Added a backend for the default Go logger

dlog/doc.go

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2019. Genome Research Ltd. All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License,
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @file doc.go
+ * @author Keith James <[email protected]>
+ */
+
+/*
+Package dlog is a log (https://golang.org/pkg/log/) backend for
+logshim (http://github.com/kjsanger/logshim).
+*/
+package dlog

dlog/log.go

@@ -0,0 +1,207 @@
+/*
+ * Copyright (C) 2019. Genome Research Ltd. All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License,
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @file log.go
+ * @author Keith James <[email protected]>
+ */
+
+package dlog
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"strings"
+	"time"
+
+	"github.com/kjsanger/logshim"
+)
+
+type levelName string
+
+const (
+	errorLevel levelName = "ERROR"
+	warnLevel  levelName = "WARN"
+	// noticeLevel levelName = "NOTICE"
+	infoLevel  levelName = "INFO"
+	debugLevel levelName = "DEBUG"
+)
+
+func translateLevel(level logshim.Level) (levelName, error) {
+	var (
+		lvn levelName
+		err error
+	)
+
+	switch level {
+	case logshim.ErrorLevel:
+		lvn = errorLevel
+	case logshim.WarnLevel:
+		lvn = warnLevel
+	case logshim.NoticeLevel:
+		fallthrough
+	case logshim.InfoLevel:
+		lvn = infoLevel
+	case logshim.DebugLevel:
+		lvn = debugLevel
+	default:
+		lvn = warnLevel
+		err = fmt.Errorf("invalid log level %d, defaulting to "+
+			"WARN level", level)
+	}
+
+	return lvn, err
+}
+
+type StdLogger struct {
+	name  string
+	Level logshim.Level
+	*log.Logger
+}
+
+func New(writer io.Writer, level logshim.Level) *StdLogger {
+	lg := log.New(writer, "", log.LstdFlags|log.Lshortfile)
+
+	_, err := translateLevel(level)
+	if err != nil {
+		log.Print(errorLevel, "log configuration error", err)
+		level = logshim.WarnLevel
+	}
+
+	return &StdLogger{"StdLog", level, lg}
+}
+
+func (log *StdLogger) Name() string {
+	return log.name
+}
+
+func (log *StdLogger) Err(err error) logshim.Message {
+	effectiveLevel := logshim.InfoLevel
+	if err != nil {
+		effectiveLevel = logshim.ErrorLevel
+	}
+
+	active := log.Level >= effectiveLevel
+	msg := &stdMessage{active, effectiveLevel, &strings.Builder{}}
+	msg.Err(err)
+	return msg
+}
+
+func (log *StdLogger) Error() logshim.Message {
+	active := log.Level >= logshim.ErrorLevel
+	msg := &stdMessage{active, logshim.ErrorLevel, &strings.Builder{}}
+	return msg
+}
+
+func (log *StdLogger) Warn() logshim.Message {
+	active := log.Level >= logshim.WarnLevel
+	msg := &stdMessage{active, logshim.WarnLevel, &strings.Builder{}}
+	return msg
+}
+
+func (log *StdLogger) Notice() logshim.Message {
+	active := log.Level >= logshim.NoticeLevel
+	msg := &stdMessage{active, logshim.InfoLevel, &strings.Builder{}}
+	return msg
+}
+
+func (log *StdLogger) Info() logshim.Message {
+	active := log.Level >= logshim.InfoLevel
+	msg := &stdMessage{active, logshim.InfoLevel, &strings.Builder{}}
+	return msg
+}
+
+func (log *StdLogger) Debug() logshim.Message {
+	active := log.Level >= logshim.DebugLevel
+	msg := &stdMessage{active, logshim.DebugLevel, &strings.Builder{}}
+	return msg
+}
+
+type stdMessage struct {
+	active  bool
+	level   logshim.Level
+	builder *strings.Builder
+}
+
+func (msg *stdMessage) Err(err error) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" error: %v", err))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Bool(key string, val bool) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" %s: %v", key, val))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Int(key string, val int) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" %s: %d", key, val))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Int64(key string, val int64) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" %s: %d", key, val))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Uint64(key string, val uint64) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" %s: %d", key, val))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Str(key string, val string) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" %s: %s", key, val))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Time(key string, val time.Time) logshim.Message {
+	if msg.active {
+		msg.builder.WriteString(fmt.Sprintf(" %s: %v", key, val))
+	}
+	return msg
+}
+
+func (msg *stdMessage) Msg(val string) {
+	if msg.active {
+		lvn, err := translateLevel(msg.level)
+		if err != nil {
+			// This should never happen because the Logger constructor corrects
+			// invalid level values.
+			log.Print(errorLevel, "log configuration error", err)
+		}
+
+		msg.builder.WriteString(" ")
+		msg.builder.WriteString(val)
+		log.Print(lvn, msg.builder.String())
+		// Once this method is called, deactivate for all future calls
+		msg.active = false
+	}
+}
+
+func (msg *stdMessage) Msgf(format string, a ...interface{}) {
+	msg.Msg(fmt.Sprintf(format, a...))
+}

dlog/log_test.go

@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2019. Genome Research Ltd. All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License,
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @file log_test.go
+ * @author Keith James <[email protected]>
+ */
+
+package dlog
+
+import (
+	"os"
+	"testing"
+
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/kjsanger/logshim"
+)
+
+func TestNew(t *testing.T) {
+	for _, level := range logshim.Levels() {
+		logger := New(os.Stderr, level)
+		assert.NotNil(t, logger, "StdLogger level %d was nil", level)
+	}
+}
+
+func TestStdLogger_Err(t *testing.T) {
+	log := New(os.Stderr, logshim.ErrorLevel)
+	assert.NotNil(t, log.Err(errors.New("test error")),
+		"Err() should return a Message")
+}
+
+func TestStdLogger_Error(t *testing.T) {
+	log := New(os.Stderr, logshim.ErrorLevel)
+	assert.NotNil(t, log.Error(), "Error() should return a Message")
+}
+
+func TestStdLogger_Warn(t *testing.T) {
+	log := New(os.Stderr, logshim.ErrorLevel)
+	assert.NotNil(t, log.Warn(), "Warn() should return a Message")
+}
+
+func TestStdLogger_Notice(t *testing.T) {
+	log := New(os.Stderr, logshim.ErrorLevel)
+	assert.NotNil(t, log.Notice(), "Notice() should return a Message")
+}
+
+func TestStdLogger_Info(t *testing.T) {
+	log := New(os.Stderr, logshim.ErrorLevel)
+	assert.NotNil(t, log.Info(), "Info() should return a Message")
+}
+
+func TestStdLogger_Debug(t *testing.T) {
+	log := New(os.Stderr, logshim.ErrorLevel)
+	assert.NotNil(t, log.Debug(), "Debug() should return a Message")
+}

go.mod

@@ -1,3 +1,8 @@
 module github.com/kjsanger/logshim
 
 go 1.12
+
+require (
+	github.com/pkg/errors v0.8.1
+	github.com/stretchr/testify v1.3.0
+)

go.sum

@@ -0,0 +1,9 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=