Logger interface and tmLogger impl based on go-kit

.gitignore

@@ -1,3 +1,2 @@
-*.swp
-*.swo
 vendor
+.glide

common/service.go

@@ -3,7 +3,7 @@ package common
 import (
 	"sync/atomic"
 
-	"github.com/tendermint/log15"
+	"github.com/tendermint/tmlibs/log"
 )
 
 type Service interface {
@@ -19,6 +19,8 @@ type Service interface {
 	IsRunning() bool
 
 	String() string
+
+	SetLogger(log.Logger)
 }
 
 /*
@@ -64,7 +66,7 @@ Typical usage:
 	}
 */
 type BaseService struct {
-	log     log15.Logger
+	Logger  log.Logger
 	name    string
 	started uint32 // atomic
 	stopped uint32 // atomic
@@ -74,27 +76,31 @@ type BaseService struct {
 	impl Service
 }
 
-func NewBaseService(log log15.Logger, name string, impl Service) *BaseService {
+func NewBaseService(logger log.Logger, name string, impl Service) *BaseService {
+	if logger == nil {
+		logger = log.NewNopLogger()
+	}
+
 	return &BaseService{
-		log:  log,
-		name: name,
-		Quit: make(chan struct{}),
-		impl: impl,
+		Logger: logger,
+		name:   name,
+		Quit:   make(chan struct{}),
+		impl:   impl,
 	}
 }
 
+func (bs *BaseService) SetLogger(l log.Logger) {
+	bs.Logger = l
+}
+
 // Implements Servce
 func (bs *BaseService) Start() (bool, error) {
 	if atomic.CompareAndSwapUint32(&bs.started, 0, 1) {
 		if atomic.LoadUint32(&bs.stopped) == 1 {
-			if bs.log != nil {
-				bs.log.Warn(Fmt("Not starting %v -- already stopped", bs.name), "impl", bs.impl)
-			}
+			bs.Logger.Error(Fmt("Not starting %v -- already stopped", bs.name), "impl", bs.impl)
 			return false, nil
 		} else {
-			if bs.log != nil {
-				bs.log.Info(Fmt("Starting %v", bs.name), "impl", bs.impl)
-			}
+			bs.Logger.Info(Fmt("Starting %v", bs.name), "impl", bs.impl)
 		}
 		err := bs.impl.OnStart()
 		if err != nil {
@@ -104,9 +110,7 @@ func (bs *BaseService) Start() (bool, error) {
 		}
 		return true, err
 	} else {
-		if bs.log != nil {
-			bs.log.Debug(Fmt("Not starting %v -- already started", bs.name), "impl", bs.impl)
-		}
+		bs.Logger.Debug(Fmt("Not starting %v -- already started", bs.name), "impl", bs.impl)
 		return false, nil
 	}
 }
@@ -119,16 +123,12 @@ func (bs *BaseService) OnStart() error { return nil }
 // Implements Service
 func (bs *BaseService) Stop() bool {
 	if atomic.CompareAndSwapUint32(&bs.stopped, 0, 1) {
-		if bs.log != nil {
-			bs.log.Info(Fmt("Stopping %v", bs.name), "impl", bs.impl)
-		}
+		bs.Logger.Info(Fmt("Stopping %v", bs.name), "impl", bs.impl)
 		bs.impl.OnStop()
 		close(bs.Quit)
 		return true
 	} else {
-		if bs.log != nil {
-			bs.log.Debug(Fmt("Stopping %v (ignoring: already stopped)", bs.name), "impl", bs.impl)
-		}
+		bs.Logger.Debug(Fmt("Stopping %v (ignoring: already stopped)", bs.name), "impl", bs.impl)
 		return false
 	}
 }
@@ -147,9 +147,7 @@ func (bs *BaseService) Reset() (bool, error) {
 		bs.Quit = make(chan struct{})
 		return true, bs.impl.OnReset()
 	} else {
-		if bs.log != nil {
-			bs.log.Debug(Fmt("Can't reset %v. Not stopped", bs.name), "impl", bs.impl)
-		}
+		bs.Logger.Debug(Fmt("Can't reset %v. Not stopped", bs.name), "impl", bs.impl)
 		return false, nil
 	}
 	// never happens
@@ -182,11 +180,11 @@ type QuitService struct {
 	BaseService
 }
 
-func NewQuitService(log log15.Logger, name string, impl Service) *QuitService {
-	if log != nil {
-		log.Warn("QuitService is deprecated, use BaseService instead")
+func NewQuitService(logger log.Logger, name string, impl Service) *QuitService {
+	if logger != nil {
+		logger.Info("QuitService is deprecated, use BaseService instead")
 	}
 	return &QuitService{
-		BaseService: *NewBaseService(log, name, impl),
+		BaseService: *NewBaseService(logger, name, impl),
 	}
 }

events/events.go

@@ -45,7 +45,7 @@ type eventSwitch struct {
 
 func NewEventSwitch() EventSwitch {
 	evsw := &eventSwitch{}
-	evsw.BaseService = *NewBaseService(log, "EventSwitch", evsw)
+	evsw.BaseService = *NewBaseService(nil, "EventSwitch", evsw)
 	return evsw
 }
 

events/log.go

@@ -1,7 +0,0 @@
-package events
-
-import (
-	"github.com/tendermint/tmlibs/logger"
-)
-
-var log = logger.New("module", "events")

glide.lock

@@ -1,5 +1,5 @@
-hash: a28817fffc1bfbba980a957b7782a84ea574fb73d5dfb01730f7e304c9dee630
-updated: 2017-05-03T10:27:41.060683376+02:00
+hash: 69359a39dbb6957c9f09167520317ad72d4bfa75f37a614b347e2510768c8a42
+updated: 2017-05-05T17:40:30.424309209Z
 imports:
 - name: github.com/fsnotify/fsnotify
   version: 4da3e2cfbabc9f751898f250b49f2439785783a1
@@ -12,11 +12,11 @@ imports:
 - name: github.com/go-logfmt/logfmt
   version: 390ab7935ee28ec6b286364bba9b4dd6410cb3d5
 - name: github.com/go-stack/stack
-  version: 100eb0c0a9c5b306ca2fb4f165df21d80ada4b82
+  version: 7a2f19628aabfe68f0766b59e74d6315f8347d22
 - name: github.com/golang/snappy
   version: 553a641470496b2327abcac10b36396bd98e45c9
 - name: github.com/hashicorp/hcl
-  version: 630949a3c5fa3c613328e1b8256052cbc2327c9b
+  version: a4b07c25de5ff55ad3b8936cea69a79a3d95a855
   subpackages:
   - hcl/ast
   - hcl/parser
@@ -35,17 +35,17 @@ imports:
 - name: github.com/magiconair/properties
   version: 51463bfca2576e06c62a8504b5c0f06d61312647
 - name: github.com/mattn/go-colorable
-  version: d228849504861217f796da67fae4f6e347643f15
+  version: ded68f7a9561c023e790de24279db7ebf473ea80
 - name: github.com/mattn/go-isatty
-  version: 30a891c33c7cde7b02a981314b4228ec99380cca
+  version: fc9e8d8ef48496124e79ae0df75490096eccf6fe
 - name: github.com/mitchellh/mapstructure
-  version: 53818660ed4955e899c0bcafa97299a388bd7c8e
+  version: cc8532a8e9a55ea36402aa21efdf403a60d34096
 - name: github.com/pelletier/go-buffruneio
   version: c37440a7cf42ac63b919c752ca73a85067e05992
 - name: github.com/pelletier/go-toml
-  version: 13d49d4606eb801b8f01ae542b4afc4c6ee3d84a
+  version: 97253b98df84f9eef872866d079e74b8265150f1
 - name: github.com/pkg/errors
-  version: bfd5150e4e41705ded2129ec33379de1cb90b513
+  version: c605e284fe17294bda444b34710735b29d1a9d90
 - name: github.com/spf13/afero
   version: 9be650865eab0c12963d8753212f4f9c66cdcf12
   subpackages:
@@ -53,15 +53,15 @@ imports:
 - name: github.com/spf13/cast
   version: acbeb36b902d72a7a4c18e8f3241075e7ab763e4
 - name: github.com/spf13/cobra
-  version: fcd0c5a1df88f5d6784cb4feead962c3f3d0b66c
+  version: db6b9a8b3f3f400c8ecb4a4d7d02245b8facad66
 - name: github.com/spf13/jwalterweatherman
   version: fa7ca7e836cf3a8bb4ebf799f472c12d7e903d66
 - name: github.com/spf13/pflag
-  version: 9ff6c6923cfffbcd502984b8e0c80539a94968b7
+  version: 80fe0fb4eba54167e2ccae1c6c950e72abf61b73
 - name: github.com/spf13/viper
-  version: 5d46e70da8c0b6f812e0b170b7a985753b5c63cb
+  version: 0967fc9aceab2ce9da34061253ac10fb99bba5b2
 - name: github.com/syndtr/goleveldb
-  version: 23851d93a2292dcc56e71a18ec9e0624d84a0f65
+  version: 8c81ea47d4c41a385645e133e15510fc6a2a74b4
   subpackages:
   - leveldb
   - leveldb/cache
@@ -76,24 +76,24 @@ imports:
   - leveldb/table
   - leveldb/util
 - name: github.com/tendermint/go-wire
-  version: 334005c236d19c632fb5f073f9de3b0fab6a522b
+  version: b53add0b622662731985485f3a19be7f684660b8
   subpackages:
   - data
   - data/base58
 - name: github.com/tendermint/log15
-  version: ae0f3d6450da9eac7074b439c8e1c3cabf0d5ce6
+  version: f91285dece9f4875421b481da3e613d83d44f29b
   subpackages:
   - term
 - name: golang.org/x/crypto
-  version: 7c6cc321c680f03b9ef0764448e780704f486b51
+  version: 5a033cc77e57eca05bdb50522851d29e03569cbe
   subpackages:
   - ripemd160
 - name: golang.org/x/sys
-  version: d75a52659825e75fff6158388dddc6a5b04f9ba5
+  version: 9ccfe848b9db8435a24c424abbc07a921adf1df5
   subpackages:
   - unix
 - name: golang.org/x/text
-  version: f4b4367115ec2de254587813edaa901bc1c723a8
+  version: 470f45bf29f4147d6fbd7dfd0a02a848e49f5bf4
   subpackages:
   - transform
   - unicode/norm
@@ -101,7 +101,7 @@ imports:
   version: cd8b52f8269e0feb286dfeef29f8fe4d5b397e0b
 testImports:
 - name: github.com/davecgh/go-spew
-  version: 6d212800a42e8ab5c146b8ace3490ee17e5225f9
+  version: 04cdfd42973bb9c8589fd6a731800cf222fde1a9
   subpackages:
   - spew
 - name: github.com/pmezard/go-difflib
@@ -109,7 +109,7 @@ testImports:
   subpackages:
   - difflib
 - name: github.com/stretchr/testify
-  version: 69483b4bd14f5845b5a1e55bca19e954e827f1d0
+  version: 4d4bfba8f1d1027c4fdbe371823030df51419987
   subpackages:
   - assert
   - require

glide.yaml

@@ -1,20 +1,30 @@
 package: github.com/tendermint/tmlibs
 import:
+- package: github.com/go-kit/kit
+  subpackages:
+  - log
+  - log/level
+  - log/term
+- package: github.com/go-logfmt/logfmt
 - package: github.com/jmhodges/levigo
+- package: github.com/pkg/errors
+- package: github.com/spf13/cobra
+- package: github.com/spf13/viper
 - package: github.com/syndtr/goleveldb
   subpackages:
   - leveldb
   - leveldb/errors
   - leveldb/opt
 - package: github.com/tendermint/go-wire
+  subpackages:
+  - data
+  - data/base58
 - package: github.com/tendermint/log15
 - package: golang.org/x/crypto
   subpackages:
   - ripemd160
-- package: github.com/go-logfmt/logfmt
-- package: github.com/spf13/cobra
-- package: github.com/spf13/viper
 testImport:
 - package: github.com/stretchr/testify
   subpackages:
   - assert
+  - require

log/logger.go

@@ -0,0 +1,27 @@
+package log
+
+import (
+	"fmt"
+
+	kitlog "github.com/go-kit/kit/log"
+)
+
+// Logger is what any Tendermint library should take.
+type Logger interface {
+	Debug(msg string, keyvals ...interface{}) error
+	Info(msg string, keyvals ...interface{}) error
+	Error(msg string, keyvals ...interface{}) error
+}
+
+// With returns a new contextual logger with keyvals prepended to those passed
+// to calls to Info, Debug or Error.
+func With(logger Logger, keyvals ...interface{}) Logger {
+	switch logger.(type) {
+	case *tmLogger:
+		return &tmLogger{kitlog.With(logger.(*tmLogger).srcLogger, keyvals...)}
+	case *nopLogger:
+		return logger
+	default:
+		panic(fmt.Sprintf("Unexpected logger of type %T", logger))
+	}
+}

log/nop_logger.go

@@ -0,0 +1,18 @@
+package log
+
+type nopLogger struct{}
+
+// NewNopLogger returns a logger that doesn't do anything.
+func NewNopLogger() Logger { return &nopLogger{} }
+
+func (nopLogger) Info(string, ...interface{}) error {
+	return nil
+}
+
+func (nopLogger) Debug(string, ...interface{}) error {
+	return nil
+}
+
+func (nopLogger) Error(string, ...interface{}) error {
+	return nil
+}

log/nop_logger_test.go

@@ -0,0 +1,18 @@
+package log_test
+
+import (
+	"testing"
+
+	"github.com/tendermint/tmlibs/log"
+)
+
+func TestNopLogger(t *testing.T) {
+	t.Parallel()
+	logger := log.NewNopLogger()
+	if err := logger.Info("Hello", "abc", 123); err != nil {
+		t.Error(err)
+	}
+	if err := log.With(logger, "def", "ghi").Debug(""); err != nil {
+		t.Error(err)
+	}
+}

log/tm_logger.go

@@ -0,0 +1,74 @@
+package log
+
+import (
+	"fmt"
+	"io"
+
+	kitlog "github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
+	"github.com/go-kit/kit/log/term"
+)
+
+const (
+	msgKey = "_msg" // "_" prefixed to avoid collisions
+)
+
+type tmLogger struct {
+	srcLogger kitlog.Logger
+}
+
+// NewTmTermLogger returns a logger that encodes msg and keyvals to the Writer
+// using go-kit's log as an underlying logger and our custom formatter. Note
+// that underlying logger could be swapped with something else.
+func NewTmLogger(w io.Writer) Logger {
+	// Color by level value
+	colorFn := func(keyvals ...interface{}) term.FgBgColor {
+		if keyvals[0] != level.Key() {
+			panic(fmt.Sprintf("expected level key to be first, got %v", keyvals[0]))
+		}
+		switch keyvals[1].(level.Value).String() {
+		case "debug":
+			return term.FgBgColor{Fg: term.DarkGray}
+		case "error":
+			return term.FgBgColor{Fg: term.Red}
+		default:
+			return term.FgBgColor{}
+		}
+	}
+
+	srcLogger := term.NewLogger(w, NewTmfmtLogger, colorFn)
+	srcLogger = level.NewFilter(srcLogger, level.AllowInfo())
+	return &tmLogger{srcLogger}
+}
+
+// WithLevel returns a copy of the logger with a level set to lvl.
+func (l *tmLogger) WithLevel(lvl string) Logger {
+	switch lvl {
+	case "info":
+		return &tmLogger{level.NewFilter(l.srcLogger, level.AllowInfo())}
+	case "debug":
+		return &tmLogger{level.NewFilter(l.srcLogger, level.AllowDebug())}
+	case "error":
+		return &tmLogger{level.NewFilter(l.srcLogger, level.AllowError())}
+	default:
+		panic(fmt.Sprintf("Unexpected level %v, expect either \"info\" or \"debug\" or \"error\"", lvl))
+	}
+}
+
+// Info logs a message at level Info.
+func (l *tmLogger) Info(msg string, keyvals ...interface{}) error {
+	lWithLevel := level.Info(l.srcLogger)
+	return kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...)
+}
+
+// Debug logs a message at level Debug.
+func (l *tmLogger) Debug(msg string, keyvals ...interface{}) error {
+	lWithLevel := level.Debug(l.srcLogger)
+	return kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...)
+}
+
+// Error logs a message at level Error.
+func (l *tmLogger) Error(msg string, keyvals ...interface{}) error {
+	lWithLevel := level.Error(l.srcLogger)
+	return kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...)
+}

log/tm_logger_test.go

@@ -0,0 +1,41 @@
+package log_test
+
+import (
+	"io/ioutil"
+	"testing"
+
+	"github.com/tendermint/tmlibs/log"
+)
+
+func TestTmLogger(t *testing.T) {
+	t.Parallel()
+	logger := log.NewTmLogger(ioutil.Discard)
+	if err := logger.Info("Hello", "abc", 123); err != nil {
+		t.Error(err)
+	}
+	if err := log.With(logger, "def", "ghi").Debug(""); err != nil {
+		t.Error(err)
+	}
+}
+
+func BenchmarkTmLoggerSimple(b *testing.B) {
+	benchmarkRunner(b, log.NewTmLogger(ioutil.Discard), baseInfoMessage)
+}
+
+func BenchmarkTmLoggerContextual(b *testing.B) {
+	benchmarkRunner(b, log.NewTmLogger(ioutil.Discard), withInfoMessage)
+}
+
+func benchmarkRunner(b *testing.B, logger log.Logger, f func(log.Logger)) {
+	lc := log.With(logger, "common_key", "common_value")
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		f(lc)
+	}
+}
+
+var (
+	baseInfoMessage = func(logger log.Logger) { logger.Info("foo_message", "foo_key", "foo_value") }
+	withInfoMessage = func(logger log.Logger) { log.With(logger, "a", "b").Info("c", "d", "f") }
+)

log/tmfmt_logger.go

@@ -0,0 +1,116 @@
+package log
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"sync"
+	"time"
+
+	kitlog "github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
+	"github.com/go-logfmt/logfmt"
+)
+
+type tmfmtEncoder struct {
+	*logfmt.Encoder
+	buf bytes.Buffer
+}
+
+func (l *tmfmtEncoder) Reset() {
+	l.Encoder.Reset()
+	l.buf.Reset()
+}
+
+var tmfmtEncoderPool = sync.Pool{
+	New: func() interface{} {
+		var enc tmfmtEncoder
+		enc.Encoder = logfmt.NewEncoder(&enc.buf)
+		return &enc
+	},
+}
+
+type tmfmtLogger struct {
+	w io.Writer
+}
+
+// NewTmFmtLogger returns a logger that encodes keyvals to the Writer in
+// Tendermint custom format.
+//
+// Each log event produces no more than one call to w.Write.
+// The passed Writer must be safe for concurrent use by multiple goroutines if
+// the returned Logger will be used concurrently.
+func NewTmfmtLogger(w io.Writer) kitlog.Logger {
+	return &tmfmtLogger{w}
+}
+
+func (l tmfmtLogger) Log(keyvals ...interface{}) error {
+	enc := tmfmtEncoderPool.Get().(*tmfmtEncoder)
+	enc.Reset()
+	defer tmfmtEncoderPool.Put(enc)
+
+	lvl := "none"
+	msg := "unknown"
+	lvlIndex := -1
+	msgIndex := -1
+
+	for i := 0; i < len(keyvals)-1; i += 2 {
+		// Extract level
+		if keyvals[i] == level.Key() {
+			lvlIndex = i
+			switch keyvals[i+1].(type) {
+			case string:
+				lvl = keyvals[i+1].(string)
+			case level.Value:
+				lvl = keyvals[i+1].(level.Value).String()
+			default:
+				panic(fmt.Sprintf("level value of unknown type %T", keyvals[i+1]))
+			}
+			continue
+		}
+
+		// and message
+		if keyvals[i] == msgKey {
+			msgIndex = i
+			msg = keyvals[i+1].(string)
+			continue
+		}
+
+		if lvlIndex > 0 && msgIndex > 0 { // found all we're looking for
+			break
+		}
+	}
+
+	// Form a custom Tendermint line
+	//
+	// Example:
+	//     D[05-02|11:06:44.322] Stopping AddrBook (ignoring: already stopped)
+	//
+	// Description:
+	//     D										- first character of the level, uppercase (ASCII only)
+	//     [05-02|11:06:44.322] - our time format (see https://golang.org/src/time/format.go)
+	//     Stopping ...					- message
+	enc.buf.WriteString(fmt.Sprintf("%c[%s] %-44s", lvl[0]-32, time.Now().UTC().Format("01-02|15:04:05.000"), msg))
+
+	for i := 0; i < len(keyvals)-1; i += 2 {
+		if i == lvlIndex || i == msgIndex {
+			continue
+		}
+		if err := enc.EncodeKeyval(keyvals[i], keyvals[i+1]); err != nil {
+			return err
+		}
+	}
+
+	// Add newline to the end of the buffer
+	if err := enc.EndRecord(); err != nil {
+		return err
+	}
+
+	// The Logger interface requires implementations to be safe for concurrent
+	// use by multiple goroutines. For this implementation that means making
+	// only one call to l.w.Write() for each call to Log.
+	if _, err := l.w.Write(enc.buf.Bytes()); err != nil {
+		return err
+	}
+	return nil
+}

log/tmfmt_logger_test.go

@@ -0,0 +1,110 @@
+package log_test
+
+import (
+	"bytes"
+	"errors"
+	"io/ioutil"
+	"math"
+	"regexp"
+	"testing"
+
+	kitlog "github.com/go-kit/kit/log"
+	"github.com/stretchr/testify/assert"
+	"github.com/tendermint/tmlibs/log"
+)
+
+func TestTmfmtLogger(t *testing.T) {
+	t.Parallel()
+	buf := &bytes.Buffer{}
+	logger := log.NewTmfmtLogger(buf)
+
+	if err := logger.Log("hello", "world"); err != nil {
+		t.Fatal(err)
+	}
+	assert.Regexp(t, regexp.MustCompile(`N\[.+\] unknown \s+ hello=world\n$`), buf.String())
+
+	buf.Reset()
+	if err := logger.Log("a", 1, "err", errors.New("error")); err != nil {
+		t.Fatal(err)
+	}
+	assert.Regexp(t, regexp.MustCompile(`N\[.+\] unknown \s+ a=1 err=error\n$`), buf.String())
+
+	buf.Reset()
+	err := logger.Log("std_map", map[int]int{1: 2}, "my_map", mymap{0: 0})
+	assert.NotNil(t, err)
+
+	buf.Reset()
+	if err := logger.Log("level", "error"); err != nil {
+		t.Fatal(err)
+	}
+	assert.Regexp(t, regexp.MustCompile(`E\[.+\] unknown \s+\n$`), buf.String())
+
+	buf.Reset()
+	if err := logger.Log("_msg", "Hello"); err != nil {
+		t.Fatal(err)
+	}
+	assert.Regexp(t, regexp.MustCompile(`N\[.+\] Hello \s+\n$`), buf.String())
+}
+
+func BenchmarkTmfmtLoggerSimple(b *testing.B) {
+	benchmarkRunnerKitlog(b, log.NewTmfmtLogger(ioutil.Discard), baseMessage)
+}
+
+func BenchmarkTmfmtLoggerContextual(b *testing.B) {
+	benchmarkRunnerKitlog(b, log.NewTmfmtLogger(ioutil.Discard), withMessage)
+}
+
+func TestTmfmtLoggerConcurrency(t *testing.T) {
+	t.Parallel()
+	testConcurrency(t, log.NewTmfmtLogger(ioutil.Discard), 10000)
+}
+
+func benchmarkRunnerKitlog(b *testing.B, logger kitlog.Logger, f func(kitlog.Logger)) {
+	lc := kitlog.With(logger, "common_key", "common_value")
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		f(lc)
+	}
+}
+
+var (
+	baseMessage = func(logger kitlog.Logger) { logger.Log("foo_key", "foo_value") }
+	withMessage = func(logger kitlog.Logger) { kitlog.With(logger, "a", "b").Log("d", "f") }
+)
+
+// These test are designed to be run with the race detector.
+
+func testConcurrency(t *testing.T, logger kitlog.Logger, total int) {
+	n := int(math.Sqrt(float64(total)))
+	share := total / n
+
+	errC := make(chan error, n)
+
+	for i := 0; i < n; i++ {
+		go func() {
+			errC <- spam(logger, share)
+		}()
+	}
+
+	for i := 0; i < n; i++ {
+		err := <-errC
+		if err != nil {
+			t.Fatalf("concurrent logging error: %v", err)
+		}
+	}
+}
+
+func spam(logger kitlog.Logger, count int) error {
+	for i := 0; i < count; i++ {
+		err := logger.Log("key", i)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+type mymap map[int]int
+
+func (m mymap) String() string { return "special_behavior" }

logger/log.go

@@ -1,10 +1,11 @@
+// DEPRECATED! Use newer log package.
 package logger
 
 import (
 	"os"
 
-	. "github.com/tendermint/tmlibs/common"
 	"github.com/tendermint/log15"
+	. "github.com/tendermint/tmlibs/common"
 )
 
 var mainHandler log15.Handler
@@ -40,14 +41,14 @@ func MainHandler() log15.Handler {
 	return mainHandler
 }
 
-func BypassHandler() log15.Handler {
-	return bypassHandler
-}
-
 func New(ctx ...interface{}) log15.Logger {
 	return NewMain(ctx...)
 }
 
+func BypassHandler() log15.Handler {
+	return bypassHandler
+}
+
 func NewMain(ctx ...interface{}) log15.Logger {
 	return log15.Root().New(ctx...)
 }