uintptr
+}
+
+func newProgramCounters(size int) *programCounters {
+	return &programCounters{make([]uintptr, size)}
+}

vendor/github.com/hashicorp/go-hclog/stdlog.go

@@ -0,0 +1,113 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"bytes"
+	"log"
+	"regexp"
+	"strings"
+)
+
+// Regex to ignore characters commonly found in timestamp formats from the
+// beginning of inputs.
+var logTimestampRegexp = regexp.MustCompile(`^[\d\s\:\/\.\+-TZ]*`)
+
+// Provides a io.Writer to shim the data out of *log.Logger
+// and back into our Logger. This is basically the only way to
+// build upon *log.Logger.
+type stdlogAdapter struct {
+	log                      Logger
+	inferLevels              bool
+	inferLevelsWithTimestamp bool
+	forceLevel               Level
+}
+
+// Take the data, infer the levels if configured, and send it through
+// a regular Logger.
+func (s *stdlogAdapter) Write(data []byte) (int, error) {
+	str := string(bytes.TrimRight(data, " \t\n"))
+
+	if s.forceLevel != NoLevel {
+		// Use pickLevel to strip log levels included in the line since we are
+		// forcing the level
+		_, str := s.pickLevel(str)
+
+		// Log at the forced level
+		s.dispatch(str, s.forceLevel)
+	} else if s.inferLevels {
+		if s.inferLevelsWithTimestamp {
+			str = s.trimTimestamp(str)
+		}
+
+		level, str := s.pickLevel(str)
+		s.dispatch(str, level)
+	} else {
+		s.log.Info(str)
+	}
+
+	return len(data), nil
+}
+
+func (s *stdlogAdapter) dispatch(str string, level Level) {
+	switch level {
+	case Trace:
+		s.log.Trace(str)
+	case Debug:
+		s.log.Debug(str)
+	case Info:
+		s.log.Info(str)
+	case Warn:
+		s.log.Warn(str)
+	case Error:
+		s.log.Error(str)
+	default:
+		s.log.Info(str)
+	}
+}
+
+// Detect, based on conventions, what log level this is.
+func (s *stdlogAdapter) pickLevel(str string) (Level, string) {
+	switch {
+	case strings.HasPrefix(str, "[DEBUG]"):
+		return Debug, strings.TrimSpace(str[7:])
+	case strings.HasPrefix(str, "[TRACE]"):
+		return Trace, strings.TrimSpace(str[7:])
+	case strings.HasPrefix(str, "[INFO]"):
+		return Info, strings.TrimSpace(str[6:])
+	case strings.HasPrefix(str, "[WARN]"):
+		return Warn, strings.TrimSpace(str[6:])
+	case strings.HasPrefix(str, "[ERROR]"):
+		return Error, strings.TrimSpace(str[7:])
+	case strings.HasPrefix(str, "[ERR]"):
+		return Error, strings.TrimSpace(str[5:])
+	default:
+		return Info, str
+	}
+}
+
+func (s *stdlogAdapter) trimTimestamp(str string) string {
+	idx := logTimestampRegexp.FindStringIndex(str)
+	return str[idx[1]:]
+}
+
+type logWriter struct {
+	l *log.Logger
+}
+
+func (l *logWriter) Write(b []byte) (int, error) {
+	l.l.Println(string(bytes.TrimRight(b, " \n\t")))
+	return len(b), nil
+}
+
+// Takes a standard library logger and returns a Logger that will write to it
+func FromStandardLogger(l *log.Logger, opts *LoggerOptions) Logger {
+	var dl LoggerOptions = *opts
+
+	// Use the time format that log.Logger uses
+	dl.DisableTime = true
+	dl.Output = &logWriter{l}
+
+	return New(&dl)
+}

vendor/github.com/hashicorp/go-hclog/writer.go

@@ -0,0 +1,85 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package hclog
+
+import (
+	"bytes"
+	"io"
+)
+
+type writer struct {
+	b     bytes.Buffer
+	w     io.Writer
+	color ColorOption
+}
+
+func newWriter(w io.Writer, color ColorOption) *writer {
+	return &writer{w: w, color: color}
+}
+
+func (w *writer) Flush(level Level) (err error) {
+	var unwritten = w.b.Bytes()
+
+	if w.color != ColorOff {
+		color := _levelToColor[level]
+		unwritten = []byte(color.Sprintf("%s", unwritten))
+	}
+
+	if lw, ok := w.w.(LevelWriter); ok {
+		_, err = lw.LevelWrite(level, unwritten)
+	} else {
+		_, err = w.w.Write(unwritten)
+	}
+	w.b.Reset()
+	return err
+}
+
+func (w *writer) Write(p []byte) (int, error) {
+	return w.b.Write(p)
+}
+
+func (w *writer) WriteByte(c byte) error {
+	return w.b.WriteByte(c)
+}
+
+func (w *writer) WriteString(s string) (int, error) {
+	return w.b.WriteString(s)
+}
+
+// LevelWriter is the interface that wraps the LevelWrite method.
+type LevelWriter interface {
+	LevelWrite(level Level, p []byte) (n int, err error)
+}
+
+// LeveledWriter writes all log messages to the standard writer,
+// except for log levels that are defined in the overrides map.
+type LeveledWriter struct {
+	standard  io.Writer
+	overrides map[Level]io.Writer
+}
+
+// NewLeveledWriter returns an initialized LeveledWriter.
+//
+// standard will be used as the default writer for all log levels,
+// except for log levels that are defined in the overrides map.
+func NewLeveledWriter(standard io.Writer, overrides map[Level]io.Writer) *LeveledWriter {
+	return &LeveledWriter{
+		standard:  standard,
+		overrides: overrides,
+	}
+}
+
+// Write implements io.Writer.
+func (lw *LeveledWriter) Write(p []byte) (int, error) {
+	return lw.standard.Write(p)
+}
+
+// LevelWrite implements LevelWriter.
+func (lw *LeveledWriter) LevelWrite(level Level, p []byte) (int, error) {
+	w, ok := lw.overrides[level]
+	if !ok {
+		w = lw.standard
+	}
+	return w.Write(p)
+}

vendor/github.com/hashicorp/go-immutable-radix/LICENSE

@@ -0,0 +1,363 @@
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+1.1. "Contributor"
+
+     means each individual or legal entity that creates, contributes to the
+     creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+
+     means the combination of the Contributions of others (if any) used by a
+     Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+
+     means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+
+     means Source Code Form to which the initial Contributor has attached the
+     notice in Exhibit A, the Executable Form of such Source Code Form, and
+     Modifications of such Source Code Form, in each case including portions
+     thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+     means
+
+     a. that the initial Contributor has attached the notice described in
+        Exhibit B to the Covered Software; or
+
+     b. that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the terms of
+        a Secondary License.
+
+1.6. "Executable Form"
+
+     means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+
+     means a work that combines Covered Software with other material, in a
+     separate file or files, that is not Covered Software.
+
+1.8. "License"
+
+     means this document.
+
+1.9. "Licensable"
+
+     means having the right to grant, to the maximum extent possible, whether
+     at the time of the initial grant or subsequently, any and all of the
+     rights conveyed by this License.
+
+1.10. "Modifications"
+
+     means any of the following:
+
+     a. any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered Software; or
+
+     b. any new file in Source Code Form that contains any Covered Software.
+
+1.11. "Patent Claims" of a Contributor
+
+      means any patent claim(s), including without limitation, method,
+      process, and apparatus claims, in any patent Licensable by such
+      Contributor that would be infringed, but for the grant of the License,
+      by the making, using, selling, offering for sale, having made, import,
+      or transfer of either its Contributions or its Contributor Version.
+
+1.12. "Secondary License"
+
+      means either the GNU General Public License, Version 2.0, the GNU Lesser
+      General Public License, Version 2.1, the GNU Affero General Public
+      License, Version 3.0, or any later versions of those licenses.
+
+1.13. "Source Code Form"
+
+      means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+
+      means an individual or a legal entity exercising rights under this
+      License. For legal entities, "You" includes any entity that controls, is
+      controlled by, or is under common control with You. For purposes of this
+      definition, "control" means (a) the power, direct or indirect, to cause
+      the direction or management of such entity, whether by contract or
+      otherwise, or (b) ownership of more than fifty percent (50%) of the
+      outstanding shares or beneficial ownership of such entity.
+
+
+2. License Grants and Conditions
+
+2.1. Grants
+
+     Each Contributor hereby grants You a world-wide, royalty-free,
+     non-exclusive license:
+
+     a. under intellectual property rights (other than patent or trademark)
+        Licensable by such Contributor to use, reproduce, make available,
+        modify, display, perform, distribute, and otherwise exploit its
+        Contributions, either on an unmodified basis, with Modifications, or
+        as part of a Larger Work; and
+
+     b. under Patent Claims of such Contributor to make, use, sell, offer for
+        sale, have made, import, and otherwise transfer either its
+        Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+     The licenses granted in Section 2.1 with respect to any Contribution
+     become effective for each Contribution on the date the Contributor first
+     distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+     The licenses granted in this Section 2 are the only rights granted under
+     this License. No additional rights or licenses will be implied from the
+     distribution or licensing of Covered Software under this License.
+     Notwithstanding Section 2.1(b) above, no patent license is granted by a
+     Contributor:
+
+     a. for any code that a Contributor has removed from Covered Software; or
+
+     b. for infringements caused by: (i) Your and any other third party's
+        modifications of Covered Software, or (ii) the combination of its
+        Contributions with other software (except as part of its Contributor
+        Version); or
+
+     c. under Patent Claims infringed by Covered Software in the absence of
+        its Contributions.
+
+     This License does not grant any rights in the trademarks, service marks,
+     or logos of any Contributor (except as may be necessary to comply with
+     the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+     No Contributor makes additional grants as a result of Your choice to
+     distribute the Covered Software under a subsequent version of this
+     License (see Section 10.2) or under the terms of a Secondary License (if
+     permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+     Each Contributor represents that the Contributor believes its
+     Contributions are its original creation(s) or it has sufficient rights to
+     grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+     This License is not intended to limit any rights You have under
+     applicable copyright doctrines of fair use, fair dealing, or other
+     equivalents.
+
+2.7. Conditions
+
+     Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
+     Section 2.1.
+
+
+3. Responsibilities
+
+3.1. Distribution of Source Form
+
+     All distribution of Covered Software in Source Code Form, including any
+     Modifications that You create or to which You contribute, must be under
+     the terms of this License. You must inform recipients that the Source
+     Code Form of the Covered Software is governed by the terms of this
+     License, and how they can obtain a copy of this License. You may not
+     attempt to alter or restrict the recipients' rights in the Source Code
+     Form.
+
+3.2. Distribution of Executable Form
+
+     If You distribute Covered Software in Executable Form then:
+
+     a. such Covered Software must also be made available in Source Code Form,
+        as described in Section 3.1, and You must inform recipients of the
+        Executable Form how they can obtain a copy of such Source Code Form by
+        reasonable means in a timely manner, at a charge no more than the cost
+        of distribution to the recipient; and
+
+     b. You may distribute such Executable Form under the terms of this
+        License, or sublicense it under different terms, provided that the
+        license for the Executable Form does not attempt to limit or alter the
+        recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+     You may create and distribute a Larger Work under terms of Your choice,
+     provided that You also comply with the requirements of this License for
+     the Covered Software. If the Larger Work is a combination of Covered
+     Software with a work governed by one or more Secondary Licenses, and the
+     Covered Software is not Incompatible With Secondary Licenses, this
+     License permits You to additionally distribute such Covered Software
+     under the terms of such Secondary License(s), so that the recipient of
+     the Larger Work may, at their option, further distribute the Covered
+     Software under the terms of either this License or such Secondary
+     License(s).
+
+3.4. Notices
+
+     You may not remove or alter the substance of any license notices
+     (including copyright notices, patent notices, disclaimers of warranty, or
+     limitations of liability) contained within the Source Code Form of the
+     Covered Software, except that You may alter any license notices to the
+     extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+     You may choose to offer, and to charge a fee for, warranty, support,
+     indemnity or liability obligations to one or more recipients of Covered
+     Software. However, You may do so only on Your own behalf, and not on
+     behalf of any Contributor. You must make it absolutely clear that any
+     such warranty, support, indemnity, or liability obligation is offered by
+     You alone, and You hereby agree to indemnify every Contributor for any
+     liability incurred by such Contributor as a result of warranty, support,
+     indemnity or liability terms You offer. You may include additional
+     disclaimers of warranty and limitations of liability specific to any
+     jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+   If it is impossible for You to comply with any of the terms of this License
+   with respect to some or all of the Covered Software due to statute,
+   judicial order, or regulation then You must: (a) comply with the terms of
+   this License to the maximum extent possible; and (b) describe the
+   limitations and the code they affect. Such description must be placed in a
+   text file included with all distributions of the Covered Software under
+   this License. Except to the extent prohibited by statute or regulation,
+   such description must be sufficiently detailed for a recipient of ordinary
+   skill to be able to understand it.
+
+5. Termination
+
+5.1. The rights granted under this License will terminate automatically if You
+     fail to comply with any of its terms. However, if You become compliant,
+     then the rights granted under this License from a particular Contributor
+     are reinstated (a) provisionally, unless and until such Contributor
+     explicitly and finally terminates Your grants, and (b) on an ongoing
+     basis, if such Contributor fails to notify You of the non-compliance by
+     some reasonable means prior to 60 days after You have come back into
+     compliance. Moreover, Your grants from a particular Contributor are
+     reinstated on an ongoing basis if such Contributor notifies You of the
+     non-compliance by some reasonable means, this is the first time You have
+     received notice of non-compliance with this License from such
+     Contributor, and You become compliant prior to 30 days after Your receipt
+     of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+     infringement claim (excluding declaratory judgment actions,
+     counter-claims, and cross-claims) alleging that a Contributor Version
+     directly or indirectly infringes any patent, then the rights granted to
+     You by any and all Contributors for the Covered Software under Section
+     2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
+     license agreements (excluding distributors and resellers) which have been
+     validly granted by You or Your distributors under this License prior to
+     termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+   Covered Software is provided under this License on an "as is" basis,
+   without warranty of any kind, either expressed, implied, or statutory,
+   including, without limitation, warranties that the Covered Software is free
+   of defects, merchantable, fit for a particular purpose or non-infringing.
+   The entire risk as to the quality and performance of the Covered Software
+   is with You. Should any Covered Software prove defective in any respect,
+   You (not any Contributor) assume the cost of any necessary servicing,
+   repair, or correction. This disclaimer of warranty constitutes an essential
+   part of this License. No use of  any Covered Software is authorized under
+   this License except under this disclaimer.
+
+7. Limitation of Liability
+
+   Under no circumstances and under no legal theory, whether tort (including
+   negligence), contract, or otherwise, shall any Contributor, or anyone who
+   distributes Covered Software as permitted above, be liable to You for any
+   direct, indirect, special, incidental, or consequential damages of any
+   character including, without limitation, damages for lost profits, loss of
+   goodwill, work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses, even if such party shall have been
+   informed of the possibility of such damages. This limitation of liability
+   shall not apply to liability for death or personal injury resulting from
+   such party's negligence to the extent applicable law prohibits such
+   limitation. Some jurisdictions do not allow the exclusion or limitation of
+   incidental or consequential damages, so this exclusion and limitation may
+   not apply to You.
+
+8. Litigation
+
+   Any litigation relating to this License may be brought only in the courts
+   of a jurisdiction where the defendant maintains its principal place of
+   business and such litigation shall be governed by laws of that
+   jurisdiction, without reference to its conflict-of-law provisions. Nothing
+   in this Section shall prevent a party's ability to bring cross-claims or
+   counter-claims.
+
+9. Miscellaneous
+
+   This License represents the complete agreement concerning the subject
+   matter hereof. If any provision of this License is held to be
+   unenforceable, such provision shall be reformed only to the extent
+   necessary to make it enforceable. Any law or regulation which provides that
+   the language of a contract shall be construed against the drafter shall not
+   be used to construe this License against a Contributor.
+
+
+10. Versions of the License
+
+10.1. New Versions
+
+      Mozilla Foundation is the license steward. Except as provided in Section
+      10.3, no one other than the license steward has the right to modify or
+      publish new versions of this License. Each version will be given a
+      distinguishing version number.
+
+10.2. Effect of New Versions
+
+      You may distribute the Covered Software under the terms of the version
+      of the License under which You originally received the Covered Software,
+      or under the terms of any subsequent version published by the license
+      steward.
+
+10.3. Modified Versions
+
+      If you create software not governed by this License, and you want to
+      create a new license for such software, you may create and use a
+      modified version of this License if you rename the license and remove
+      any references to the name of the license steward (except to note that
+      such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+      Licenses If You choose to distribute Source Code Form that is
+      Incompatible With Secondary Licenses under the terms of this version of
+      the License, the notice described in Exhibit B of this License must be
+      attached.
+
+Exhibit A - Source Code Form License Notice
+
+      This Source Code Form is subject to the
+      terms of the Mozilla Public License, v.
+      2.0. If a copy of the MPL was not
+      distributed with this file, You can
+      obtain one at
+      http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file,
+then You may include the notice in a location (such as a LICENSE file in a
+relevant directory) where a recipient would be likely to look for such a
+notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+
+      This Source Code Form is "Incompatible
+      With Secondary Licenses", as defined by
+      the Mozilla Public License, v. 2.0.
+

vendor/github.com/hashicorp/go-immutable-radix/README.md

@@ -0,0 +1,66 @@
+go-immutable-radix [![CircleCI](https://circleci.com/gh/hashicorp/go-immutable-radix/tree/master.svg?style=svg)](https://circleci.com/gh/hashicorp/go-immutable-radix/tree/master)
+=========
+
+Provides the `iradix` package that implements an immutable [radix tree](http://en.wikipedia.org/wiki/Radix_tree).
+The package only provides a single `Tree` implementation, optimized for sparse nodes.
+
+As a radix tree, it provides the following:
+ * O(k) operations. In many cases, this can be faster than a hash table since
+   the hash function is an O(k) operation, and hash tables have very poor cache locality.
+ * Minimum / Maximum value lookups
+ * Ordered iteration
+
+A tree supports using a transaction to batch multiple updates (insert, delete)
+in a more efficient manner than performing each operation one at a time.
+
+For a mutable variant, see [go-radix](https://github.com/armon/go-radix).
+
+Documentation
+=============
+
+The full documentation is available on [Godoc](http://godoc.org/github.com/hashicorp/go-immutable-radix).
+
+Example
+=======
+
+Below is a simple example of usage
+
+```go
+// Create a tree
+r := iradix.New()
+r, _, _ = r.Insert([]byte("foo"), 1)
+r, _, _ = r.Insert([]byte("bar"), 2)
+r, _, _ = r.Insert([]byte("foobar"), 2)
+
+// Find the longest prefix match
+m, _, _ := r.Root().LongestPrefix([]byte("foozip"))
+if string(m) != "foo" {
+    panic("should be foo")
+}
+```
+
+Here is an example of performing a range scan of the keys.
+
+```go
+// Create a tree
+r := iradix.New()
+r, _, _ = r.Insert([]byte("001"), 1)
+r, _, _ = r.Insert([]byte("002"), 2)
+r, _, _ = r.Insert([]byte("005"), 5)
+r, _, _ = r.Insert([]byte("010"), 10)
+r, _, _ = r.Insert([]byte("100"), 10)
+
+// Range scan over the keys that sort lexicographically between [003, 050)
+it := r.Root().Iterator()
+it.SeekLowerBound([]byte("003"))
+for key, _, ok := it.Next(); ok; key, _, ok = it.Next() {
+  if key >= "050" {
+      break
+  }
+  fmt.Println(key)
+}
+// Output:
+//  005
+//  010
+```
+

vendor/github.com/hashicorp/go-immutable-radix/edges.go

@@ -0,0 +1,21 @@
+package iradix
+
+import "sort"
+
+type edges []edge
+
+func (e edges) Len() int {
+	return len(e)
+}
+
+func (e edges) Less(i, j int) bool {
+	return e[i].label < e[j].label
+}
+
+func (e edges) Swap(i, j int) {
+	e[i], e[j] = e[j], e[i]
+}
+
+func (e edges) Sort() {
+	sort.Sort(e)
+}

vendor/github.com/hashicorp/go-immutable-radix/iradix.go

@@ -0,0 +1,676 @@
+package iradix
+
+import (
+	"bytes"
+	"strings"
+
+	"github.com/hashicorp/golang-lru/simplelru"
+)
+
+const (
+	// defaultModifiedCache is the default size of the modified node
+	// cache used per transaction. This is used to cache the updates
+	// to the nodes near the root, while the leaves do not need to be
+	// cached. This is important for very large transactions to prevent
+	// the modified cache from growing to be enormous. This is also used
+	// to set the max size of the mutation notify maps since those should
+	// also be bounded in a similar way.
+	defaultModifiedCache = 8192
+)
+
+// Tree implements an immutable radix tree. This can be treated as a
+// Dictionary abstract data type. The main advantage over a standard
+// hash map is prefix-based lookups and ordered iteration. The immutability
+// means that it is safe to concurrently read from a Tree without any
+// coordination.
+type Tree struct {
+	root *Node
+	size int
+}
+
+// New returns an empty Tree
+func New() *Tree {
+	t := &Tree{
+		root: &Node{
+			mutateCh: make(chan struct{}),
+		},
+	}
+	return t
+}
+
+// Len is used to return the number of elements in the tree
+func (t *Tree) Len() int {
+	return t.size
+}
+
+// Txn is a transaction on the tree. This transaction is applied
+// atomically and returns a new tree when committed. A transaction
+// is not thread safe, and should only be used by a single goroutine.
+type Txn struct {
+	// root is the modified root for the transaction.
+	root *Node
+
+	// snap is a snapshot of the root node for use if we have to run the
+	// slow notify algorithm.
+	snap *Node
+
+	// size tracks the size of the tree as it is modified during the
+	// transaction.
+	size int
+
+	// writable is a cache of writable nodes that have been created during
+	// the course of the transaction. This allows us to re-use the same
+	// nodes for further writes and avoid unnecessary copies of nodes that
+	// have never been exposed outside the transaction. This will only hold
+	// up to defaultModifiedCache number of entries.
+	writable *simplelru.LRU
+
+	// trackChannels is used to hold channels that need to be notified to
+	// signal mutation of the tree. This will only hold up to
+	// defaultModifiedCache number of entries, after which we will set the
+	// trackOverflow flag, which will cause us to use a more expensive
+	// algorithm to perform the notifications. Mutation tracking is only
+	// performed if trackMutate is true.
+	trackChannels map[chan struct{}]struct{}
+	trackOverflow bool
+	trackMutate   bool
+}
+
+// Txn starts a new transaction that can be used to mutate the tree
+func (t *Tree) Txn() *Txn {
+	txn := &Txn{
+		root: t.root,
+		snap: t.root,
+		size: t.size,
+	}
+	return txn
+}
+
+// Clone makes an independent copy of the transaction. The new transaction
+// does not track any nodes and has TrackMutate turned off. The cloned transaction will contain any uncommitted writes in the original transaction but further mutations to either will be independent and result in different radix trees on Commit. A cloned transaction may be passed to another goroutine and mutated there independently however each transaction may only be mutated in a single thread.
+func (t *Txn) Clone() *Txn {
+	// reset the writable node cache to avoid leaking future writes into the clone
+	t.writable = nil
+
+	txn := &Txn{
+		root: t.root,
+		snap: t.snap,
+		size: t.size,
+	}
+	return txn
+}
+
+// TrackMutate can be used to toggle if mutations are tracked. If this is enabled
+// then notifications will be issued for affected internal nodes and leaves when
+// the transaction is committed.
+func (t *Txn) TrackMutate(track bool) {
+	t.trackMutate = track
+}
+
+// trackChannel safely attempts to track the given mutation channel, setting the
+// overflow flag if we can no longer track any more. This limits the amount of
+// state that will accumulate during a transaction and we have a slower algorithm
+// to switch to if we overflow.
+func (t *Txn) trackChannel(ch chan struct{}) {
+	// In overflow, make sure we don't store any more objects.
+	if t.trackOverflow {
+		return
+	}
+
+	// If this would overflow the state we reject it and set the flag (since
+	// we aren't tracking everything that's required any longer).
+	if len(t.trackChannels) >= defaultModifiedCache {
+		// Mark that we are in the overflow state
+		t.trackOverflow = true
+
+		// Clear the map so that the channels can be garbage collected. It is
+		// safe to do this since we have already overflowed and will be using
+		// the slow notify algorithm.
+		t.trackChannels = nil
+		return
+	}
+
+	// Create the map on the fly when we need it.
+	if t.trackChannels == nil {
+		t.trackChannels = make(map[chan struct{}]struct{})
+	}
+
+	// Otherwise we are good to track it.
+	t.trackChannels[ch] = struct{}{}
+}
+
+// writeNode returns a node to be modified, if the current node has already been
+// modified during the course of the transaction, it is used in-place. Set
+// forLeafUpdate to true if you are getting a write node to update the leaf,
+// which will set leaf mutation tracking appropriately as well.
+func (t *Txn) writeNode(n *Node, forLeafUpdate bool) *Node {
+	// Ensure the writable set exists.
+	if t.writable == nil {
+		lru, err := simplelru.NewLRU(defaultModifiedCache, nil)
+		if err != nil {
+			panic(err)
+		}
+		t.writable = lru
+	}
+
+	// If this node has already been modified, we can continue to use it
+	// during this transaction. We know that we don't need to track it for
+	// a node update since the node is writable, but if this is for a leaf
+	// update we track it, in case the initial write to this node didn't
+	// update the leaf.
+	if _, ok := t.writable.Get(n); ok {
+		if t.trackMutate && forLeafUpdate && n.leaf != nil {
+			t.trackChannel(n.leaf.mutateCh)
+		}
+		return n
+	}
+
+	// Mark this node as being mutated.
+	if t.trackMutate {
+		t.trackChannel(n.mutateCh)
+	}
+
+	// Mark its leaf as being mutated, if appropriate.
+	if t.trackMutate && forLeafUpdate && n.leaf != nil {
+		t.trackChannel(n.leaf.mutateCh)
+	}
+
+	// Copy the existing node. If you have set forLeafUpdate it will be
+	// safe to replace this leaf with another after you get your node for
+	// writing. You MUST replace it, because the channel associated with
+	// this leaf will be closed when this transaction is committed.
+	nc := &Node{
+		mutateCh: make(chan struct{}),
+		leaf:     n.leaf,
+	}
+	if n.prefix != nil {
+		nc.prefix = make([]byte, len(n.prefix))
+		copy(nc.prefix, n.prefix)
+	}
+	if len(n.edges) != 0 {
+		nc.edges = make([]edge, len(n.edges))
+		copy(nc.edges, n.edges)
+	}
+
+	// Mark this node as writable.
+	t.writable.Add(nc, nil)
+	return nc
+}
+
+// Visit all the nodes in the tree under n, and add their mutateChannels to the transaction
+// Returns the size of the subtree visited
+func (t *Txn) trackChannelsAndCount(n *Node) int {
+	// Count only leaf nodes
+	leaves := 0
+	if n.leaf != nil {
+		leaves = 1
+	}
+	// Mark this node as being mutated.
+	if t.trackMutate {
+		t.trackChannel(n.mutateCh)
+	}
+
+	// Mark its leaf as being mutated, if appropriate.
+	if t.trackMutate && n.leaf != nil {
+		t.trackChannel(n.leaf.mutateCh)
+	}
+
+	// Recurse on the children
+	for _, e := range n.edges {
+		leaves += t.trackChannelsAndCount(e.node)
+	}
+	return leaves
+}
+
+// mergeChild is called to collapse the given node with its child. This is only
+// called when the given node is not a leaf and has a single edge.
+func (t *Txn) mergeChild(n *Node) {
+	// Mark the child node as being mutated since we are about to abandon
+	// it. We don't need to mark the leaf since we are retaining it if it
+	// is there.
+	e := n.edges[0]
+	child := e.node
+	if t.trackMutate {
+		t.trackChannel(child.mutateCh)
+	}
+
+	// Merge the nodes.
+	n.prefix = concat(n.prefix, child.prefix)
+	n.leaf = child.leaf
+	if len(child.edges) != 0 {
+		n.edges = make([]edge, len(child.edges))
+		copy(n.edges, child.edges)
+	} else {
+		n.edges = nil
+	}
+}
+
+// insert does a recursive insertion
+func (t *Txn) insert(n *Node, k, search []byte, v interface{}) (*Node, interface{}, bool) {
+	// Handle key exhaustion
+	if len(search) == 0 {
+		var oldVal interface{}
+		didUpdate := false
+		if n.isLeaf() {
+			oldVal = n.leaf.val
+			didUpdate = true
+		}
+
+		nc := t.writeNode(n, true)
+		nc.leaf = &leafNode{
+			mutateCh: make(chan struct{}),
+			key:      k,
+			val:      v,
+		}
+		return nc, oldVal, didUpdate
+	}
+
+	// Look for the edge
+	idx, child := n.getEdge(search[0])
+
+	// No edge, create one
+	if child == nil {
+		e := edge{
+			label: search[0],
+			node: &Node{
+				mutateCh: make(chan struct{}),
+				leaf: &leafNode{
+					mutateCh: make(chan struct{}),
+					key:      k,
+					val:      v,
+				},
+				prefix: search,
+			},
+		}
+		nc := t.writeNode(n, false)
+		nc.addEdge(e)
+		return nc, nil, false
+	}
+
+	// Determine longest prefix of the search key on match
+	commonPrefix := longestPrefix(search, child.prefix)
+	if commonPrefix == len(child.prefix) {
+		search = search[commonPrefix:]
+		newChild, oldVal, didUpdate := t.insert(child, k, search, v)
+		if newChild != nil {
+			nc := t.writeNode(n, false)
+			nc.edges[idx].node = newChild
+			return nc, oldVal, didUpdate
+		}
+		return nil, oldVal, didUpdate
+	}
+
+	// Split the node
+	nc := t.writeNode(n, false)
+	splitNode := &Node{
+		mutateCh: make(chan struct{}),
+		prefix:   search[:commonPrefix],
+	}
+	nc.replaceEdge(edge{
+		label: search[0],
+		node:  splitNode,
+	})
+
+	// Restore the existing child node
+	modChild := t.writeNode(child, false)
+	splitNode.addEdge(edge{
+		label: modChild.prefix[commonPrefix],
+		node:  modChild,
+	})
+	modChild.prefix = modChild.prefix[commonPrefix:]
+
+	// Create a new leaf node
+	leaf := &leafNode{
+		mutateCh: make(chan struct{}),
+		key:      k,
+		val:      v,
+	}
+
+	// If the new key is a subset, add to to this node
+	search = search[commonPrefix:]
+	if len(search) == 0 {
+		splitNode.leaf = leaf
+		return nc, nil, false
+	}
+
+	// Create a new edge for the node
+	splitNode.addEdge(edge{
+		label: search[0],
+		node: &Node{
+			mutateCh: make(chan struct{}),
+			leaf:     leaf,
+			prefix:   search,
+		},
+	})
+	return nc, nil, false
+}
+
+// delete does a recursive deletion
+func (t *Txn) delete(parent, n *Node, search []byte) (*Node, *leafNode) {
+	// Check for key exhaustion
+	if len(search) == 0 {
+		if !n.isLeaf() {
+			return nil, nil
+		}
+		// Copy the pointer in case we are in a transaction that already
+		// modified this node since the node will be reused. Any changes
+		// made to the node will not affect returning the original leaf
+		// value.
+		oldLeaf := n.leaf
+
+		// Remove the leaf node
+		nc := t.writeNode(n, true)
+		nc.leaf = nil
+
+		// Check if this node should be merged
+		if n != t.root && len(nc.edges) == 1 {
+			t.mergeChild(nc)
+		}
+		return nc, oldLeaf
+	}
+
+	// Look for an edge
+	label := search[0]
+	idx, child := n.getEdge(label)
+	if child == nil || !bytes.HasPrefix(search, child.prefix) {
+		return nil, nil
+	}
+
+	// Consume the search prefix
+	search = search[len(child.prefix):]
+	newChild, leaf := t.delete(n, child, search)
+	if newChild == nil {
+		return nil, nil
+	}
+
+	// Copy this node. WATCH OUT - it's safe to pass "false" here because we
+	// will only ADD a leaf via nc.mergeChild() if there isn't one due to
+	// the !nc.isLeaf() check in the logic just below. This is pretty subtle,
+	// so be careful if you change any of the logic here.
+	nc := t.writeNode(n, false)
+
+	// Delete the edge if the node has no edges
+	if newChild.leaf == nil && len(newChild.edges) == 0 {
+		nc.delEdge(label)
+		if n != t.root && len(nc.edges) == 1 && !nc.isLeaf() {
+			t.mergeChild(nc)
+		}
+	} else {
+		nc.edges[idx].node = newChild
+	}
+	return nc, leaf
+}
+
+// delete does a recursive deletion
+func (t *Txn) deletePrefix(parent, n *Node, search []byte) (*Node, int) {
+	// Check for key exhaustion
+	if len(search) == 0 {
+		nc := t.writeNode(n, true)
+		if n.isLeaf() {
+			nc.leaf = nil
+		}
+		nc.edges = nil
+		return nc, t.trackChannelsAndCount(n)
+	}
+
+	// Look for an edge
+	label := search[0]
+	idx, child := n.getEdge(label)
+	// We make sure that either the child node's prefix starts with the search term, or the search term starts with the child node's prefix
+	// Need to do both so that we can delete prefixes that don't correspond to any node in the tree
+	if child == nil || (!bytes.HasPrefix(child.prefix, search) && !bytes.HasPrefix(search, child.prefix)) {
+		return nil, 0
+	}
+
+	// Consume the search prefix
+	if len(child.prefix) > len(search) {
+		search = []byte("")
+	} else {
+		search = search[len(child.prefix):]
+	}
+	newChild, numDeletions := t.deletePrefix(n, child, search)
+	if newChild == nil {
+		return nil, 0
+	}
+	// Copy this node. WATCH OUT - it's safe to pass "false" here because we
+	// will only ADD a leaf via nc.mergeChild() if there isn't one due to
+	// the !nc.isLeaf() check in the logic just below. This is pretty subtle,
+	// so be careful if you change any of the logic here.
+
+	nc := t.writeNode(n, false)
+
+	// Delete the edge if the node has no edges
+	if newChild.leaf == nil && len(newChild.edges) == 0 {
+		nc.delEdge(label)
+		if n != t.root && len(nc.edges) == 1 && !nc.isLeaf() {
+			t.mergeChild(nc)
+		}
+	} else {
+		nc.edges[idx].node = newChild
+	}
+	return nc, numDeletions
+}
+
+// Insert is used to add or update a given key. The return provides
+// the previous value and a bool indicating if any was set.
+func (t *Txn) Insert(k []byte, v interface{}) (interface{}, bool) {
+	newRoot, oldVal, didUpdate := t.insert(t.root, k, k, v)
+	if newRoot != nil {
+		t.root = newRoot
+	}
+	if !didUpdate {
+		t.size++
+	}
+	return oldVal, didUpdate
+}
+
+// Delete is used to delete a given key. Returns the old value if any,
+// and a bool indicating if the key was set.
+func (t *Txn) Delete(k []byte) (interface{}, bool) {
+	newRoot, leaf := t.delete(nil, t.root, k)
+	if newRoot != nil {
+		t.root = newRoot
+	}
+	if leaf != nil {
+		t.size--
+		return leaf.val, true
+	}
+	return nil, false
+}
+
+// DeletePrefix is used to delete an entire subtree that matches the prefix
+// This will delete all nodes under that prefix
+func (t *Txn) DeletePrefix(prefix []byte) bool {
+	newRoot, numDeletions := t.deletePrefix(nil, t.root, prefix)
+	if newRoot != nil {
+		t.root = newRoot
+		t.size = t.size - numDeletions
+		return true
+	}
+	return false
+
+}
+
+// Root returns the current root of the radix tree within this
+// transaction. The root is not safe across insert and delete operations,
+// but can be used to read the current state during a transaction.
+func (t *Txn) Root() *Node {
+	return t.root
+}
+
+// Get is used to lookup a specific key, returning
+// the value and if it was found
+func (t *Txn) Get(k []byte) (interface{}, bool) {
+	return t.root.Get(k)
+}
+
+// GetWatch is used to lookup a specific key, returning
+// the watch channel, value and if it was found
+func (t *Txn) GetWatch(k []byte) (<-chan struct{}, interface{}, bool) {
+	return t.root.GetWatch(k)
+}
+
+// Commit is used to finalize the transaction and return a new tree. If mutation
+// tracking is turned on then notifications will also be issued.
+func (t *Txn) Commit() *Tree {
+	nt := t.CommitOnly()
+	if t.trackMutate {
+		t.Notify()
+	}
+	return nt
+}
+
+// CommitOnly is used to finalize the transaction and return a new tree, but
+// does not issue any notifications until Notify is called.
+func (t *Txn) CommitOnly() *Tree {
+	nt := &Tree{t.root, t.size}
+	t.writable = nil
+	return nt
+}
+
+// slowNotify does a complete comparison of the before and after trees in order
+// to trigger notifications. This doesn't require any additional state but it
+// is very expensive to compute.
+func (t *Txn) slowNotify() {
+	snapIter := t.snap.rawIterator()
+	rootIter := t.root.rawIterator()
+	for snapIter.Front() != nil || rootIter.Front() != nil {
+		// If we've exhausted the nodes in the old snapshot, we know
+		// there's nothing remaining to notify.
+		if snapIter.Front() == nil {
+			return
+		}
+		snapElem := snapIter.Front()
+
+		// If we've exhausted the nodes in the new root, we know we need
+		// to invalidate everything that remains in the old snapshot. We
+		// know from the loop condition there's something in the old
+		// snapshot.
+		if rootIter.Front() == nil {
+			close(snapElem.mutateCh)
+			if snapElem.isLeaf() {
+				close(snapElem.leaf.mutateCh)
+			}
+			snapIter.Next()
+			continue
+		}
+
+		// Do one string compare so we can check the various conditions
+		// below without repeating the compare.
+		cmp := strings.Compare(snapIter.Path(), rootIter.Path())
+
+		// If the snapshot is behind the root, then we must have deleted
+		// this node during the transaction.
+		if cmp < 0 {
+			close(snapElem.mutateCh)
+			if snapElem.isLeaf() {
+				close(snapElem.leaf.mutateCh)
+			}
+			snapIter.Next()
+			continue
+		}
+
+		// If the snapshot is ahead of the root, then we must have added
+		// this node during the transaction.
+		if cmp > 0 {
+			rootIter.Next()
+			continue
+		}
+
+		// If we have the same path, then we need to see if we mutated a
+		// node and possibly the leaf.
+		rootElem := rootIter.Front()
+		if snapElem != rootElem {
+			close(snapElem.mutateCh)
+			if snapElem.leaf != nil && (snapElem.leaf != rootElem.leaf) {
+				close(snapElem.leaf.mutateCh)
+			}
+		}
+		snapIter.Next()
+		rootIter.Next()
+	}
+}
+
+// Notify is used along with TrackMutate to trigger notifications. This must
+// only be done once a transaction is committed via CommitOnly, and it is called
+// automatically by Commit.
+func (t *Txn) Notify() {
+	if !t.trackMutate {
+		return
+	}
+
+	// If we've overflowed the tracking state we can't use it in any way and
+	// need to do a full tree compare.
+	if t.trackOverflow {
+		t.slowNotify()
+	} else {
+		for ch := range t.trackChannels {
+			close(ch)
+		}
+	}
+
+	// Clean up the tracking state so that a re-notify is safe (will trigger
+	// the else clause above which will be a no-op).
+	t.trackChannels = nil
+	t.trackOverflow = false
+}
+
+// Insert is used to add or update a given key. The return provides
+// the new tree, previous value and a bool indicating if any was set.
+func (t *Tree) Insert(k []byte, v interface{}) (*Tree, interface{}, bool) {
+	txn := t.Txn()
+	old, ok := txn.Insert(k, v)
+	return txn.Commit(), old, ok
+}
+
+// Delete is used to delete a given key. Returns the new tree,
+// old value if any, and a bool indicating if the key was set.
+func (t *Tree) Delete(k []byte) (*Tree, interface{}, bool) {
+	txn := t.Txn()
+	old, ok := txn.Delete(k)
+	return txn.Commit(), old, ok
+}
+
+// DeletePrefix is used to delete all nodes starting with a given prefix. Returns the new tree,
+// and a bool indicating if the prefix matched any nodes
+func (t *Tree) DeletePrefix(k []byte) (*Tree, bool) {
+	txn := t.Txn()
+	ok := txn.DeletePrefix(k)
+	return txn.Commit(), ok
+}
+
+// Root returns the root node of the tree which can be used for richer
+// query operations.
+func (t *Tree) Root() *Node {
+	return t.root
+}
+
+// Get is used to lookup a specific key, returning
+// the value and if it was found
+func (t *Tree) Get(k []byte) (interface{}, bool) {
+	return t.root.Get(k)
+}
+
+// longestPrefix finds the length of the shared prefix
+// of two strings
+func longestPrefix(k1, k2 []byte) int {
+	max := len(k1)
+	if l := len(k2); l < max {
+		max = l
+	}
+	var i int
+	for i = 0; i < max; i++ {
+		if k1[i] != k2[i] {
+			break
+		}
+	}
+	return i
+}
+
+// concat two byte slices, returning a third new copy
+func concat(a, b []byte) []byte {
+	c := make([]byte, len(a)+len(b))
+	copy(c, a)
+	copy(c[len(a):], b)
+	return c
+}

vendor/github.com/hashicorp/go-immutable-radix/iter.go

@@ -0,0 +1,205 @@
+package iradix
+
+import (
+	"bytes"
+)
+
+// Iterator is used to iterate over a set of nodes
+// in pre-order
+type Iterator struct {
+	node  *Node
+	stack []edges
+}
+
+// SeekPrefixWatch is used to seek the iterator to a given prefix
+// and returns the watch channel of the finest granularity
+func (i *Iterator) SeekPrefixWatch(prefix []byte) (watch <-chan struct{}) {
+	// Wipe the stack
+	i.stack = nil
+	n := i.node
+	watch = n.mutateCh
+	search := prefix
+	for {
+		// Check for key exhaustion
+		if len(search) == 0 {
+			i.node = n
+			return
+		}
+
+		// Look for an edge
+		_, n = n.getEdge(search[0])
+		if n == nil {
+			i.node = nil
+			return
+		}
+
+		// Update to the finest granularity as the search makes progress
+		watch = n.mutateCh
+
+		// Consume the search prefix
+		if bytes.HasPrefix(search, n.prefix) {
+			search = search[len(n.prefix):]
+
+		} else if bytes.HasPrefix(n.prefix, search) {
+			i.node = n
+			return
+		} else {
+			i.node = nil
+			return
+		}
+	}
+}
+
+// SeekPrefix is used to seek the iterator to a given prefix
+func (i *Iterator) SeekPrefix(prefix []byte) {
+	i.SeekPrefixWatch(prefix)
+}
+
+func (i *Iterator) recurseMin(n *Node) *Node {
+	// Traverse to the minimum child
+	if n.leaf != nil {
+		return n
+	}
+	nEdges := len(n.edges)
+	if nEdges > 1 {
+		// Add all the other edges to the stack (the min node will be added as
+		// we recurse)
+		i.stack = append(i.stack, n.edges[1:])
+	}
+	if nEdges > 0 {
+		return i.recurseMin(n.edges[0].node)
+	}
+	// Shouldn't be possible
+	return nil
+}
+
+// SeekLowerBound is used to seek the iterator to the smallest key that is
+// greater or equal to the given key. There is no watch variant as it's hard to
+// predict based on the radix structure which node(s) changes might affect the
+// result.
+func (i *Iterator) SeekLowerBound(key []byte) {
+	// Wipe the stack. Unlike Prefix iteration, we need to build the stack as we
+	// go because we need only a subset of edges of many nodes in the path to the
+	// leaf with the lower bound. Note that the iterator will still recurse into
+	// children that we don't traverse on the way to the reverse lower bound as it
+	// walks the stack.
+	i.stack = []edges{}
+	// i.node starts off in the common case as pointing to the root node of the
+	// tree. By the time we return we have either found a lower bound and setup
+	// the stack to traverse all larger keys, or we have not and the stack and
+	// node should both be nil to prevent the iterator from assuming it is just
+	// iterating the whole tree from the root node. Either way this needs to end
+	// up as nil so just set it here.
+	n := i.node
+	i.node = nil
+	search := key
+
+	found := func(n *Node) {
+		i.stack = append(i.stack, edges{edge{node: n}})
+	}
+
+	findMin := func(n *Node) {
+		n = i.recurseMin(n)
+		if n != nil {
+			found(n)
+			return
+		}
+	}
+
+	for {
+		// Compare current prefix with the search key's same-length prefix.
+		var prefixCmp int
+		if len(n.prefix) < len(search) {
+			prefixCmp = bytes.Compare(n.prefix, search[0:len(n.prefix)])
+		} else {
+			prefixCmp = bytes.Compare(n.prefix, search)
+		}
+
+		if prefixCmp > 0 {
+			// Prefix is larger, that means the lower bound is greater than the search
+			// and from now on we need to follow the minimum path to the smallest
+			// leaf under this subtree.
+			findMin(n)
+			return
+		}
+
+		if prefixCmp < 0 {
+			// Prefix is smaller than search prefix, that means there is no lower
+			// bound
+			i.node = nil
+			return
+		}
+
+		// Prefix is equal, we are still heading for an exact match. If this is a
+		// leaf and an exact match we're done.
+		if n.leaf != nil && bytes.Equal(n.leaf.key, key) {
+			found(n)
+			return
+		}
+
+		// Consume the search prefix if the current node has one. Note that this is
+		// safe because if n.prefix is longer than the search slice prefixCmp would
+		// have been > 0 above and the method would have already returned.
+		search = search[len(n.prefix):]
+
+		if len(search) == 0 {
+			// We've exhausted the search key, but the current node is not an exact
+			// match or not a leaf. That means that the leaf value if it exists, and
+			// all child nodes must be strictly greater, the smallest key in this
+			// subtree must be the lower bound.
+			findMin(n)
+			return
+		}
+
+		// Otherwise, take the lower bound next edge.
+		idx, lbNode := n.getLowerBoundEdge(search[0])
+		if lbNode == nil {
+			return
+		}
+
+		// Create stack edges for the all strictly higher edges in this node.
+		if idx+1 < len(n.edges) {
+			i.stack = append(i.stack, n.edges[idx+1:])
+		}
+
+		// Recurse
+		n = lbNode
+	}
+}
+
+// Next returns the next node in order
+func (i *Iterator) Next() ([]byte, interface{}, bool) {
+	// Initialize our stack if needed
+	if i.stack == nil && i.node != nil {
+		i.stack = []edges{
+			{
+				edge{node: i.node},
+			},
+		}
+	}
+
+	for len(i.stack) > 0 {
+		// Inspect the last element of the stack
+		n := len(i.stack)
+		last := i.stack[n-1]
+		elem := last[0].node
+
+		// Update the stack
+		if len(last) > 1 {
+			i.stack[n-1] = last[1:]
+		} else {
+			i.stack = i.stack[:n-1]
+		}
+
+		// Push the edges onto the frontier
+		if len(elem.edges) > 0 {
+			i.stack = append(i.stack, elem.edges)
+		}
+
+		// Return the leaf values if any
+		if elem.leaf != nil {
+			return elem.leaf.key, elem.leaf.val, true
+		}
+	}
+	return nil, nil, false
+}

vendor/github.com/hashicorp/go-immutable-radix/node.go

@@ -0,0 +1,334 @@
+package iradix
+
+import (
+	"bytes"
+	"sort"
+)
+
+// WalkFn is used when walking the tree. Takes a
+// key and value, returning if iteration should
+// be terminated.
+type WalkFn func(k []byte, v interface{}) bool
+
+// leafNode is used to represent a value
+type leafNode struct {
+	mutateCh chan struct{}
+	key      []byte
+	val      interface{}
+}
+
+// edge is used to represent an edge node
+type edge struct {
+	label byte
+	node  *Node
+}
+
+// Node is an immutable node in the radix tree
+type Node struct {
+	// mutateCh is closed if this node is modified
+	mutateCh chan struct{}
+
+	// leaf is used to store possible leaf
+	leaf *leafNode
+
+	// prefix is the common prefix we ignore
+	prefix []byte
+
+	// Edges should be stored in-order for iteration.
+	// We avoid a fully materialized slice to save memory,
+	// since in most cases we expect to be sparse
+	edges edges
+}
+
+func (n *Node) isLeaf() bool {
+	return n.leaf != nil
+}
+
+func (n *Node) addEdge(e edge) {
+	num := len(n.edges)
+	idx := sort.Search(num, func(i int) bool {
+		return n.edges[i].label >= e.label
+	})
+	n.edges = append(n.edges, e)
+	if idx != num {
+		copy(n.edges[idx+1:], n.edges[idx:num])
+		n.edges[idx] = e
+	}
+}
+
+func (n *Node) replaceEdge(e edge) {
+	num := len(n.edges)
+	idx := sort.Search(num, func(i int) bool {
+		return n.edges[i].label >= e.label
+	})
+	if idx < num && n.edges[idx].label == e.label {
+		n.edges[idx].node = e.node
+		return
+	}
+	panic("replacing missing edge")
+}
+
+func (n *Node) getEdge(label byte) (int, *Node) {
+	num := len(n.edges)
+	idx := sort.Search(num, func(i int) bool {
+		return n.edges[i].label >= label
+	})
+	if idx < num && n.edges[idx].label == label {
+		return idx, n.edges[idx].node
+	}
+	return -1, nil
+}
+
+func (n *Node) getLowerBoundEdge(label byte) (int, *Node) {
+	num := len(n.edges)
+	idx := sort.Search(num, func(i int) bool {
+		return n.edges[i].label >= label
+	})
+	// we want lower bound behavior so return even if it's not an exact match
+	if idx < num {
+		return idx, n.edges[idx].node
+	}
+	return -1, nil
+}
+
+func (n *Node) delEdge(label byte) {
+	num := len(n.edges)
+	idx := sort.Search(num, func(i int) bool {
+		return n.edges[i].label >= label
+	})
+	if idx < num && n.edges[idx].label == label {
+		copy(n.edges[idx:], n.edges[idx+1:])
+		n.edges[len(n.edges)-1] = edge{}
+		n.edges = n.edges[:len(n.edges)-1]
+	}
+}
+
+func (n *Node) GetWatch(k []byte) (<-chan struct{}, interface{}, bool) {
+	search := k
+	watch := n.mutateCh
+	for {
+		// Check for key exhaustion
+		if len(search) == 0 {
+			if n.isLeaf() {
+				return n.leaf.mutateCh, n.leaf.val, true
+			}
+			break
+		}
+
+		// Look for an edge
+		_, n = n.getEdge(search[0])
+		if n == nil {
+			break
+		}
+
+		// Update to the finest granularity as the search makes progress
+		watch = n.mutateCh
+
+		// Consume the search prefix
+		if bytes.HasPrefix(search, n.prefix) {
+			search = search[len(n.prefix):]
+		} else {
+			break
+		}
+	}
+	return watch, nil, false
+}
+
+func (n *Node) Get(k []byte) (interface{}, bool) {
+	_, val, ok := n.GetWatch(k)
+	return val, ok
+}
+
+// LongestPrefix is like Get, but instead of an
+// exact match, it will return the longest prefix match.
+func (n *Node) LongestPrefix(k []byte) ([]byte, interface{}, bool) {
+	var last *leafNode
+	search := k
+	for {
+		// Look for a leaf node
+		if n.isLeaf() {
+			last = n.leaf
+		}
+
+		// Check for key exhaution
+		if len(search) == 0 {
+			break
+		}
+
+		// Look for an edge
+		_, n = n.getEdge(search[0])
+		if n == nil {
+			break
+		}
+
+		// Consume the search prefix
+		if bytes.HasPrefix(search, n.prefix) {
+			search = search[len(n.prefix):]
+		} else {
+			break
+		}
+	}
+	if last != nil {
+		return last.key, last.val, true
+	}
+	return nil, nil, false
+}
+
+// Minimum is used to return the minimum value in the tree
+func (n *Node) Minimum() ([]byte, interface{}, bool) {
+	for {
+		if n.isLeaf() {
+			return n.leaf.key, n.leaf.val, true
+		}
+		if len(n.edges) > 0 {
+			n = n.edges[0].node
+		} else {
+			break
+		}
+	}
+	return nil, nil, false
+}
+
+// Maximum is used to return the maximum value in the tree
+func (n *Node) Maximum() ([]byte, interface{}, bool) {
+	for {
+		if num := len(n.edges); num > 0 {
+			n = n.edges[num-1].node
+			continue
+		}
+		if n.isLeaf() {
+			return n.leaf.key, n.leaf.val, true
+		} else {
+			break
+		}
+	}
+	return nil, nil, false
+}
+
+// Iterator is used to return an iterator at
+// the given node to walk the tree
+func (n *Node) Iterator() *Iterator {
+	return &Iterator{node: n}
+}
+
+// ReverseIterator is used to return an iterator at
+// the given node to walk the tree backwards
+func (n *Node) ReverseIterator() *ReverseIterator {
+	return NewReverseIterator(n)
+}
+
+// rawIterator is used to return a raw iterator at the given node to walk the
+// tree.
+func (n *Node) rawIterator() *rawIterator {
+	iter := &rawIterator{node: n}
+	iter.Next()
+	return iter
+}
+
+// Walk is used to walk the tree
+func (n *Node) Walk(fn WalkFn) {
+	recursiveWalk(n, fn)
+}
+
+// WalkBackwards is used to walk the tree in reverse order
+func (n *Node) WalkBackwards(fn WalkFn) {
+	reverseRecursiveWalk(n, fn)
+}
+
+// WalkPrefix is used to walk the tree under a prefix
+func (n *Node) WalkPrefix(prefix []byte, fn WalkFn) {
+	search := prefix
+	for {
+		// Check for key exhaution
+		if len(search) == 0 {
+			recursiveWalk(n, fn)
+			return
+		}
+
+		// Look for an edge
+		_, n = n.getEdge(search[0])
+		if n == nil {
+			break
+		}
+
+		// Consume the search prefix
+		if bytes.HasPrefix(search, n.prefix) {
+			search = search[len(n.prefix):]
+
+		} else if bytes.HasPrefix(n.prefix, search) {
+			// Child may be under our search prefix
+			recursiveWalk(n, fn)
+			return
+		} else {
+			break
+		}
+	}
+}
+
+// WalkPath is used to walk the tree, but only visiting nodes
+// from the root down to a given leaf. Where WalkPrefix walks
+// all the entries *under* the given prefix, this walks the
+// entries *above* the given prefix.
+func (n *Node) WalkPath(path []byte, fn WalkFn) {
+	search := path
+	for {
+		// Visit the leaf values if any
+		if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
+			return
+		}
+
+		// Check for key exhaution
+		if len(search) == 0 {
+			return
+		}
+
+		// Look for an edge
+		_, n = n.getEdge(search[0])
+		if n == nil {
+			return
+		}
+
+		// Consume the search prefix
+		if bytes.HasPrefix(search, n.prefix) {
+			search = search[len(n.prefix):]
+		} else {
+			break
+		}
+	}
+}
+
+// recursiveWalk is used to do a pre-order walk of a node
+// recursively. Returns true if the walk should be aborted
+func recursiveWalk(n *Node, fn WalkFn) bool {
+	// Visit the leaf values if any
+	if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
+		return true
+	}
+
+	// Recurse on the children
+	for _, e := range n.edges {
+		if recursiveWalk(e.node, fn) {
+			return true
+		}
+	}
+	return false
+}
+
+// reverseRecursiveWalk is used to do a reverse pre-order
+// walk of a node recursively. Returns true if the walk
+// should be aborted
+func reverseRecursiveWalk(n *Node, fn WalkFn) bool {
+	// Visit the leaf values if any
+	if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
+		return true
+	}
+
+	// Recurse on the children in reverse order
+	for i := len(n.edges) - 1; i >= 0; i-- {
+		e := n.edges[i]
+		if reverseRecursiveWalk(e.node, fn) {
+			return true
+		}
+	}
+	return false
+}

vendor/github.com/hashicorp/go-immutable-radix/raw_iter.go

@@ -0,0 +1,78 @@
+package iradix
+
+// rawIterator visits each of the nodes in the tree, even the ones that are not
+// leaves. It keeps track of the effective path (what a leaf at a given node
+// would be called), which is useful for comparing trees.
+type rawIterator struct {
+	// node is the starting node in the tree for the iterator.
+	node *Node
+
+	// stack keeps track of edges in the frontier.
+	stack []rawStackEntry
+
+	// pos is the current position of the iterator.
+	pos *Node
+
+	// path is the effective path of the current iterator position,
+	// regardless of whether the current node is a leaf.
+	path string
+}
+
+// rawStackEntry is used to keep track of the cumulative common path as well as
+// its associated edges in the frontier.
+type rawStackEntry struct {
+	path  string
+	edges edges
+}
+
+// Front returns the current node that has been iterated to.
+func (i *rawIterator) Front() *Node {
+	return i.pos
+}
+
+// Path returns the effective path of the current node, even if it's not actually
+// a leaf.
+func (i *rawIterator) Path() string {
+	return i.path
+}
+
+// Next advances the iterator to the next node.
+func (i *rawIterator) Next() {
+	// Initialize our stack if needed.
+	if i.stack == nil && i.node != nil {
+		i.stack = []rawStackEntry{
+			{
+				edges: edges{
+					edge{node: i.node},
+				},
+			},
+		}
+	}
+
+	for len(i.stack) > 0 {
+		// Inspect the last element of the stack.
+		n := len(i.stack)
+		last := i.stack[n-1]
+		elem := last.edges[0].node
+
+		// Update the stack.
+		if len(last.edges) > 1 {
+			i.stack[n-1].edges = last.edges[1:]
+		} else {
+			i.stack = i.stack[:n-1]
+		}
+
+		// Push the edges onto the frontier.
+		if len(elem.edges) > 0 {
+			path := last.path + string(elem.prefix)
+			i.stack = append(i.stack, rawStackEntry{path, elem.edges})
+		}
+
+		i.pos = elem
+		i.path = last.path + string(elem.prefix)
+		return
+	}
+
+	i.pos = nil
+	i.path = ""
+}

vendor/github.com/hashicorp/go-immutable-radix/reverse_iter.go

@@ -0,0 +1,239 @@
+package iradix
+
+import (
+	"bytes"
+)
+
+// ReverseIterator is used to iterate over a set of nodes
+// in reverse in-order
+type ReverseIterator struct {
+	i *Iterator
+
+	// expandedParents stores the set of parent nodes whose relevant children have
+	// already been pushed into the stack. This can happen during seek or during
+	// iteration.
+	//
+	// Unlike forward iteration we need to recurse into children before we can
+	// output the value stored in an internal leaf since all children are greater.
+	// We use this to track whether we have already ensured all the children are
+	// in the stack.
+	expandedParents map[*Node]struct{}
+}
+
+// NewReverseIterator returns a new ReverseIterator at a node
+func NewReverseIterator(n *Node) *ReverseIterator {
+	return &ReverseIterator{
+		i: &Iterator{node: n},
+	}
+}
+
+// SeekPrefixWatch is used to seek the iterator to a given prefix
+// and returns the watch channel of the finest granularity
+func (ri *ReverseIterator) SeekPrefixWatch(prefix []byte) (watch <-chan struct{}) {
+	return ri.i.SeekPrefixWatch(prefix)
+}
+
+// SeekPrefix is used to seek the iterator to a given prefix
+func (ri *ReverseIterator) SeekPrefix(prefix []byte) {
+	ri.i.SeekPrefixWatch(prefix)
+}
+
+// SeekReverseLowerBound is used to seek the iterator to the largest key that is
+// lower or equal to the given key. There is no watch variant as it's hard to
+// predict based on the radix structure which node(s) changes might affect the
+// result.
+func (ri *ReverseIterator) SeekReverseLowerBound(key []byte) {
+	// Wipe the stack. Unlike Prefix iteration, we need to build the stack as we
+	// go because we need only a subset of edges of many nodes in the path to the
+	// leaf with the lower bound. Note that the iterator will still recurse into
+	// children that we don't traverse on the way to the reverse lower bound as it
+	// walks the stack.
+	ri.i.stack = []edges{}
+	// ri.i.node starts off in the common case as pointing to the root node of the
+	// tree. By the time we return we have either found a lower bound and setup
+	// the stack to traverse all larger keys, or we have not and the stack and
+	// node should both be nil to prevent the iterator from assuming it is just
+	// iterating the whole tree from the root node. Either way this needs to end
+	// up as nil so just set it here.
+	n := ri.i.node
+	ri.i.node = nil
+	search := key
+
+	if ri.expandedParents == nil {
+		ri.expandedParents = make(map[*Node]struct{})
+	}
+
+	found := func(n *Node) {
+		ri.i.stack = append(ri.i.stack, edges{edge{node: n}})
+		// We need to mark this node as expanded in advance too otherwise the
+		// iterator will attempt to walk all of its children even though they are
+		// greater than the lower bound we have found. We've expanded it in the
+		// sense that all of its children that we want to walk are already in the
+		// stack (i.e. none of them).
+		ri.expandedParents[n] = struct{}{}
+	}
+
+	for {
+		// Compare current prefix with the search key's same-length prefix.
+		var prefixCmp int
+		if len(n.prefix) < len(search) {
+			prefixCmp = bytes.Compare(n.prefix, search[0:len(n.prefix)])
+		} else {
+			prefixCmp = bytes.Compare(n.prefix, search)
+		}
+
+		if prefixCmp < 0 {
+			// Prefix is smaller than search prefix, that means there is no exact
+			// match for the search key. But we are looking in reverse, so the reverse
+			// lower bound will be the largest leaf under this subtree, since it is
+			// the value that would come right before the current search key if it
+			// were in the tree. So we need to follow the maximum path in this subtree
+			// to find it. Note that this is exactly what the iterator will already do
+			// if it finds a node in the stack that has _not_ been marked as expanded
+			// so in this one case we don't call `found` and instead let the iterator
+			// do the expansion and recursion through all the children.
+			ri.i.stack = append(ri.i.stack, edges{edge{node: n}})
+			return
+		}
+
+		if prefixCmp > 0 {
+			// Prefix is larger than search prefix, or there is no prefix but we've
+			// also exhausted the search key. Either way, that means there is no
+			// reverse lower bound since nothing comes before our current search
+			// prefix.
+			return
+		}
+
+		// If this is a leaf, something needs to happen! Note that if it's a leaf
+		// and prefixCmp was zero (which it must be to get here) then the leaf value
+		// is either an exact match for the search, or it's lower. It can't be
+		// greater.
+		if n.isLeaf() {
+
+			// Firstly, if it's an exact match, we're done!
+			if bytes.Equal(n.leaf.key, key) {
+				found(n)
+				return
+			}
+
+			// It's not so this node's leaf value must be lower and could still be a
+			// valid contender for reverse lower bound.
+
+			// If it has no children then we are also done.
+			if len(n.edges) == 0 {
+				// This leaf is the lower bound.
+				found(n)
+				return
+			}
+
+			// Finally, this leaf is internal (has children) so we'll keep searching,
+			// but we need to add it to the iterator's stack since it has a leaf value
+			// that needs to be iterated over. It needs to be added to the stack
+			// before its children below as it comes first.
+			ri.i.stack = append(ri.i.stack, edges{edge{node: n}})
+			// We also need to mark it as expanded since we'll be adding any of its
+			// relevant children below and so don't want the iterator to re-add them
+			// on its way back up the stack.
+			ri.expandedParents[n] = struct{}{}
+		}
+
+		// Consume the search prefix. Note that this is safe because if n.prefix is
+		// longer than the search slice prefixCmp would have been > 0 above and the
+		// method would have already returned.
+		search = search[len(n.prefix):]
+
+		if len(search) == 0 {
+			// We've exhausted the search key but we are not at a leaf. That means all
+			// children are greater than the search key so a reverse lower bound
+			// doesn't exist in this subtree. Note that there might still be one in
+			// the whole radix tree by following a different path somewhere further
+			// up. If that's the case then the iterator's stack will contain all the
+			// smaller nodes already and Previous will walk through them correctly.
+			return
+		}
+
+		// Otherwise, take the lower bound next edge.
+		idx, lbNode := n.getLowerBoundEdge(search[0])
+
+		// From here, we need to update the stack with all values lower than
+		// the lower bound edge. Since getLowerBoundEdge() returns -1 when the
+		// search prefix is larger than all edges, we need to place idx at the
+		// last edge index so they can all be place in the stack, since they
+		// come before our search prefix.
+		if idx == -1 {
+			idx = len(n.edges)
+		}
+
+		// Create stack edges for the all strictly lower edges in this node.
+		if len(n.edges[:idx]) > 0 {
+			ri.i.stack = append(ri.i.stack, n.edges[:idx])
+		}
+
+		// Exit if there's no lower bound edge. The stack will have the previous
+		// nodes already.
+		if lbNode == nil {
+			return
+		}
+
+		// Recurse
+		n = lbNode
+	}
+}
+
+// Previous returns the previous node in reverse order
+func (ri *ReverseIterator) Previous() ([]byte, interface{}, bool) {
+	// Initialize our stack if needed
+	if ri.i.stack == nil && ri.i.node != nil {
+		ri.i.stack = []edges{
+			{
+				edge{node: ri.i.node},
+			},
+		}
+	}
+
+	if ri.expandedParents == nil {
+		ri.expandedParents = make(map[*Node]struct{})
+	}
+
+	for len(ri.i.stack) > 0 {
+		// Inspect the last element of the stack
+		n := len(ri.i.stack)
+		last := ri.i.stack[n-1]
+		m := len(last)
+		elem := last[m-1].node
+
+		_, alreadyExpanded := ri.expandedParents[elem]
+
+		// If this is an internal node and we've not seen it already, we need to
+		// leave it in the stack so we can return its possible leaf value _after_
+		// we've recursed through all its children.
+		if len(elem.edges) > 0 && !alreadyExpanded {
+			// record that we've seen this node!
+			ri.expandedParents[elem] = struct{}{}
+			// push child edges onto stack and skip the rest of the loop to recurse
+			// into the largest one.
+			ri.i.stack = append(ri.i.stack, elem.edges)
+			continue
+		}
+
+		// Remove the node from the stack
+		if m > 1 {
+			ri.i.stack[n-1] = last[:m-1]
+		} else {
+			ri.i.stack = ri.i.stack[:n-1]
+		}
+		// We don't need this state any more as it's no longer in the stack so we
+		// won't visit it again
+		if alreadyExpanded {
+			delete(ri.expandedParents, elem)
+		}
+
+		// If this is a leaf, return it
+		if elem.leaf != nil {
+			return elem.leaf.key, elem.leaf.val, true
+		}
+
+		// it's not a leaf so keep walking the stack to find the previous leaf
+	}
+	return nil, nil, false
+}

vendor/github.com/hashicorp/go-metrics/LICENSE

@@ -0,0 +1,18 @@
+Copyright (c) 2013 HashiCorp, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/hashicorp/go-metrics/README.md

@@ -0,0 +1,131 @@
+go-metrics
+==========
+
+This library provides a `metrics` package which can be used to instrument code,
+expose application metrics, and profile runtime performance in a flexible manner.
+
+Current API: [![GoDoc](https://godoc.org/github.com/hashicorp/go-metrics?status.svg)](https://godoc.org/github.com/hashicorp/go-metrics)
+
+Sinks
+-----
+
+The `metrics` package makes use of a `MetricSink` interface to support delivery
+to any type of backend. Currently the following sinks are provided:
+
+* StatsiteSink : Sinks to a [statsite](https://github.com/statsite/statsite/) instance (TCP)
+* StatsdSink: Sinks to a [StatsD](https://github.com/statsd/statsd/) / statsite instance (UDP)
+* PrometheusSink: Sinks to a [Prometheus](http://prometheus.io/) metrics endpoint (exposed via HTTP for scrapes)
+* InmemSink : Provides in-memory aggregation, can be used to export stats
+* FanoutSink : Sinks to multiple sinks. Enables writing to multiple statsite instances for example.
+* BlackholeSink : Sinks to nowhere
+
+In addition to the sinks, the `InmemSignal` can be used to catch a signal,
+and dump a formatted output of recent metrics. For example, when a process gets
+a SIGUSR1, it can dump to stderr recent performance metrics for debugging.
+
+Labels
+------
+
+Most metrics do have an equivalent ending with `WithLabels`, such methods
+allow to push metrics with labels and use some features of underlying Sinks
+(ex: translated into Prometheus labels).
+
+Since some of these labels may increase the cardinality of metrics, the
+library allows filtering labels using a allow/block list filtering system
+which is global to all metrics.
+
+* If `Config.AllowedLabels` is not nil, then only labels specified in this value will be sent to underlying Sink, otherwise, all labels are sent by default.
+* If `Config.BlockedLabels` is not nil, any label specified in this value will not be sent to underlying Sinks.
+
+By default, both `Config.AllowedLabels` and `Config.BlockedLabels` are nil, meaning that
+no tags are filtered at all, but it allows a user to globally block some tags with high
+cardinality at the application level.
+
+Backwards Compatibility
+-----------------------
+v0.5.0 of the library renamed the Go module from `github.com/armon/go-metrics` to `github.com/hashicorp/go-metrics`. 
+While this did not introduce any breaking changes to the API, the change did subtly break backwards compatibility.
+
+In essence, Go treats a renamed module as entirely distinct and will happily compile both modules into the same binary.
+Due to most uses of the go-metrics library involving emitting metrics via the global metrics handler, having two global
+metrics handlers could cause a subset of metrics to be effectively lost. As an example, if your application configures
+go-metrics exporting via the `armon` namespace, then any metrics sent to go-metrics via the `hashicorp` namespaced module
+will never get exported.
+
+Eventually all usage of `armon/go-metrics` should be replaced with usage of `hashicorp/go-metrics`. However, a single
+point-in-time coordinated update across all libraries that an application may depend on isn't always feasible. To facilitate migrations, 
+a `github.com/hashicorp/go-metrics/compat` package has been introduced. This package and sub-packages are API compatible with
+`armon/go-metrics`. Libraries should be updated to use this package for emitting metrics via the global handlers. Internally,
+the package will route metrics to either `armon/go-metrics` or `hashicorp/go-metrics`. This is achieved at a global level
+within an application via the use of Go build tags.
+
+**Build Tags**
+* `armonmetrics` - Using this tag will cause metrics to be routed to `armon/go-metrics`
+* `hashicorpmetrics` - Using this tag will cause all metrics to be routed to `hashicorp/go-metrics`
+
+If no build tag is specified, the default behavior is to use `armon/go-metrics`. The overall migration path would be as follows:
+
+1. Upgrade libraries using `armon/go-metrics` to consume `hashicorp/go-metrics/compat` instead.
+2. Update library dependencies of applications that use `armon/go-metrics`. 
+   * This doesn't need to be one big atomic update but can be slower due to the default behavior remaining unaltered.
+   * At this point all metrics will still be emitted to `armon/go-metrics`
+3. Update the application to use `hashicorp/go-metrics`
+   * Replace all application imports of `github.com/armon/go-metrics` with `github.com/hashicorp/go-metrics`
+   * Libraries are unaltered at this stage.
+   * Instrument your build system to build with the `hashicorpmetrics` tag.
+
+Your migration is effectively finished and your application is now exclusively using `hashicorp/go-metrics`. A future release of the library
+will change the default behavior to use `hashicorp/go-metrics` instead of `armon/go-metrics`. At that point in time, any application that
+needs more time before performing the migration must instrument their build system to include the `armonmetrics` tag. A subsequent release
+after that will eventually remove the compatibility layer all together. The rough timeline for this will be mid-2025 for changing the default 
+behavior and then the end of 2025 for removal of the compatibility layer.
+
+
+Examples
+--------
+
+Here is an example of using the package:
+
+```go
+func SlowMethod() {
+    // Profiling the runtime of a method
+    defer metrics.MeasureSince([]string{"SlowMethod"}, time.Now())
+}
+
+// Configure a statsite sink as the global metrics sink
+sink, _ := metrics.NewStatsiteSink("statsite:8125")
+metrics.NewGlobal(metrics.DefaultConfig("service-name"), sink)
+
+// Emit a Key/Value pair
+metrics.EmitKey([]string{"questions", "meaning of life"}, 42)
+```
+
+Here is an example of setting up a signal handler:
+
+```go
+// Setup the inmem sink and signal handler
+inm := metrics.NewInmemSink(10*time.Second, time.Minute)
+sig := metrics.DefaultInmemSignal(inm)
+metrics.NewGlobal(metrics.DefaultConfig("service-name"), inm)
+
+// Run some code
+inm.SetGauge([]string{"foo"}, 42)
+inm.EmitKey([]string{"bar"}, 30)
+
+inm.IncrCounter([]string{"baz"}, 42)
+inm.IncrCounter([]string{"baz"}, 1)
+inm.IncrCounter([]string{"baz"}, 80)
+
+inm.AddSample([]string{"method", "wow"}, 42)
+inm.AddSample([]string{"method", "wow"}, 100)
+inm.AddSample([]string{"method", "wow"}, 22)
+
+....
+```
+
+When a signal comes in, output like the following will be dumped to stderr:
+
+    [2014-01-28 14:57:33.04 -0800 PST][G] 'foo': 42.000
+    [2014-01-28 14:57:33.04 -0800 PST][P] 'bar': 30.000
+    [2014-01-28 14:57:33.04 -0800 PST][C] 'baz': Count: 3 Min: 1.000 Mean: 41.000 Max: 80.000 Stddev: 39.509
+    [2014-01-28 14:57:33.04 -0800 PST][S] 'method.wow': Count: 3 Min: 22.000 Mean: 54.667 Max: 100.000 Stddev: 40.513

vendor/github.com/hashicorp/go-metrics/compat/armon.go

@@ -0,0 +1,129 @@
+//go:build armonmetrics || ignore || !hashicorpmetrics
+// +build armonmetrics ignore !hashicorpmetrics
+
+package metrics
+
+import (
+	"io"
+	"net/url"
+	"syscall"
+	"time"
+
+	"github.com/armon/go-metrics"
+)
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	DefaultSignal = metrics.DefaultSignal
+)
+
+func AddSample(key []string, val float32) {
+	metrics.AddSample(key, val)
+}
+func AddSampleWithLabels(key []string, val float32, labels []Label) {
+	metrics.AddSampleWithLabels(key, val, labels)
+}
+func EmitKey(key []string, val float32) {
+	metrics.EmitKey(key, val)
+}
+func IncrCounter(key []string, val float32) {
+	metrics.IncrCounter(key, val)
+}
+func IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	metrics.IncrCounterWithLabels(key, val, labels)
+}
+func MeasureSince(key []string, start time.Time) {
+	metrics.MeasureSince(key, start)
+}
+func MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	metrics.MeasureSinceWithLabels(key, start, labels)
+}
+func SetGauge(key []string, val float32) {
+	metrics.SetGauge(key, val)
+}
+func SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	metrics.SetGaugeWithLabels(key, val, labels)
+}
+func Shutdown() {
+	metrics.Shutdown()
+}
+func UpdateFilter(allow, block []string) {
+	metrics.UpdateFilter(allow, block)
+}
+func UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	metrics.UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels)
+}
+
+type AggregateSample = metrics.AggregateSample
+type BlackholeSink = metrics.BlackholeSink
+type Config = metrics.Config
+type Encoder = metrics.Encoder
+type FanoutSink = metrics.FanoutSink
+type GaugeValue = metrics.GaugeValue
+type InmemSignal = metrics.InmemSignal
+type InmemSink = metrics.InmemSink
+type IntervalMetrics = metrics.IntervalMetrics
+type Label = metrics.Label
+type MetricSink = metrics.MetricSink
+type Metrics = metrics.Metrics
+type MetricsSummary = metrics.MetricsSummary
+type PointValue = metrics.PointValue
+type SampledValue = metrics.SampledValue
+type ShutdownSink = metrics.ShutdownSink
+type StatsdSink = metrics.StatsdSink
+type StatsiteSink = metrics.StatsiteSink
+
+func DefaultConfig(serviceName string) *Config {
+	return metrics.DefaultConfig(serviceName)
+}
+
+func DefaultInmemSignal(inmem *InmemSink) *InmemSignal {
+	return metrics.DefaultInmemSignal(inmem)
+}
+func NewInmemSignal(inmem *InmemSink, sig syscall.Signal, w io.Writer) *InmemSignal {
+	return metrics.NewInmemSignal(inmem, sig, w)
+}
+
+func NewInmemSink(interval, retain time.Duration) *InmemSink {
+	return metrics.NewInmemSink(interval, retain)
+}
+
+func NewIntervalMetrics(intv time.Time) *IntervalMetrics {
+	return metrics.NewIntervalMetrics(intv)
+}
+
+func NewInmemSinkFromURL(u *url.URL) (MetricSink, error) {
+	return metrics.NewInmemSinkFromURL(u)
+}
+
+func NewMetricSinkFromURL(urlStr string) (MetricSink, error) {
+	return metrics.NewMetricSinkFromURL(urlStr)
+}
+
+func NewStatsdSinkFromURL(u *url.URL) (MetricSink, error) {
+	return metrics.NewStatsdSinkFromURL(u)
+}
+
+func NewStatsiteSinkFromURL(u *url.URL) (MetricSink, error) {
+	return metrics.NewStatsiteSinkFromURL(u)
+}
+
+func Default() *Metrics {
+	return metrics.Default()
+}
+
+func New(conf *Config, sink MetricSink) (*Metrics, error) {
+	return metrics.New(conf, sink)
+}
+
+func NewGlobal(conf *Config, sink MetricSink) (*Metrics, error) {
+	return metrics.NewGlobal(conf, sink)
+}
+
+func NewStatsdSink(addr string) (*StatsdSink, error) {
+	return metrics.NewStatsdSink(addr)
+}
+
+func NewStatsiteSink(addr string) (*StatsiteSink, error) {
+	return metrics.NewStatsiteSink(addr)
+}

vendor/github.com/hashicorp/go-metrics/compat/hashicorp.go

@@ -0,0 +1,129 @@
+//go:build hashicorpmetrics
+// +build hashicorpmetrics
+
+package metrics
+
+import (
+	"io"
+	"net/url"
+	"syscall"
+	"time"
+
+	"github.com/hashicorp/go-metrics"
+)
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	DefaultSignal = metrics.DefaultSignal
+)
+
+func AddSample(key []string, val float32) {
+	metrics.AddSample(key, val)
+}
+func AddSampleWithLabels(key []string, val float32, labels []Label) {
+	metrics.AddSampleWithLabels(key, val, labels)
+}
+func EmitKey(key []string, val float32) {
+	metrics.EmitKey(key, val)
+}
+func IncrCounter(key []string, val float32) {
+	metrics.IncrCounter(key, val)
+}
+func IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	metrics.IncrCounterWithLabels(key, val, labels)
+}
+func MeasureSince(key []string, start time.Time) {
+	metrics.MeasureSince(key, start)
+}
+func MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	metrics.MeasureSinceWithLabels(key, start, labels)
+}
+func SetGauge(key []string, val float32) {
+	metrics.SetGauge(key, val)
+}
+func SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	metrics.SetGaugeWithLabels(key, val, labels)
+}
+func Shutdown() {
+	metrics.Shutdown()
+}
+func UpdateFilter(allow, block []string) {
+	metrics.UpdateFilter(allow, block)
+}
+func UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	metrics.UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels)
+}
+
+type AggregateSample = metrics.AggregateSample
+type BlackholeSink = metrics.BlackholeSink
+type Config = metrics.Config
+type Encoder = metrics.Encoder
+type FanoutSink = metrics.FanoutSink
+type GaugeValue = metrics.GaugeValue
+type InmemSignal = metrics.InmemSignal
+type InmemSink = metrics.InmemSink
+type IntervalMetrics = metrics.IntervalMetrics
+type Label = metrics.Label
+type MetricSink = metrics.MetricSink
+type Metrics = metrics.Metrics
+type MetricsSummary = metrics.MetricsSummary
+type PointValue = metrics.PointValue
+type SampledValue = metrics.SampledValue
+type ShutdownSink = metrics.ShutdownSink
+type StatsdSink = metrics.StatsdSink
+type StatsiteSink = metrics.StatsiteSink
+
+func DefaultConfig(serviceName string) *Config {
+	return metrics.DefaultConfig(serviceName)
+}
+
+func DefaultInmemSignal(inmem *InmemSink) *InmemSignal {
+	return metrics.DefaultInmemSignal(inmem)
+}
+func NewInmemSignal(inmem *InmemSink, sig syscall.Signal, w io.Writer) *InmemSignal {
+	return metrics.NewInmemSignal(inmem, sig, w)
+}
+
+func NewInmemSink(interval, retain time.Duration) *InmemSink {
+	return metrics.NewInmemSink(interval, retain)
+}
+
+func NewIntervalMetrics(intv time.Time) *IntervalMetrics {
+	return metrics.NewIntervalMetrics(intv)
+}
+
+func NewInmemSinkFromURL(u *url.URL) (MetricSink, error) {
+	return metrics.NewInmemSinkFromURL(u)
+}
+
+func NewMetricSinkFromURL(urlStr string) (MetricSink, error) {
+	return metrics.NewMetricSinkFromURL(urlStr)
+}
+
+func NewStatsdSinkFromURL(u *url.URL) (MetricSink, error) {
+	return metrics.NewStatsdSinkFromURL(u)
+}
+
+func NewStatsiteSinkFromURL(u *url.URL) (MetricSink, error) {
+	return metrics.NewStatsiteSinkFromURL(u)
+}
+
+func Default() *Metrics {
+	return metrics.Default()
+}
+
+func New(conf *Config, sink MetricSink) (*Metrics, error) {
+	return metrics.New(conf, sink)
+}
+
+func NewGlobal(conf *Config, sink MetricSink) (*Metrics, error) {
+	return metrics.NewGlobal(conf, sink)
+}
+
+func NewStatsdSink(addr string) (*StatsdSink, error) {
+	return metrics.NewStatsdSink(addr)
+}
+
+func NewStatsiteSink(addr string) (*StatsiteSink, error) {
+	return metrics.NewStatsiteSink(addr)
+}

vendor/github.com/hashicorp/go-metrics/const_js.go

@@ -0,0 +1,9 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	DefaultSignal = 0x1e
+)

vendor/github.com/hashicorp/go-metrics/const_unix.go

@@ -0,0 +1,16 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+//go:build !windows && !js
+// +build !windows,!js
+
+package metrics
+
+import (
+	"syscall"
+)
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	DefaultSignal = syscall.SIGUSR1
+)

vendor/github.com/hashicorp/go-metrics/const_windows.go

@@ -0,0 +1,16 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+// +build windows
+
+package metrics
+
+import (
+	"syscall"
+)
+
+const (
+	// DefaultSignal is used with DefaultInmemSignal
+	// Windows has no SIGUSR1, use SIGBREAK
+	DefaultSignal = syscall.Signal(21)
+)

vendor/github.com/hashicorp/go-metrics/inmem.go

@@ -0,0 +1,363 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+var spaceReplacer = strings.NewReplacer(" ", "_")
+
+// InmemSink provides a MetricSink that does in-memory aggregation
+// without sending metrics over a network. It can be embedded within
+// an application to provide profiling information.
+type InmemSink struct {
+	// How long is each aggregation interval
+	interval time.Duration
+
+	// Retain controls how many metrics interval we keep
+	retain time.Duration
+
+	// maxIntervals is the maximum length of intervals.
+	// It is retain / interval.
+	maxIntervals int
+
+	// intervals is a slice of the retained intervals
+	intervals    []*IntervalMetrics
+	intervalLock sync.RWMutex
+
+	rateDenom float64
+}
+
+// IntervalMetrics stores the aggregated metrics
+// for a specific interval
+type IntervalMetrics struct {
+	sync.RWMutex
+
+	// The start time of the interval
+	Interval time.Time
+
+	// Gauges maps the key to the last set value
+	Gauges map[string]GaugeValue
+
+	// PrecisionGauges maps the key to the last set value
+	PrecisionGauges map[string]PrecisionGaugeValue
+
+	// Points maps the string to the list of emitted values
+	// from EmitKey
+	Points map[string][]float32
+
+	// Counters maps the string key to a sum of the counter
+	// values
+	Counters map[string]SampledValue
+
+	// Samples maps the key to an AggregateSample,
+	// which has the rolled up view of a sample
+	Samples map[string]SampledValue
+
+	// done is closed when this interval has ended, and a new IntervalMetrics
+	// has been created to receive any future metrics.
+	done chan struct{}
+}
+
+// NewIntervalMetrics creates a new IntervalMetrics for a given interval
+func NewIntervalMetrics(intv time.Time) *IntervalMetrics {
+	return &IntervalMetrics{
+		Interval:        intv,
+		Gauges:          make(map[string]GaugeValue),
+		PrecisionGauges: make(map[string]PrecisionGaugeValue),
+		Points:          make(map[string][]float32),
+		Counters:        make(map[string]SampledValue),
+		Samples:         make(map[string]SampledValue),
+		done:            make(chan struct{}),
+	}
+}
+
+// AggregateSample is used to hold aggregate metrics
+// about a sample
+type AggregateSample struct {
+	Count       int       // The count of emitted pairs
+	Rate        float64   // The values rate per time unit (usually 1 second)
+	Sum         float64   // The sum of values
+	SumSq       float64   `json:"-"` // The sum of squared values
+	Min         float64   // Minimum value
+	Max         float64   // Maximum value
+	LastUpdated time.Time `json:"-"` // When value was last updated
+}
+
+// Computes a Stddev of the values
+func (a *AggregateSample) Stddev() float64 {
+	num := (float64(a.Count) * a.SumSq) - math.Pow(a.Sum, 2)
+	div := float64(a.Count * (a.Count - 1))
+	if div == 0 {
+		return 0
+	}
+	return math.Sqrt(num / div)
+}
+
+// Computes a mean of the values
+func (a *AggregateSample) Mean() float64 {
+	if a.Count == 0 {
+		return 0
+	}
+	return a.Sum / float64(a.Count)
+}
+
+// Ingest is used to update a sample
+func (a *AggregateSample) Ingest(v float64, rateDenom float64) {
+	a.Count++
+	a.Sum += v
+	a.SumSq += (v * v)
+	if v < a.Min || a.Count == 1 {
+		a.Min = v
+	}
+	if v > a.Max || a.Count == 1 {
+		a.Max = v
+	}
+	a.Rate = float64(a.Sum) / rateDenom
+	a.LastUpdated = time.Now()
+}
+
+func (a *AggregateSample) String() string {
+	if a.Count == 0 {
+		return "Count: 0"
+	} else if a.Stddev() == 0 {
+		return fmt.Sprintf("Count: %d Sum: %0.3f LastUpdated: %s", a.Count, a.Sum, a.LastUpdated)
+	} else {
+		return fmt.Sprintf("Count: %d Min: %0.3f Mean: %0.3f Max: %0.3f Stddev: %0.3f Sum: %0.3f LastUpdated: %s",
+			a.Count, a.Min, a.Mean(), a.Max, a.Stddev(), a.Sum, a.LastUpdated)
+	}
+}
+
+// NewInmemSinkFromURL creates an InmemSink from a URL. It is used
+// (and tested) from NewMetricSinkFromURL.
+func NewInmemSinkFromURL(u *url.URL) (MetricSink, error) {
+	params := u.Query()
+
+	interval, err := time.ParseDuration(params.Get("interval"))
+	if err != nil {
+		return nil, fmt.Errorf("Bad 'interval' param: %s", err)
+	}
+
+	retain, err := time.ParseDuration(params.Get("retain"))
+	if err != nil {
+		return nil, fmt.Errorf("Bad 'retain' param: %s", err)
+	}
+
+	return NewInmemSink(interval, retain), nil
+}
+
+// NewInmemSink is used to construct a new in-memory sink.
+// Uses an aggregation interval and maximum retention period.
+func NewInmemSink(interval, retain time.Duration) *InmemSink {
+	rateTimeUnit := time.Second
+	i := &InmemSink{
+		interval:     interval,
+		retain:       retain,
+		maxIntervals: int(retain / interval),
+		rateDenom:    float64(interval.Nanoseconds()) / float64(rateTimeUnit.Nanoseconds()),
+	}
+	i.intervals = make([]*IntervalMetrics, 0, i.maxIntervals)
+	return i
+}
+
+func (i *InmemSink) SetGauge(key []string, val float32) {
+	i.SetGaugeWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+	intv.Gauges[k] = GaugeValue{Name: name, Value: val, Labels: labels}
+}
+
+func (i *InmemSink) SetPrecisionGauge(key []string, val float64) {
+	i.SetPrecisionGaugeWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+	intv.PrecisionGauges[k] = PrecisionGaugeValue{Name: name, Value: val, Labels: labels}
+}
+
+func (i *InmemSink) EmitKey(key []string, val float32) {
+	k := i.flattenKey(key)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+	vals := intv.Points[k]
+	intv.Points[k] = append(vals, val)
+}
+
+func (i *InmemSink) IncrCounter(key []string, val float32) {
+	i.IncrCounterWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+
+	agg, ok := intv.Counters[k]
+	if !ok {
+		agg = SampledValue{
+			Name:            name,
+			AggregateSample: &AggregateSample{},
+			Labels:          labels,
+		}
+		intv.Counters[k] = agg
+	}
+	agg.Ingest(float64(val), i.rateDenom)
+}
+
+func (i *InmemSink) AddSample(key []string, val float32) {
+	i.AddSampleWithLabels(key, val, nil)
+}
+
+func (i *InmemSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	k, name := i.flattenKeyLabels(key, labels)
+	intv := i.getInterval()
+
+	intv.Lock()
+	defer intv.Unlock()
+
+	agg, ok := intv.Samples[k]
+	if !ok {
+		agg = SampledValue{
+			Name:            name,
+			AggregateSample: &AggregateSample{},
+			Labels:          labels,
+		}
+		intv.Samples[k] = agg
+	}
+	agg.Ingest(float64(val), i.rateDenom)
+}
+
+// Data is used to retrieve all the aggregated metrics
+// Intervals may be in use, and a read lock should be acquired
+func (i *InmemSink) Data() []*IntervalMetrics {
+	// Get the current interval, forces creation
+	i.getInterval()
+
+	i.intervalLock.RLock()
+	defer i.intervalLock.RUnlock()
+
+	n := len(i.intervals)
+	intervals := make([]*IntervalMetrics, n)
+
+	copy(intervals[:n-1], i.intervals[:n-1])
+	current := i.intervals[n-1]
+
+	// make its own copy for current interval
+	intervals[n-1] = &IntervalMetrics{}
+	copyCurrent := intervals[n-1]
+	current.RLock()
+	*copyCurrent = *current
+	// RWMutex is not safe to copy, so create a new instance on the copy
+	copyCurrent.RWMutex = sync.RWMutex{}
+
+	copyCurrent.Gauges = make(map[string]GaugeValue, len(current.Gauges))
+	for k, v := range current.Gauges {
+		copyCurrent.Gauges[k] = v
+	}
+	copyCurrent.PrecisionGauges = make(map[string]PrecisionGaugeValue, len(current.PrecisionGauges))
+	for k, v := range current.PrecisionGauges {
+		copyCurrent.PrecisionGauges[k] = v
+	}
+	// saved values will be not change, just copy its link
+	copyCurrent.Points = make(map[string][]float32, len(current.Points))
+	for k, v := range current.Points {
+		copyCurrent.Points[k] = v
+	}
+	copyCurrent.Counters = make(map[string]SampledValue, len(current.Counters))
+	for k, v := range current.Counters {
+		copyCurrent.Counters[k] = v.deepCopy()
+	}
+	copyCurrent.Samples = make(map[string]SampledValue, len(current.Samples))
+	for k, v := range current.Samples {
+		copyCurrent.Samples[k] = v.deepCopy()
+	}
+	current.RUnlock()
+
+	return intervals
+}
+
+// getInterval returns the current interval. A new interval is created if no
+// previous interval exists, or if the current time is beyond the window for the
+// current interval.
+func (i *InmemSink) getInterval() *IntervalMetrics {
+	intv := time.Now().Truncate(i.interval)
+
+	// Attempt to return the existing interval first, because it only requires
+	// a read lock.
+	i.intervalLock.RLock()
+	n := len(i.intervals)
+	if n > 0 && i.intervals[n-1].Interval == intv {
+		defer i.intervalLock.RUnlock()
+		return i.intervals[n-1]
+	}
+	i.intervalLock.RUnlock()
+
+	i.intervalLock.Lock()
+	defer i.intervalLock.Unlock()
+
+	// Re-check for an existing interval now that the lock is re-acquired.
+	n = len(i.intervals)
+	if n > 0 && i.intervals[n-1].Interval == intv {
+		return i.intervals[n-1]
+	}
+
+	current := NewIntervalMetrics(intv)
+	i.intervals = append(i.intervals, current)
+	if n > 0 {
+		close(i.intervals[n-1].done)
+	}
+
+	n++
+	// Prune old intervals if the count exceeds the max.
+	if n >= i.maxIntervals {
+		copy(i.intervals[0:], i.intervals[n-i.maxIntervals:])
+		i.intervals = i.intervals[:i.maxIntervals]
+	}
+	return current
+}
+
+// Flattens the key for formatting, removes spaces
+func (i *InmemSink) flattenKey(parts []string) string {
+	buf := &bytes.Buffer{}
+
+	joined := strings.Join(parts, ".")
+
+	spaceReplacer.WriteString(buf, joined)
+
+	return buf.String()
+}
+
+// Flattens the key for formatting along with its labels, removes spaces
+func (i *InmemSink) flattenKeyLabels(parts []string, labels []Label) (string, string) {
+	key := i.flattenKey(parts)
+	buf := bytes.NewBufferString(key)
+
+	for _, label := range labels {
+		spaceReplacer.WriteString(buf, fmt.Sprintf(";%s=%s", label.Name, label.Value))
+	}
+
+	return buf.String(), key
+}

vendor/github.com/hashicorp/go-metrics/inmem_endpoint.go

@@ -0,0 +1,190 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"sort"
+	"time"
+)
+
+// MetricsSummary holds a roll-up of metrics info for a given interval
+type MetricsSummary struct {
+	Timestamp       string
+	Gauges          []GaugeValue
+	PrecisionGauges []PrecisionGaugeValue
+	Points          []PointValue
+	Counters        []SampledValue
+	Samples         []SampledValue
+}
+
+type GaugeValue struct {
+	Name  string
+	Hash  string `json:"-"`
+	Value float32
+
+	Labels        []Label           `json:"-"`
+	DisplayLabels map[string]string `json:"Labels"`
+}
+
+type PrecisionGaugeValue struct {
+	Name  string
+	Hash  string `json:"-"`
+	Value float64
+
+	Labels        []Label           `json:"-"`
+	DisplayLabels map[string]string `json:"Labels"`
+}
+
+type PointValue struct {
+	Name   string
+	Points []float32
+}
+
+type SampledValue struct {
+	Name string
+	Hash string `json:"-"`
+	*AggregateSample
+	Mean   float64
+	Stddev float64
+
+	Labels        []Label           `json:"-"`
+	DisplayLabels map[string]string `json:"Labels"`
+}
+
+// deepCopy allocates a new instance of AggregateSample
+func (source *SampledValue) deepCopy() SampledValue {
+	dest := *source
+	if source.AggregateSample != nil {
+		dest.AggregateSample = &AggregateSample{}
+		*dest.AggregateSample = *source.AggregateSample
+	}
+	return dest
+}
+
+// DisplayMetrics returns a summary of the metrics from the most recent finished interval.
+func (i *InmemSink) DisplayMetrics(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	data := i.Data()
+
+	var interval *IntervalMetrics
+	n := len(data)
+	switch {
+	case n == 0:
+		return nil, fmt.Errorf("no metric intervals have been initialized yet")
+	case n == 1:
+		// Show the current interval if it's all we have
+		interval = data[0]
+	default:
+		// Show the most recent finished interval if we have one
+		interval = data[n-2]
+	}
+
+	return newMetricSummaryFromInterval(interval), nil
+}
+
+func newMetricSummaryFromInterval(interval *IntervalMetrics) MetricsSummary {
+	interval.RLock()
+	defer interval.RUnlock()
+
+	summary := MetricsSummary{
+		Timestamp:       interval.Interval.Round(time.Second).UTC().String(),
+		Gauges:          make([]GaugeValue, 0, len(interval.Gauges)),
+		PrecisionGauges: make([]PrecisionGaugeValue, 0, len(interval.PrecisionGauges)),
+		Points:          make([]PointValue, 0, len(interval.Points)),
+	}
+
+	// Format and sort the output of each metric type, so it gets displayed in a
+	// deterministic order.
+	for name, points := range interval.Points {
+		summary.Points = append(summary.Points, PointValue{name, points})
+	}
+	sort.Slice(summary.Points, func(i, j int) bool {
+		return summary.Points[i].Name < summary.Points[j].Name
+	})
+
+	for hash, value := range interval.Gauges {
+		value.Hash = hash
+		value.DisplayLabels = make(map[string]string)
+		for _, label := range value.Labels {
+			value.DisplayLabels[label.Name] = label.Value
+		}
+		value.Labels = nil
+
+		summary.Gauges = append(summary.Gauges, value)
+	}
+	sort.Slice(summary.Gauges, func(i, j int) bool {
+		return summary.Gauges[i].Hash < summary.Gauges[j].Hash
+	})
+
+	for hash, value := range interval.PrecisionGauges {
+		value.Hash = hash
+		value.DisplayLabels = make(map[string]string)
+		for _, label := range value.Labels {
+			value.DisplayLabels[label.Name] = label.Value
+		}
+		value.Labels = nil
+
+		summary.PrecisionGauges = append(summary.PrecisionGauges, value)
+	}
+	sort.Slice(summary.PrecisionGauges, func(i, j int) bool {
+		return summary.PrecisionGauges[i].Hash < summary.PrecisionGauges[j].Hash
+	})
+
+	summary.Counters = formatSamples(interval.Counters)
+	summary.Samples = formatSamples(interval.Samples)
+
+	return summary
+}
+
+func formatSamples(source map[string]SampledValue) []SampledValue {
+	output := make([]SampledValue, 0, len(source))
+	for hash, sample := range source {
+		displayLabels := make(map[string]string)
+		for _, label := range sample.Labels {
+			displayLabels[label.Name] = label.Value
+		}
+
+		output = append(output, SampledValue{
+			Name:            sample.Name,
+			Hash:            hash,
+			AggregateSample: sample.AggregateSample,
+			Mean:            sample.AggregateSample.Mean(),
+			Stddev:          sample.AggregateSample.Stddev(),
+			DisplayLabels:   displayLabels,
+		})
+	}
+	sort.Slice(output, func(i, j int) bool {
+		return output[i].Hash < output[j].Hash
+	})
+
+	return output
+}
+
+type Encoder interface {
+	Encode(interface{}) error
+}
+
+// Stream writes metrics using encoder.Encode each time an interval ends. Runs
+// until the request context is cancelled, or the encoder returns an error.
+// The caller is responsible for logging any errors from encoder.
+func (i *InmemSink) Stream(ctx context.Context, encoder Encoder) {
+	interval := i.getInterval()
+
+	for {
+		select {
+		case <-interval.done:
+			summary := newMetricSummaryFromInterval(interval)
+			if err := encoder.Encode(summary); err != nil {
+				return
+			}
+
+			// update interval to the next one
+			interval = i.getInterval()
+		case <-ctx.Done():
+			return
+		}
+	}
+}

vendor/github.com/hashicorp/go-metrics/inmem_signal.go

@@ -0,0 +1,124 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"os/signal"
+	"strings"
+	"sync"
+	"syscall"
+)
+
+// InmemSignal is used to listen for a given signal, and when received,
+// to dump the current metrics from the InmemSink to an io.Writer
+type InmemSignal struct {
+	signal syscall.Signal
+	inm    *InmemSink
+	w      io.Writer
+	sigCh  chan os.Signal
+
+	stop     bool
+	stopCh   chan struct{}
+	stopLock sync.Mutex
+}
+
+// NewInmemSignal creates a new InmemSignal which listens for a given signal,
+// and dumps the current metrics out to a writer
+func NewInmemSignal(inmem *InmemSink, sig syscall.Signal, w io.Writer) *InmemSignal {
+	i := &InmemSignal{
+		signal: sig,
+		inm:    inmem,
+		w:      w,
+		sigCh:  make(chan os.Signal, 1),
+		stopCh: make(chan struct{}),
+	}
+	signal.Notify(i.sigCh, sig)
+	go i.run()
+	return i
+}
+
+// DefaultInmemSignal returns a new InmemSignal that responds to SIGUSR1
+// and writes output to stderr. Windows uses SIGBREAK
+func DefaultInmemSignal(inmem *InmemSink) *InmemSignal {
+	return NewInmemSignal(inmem, DefaultSignal, os.Stderr)
+}
+
+// Stop is used to stop the InmemSignal from listening
+func (i *InmemSignal) Stop() {
+	i.stopLock.Lock()
+	defer i.stopLock.Unlock()
+
+	if i.stop {
+		return
+	}
+	i.stop = true
+	close(i.stopCh)
+	signal.Stop(i.sigCh)
+}
+
+// run is a long running routine that handles signals
+func (i *InmemSignal) run() {
+	for {
+		select {
+		case <-i.sigCh:
+			i.dumpStats()
+		case <-i.stopCh:
+			return
+		}
+	}
+}
+
+// dumpStats is used to dump the data to output writer
+func (i *InmemSignal) dumpStats() {
+	buf := bytes.NewBuffer(nil)
+
+	data := i.inm.Data()
+	// Skip the last period which is still being aggregated
+	for j := 0; j < len(data)-1; j++ {
+		intv := data[j]
+		intv.RLock()
+		for _, val := range intv.Gauges {
+			name := i.flattenLabels(val.Name, val.Labels)
+			fmt.Fprintf(buf, "[%v][G] '%s': %0.3f\n", intv.Interval, name, val.Value)
+		}
+		for _, val := range intv.PrecisionGauges {
+			name := i.flattenLabels(val.Name, val.Labels)
+			fmt.Fprintf(buf, "[%v][G] '%s': %0.3f\n", intv.Interval, name, val.Value)
+		}
+		for name, vals := range intv.Points {
+			for _, val := range vals {
+				fmt.Fprintf(buf, "[%v][P] '%s': %0.3f\n", intv.Interval, name, val)
+			}
+		}
+		for _, agg := range intv.Counters {
+			name := i.flattenLabels(agg.Name, agg.Labels)
+			fmt.Fprintf(buf, "[%v][C] '%s': %s\n", intv.Interval, name, agg.AggregateSample)
+		}
+		for _, agg := range intv.Samples {
+			name := i.flattenLabels(agg.Name, agg.Labels)
+			fmt.Fprintf(buf, "[%v][S] '%s': %s\n", intv.Interval, name, agg.AggregateSample)
+		}
+		intv.RUnlock()
+	}
+
+	// Write out the bytes
+	i.w.Write(buf.Bytes())
+}
+
+// Flattens the key for formatting along with its labels, removes spaces
+func (i *InmemSignal) flattenLabels(name string, labels []Label) string {
+	buf := bytes.NewBufferString(name)
+	replacer := strings.NewReplacer(" ", "_", ":", "_")
+
+	for _, label := range labels {
+		replacer.WriteString(buf, ".")
+		replacer.WriteString(buf, label.Value)
+	}
+
+	return buf.String()
+}

vendor/github.com/hashicorp/go-metrics/metrics.go

@@ -0,0 +1,336 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"runtime"
+	"strings"
+	"time"
+
+	iradix "github.com/hashicorp/go-immutable-radix"
+)
+
+type Label struct {
+	Name  string
+	Value string
+}
+
+func (m *Metrics) SetGauge(key []string, val float32) {
+	m.SetGaugeWithLabels(key, val, nil)
+}
+
+func (m *Metrics) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" {
+		if m.EnableHostnameLabel {
+			labels = append(labels, Label{"host", m.HostName})
+		} else if m.EnableHostname {
+			key = insert(0, m.HostName, key)
+		}
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "gauge", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.SetGaugeWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) SetPrecisionGauge(key []string, val float64) {
+	m.SetPrecisionGaugeWithLabels(key, val, nil)
+}
+
+func (m *Metrics) SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {
+	if m.HostName != "" {
+		if m.EnableHostnameLabel {
+			labels = append(labels, Label{"host", m.HostName})
+		} else if m.EnableHostname {
+			key = insert(0, m.HostName, key)
+		}
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "gauge", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	sink, ok := m.sink.(PrecisionGaugeMetricSink)
+	if !ok {
+		// Sink does not implement PrecisionGaugeMetricSink.
+	} else {
+		sink.SetPrecisionGaugeWithLabels(key, val, labelsFiltered)
+	}
+}
+
+func (m *Metrics) EmitKey(key []string, val float32) {
+	if m.EnableTypePrefix {
+		key = insert(0, "kv", key)
+	}
+	if m.ServiceName != "" {
+		key = insert(0, m.ServiceName, key)
+	}
+	allowed, _ := m.allowMetric(key, nil)
+	if !allowed {
+		return
+	}
+	m.sink.EmitKey(key, val)
+}
+
+func (m *Metrics) IncrCounter(key []string, val float32) {
+	m.IncrCounterWithLabels(key, val, nil)
+}
+
+func (m *Metrics) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "counter", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.IncrCounterWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) AddSample(key []string, val float32) {
+	m.AddSampleWithLabels(key, val, nil)
+}
+
+func (m *Metrics) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "sample", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.AddSampleWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) MeasureSince(key []string, start time.Time) {
+	m.MeasureSinceWithLabels(key, start, nil)
+}
+
+func (m *Metrics) MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "timer", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	now := time.Now()
+	elapsed := now.Sub(start)
+	msec := float32(elapsed.Nanoseconds()) / float32(m.TimerGranularity)
+	m.sink.AddSampleWithLabels(key, msec, labelsFiltered)
+}
+
+// UpdateFilter overwrites the existing filter with the given rules.
+func (m *Metrics) UpdateFilter(allow, block []string) {
+	m.UpdateFilterAndLabels(allow, block, m.AllowedLabels, m.BlockedLabels)
+}
+
+// UpdateFilterAndLabels overwrites the existing filter with the given rules.
+func (m *Metrics) UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	m.filterLock.Lock()
+	defer m.filterLock.Unlock()
+
+	m.AllowedPrefixes = allow
+	m.BlockedPrefixes = block
+
+	if allowedLabels == nil {
+		// Having a white list means we take only elements from it
+		m.allowedLabels = nil
+	} else {
+		m.allowedLabels = make(map[string]bool)
+		for _, v := range allowedLabels {
+			m.allowedLabels[v] = true
+		}
+	}
+	m.blockedLabels = make(map[string]bool)
+	for _, v := range blockedLabels {
+		m.blockedLabels[v] = true
+	}
+	m.AllowedLabels = allowedLabels
+	m.BlockedLabels = blockedLabels
+
+	m.filter = iradix.New()
+	for _, prefix := range m.AllowedPrefixes {
+		m.filter, _, _ = m.filter.Insert([]byte(prefix), true)
+	}
+	for _, prefix := range m.BlockedPrefixes {
+		m.filter, _, _ = m.filter.Insert([]byte(prefix), false)
+	}
+}
+
+func (m *Metrics) Shutdown() {
+	if ss, ok := m.sink.(ShutdownSink); ok {
+		ss.Shutdown()
+	}
+}
+
+// labelIsAllowed return true if a should be included in metric
+// the caller should lock m.filterLock while calling this method
+func (m *Metrics) labelIsAllowed(label *Label) bool {
+	labelName := (*label).Name
+	if m.blockedLabels != nil {
+		_, ok := m.blockedLabels[labelName]
+		if ok {
+			// If present, let's remove this label
+			return false
+		}
+	}
+	if m.allowedLabels != nil {
+		_, ok := m.allowedLabels[labelName]
+		return ok
+	}
+	// Allow by default
+	return true
+}
+
+// filterLabels return only allowed labels
+// the caller should lock m.filterLock while calling this method
+func (m *Metrics) filterLabels(labels []Label) []Label {
+	if labels == nil {
+		return nil
+	}
+	toReturn := []Label{}
+	for _, label := range labels {
+		if m.labelIsAllowed(&label) {
+			toReturn = append(toReturn, label)
+		}
+	}
+	return toReturn
+}
+
+// Returns whether the metric should be allowed based on configured prefix filters
+// Also return the applicable labels
+func (m *Metrics) allowMetric(key []string, labels []Label) (bool, []Label) {
+	m.filterLock.RLock()
+	defer m.filterLock.RUnlock()
+
+	if m.filter == nil || m.filter.Len() == 0 {
+		return m.Config.FilterDefault, m.filterLabels(labels)
+	}
+
+	_, allowed, ok := m.filter.Root().LongestPrefix([]byte(strings.Join(key, ".")))
+	if !ok {
+		return m.Config.FilterDefault, m.filterLabels(labels)
+	}
+
+	return allowed.(bool), m.filterLabels(labels)
+}
+
+// Periodically collects runtime stats to publish
+func (m *Metrics) collectStats() {
+	for {
+		time.Sleep(m.ProfileInterval)
+		m.EmitRuntimeStats()
+	}
+}
+
+// Emits various runtime statsitics
+func (m *Metrics) EmitRuntimeStats() {
+	// Export number of Goroutines
+	numRoutines := runtime.NumGoroutine()
+	m.SetGauge([]string{"runtime", "num_goroutines"}, float32(numRoutines))
+
+	// Export memory stats
+	var stats runtime.MemStats
+	runtime.ReadMemStats(&stats)
+	m.SetGauge([]string{"runtime", "alloc_bytes"}, float32(stats.Alloc))
+	m.SetGauge([]string{"runtime", "sys_bytes"}, float32(stats.Sys))
+	m.SetGauge([]string{"runtime", "malloc_count"}, float32(stats.Mallocs))
+	m.SetGauge([]string{"runtime", "free_count"}, float32(stats.Frees))
+	m.SetGauge([]string{"runtime", "heap_objects"}, float32(stats.HeapObjects))
+	m.SetGauge([]string{"runtime", "total_gc_pause_ns"}, float32(stats.PauseTotalNs))
+	m.SetGauge([]string{"runtime", "total_gc_runs"}, float32(stats.NumGC))
+
+	// Export info about the last few GC runs
+	num := stats.NumGC
+
+	// Handle wrap around
+	if num < m.lastNumGC {
+		m.lastNumGC = 0
+	}
+
+	// Ensure we don't scan more than 256
+	if num-m.lastNumGC >= 256 {
+		m.lastNumGC = num - 255
+	}
+
+	for i := m.lastNumGC; i < num; i++ {
+		pause := stats.PauseNs[i%256]
+		m.AddSample([]string{"runtime", "gc_pause_ns"}, float32(pause))
+	}
+	m.lastNumGC = num
+}
+
+// Creates a new slice with the provided string value as the first element
+// and the provided slice values as the remaining values.
+// Ordering of the values in the provided input slice is kept in tact in the output slice.
+func insert(i int, v string, s []string) []string {
+	// Allocate new slice to avoid modifying the input slice
+	newS := make([]string, len(s)+1)
+
+	// Copy s[0, i-1] into newS
+	for j := 0; j < i; j++ {
+		newS[j] = s[j]
+	}
+
+	// Insert provided element at index i
+	newS[i] = v
+
+	// Copy s[i, len(s)-1] into newS starting at newS[i+1]
+	for j := i; j < len(s); j++ {
+		newS[j+1] = s[j]
+	}
+
+	return newS
+}

vendor/github.com/hashicorp/go-metrics/sink.go

@@ -0,0 +1,156 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"fmt"
+	"net/url"
+)
+
+// The MetricSink interface is used to transmit metrics information
+// to an external system
+type MetricSink interface {
+	// A Gauge should retain the last value it is set to
+	SetGauge(key []string, val float32)
+	SetGaugeWithLabels(key []string, val float32, labels []Label)
+
+	// Should emit a Key/Value pair for each call
+	EmitKey(key []string, val float32)
+
+	// Counters should accumulate values
+	IncrCounter(key []string, val float32)
+	IncrCounterWithLabels(key []string, val float32, labels []Label)
+
+	// Samples are for timing information, where quantiles are used
+	AddSample(key []string, val float32)
+	AddSampleWithLabels(key []string, val float32, labels []Label)
+}
+
+// PrecisionGaugeMetricSink interfae is used to support 64 bit precisions for Sinks, if needed.
+type PrecisionGaugeMetricSink interface {
+	SetPrecisionGauge(key []string, val float64)
+	SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label)
+}
+
+type ShutdownSink interface {
+	MetricSink
+
+	// Shutdown the metric sink, flush metrics to storage, and cleanup resources.
+	// Called immediately prior to application exit. Implementations must block
+	// until metrics are flushed to storage.
+	Shutdown()
+}
+
+// BlackholeSink is used to just blackhole messages
+type BlackholeSink struct{}
+
+func (*BlackholeSink) SetGauge(key []string, val float32)                                    {}
+func (*BlackholeSink) SetGaugeWithLabels(key []string, val float32, labels []Label)          {}
+func (*BlackholeSink) SetPrecisionGauge(key []string, val float64)                           {}
+func (*BlackholeSink) SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {}
+func (*BlackholeSink) EmitKey(key []string, val float32)                                     {}
+func (*BlackholeSink) IncrCounter(key []string, val float32)                                 {}
+func (*BlackholeSink) IncrCounterWithLabels(key []string, val float32, labels []Label)       {}
+func (*BlackholeSink) AddSample(key []string, val float32)                                   {}
+func (*BlackholeSink) AddSampleWithLabels(key []string, val float32, labels []Label)         {}
+
+// FanoutSink is used to sink to fanout values to multiple sinks
+type FanoutSink []MetricSink
+
+func (fh FanoutSink) SetGauge(key []string, val float32) {
+	fh.SetGaugeWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	for _, s := range fh {
+		s.SetGaugeWithLabels(key, val, labels)
+	}
+}
+
+func (fh FanoutSink) SetPrecisionGauge(key []string, val float64) {
+	fh.SetPrecisionGaugeWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {
+	for _, s := range fh {
+		// The Sink needs to implement PrecisionGaugeMetricSink, in case it doesn't, the metric value won't be set and ingored instead
+		if s64, ok := s.(PrecisionGaugeMetricSink); ok {
+			s64.SetPrecisionGaugeWithLabels(key, val, labels)
+		}
+	}
+}
+
+func (fh FanoutSink) EmitKey(key []string, val float32) {
+	for _, s := range fh {
+		s.EmitKey(key, val)
+	}
+}
+
+func (fh FanoutSink) IncrCounter(key []string, val float32) {
+	fh.IncrCounterWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	for _, s := range fh {
+		s.IncrCounterWithLabels(key, val, labels)
+	}
+}
+
+func (fh FanoutSink) AddSample(key []string, val float32) {
+	fh.AddSampleWithLabels(key, val, nil)
+}
+
+func (fh FanoutSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	for _, s := range fh {
+		s.AddSampleWithLabels(key, val, labels)
+	}
+}
+
+func (fh FanoutSink) Shutdown() {
+	for _, s := range fh {
+		if ss, ok := s.(ShutdownSink); ok {
+			ss.Shutdown()
+		}
+	}
+}
+
+// sinkURLFactoryFunc is an generic interface around the *SinkFromURL() function provided
+// by each sink type
+type sinkURLFactoryFunc func(*url.URL) (MetricSink, error)
+
+// sinkRegistry supports the generic NewMetricSink function by mapping URL
+// schemes to metric sink factory functions
+var sinkRegistry = map[string]sinkURLFactoryFunc{
+	"statsd":   NewStatsdSinkFromURL,
+	"statsite": NewStatsiteSinkFromURL,
+	"inmem":    NewInmemSinkFromURL,
+}
+
+// NewMetricSinkFromURL allows a generic URL input to configure any of the
+// supported sinks. The scheme of the URL identifies the type of the sink, the
+// and query parameters are used to set options.
+//
+// "statsd://" - Initializes a StatsdSink. The host and port are passed through
+// as the "addr" of the sink
+//
+// "statsite://" - Initializes a StatsiteSink. The host and port become the
+// "addr" of the sink
+//
+// "inmem://" - Initializes an InmemSink. The host and port are ignored. The
+// "interval" and "duration" query parameters must be specified with valid
+// durations, see NewInmemSink for details.
+func NewMetricSinkFromURL(urlStr string) (MetricSink, error) {
+	u, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, err
+	}
+
+	sinkURLFactoryFunc := sinkRegistry[u.Scheme]
+	if sinkURLFactoryFunc == nil {
+		return nil, fmt.Errorf(
+			"cannot create metric sink, unrecognized sink name: %q", u.Scheme)
+	}
+
+	return sinkURLFactoryFunc(u)
+}

vendor/github.com/hashicorp/go-metrics/start.go

@@ -0,0 +1,176 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	iradix "github.com/hashicorp/go-immutable-radix"
+)
+
+// Config is used to configure metrics settings
+type Config struct {
+	ServiceName          string        // Prefixed with keys to separate services
+	HostName             string        // Hostname to use. If not provided and EnableHostname, it will be os.Hostname
+	EnableHostname       bool          // Enable prefixing gauge values with hostname
+	EnableHostnameLabel  bool          // Enable adding hostname to labels
+	EnableServiceLabel   bool          // Enable adding service to labels
+	EnableRuntimeMetrics bool          // Enables profiling of runtime metrics (GC, Goroutines, Memory)
+	EnableTypePrefix     bool          // Prefixes key with a type ("counter", "gauge", "timer")
+	TimerGranularity     time.Duration // Granularity of timers.
+	ProfileInterval      time.Duration // Interval to profile runtime metrics
+
+	AllowedPrefixes []string // A list of metric prefixes to allow, with '.' as the separator
+	BlockedPrefixes []string // A list of metric prefixes to block, with '.' as the separator
+	AllowedLabels   []string // A list of metric labels to allow, with '.' as the separator
+	BlockedLabels   []string // A list of metric labels to block, with '.' as the separator
+	FilterDefault   bool     // Whether to allow metrics by default
+}
+
+// Metrics represents an instance of a metrics sink that can
+// be used to emit
+type Metrics struct {
+	Config
+	lastNumGC     uint32
+	sink          MetricSink
+	filter        *iradix.Tree
+	allowedLabels map[string]bool
+	blockedLabels map[string]bool
+	filterLock    sync.RWMutex // Lock filters and allowedLabels/blockedLabels access
+}
+
+// Shared global metrics instance
+var globalMetrics atomic.Value // *Metrics
+
+func init() {
+	// Initialize to a blackhole sink to avoid errors
+	globalMetrics.Store(&Metrics{sink: &BlackholeSink{}})
+}
+
+// Default returns the shared global metrics instance.
+func Default() *Metrics {
+	return globalMetrics.Load().(*Metrics)
+}
+
+// DefaultConfig provides a sane default configuration
+func DefaultConfig(serviceName string) *Config {
+	c := &Config{
+		ServiceName:          serviceName, // Use client provided service
+		HostName:             "",
+		EnableHostname:       true,             // Enable hostname prefix
+		EnableRuntimeMetrics: true,             // Enable runtime profiling
+		EnableTypePrefix:     false,            // Disable type prefix
+		TimerGranularity:     time.Millisecond, // Timers are in milliseconds
+		ProfileInterval:      time.Second,      // Poll runtime every second
+		FilterDefault:        true,             // Don't filter metrics by default
+	}
+
+	// Try to get the hostname
+	name, _ := os.Hostname()
+	c.HostName = name
+	return c
+}
+
+// New is used to create a new instance of Metrics
+func New(conf *Config, sink MetricSink) (*Metrics, error) {
+	met := &Metrics{}
+	met.Config = *conf
+	met.sink = sink
+	met.UpdateFilterAndLabels(conf.AllowedPrefixes, conf.BlockedPrefixes, conf.AllowedLabels, conf.BlockedLabels)
+
+	// Start the runtime collector
+	if conf.EnableRuntimeMetrics {
+		go met.collectStats()
+	}
+	return met, nil
+}
+
+// NewGlobal is the same as New, but it assigns the metrics object to be
+// used globally as well as returning it.
+func NewGlobal(conf *Config, sink MetricSink) (*Metrics, error) {
+	metrics, err := New(conf, sink)
+	if err == nil {
+		globalMetrics.Store(metrics)
+	}
+	return metrics, err
+}
+
+// Proxy all the methods to the globalMetrics instance
+
+// Set gauge key and value with 32 bit precision
+func SetGauge(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).SetGauge(key, val)
+}
+
+// Set gauge key and value with 32 bit precision
+func SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	globalMetrics.Load().(*Metrics).SetGaugeWithLabels(key, val, labels)
+}
+
+// Set gauge key and value with 64 bit precision
+// The Sink needs to implement PrecisionGaugeMetricSink, in case it doesn't,  the metric value won't be set and ingored instead
+func SetPrecisionGauge(key []string, val float64) {
+	globalMetrics.Load().(*Metrics).SetPrecisionGauge(key, val)
+}
+
+// Set gauge key, value with 64 bit precision, and labels
+// The Sink needs to implement PrecisionGaugeMetricSink, in case it doesn't, the metric value won't be set and ingored instead
+func SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {
+	globalMetrics.Load().(*Metrics).SetPrecisionGaugeWithLabels(key, val, labels)
+}
+
+func EmitKey(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).EmitKey(key, val)
+}
+
+func IncrCounter(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).IncrCounter(key, val)
+}
+
+func IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	globalMetrics.Load().(*Metrics).IncrCounterWithLabels(key, val, labels)
+}
+
+func AddSample(key []string, val float32) {
+	globalMetrics.Load().(*Metrics).AddSample(key, val)
+}
+
+func AddSampleWithLabels(key []string, val float32, labels []Label) {
+	globalMetrics.Load().(*Metrics).AddSampleWithLabels(key, val, labels)
+}
+
+func MeasureSince(key []string, start time.Time) {
+	globalMetrics.Load().(*Metrics).MeasureSince(key, start)
+}
+
+func MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	globalMetrics.Load().(*Metrics).MeasureSinceWithLabels(key, start, labels)
+}
+
+func UpdateFilter(allow, block []string) {
+	globalMetrics.Load().(*Metrics).UpdateFilter(allow, block)
+}
+
+// UpdateFilterAndLabels set allow/block prefixes of metrics while allowedLabels
+// and blockedLabels - when not nil - allow filtering of labels in order to
+// block/allow globally labels (especially useful when having large number of
+// values for a given label). See README.md for more information about usage.
+func UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	globalMetrics.Load().(*Metrics).UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels)
+}
+
+// Shutdown disables metric collection, then blocks while attempting to flush metrics to storage.
+// WARNING: Not all MetricSink backends support this functionality, and calling this will cause them to leak resources.
+// This is intended for use immediately prior to application exit.
+func Shutdown() {
+	m := globalMetrics.Load().(*Metrics)
+	// Swap whatever MetricSink is currently active with a BlackholeSink. Callers must not have a
+	// reason to expect that calls to the library will successfully collect metrics after Shutdown
+	// has been called.
+	globalMetrics.Store(&Metrics{sink: &BlackholeSink{}})
+	m.Shutdown()
+}

vendor/github.com/hashicorp/go-metrics/statsd.go

@@ -0,0 +1,197 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"net"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const (
+	// statsdMaxLen is the maximum size of a packet
+	// to send to statsd
+	statsdMaxLen = 1400
+)
+
+// StatsdSink provides a MetricSink that can be used
+// with a statsite or statsd metrics server. It uses
+// only UDP packets, while StatsiteSink uses TCP.
+type StatsdSink struct {
+	addr        string
+	metricQueue chan string
+}
+
+// NewStatsdSinkFromURL creates an StatsdSink from a URL. It is used
+// (and tested) from NewMetricSinkFromURL.
+func NewStatsdSinkFromURL(u *url.URL) (MetricSink, error) {
+	return NewStatsdSink(u.Host)
+}
+
+// NewStatsdSink is used to create a new StatsdSink
+func NewStatsdSink(addr string) (*StatsdSink, error) {
+	s := &StatsdSink{
+		addr:        addr,
+		metricQueue: make(chan string, 4096),
+	}
+	go s.flushMetrics()
+	return s, nil
+}
+
+// Close is used to stop flushing to statsd
+func (s *StatsdSink) Shutdown() {
+	close(s.metricQueue)
+}
+
+func (s *StatsdSink) SetGauge(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsdSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsdSink) SetPrecisionGauge(key []string, val float64) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsdSink) SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsdSink) EmitKey(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|kv\n", flatKey, val))
+}
+
+func (s *StatsdSink) IncrCounter(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsdSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsdSink) AddSample(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+func (s *StatsdSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+// Flattens the key for formatting, removes spaces
+func (s *StatsdSink) flattenKey(parts []string) string {
+	joined := strings.Join(parts, ".")
+	return strings.Map(func(r rune) rune {
+		switch r {
+		case ':':
+			fallthrough
+		case ' ':
+			return '_'
+		default:
+			return r
+		}
+	}, joined)
+}
+
+// Flattens the key along with labels for formatting, removes spaces
+func (s *StatsdSink) flattenKeyLabels(parts []string, labels []Label) string {
+	for _, label := range labels {
+		parts = append(parts, label.Value)
+	}
+	return s.flattenKey(parts)
+}
+
+// Does a non-blocking push to the metrics queue
+func (s *StatsdSink) pushMetric(m string) {
+	select {
+	case s.metricQueue <- m:
+	default:
+	}
+}
+
+// Flushes metrics
+func (s *StatsdSink) flushMetrics() {
+	var sock net.Conn
+	var err error
+	var wait <-chan time.Time
+	ticker := time.NewTicker(flushInterval)
+	defer ticker.Stop()
+
+CONNECT:
+	// Create a buffer
+	buf := bytes.NewBuffer(nil)
+
+	// Attempt to connect
+	sock, err = net.Dial("udp", s.addr)
+	if err != nil {
+		log.Printf("[ERR] Error connecting to statsd! Err: %s", err)
+		goto WAIT
+	}
+
+	for {
+		select {
+		case metric, ok := <-s.metricQueue:
+			// Get a metric from the queue
+			if !ok {
+				goto QUIT
+			}
+
+			// Check if this would overflow the packet size
+			if len(metric)+buf.Len() > statsdMaxLen {
+				_, err := sock.Write(buf.Bytes())
+				buf.Reset()
+				if err != nil {
+					log.Printf("[ERR] Error writing to statsd! Err: %s", err)
+					goto WAIT
+				}
+			}
+
+			// Append to the buffer
+			buf.WriteString(metric)
+
+		case <-ticker.C:
+			if buf.Len() == 0 {
+				continue
+			}
+
+			_, err := sock.Write(buf.Bytes())
+			buf.Reset()
+			if err != nil {
+				log.Printf("[ERR] Error flushing to statsd! Err: %s", err)
+				goto WAIT
+			}
+		}
+	}
+
+WAIT:
+	// Wait for a while
+	wait = time.After(time.Duration(5) * time.Second)
+	for {
+		select {
+		// Dequeue the messages to avoid backlog
+		case _, ok := <-s.metricQueue:
+			if !ok {
+				goto QUIT
+			}
+		case <-wait:
+			goto CONNECT
+		}
+	}
+QUIT:
+	s.metricQueue = nil
+}

vendor/github.com/hashicorp/go-metrics/statsite.go

@@ -0,0 +1,185 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"net"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const (
+	// We force flush the statsite metrics after this period of
+	// inactivity. Prevents stats from getting stuck in a buffer
+	// forever.
+	flushInterval = 100 * time.Millisecond
+)
+
+// NewStatsiteSinkFromURL creates an StatsiteSink from a URL. It is used
+// (and tested) from NewMetricSinkFromURL.
+func NewStatsiteSinkFromURL(u *url.URL) (MetricSink, error) {
+	return NewStatsiteSink(u.Host)
+}
+
+// StatsiteSink provides a MetricSink that can be used with a
+// statsite metrics server
+type StatsiteSink struct {
+	addr        string
+	metricQueue chan string
+}
+
+// NewStatsiteSink is used to create a new StatsiteSink
+func NewStatsiteSink(addr string) (*StatsiteSink, error) {
+	s := &StatsiteSink{
+		addr:        addr,
+		metricQueue: make(chan string, 4096),
+	}
+	go s.flushMetrics()
+	return s, nil
+}
+
+// Close is used to stop flushing to statsite
+func (s *StatsiteSink) Shutdown() {
+	close(s.metricQueue)
+}
+
+func (s *StatsiteSink) SetGauge(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsiteSink) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsiteSink) SetPrecisionGauge(key []string, val float64) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsiteSink) SetPrecisionGaugeWithLabels(key []string, val float64, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|g\n", flatKey, val))
+}
+
+func (s *StatsiteSink) EmitKey(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|kv\n", flatKey, val))
+}
+
+func (s *StatsiteSink) IncrCounter(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsiteSink) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|c\n", flatKey, val))
+}
+
+func (s *StatsiteSink) AddSample(key []string, val float32) {
+	flatKey := s.flattenKey(key)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+func (s *StatsiteSink) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	flatKey := s.flattenKeyLabels(key, labels)
+	s.pushMetric(fmt.Sprintf("%s:%f|ms\n", flatKey, val))
+}
+
+// Flattens the key for formatting, removes spaces
+func (s *StatsiteSink) flattenKey(parts []string) string {
+	joined := strings.Join(parts, ".")
+	return strings.Map(func(r rune) rune {
+		switch r {
+		case ':':
+			fallthrough
+		case ' ':
+			return '_'
+		default:
+			return r
+		}
+	}, joined)
+}
+
+// Flattens the key along with labels for formatting, removes spaces
+func (s *StatsiteSink) flattenKeyLabels(parts []string, labels []Label) string {
+	for _, label := range labels {
+		parts = append(parts, label.Value)
+	}
+	return s.flattenKey(parts)
+}
+
+// Does a non-blocking push to the metrics queue
+func (s *StatsiteSink) pushMetric(m string) {
+	select {
+	case s.metricQueue <- m:
+	default:
+	}
+}
+
+// Flushes metrics
+func (s *StatsiteSink) flushMetrics() {
+	var sock net.Conn
+	var err error
+	var wait <-chan time.Time
+	var buffered *bufio.Writer
+	ticker := time.NewTicker(flushInterval)
+	defer ticker.Stop()
+
+CONNECT:
+	// Attempt to connect
+	sock, err = net.Dial("tcp", s.addr)
+	if err != nil {
+		log.Printf("[ERR] Error connecting to statsite! Err: %s", err)
+		goto WAIT
+	}
+
+	// Create a buffered writer
+	buffered = bufio.NewWriter(sock)
+
+	for {
+		select {
+		case metric, ok := <-s.metricQueue:
+			// Get a metric from the queue
+			if !ok {
+				goto QUIT
+			}
+
+			// Try to send to statsite
+			_, err := buffered.Write([]byte(metric))
+			if err != nil {
+				log.Printf("[ERR] Error writing to statsite! Err: %s", err)
+				goto WAIT
+			}
+		case <-ticker.C:
+			if err := buffered.Flush(); err != nil {
+				log.Printf("[ERR] Error flushing to statsite! Err: %s", err)
+				goto WAIT
+			}
+		}
+	}
+
+WAIT:
+	// Wait for a while
+	wait = time.After(time.Duration(5) * time.Second)
+	for {
+		select {
+		// Dequeue the messages to avoid backlog
+		case _, ok := <-s.metricQueue:
+			if !ok {
+				goto QUIT
+			}
+		case <-wait:
+			goto CONNECT
+		}
+	}
+QUIT:
+	s.metricQueue = nil
+}

vendor/github.com/hashicorp/go-msgpack/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2012-2015 Ugorji Nwoke.
+All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/hashicorp/go-msgpack/codec/cbor.go

@@ -0,0 +1,767 @@
+// Copyright (c) 2012-2018 Ugorji Nwoke. All rights reserved.
+// Use of this source code is governed by a MIT license found in the LICENSE file.
+
+package codec
+
+import (
+	"math"
+	"reflect"
+	"time"
+)
+
+const (
+	cborMajorUint byte = iota
+	cborMajorNegInt
+	cborMajorBytes
+	cborMajorText
+	cborMajorArray
+	cborMajorMap
+	cborMajorTag
+	cborMajorOther
+)
+
+const (
+	cborBdFalse byte = 0xf4 + iota
+	cborBdTrue
+	cborBdNil
+	cborBdUndefined
+	cborBdExt
+	cborBdFloat16
+	cborBdFloat32
+	cborBdFloat64
+)
+
+const (
+	cborBdIndefiniteBytes  byte = 0x5f
+	cborBdIndefiniteString byte = 0x7f
+	cborBdIndefiniteArray  byte = 0x9f
+	cborBdIndefiniteMap    byte = 0xbf
+	cborBdBreak            byte = 0xff
+)
+
+// These define some in-stream descriptors for
+// manual encoding e.g. when doing explicit indefinite-length
+const (
+	CborStreamBytes  byte = 0x5f
+	CborStreamString byte = 0x7f
+	CborStreamArray  byte = 0x9f
+	CborStreamMap    byte = 0xbf
+	CborStreamBreak  byte = 0xff
+)
+
+const (
+	cborBaseUint   byte = 0x00
+	cborBaseNegInt byte = 0x20
+	cborBaseBytes  byte = 0x40
+	cborBaseString byte = 0x60
+	cborBaseArray  byte = 0x80
+	cborBaseMap    byte = 0xa0
+	cborBaseTag    byte = 0xc0
+	cborBaseSimple byte = 0xe0
+)
+
+func cbordesc(bd byte) string {
+	switch bd {
+	case cborBdNil:
+		return "nil"
+	case cborBdFalse:
+		return "false"
+	case cborBdTrue:
+		return "true"
+	case cborBdFloat16, cborBdFloat32, cborBdFloat64:
+		return "float"
+	case cborBdIndefiniteBytes:
+		return "bytes*"
+	case cborBdIndefiniteString:
+		return "string*"
+	case cborBdIndefiniteArray:
+		return "array*"
+	case cborBdIndefiniteMap:
+		return "map*"
+	default:
+		switch {
+		case bd >= cborBaseUint && bd < cborBaseNegInt:
+			return "(u)int"
+		case bd >= cborBaseNegInt && bd < cborBaseBytes:
+			return "int"
+		case bd >= cborBaseBytes && bd < cborBaseString:
+			return "bytes"
+		case bd >= cborBaseString && bd < cborBaseArray:
+			return "string"
+		case bd >= cborBaseArray && bd < cborBaseMap:
+			return "array"
+		case bd >= cborBaseMap && bd < cborBaseTag:
+			return "map"
+		case bd >= cborBaseTag && bd < cborBaseSimple:
+			return "ext"
+		default:
+			return "unknown"
+		}
+	}
+}
+
+// -------------------
+
+type cborEncDriver struct {
+	noBuiltInTypes
+	encDriverNoopContainerWriter
+	e *Encoder
+	w *encWriterSwitch
+	h *CborHandle
+	x [8]byte
+	// _ [3]uint64 // padding
+}
+
+func (e *cborEncDriver) EncodeNil() {
+	e.w.writen1(cborBdNil)
+}
+
+func (e *cborEncDriver) EncodeBool(b bool) {
+	if b {
+		e.w.writen1(cborBdTrue)
+	} else {
+		e.w.writen1(cborBdFalse)
+	}
+}
+
+func (e *cborEncDriver) EncodeFloat32(f float32) {
+	e.w.writen1(cborBdFloat32)
+	bigenHelper{e.x[:4], e.w}.writeUint32(math.Float32bits(f))
+}
+
+func (e *cborEncDriver) EncodeFloat64(f float64) {
+	e.w.writen1(cborBdFloat64)
+	bigenHelper{e.x[:8], e.w}.writeUint64(math.Float64bits(f))
+}
+
+func (e *cborEncDriver) encUint(v uint64, bd byte) {
+	if v <= 0x17 {
+		e.w.writen1(byte(v) + bd)
+	} else if v <= math.MaxUint8 {
+		e.w.writen2(bd+0x18, uint8(v))
+	} else if v <= math.MaxUint16 {
+		e.w.writen1(bd + 0x19)
+		bigenHelper{e.x[:2], e.w}.writeUint16(uint16(v))
+	} else if v <= math.MaxUint32 {
+		e.w.writen1(bd + 0x1a)
+		bigenHelper{e.x[:4], e.w}.writeUint32(uint32(v))
+	} else { // if v <= math.MaxUint64 {
+		e.w.writen1(bd + 0x1b)
+		bigenHelper{e.x[:8], e.w}.writeUint64(v)
+	}
+}
+
+func (e *cborEncDriver) EncodeInt(v int64) {
+	if v < 0 {
+		e.encUint(uint64(-1-v), cborBaseNegInt)
+	} else {
+		e.encUint(uint64(v), cborBaseUint)
+	}
+}
+
+func (e *cborEncDriver) EncodeUint(v uint64) {
+	e.encUint(v, cborBaseUint)
+}
+
+func (e *cborEncDriver) encLen(bd byte, length int) {
+	e.encUint(uint64(length), bd)
+}
+
+func (e *cborEncDriver) EncodeTime(t time.Time) {
+	if t.IsZero() {
+		e.EncodeNil()
+	} else if e.h.TimeRFC3339 {
+		e.encUint(0, cborBaseTag)
+		e.EncodeStringEnc(cUTF8, t.Format(time.RFC3339Nano))
+	} else {
+		e.encUint(1, cborBaseTag)
+		t = t.UTC().Round(time.Microsecond)
+		sec, nsec := t.Unix(), uint64(t.Nanosecond())
+		if nsec == 0 {
+			e.EncodeInt(sec)
+		} else {
+			e.EncodeFloat64(float64(sec) + float64(nsec)/1e9)
+		}
+	}
+}
+
+func (e *cborEncDriver) EncodeExt(rv interface{}, xtag uint64, ext Ext, en *Encoder) {
+	e.encUint(uint64(xtag), cborBaseTag)
+	if v := ext.ConvertExt(rv); v == nil {
+		e.EncodeNil()
+	} else {
+		en.encode(v)
+	}
+}
+
+func (e *cborEncDriver) EncodeRawExt(re *RawExt, en *Encoder) {
+	e.encUint(uint64(re.Tag), cborBaseTag)
+	// only encodes re.Value (never re.Data)
+	// if false && re.Data != nil {
+	// 	en.encode(re.Data)
+	// } else if re.Value != nil {
+	if re.Value != nil {
+		en.encode(re.Value)
+	} else {
+		e.EncodeNil()
+	}
+}
+
+func (e *cborEncDriver) WriteArrayStart(length int) {
+	if e.h.IndefiniteLength {
+		e.w.writen1(cborBdIndefiniteArray)
+	} else {
+		e.encLen(cborBaseArray, length)
+	}
+}
+
+func (e *cborEncDriver) WriteMapStart(length int) {
+	if e.h.IndefiniteLength {
+		e.w.writen1(cborBdIndefiniteMap)
+	} else {
+		e.encLen(cborBaseMap, length)
+	}
+}
+
+func (e *cborEncDriver) WriteMapEnd() {
+	if e.h.IndefiniteLength {
+		e.w.writen1(cborBdBreak)
+	}
+}
+
+func (e *cborEncDriver) WriteArrayEnd() {
+	if e.h.IndefiniteLength {
+		e.w.writen1(cborBdBreak)
+	}
+}
+
+func (e *cborEncDriver) EncodeString(c charEncoding, v string) {
+	e.encStringBytesS(cborBaseString, v)
+}
+
+func (e *cborEncDriver) EncodeStringEnc(c charEncoding, v string) {
+	e.encStringBytesS(cborBaseString, v)
+}
+
+func (e *cborEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
+	if v == nil {
+		e.EncodeNil()
+	} else if c == cRAW {
+		e.encStringBytesS(cborBaseBytes, stringView(v))
+	} else {
+		e.encStringBytesS(cborBaseString, stringView(v))
+	}
+}
+
+func (e *cborEncDriver) EncodeStringBytesRaw(v []byte) {
+	if v == nil {
+		e.EncodeNil()
+	} else {
+		e.encStringBytesS(cborBaseBytes, stringView(v))
+	}
+}
+
+func (e *cborEncDriver) encStringBytesS(bb byte, v string) {
+	if e.h.IndefiniteLength {
+		if bb == cborBaseBytes {
+			e.w.writen1(cborBdIndefiniteBytes)
+		} else {
+			e.w.writen1(cborBdIndefiniteString)
+		}
+		var vlen uint = uint(len(v))
+		blen := vlen / 4
+		if blen == 0 {
+			blen = 64
+		} else if blen > 1024 {
+			blen = 1024
+		}
+		for i := uint(0); i < vlen; {
+			var v2 string
+			i2 := i + blen
+			if i2 < vlen {
+				v2 = v[i:i2]
+			} else {
+				v2 = v[i:]
+			}
+			e.encLen(bb, len(v2))
+			e.w.writestr(v2)
+			i = i2
+		}
+		e.w.writen1(cborBdBreak)
+	} else {
+		e.encLen(bb, len(v))
+		e.w.writestr(v)
+	}
+}
+
+// ----------------------
+
+type cborDecDriver struct {
+	d      *Decoder
+	h      *CborHandle
+	r      *decReaderSwitch
+	br     bool // bytes reader
+	bdRead bool
+	bd     byte
+	noBuiltInTypes
+	// decNoSeparator
+	decDriverNoopContainerReader
+	// _ [3]uint64 // padding
+}
+
+func (d *cborDecDriver) readNextBd() {
+	d.bd = d.r.readn1()
+	d.bdRead = true
+}
+
+func (d *cborDecDriver) uncacheRead() {
+	if d.bdRead {
+		d.r.unreadn1()
+		d.bdRead = false
+	}
+}
+
+func (d *cborDecDriver) ContainerType() (vt valueType) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	if d.bd == cborBdNil {
+		return valueTypeNil
+	} else if d.bd == cborBdIndefiniteBytes || (d.bd >= cborBaseBytes && d.bd < cborBaseString) {
+		return valueTypeBytes
+	} else if d.bd == cborBdIndefiniteString || (d.bd >= cborBaseString && d.bd < cborBaseArray) {
+		return valueTypeString
+	} else if d.bd == cborBdIndefiniteArray || (d.bd >= cborBaseArray && d.bd < cborBaseMap) {
+		return valueTypeArray
+	} else if d.bd == cborBdIndefiniteMap || (d.bd >= cborBaseMap && d.bd < cborBaseTag) {
+		return valueTypeMap
+	}
+	// else {
+	// d.d.errorf("isContainerType: unsupported parameter: %v", vt)
+	// }
+	return valueTypeUnset
+}
+
+func (d *cborDecDriver) TryDecodeAsNil() bool {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	// treat Nil and Undefined as nil values
+	if d.bd == cborBdNil || d.bd == cborBdUndefined {
+		d.bdRead = false
+		return true
+	}
+	return false
+}
+
+func (d *cborDecDriver) CheckBreak() bool {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	if d.bd == cborBdBreak {
+		d.bdRead = false
+		return true
+	}
+	return false
+}
+
+func (d *cborDecDriver) decUint() (ui uint64) {
+	v := d.bd & 0x1f
+	if v <= 0x17 {
+		ui = uint64(v)
+	} else {
+		if v == 0x18 {
+			ui = uint64(d.r.readn1())
+		} else if v == 0x19 {
+			ui = uint64(bigen.Uint16(d.r.readx(2)))
+		} else if v == 0x1a {
+			ui = uint64(bigen.Uint32(d.r.readx(4)))
+		} else if v == 0x1b {
+			ui = uint64(bigen.Uint64(d.r.readx(8)))
+		} else {
+			d.d.errorf("invalid descriptor decoding uint: %x/%s", d.bd, cbordesc(d.bd))
+			return
+		}
+	}
+	return
+}
+
+func (d *cborDecDriver) decCheckInteger() (neg bool) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	major := d.bd >> 5
+	if major == cborMajorUint {
+	} else if major == cborMajorNegInt {
+		neg = true
+	} else {
+		d.d.errorf("not an integer - invalid major %v from descriptor %x/%s",
+			major, d.bd, cbordesc(d.bd))
+		return
+	}
+	return
+}
+
+func (d *cborDecDriver) DecodeInt64() (i int64) {
+	neg := d.decCheckInteger()
+	ui := d.decUint()
+	// check if this number can be converted to an int without overflow
+	if neg {
+		i = -(chkOvf.SignedIntV(ui + 1))
+	} else {
+		i = chkOvf.SignedIntV(ui)
+	}
+	d.bdRead = false
+	return
+}
+
+func (d *cborDecDriver) DecodeUint64() (ui uint64) {
+	if d.decCheckInteger() {
+		d.d.errorf("assigning negative signed value to unsigned type")
+		return
+	}
+	ui = d.decUint()
+	d.bdRead = false
+	return
+}
+
+func (d *cborDecDriver) DecodeFloat64() (f float64) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	if bd := d.bd; bd == cborBdFloat16 {
+		f = float64(math.Float32frombits(halfFloatToFloatBits(bigen.Uint16(d.r.readx(2)))))
+	} else if bd == cborBdFloat32 {
+		f = float64(math.Float32frombits(bigen.Uint32(d.r.readx(4))))
+	} else if bd == cborBdFloat64 {
+		f = math.Float64frombits(bigen.Uint64(d.r.readx(8)))
+	} else if bd >= cborBaseUint && bd < cborBaseBytes {
+		f = float64(d.DecodeInt64())
+	} else {
+		d.d.errorf("float only valid from float16/32/64 - invalid descriptor %x/%s", bd, cbordesc(bd))
+		return
+	}
+	d.bdRead = false
+	return
+}
+
+// bool can be decoded from bool only (single byte).
+func (d *cborDecDriver) DecodeBool() (b bool) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	if bd := d.bd; bd == cborBdTrue {
+		b = true
+	} else if bd == cborBdFalse {
+	} else {
+		d.d.errorf("not bool - %s %x/%s", msgBadDesc, d.bd, cbordesc(d.bd))
+		return
+	}
+	d.bdRead = false
+	return
+}
+
+func (d *cborDecDriver) ReadMapStart() (length int) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	d.bdRead = false
+	if d.bd == cborBdIndefiniteMap {
+		return -1
+	}
+	return d.decLen()
+}
+
+func (d *cborDecDriver) ReadArrayStart() (length int) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	d.bdRead = false
+	if d.bd == cborBdIndefiniteArray {
+		return -1
+	}
+	return d.decLen()
+}
+
+func (d *cborDecDriver) decLen() int {
+	return int(d.decUint())
+}
+
+func (d *cborDecDriver) decAppendIndefiniteBytes(bs []byte) []byte {
+	d.bdRead = false
+	for {
+		if d.CheckBreak() {
+			break
+		}
+		if major := d.bd >> 5; major != cborMajorBytes && major != cborMajorText {
+			d.d.errorf("expect bytes/string major type in indefinite string/bytes;"+
+				" got major %v from descriptor %x/%x", major, d.bd, cbordesc(d.bd))
+			return nil
+		}
+		n := d.decLen()
+		oldLen := len(bs)
+		newLen := oldLen + n
+		if newLen > cap(bs) {
+			bs2 := make([]byte, newLen, 2*cap(bs)+n)
+			copy(bs2, bs)
+			bs = bs2
+		} else {
+			bs = bs[:newLen]
+		}
+		d.r.readb(bs[oldLen:newLen])
+		// bs = append(bs, d.r.readn()...)
+		d.bdRead = false
+	}
+	d.bdRead = false
+	return bs
+}
+
+func (d *cborDecDriver) DecodeBytes(bs []byte, zerocopy bool) (bsOut []byte) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	if d.bd == cborBdNil || d.bd == cborBdUndefined {
+		d.bdRead = false
+		return nil
+	}
+	if d.bd == cborBdIndefiniteBytes || d.bd == cborBdIndefiniteString {
+		d.bdRead = false
+		if bs == nil {
+			if zerocopy {
+				return d.decAppendIndefiniteBytes(d.d.b[:0])
+			}
+			return d.decAppendIndefiniteBytes(zeroByteSlice)
+		}
+		return d.decAppendIndefiniteBytes(bs[:0])
+	}
+	// check if an "array" of uint8's (see ContainerType for how to infer if an array)
+	if d.bd == cborBdIndefiniteArray || (d.bd >= cborBaseArray && d.bd < cborBaseMap) {
+		bsOut, _ = fastpathTV.DecSliceUint8V(bs, true, d.d)
+		return
+	}
+	clen := d.decLen()
+	d.bdRead = false
+	if zerocopy {
+		if d.br {
+			return d.r.readx(uint(clen))
+		} else if len(bs) == 0 {
+			bs = d.d.b[:]
+		}
+	}
+	return decByteSlice(d.r, clen, d.h.MaxInitLen, bs)
+}
+
+func (d *cborDecDriver) DecodeString() (s string) {
+	return string(d.DecodeBytes(d.d.b[:], true))
+}
+
+func (d *cborDecDriver) DecodeStringAsBytes() (s []byte) {
+	return d.DecodeBytes(d.d.b[:], true)
+}
+
+func (d *cborDecDriver) DecodeTime() (t time.Time) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	if d.bd == cborBdNil || d.bd == cborBdUndefined {
+		d.bdRead = false
+		return
+	}
+	xtag := d.decUint()
+	d.bdRead = false
+	return d.decodeTime(xtag)
+}
+
+func (d *cborDecDriver) decodeTime(xtag uint64) (t time.Time) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	switch xtag {
+	case 0:
+		var err error
+		if t, err = time.Parse(time.RFC3339, stringView(d.DecodeStringAsBytes())); err != nil {
+			d.d.errorv(err)
+		}
+	case 1:
+		// decode an int64 or a float, and infer time.Time from there.
+		// for floats, round to microseconds, as that is what is guaranteed to fit well.
+		switch {
+		case d.bd == cborBdFloat16, d.bd == cborBdFloat32:
+			f1, f2 := math.Modf(d.DecodeFloat64())
+			t = time.Unix(int64(f1), int64(f2*1e9))
+		case d.bd == cborBdFloat64:
+			f1, f2 := math.Modf(d.DecodeFloat64())
+			t = time.Unix(int64(f1), int64(f2*1e9))
+		case d.bd >= cborBaseUint && d.bd < cborBaseNegInt,
+			d.bd >= cborBaseNegInt && d.bd < cborBaseBytes:
+			t = time.Unix(d.DecodeInt64(), 0)
+		default:
+			d.d.errorf("time.Time can only be decoded from a number (or RFC3339 string)")
+		}
+	default:
+		d.d.errorf("invalid tag for time.Time - expecting 0 or 1, got 0x%x", xtag)
+	}
+	t = t.UTC().Round(time.Microsecond)
+	return
+}
+
+func (d *cborDecDriver) DecodeExt(rv interface{}, xtag uint64, ext Ext) (realxtag uint64) {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+	u := d.decUint()
+	d.bdRead = false
+	realxtag = u
+	if ext == nil {
+		re := rv.(*RawExt)
+		re.Tag = realxtag
+		d.d.decode(&re.Value)
+	} else if xtag != realxtag {
+		d.d.errorf("Wrong extension tag. Got %b. Expecting: %v", realxtag, xtag)
+		return
+	} else {
+		var v interface{}
+		d.d.decode(&v)
+		ext.UpdateExt(rv, v)
+	}
+	d.bdRead = false
+	return
+}
+
+func (d *cborDecDriver) DecodeNaked() {
+	if !d.bdRead {
+		d.readNextBd()
+	}
+
+	n := d.d.naked()
+	var decodeFurther bool
+
+	switch d.bd {
+	case cborBdNil:
+		n.v = valueTypeNil
+	case cborBdFalse:
+		n.v = valueTypeBool
+		n.b = false
+	case cborBdTrue:
+		n.v = valueTypeBool
+		n.b = true
+	case cborBdFloat16, cborBdFloat32, cborBdFloat64:
+		n.v = valueTypeFloat
+		n.f = d.DecodeFloat64()
+	case cborBdIndefiniteBytes:
+		decNakedReadRawBytes(d, d.d, n, d.h.RawToString)
+	case cborBdIndefiniteString:
+		n.v = valueTypeString
+		n.s = d.DecodeString()
+	case cborBdIndefiniteArray:
+		n.v = valueTypeArray
+		decodeFurther = true
+	case cborBdIndefiniteMap:
+		n.v = valueTypeMap
+		decodeFurther = true
+	default:
+		switch {
+		case d.bd >= cborBaseUint && d.bd < cborBaseNegInt:
+			if d.h.SignedInteger {
+				n.v = valueTypeInt
+				n.i = d.DecodeInt64()
+			} else {
+				n.v = valueTypeUint
+				n.u = d.DecodeUint64()
+			}
+		case d.bd >= cborBaseNegInt && d.bd < cborBaseBytes:
+			n.v = valueTypeInt
+			n.i = d.DecodeInt64()
+		case d.bd >= cborBaseBytes && d.bd < cborBaseString:
+			decNakedReadRawBytes(d, d.d, n, d.h.RawToString)
+		case d.bd >= cborBaseString && d.bd < cborBaseArray:
+			n.v = valueTypeString
+			n.s = d.DecodeString()
+		case d.bd >= cborBaseArray && d.bd < cborBaseMap:
+			n.v = valueTypeArray
+			decodeFurther = true
+		case d.bd >= cborBaseMap && d.bd < cborBaseTag:
+			n.v = valueTypeMap
+			decodeFurther = true
+		case d.bd >= cborBaseTag && d.bd < cborBaseSimple:
+			n.v = valueTypeExt
+			n.u = d.decUint()
+			n.l = nil
+			if n.u == 0 || n.u == 1 {
+				d.bdRead = false
+				n.v = valueTypeTime
+				n.t = d.decodeTime(n.u)
+			}
+			// d.bdRead = false
+			// d.d.decode(&re.Value) // handled by decode itself.
+			// decodeFurther = true
+		default:
+			d.d.errorf("decodeNaked: Unrecognized d.bd: 0x%x", d.bd)
+			return
+		}
+	}
+
+	if !decodeFurther {
+		d.bdRead = false
+	}
+}
+
+// -------------------------
+
+// CborHandle is a Handle for the CBOR encoding format,
+// defined at http://tools.ietf.org/html/rfc7049 and documented further at http://cbor.io .
+//
+// CBOR is comprehensively supported, including support for:
+//   - indefinite-length arrays/maps/bytes/strings
+//   - (extension) tags in range 0..0xffff (0 .. 65535)
+//   - half, single and double-precision floats
+//   - all numbers (1, 2, 4 and 8-byte signed and unsigned integers)
+//   - nil, true, false, ...
+//   - arrays and maps, bytes and text strings
+//
+// None of the optional extensions (with tags) defined in the spec are supported out-of-the-box.
+// Users can implement them as needed (using SetExt), including spec-documented ones:
+//   - timestamp, BigNum, BigFloat, Decimals,
+//   - Encoded Text (e.g. URL, regexp, base64, MIME Message), etc.
+type CborHandle struct {
+	binaryEncodingType
+	noElemSeparators
+	BasicHandle
+
+	// IndefiniteLength=true, means that we encode using indefinitelength
+	IndefiniteLength bool
+
+	// TimeRFC3339 says to encode time.Time using RFC3339 format.
+	// If unset, we encode time.Time using seconds past epoch.
+	TimeRFC3339 bool
+
+	// _ [1]uint64 // padding
+}
+
+// Name returns the name of the handle: cbor
+func (h *CborHandle) Name() string { return "cbor" }
+
+// SetInterfaceExt sets an extension
+func (h *CborHandle) SetInterfaceExt(rt reflect.Type, tag uint64, ext InterfaceExt) (err error) {
+	return h.SetExt(rt, tag, &extWrapper{bytesExtFailer{}, ext})
+}
+
+func (h *CborHandle) newEncDriver(e *Encoder) encDriver {
+	return &cborEncDriver{e: e, w: e.w, h: h}
+}
+
+func (h *CborHandle) newDecDriver(d *Decoder) decDriver {
+	return &cborDecDriver{d: d, h: h, r: d.r, br: d.bytes}
+}
+
+func (e *cborEncDriver) reset() {
+	e.w = e.e.w
+}
+
+func (d *cborDecDriver) reset() {
+	d.r, d.br = d.d.r, d.d.bytes
+	d.bd, d.bdRead = 0, false
+}
+
+var _ decDriver = (*cborDecDriver)(nil)
+var _ encDriver = (*cborEncDriver)(nil)

vendor/github.com/hashicorp/go-msgpack/codec/codecgen.go

@@ -0,0 +1,13 @@
+// +build codecgen generated
+
+package codec
+
+// this file is here, to set the codecgen variable to true
+// when the build tag codecgen is set.
+//
+// this allows us do specific things e.g. skip missing fields tests,
+// when running in codecgen mode.
+
+func init() {
+	codecgen = true
+}

vendor/github.com/hashicorp/go-msgpack/codec/doc.go

@@ -0,0 +1,245 @@
+// Copyright (c) 2012-2018 Ugorji Nwoke. All rights reserved.
+// Use of this source code is governed by a MIT license found in the LICENSE file.
+
+/*
+Package codec provides a
+High Performance, Feature-Rich Idiomatic Go 1.4+ codec/encoding library
+for binc, msgpack, cbor, json.
+
+Supported Serialization formats are:
+
+  - msgpack: https://github.com/msgpack/msgpack
+  - binc:    http://github.com/ugorji/binc
+  - cbor:    http://cbor.io http://tools.ietf.org/html/rfc7049
+  - json:    http://json.org http://tools.ietf.org/html/rfc7159
+  - simple:
+
+This package will carefully use 'package unsafe' for performance reasons in specific places.
+You can build without unsafe use by passing the safe or appengine tag
+i.e. 'go install -tags=safe ...'. Note that unsafe is only supported for the last 4
+go releases e.g. current go release is go 1.12, so we support unsafe use only from
+go 1.9+ . This is because supporting unsafe requires knowledge of implementation details.
+
+For detailed usage information, read the primer at http://ugorji.net/blog/go-codec-primer .
+
+The idiomatic Go support is as seen in other encoding packages in
+the standard library (ie json, xml, gob, etc).
+
+Rich Feature Set includes:
+
+  - Simple but extremely powerful and feature-rich API
+  - Support for go1.4 and above, while selectively using newer APIs for later releases
+  - Excellent code coverage ( > 90% )
+  - Very High Performance.
+    Our extensive benchmarks show us outperforming Gob, Json, Bson, etc by 2-4X.
+  - Careful selected use of 'unsafe' for targeted performance gains.
+    100% mode exists where 'unsafe' is not used at all.
+  - Lock-free (sans mutex) concurrency for scaling to 100's of cores
+  - In-place updates during decode, with option to zero value in maps and slices prior to decode
+  - Coerce types where appropriate
+    e.g. decode an int in the stream into a float, decode numbers from formatted strings, etc
+  - Corner Cases:
+    Overflows, nil maps/slices, nil values in streams are handled correctly
+  - Standard field renaming via tags
+  - Support for omitting empty fields during an encoding
+  - Encoding from any value and decoding into pointer to any value
+    (struct, slice, map, primitives, pointers, interface{}, etc)
+  - Extensions to support efficient encoding/decoding of any named types
+  - Support encoding.(Binary|Text)(M|Unm)arshaler interfaces
+  - Support IsZero() bool to determine if a value is a zero value.
+    Analogous to time.Time.IsZero() bool.
+  - Decoding without a schema (into a interface{}).
+    Includes Options to configure what specific map or slice type to use
+    when decoding an encoded list or map into a nil interface{}
+  - Mapping a non-interface type to an interface, so we can decode appropriately
+    into any interface type with a correctly configured non-interface value.
+  - Encode a struct as an array, and decode struct from an array in the data stream
+  - Option to encode struct keys as numbers (instead of strings)
+    (to support structured streams with fields encoded as numeric codes)
+  - Comprehensive support for anonymous fields
+  - Fast (no-reflection) encoding/decoding of common maps and slices
+  - Code-generation for faster performance.
+  - Support binary (e.g. messagepack, cbor) and text (e.g. json) formats
+  - Support indefinite-length formats to enable true streaming
+    (for formats which support it e.g. json, cbor)
+  - Support canonical encoding, where a value is ALWAYS encoded as same sequence of bytes.
+    This mostly applies to maps, where iteration order is non-deterministic.
+  - NIL in data stream decoded as zero value
+  - Never silently skip data when decoding.
+    User decides whether to return an error or silently skip data when keys or indexes
+    in the data stream do not map to fields in the struct.
+  - Detect and error when encoding a cyclic reference (instead of stack overflow shutdown)
+  - Encode/Decode from/to chan types (for iterative streaming support)
+  - Drop-in replacement for encoding/json. `json:` key in struct tag supported.
+  - Provides a RPC Server and Client Codec for net/rpc communication protocol.
+  - Handle unique idiosyncrasies of codecs e.g.
+    - For messagepack, configure how ambiguities in handling raw bytes are resolved
+    - For messagepack, provide rpc server/client codec to support
+      msgpack-rpc protocol defined at:
+      https://github.com/msgpack-rpc/msgpack-rpc/blob/master/spec.md
+
+Extension Support
+
+Users can register a function to handle the encoding or decoding of
+their custom types.
+
+There are no restrictions on what the custom type can be. Some examples:
+
+    type BisSet   []int
+    type BitSet64 uint64
+    type UUID     string
+    type MyStructWithUnexportedFields struct { a int; b bool; c []int; }
+    type GifImage struct { ... }
+
+As an illustration, MyStructWithUnexportedFields would normally be
+encoded as an empty map because it has no exported fields, while UUID
+would be encoded as a string. However, with extension support, you can
+encode any of these however you like.
+
+Custom Encoding and Decoding
+
+This package maintains symmetry in the encoding and decoding halfs.
+We determine how to encode or decode by walking this decision tree
+
+  - is type a codec.Selfer?
+  - is there an extension registered for the type?
+  - is format binary, and is type a encoding.BinaryMarshaler and BinaryUnmarshaler?
+  - is format specifically json, and is type a encoding/json.Marshaler and Unmarshaler?
+  - is format text-based, and type an encoding.TextMarshaler and TextUnmarshaler?
+  - else we use a pair of functions based on the "kind" of the type e.g. map, slice, int64, etc
+
+This symmetry is important to reduce chances of issues happening because the
+encoding and decoding sides are out of sync e.g. decoded via very specific
+encoding.TextUnmarshaler but encoded via kind-specific generalized mode.
+
+Consequently, if a type only defines one-half of the symmetry
+(e.g. it implements UnmarshalJSON() but not MarshalJSON() ),
+then that type doesn't satisfy the check and we will continue walking down the
+decision tree.
+
+RPC
+
+RPC Client and Server Codecs are implemented, so the codecs can be used
+with the standard net/rpc package.
+
+Usage
+
+The Handle is SAFE for concurrent READ, but NOT SAFE for concurrent modification.
+
+The Encoder and Decoder are NOT safe for concurrent use.
+
+Consequently, the usage model is basically:
+
+    - Create and initialize the Handle before any use.
+      Once created, DO NOT modify it.
+    - Multiple Encoders or Decoders can now use the Handle concurrently.
+      They only read information off the Handle (never write).
+    - However, each Encoder or Decoder MUST not be used concurrently
+    - To re-use an Encoder/Decoder, call Reset(...) on it first.
+      This allows you use state maintained on the Encoder/Decoder.
+
+Sample usage model:
+
+    // create and configure Handle
+    var (
+      bh codec.BincHandle
+      mh codec.MsgpackHandle
+      ch codec.CborHandle
+    )
+
+    mh.MapType = reflect.TypeOf(map[string]interface{}(nil))
+
+    // configure extensions
+    // e.g. for msgpack, define functions and enable Time support for tag 1
+    // mh.SetExt(reflect.TypeOf(time.Time{}), 1, myExt)
+
+    // create and use decoder/encoder
+    var (
+      r io.Reader
+      w io.Writer
+      b []byte
+      h = &bh // or mh to use msgpack
+    )
+
+    dec = codec.NewDecoder(r, h)
+    dec = codec.NewDecoderBytes(b, h)
+    err = dec.Decode(&v)
+
+    enc = codec.NewEncoder(w, h)
+    enc = codec.NewEncoderBytes(&b, h)
+    err = enc.Encode(v)
+
+    //RPC Server
+    go func() {
+        for {
+            conn, err := listener.Accept()
+            rpcCodec := codec.GoRpc.ServerCodec(conn, h)
+            //OR rpcCodec := codec.MsgpackSpecRpc.ServerCodec(conn, h)
+            rpc.ServeCodec(rpcCodec)
+        }
+    }()
+
+    //RPC Communication (client side)
+    conn, err = net.Dial("tcp", "localhost:5555")
+    rpcCodec := codec.GoRpc.ClientCodec(conn, h)
+    //OR rpcCodec := codec.MsgpackSpecRpc.ClientCodec(conn, h)
+    client := rpc.NewClientWithCodec(rpcCodec)
+
+Running Tests
+
+To run tests, use the following:
+
+    go test
+
+To run the full suite of tests, use the following:
+
+    go test -tags alltests -run Suite
+
+You can run the tag 'safe' to run tests or build in safe mode. e.g.
+
+    go test -tags safe -run Json
+    go test -tags "alltests safe" -run Suite
+
+Running Benchmarks
+
+    cd bench
+    go test -bench . -benchmem -benchtime 1s
+    
+Please see http://github.com/ugorji/go-codec-bench .
+
+Managing Binary Size
+
+This package could add up to 10MB to the size of your binaries.
+
+This is because we include some a auto-generated file: `fast-path.generated.go`
+to help with performance when encoding/decoding slices and maps of
+built in numeric, boolean, string and interface{} types.
+
+You can override this by building (or running tests and benchmarks)
+with the tag: `notfastpath`.
+
+    go install -tags notfastpath
+    go build -tags notfastpath
+    go test -tags notfastpath
+
+Be aware that, at least in our representative microbenchmarks for cbor (for example),
+we see up to 33% increase in decoding and 50% increase in encoding speeds.
+YMMV.
+
+Caveats
+
+Struct fields matching the following are ignored during encoding and decoding
+    - struct tag value set to -
+    - func, complex numbers, unsafe pointers
+    - unexported and not embedded
+    - unexported and embedded and not struct kind
+    - unexported and embedded pointers (from go1.10)
+
+Every other field in a struct will be encoded/decoded.
+
+Embedded fields are encoded as if they exist in the top-level struct,
+with some caveats. See Encode documentation.
+
+*/
+package codec
+