use the standard library log package for logging

utils/log.go

@@ -1,11 +1,9 @@
 package utils
 
 import (
-	"fmt"
-	"io"
+	"log"
 	"os"
 	"strconv"
-	"sync"
 	"time"
 )
 
@@ -26,18 +24,10 @@ const (
 )
 
 var (
-	logLevel             = LogLevelNothing
-	out        io.Writer = os.Stdout
-	timeFormat           = "15:04:05.000"
-
-	mutex sync.Mutex
+	logLevel   = LogLevelNothing
+	timeFormat = ""
 )
 
-// SetLogWriter sets the log writer.
-func SetLogWriter(w io.Writer) {
-	out = w
-}
-
 // SetLogLevel sets the log level
 func SetLogLevel(level LogLevel) {
 	logLevel = level
@@ -46,42 +36,36 @@ func SetLogLevel(level LogLevel) {
 // SetLogTimeFormat sets the format of the timestamp
 // an empty string disables the logging of timestamps
 func SetLogTimeFormat(format string) {
+	log.SetFlags(0) // disable timestamp logging done by the log package
 	timeFormat = format
 }
 
 // Debugf logs something
 func Debugf(format string, args ...interface{}) {
 	if logLevel == LogLevelDebug {
-		mutex.Lock()
-		logTimestamp()
-		fmt.Fprintf(out, format+"\n", args...)
-		mutex.Unlock()
+		logMessage(format, args...)
 	}
 }
 
 // Infof logs something
 func Infof(format string, args ...interface{}) {
 	if logLevel <= LogLevelInfo {
-		mutex.Lock()
-		logTimestamp()
-		fmt.Fprintf(out, format+"\n", args...)
-		mutex.Unlock()
+		logMessage(format, args...)
 	}
 }
 
 // Errorf logs something
 func Errorf(format string, args ...interface{}) {
 	if logLevel <= LogLevelError {
-		mutex.Lock()
-		logTimestamp()
-		fmt.Fprintf(out, format+"\n", args...)
-		mutex.Unlock()
+		logMessage(format, args...)
 	}
 }
 
-func logTimestamp() {
+func logMessage(format string, args ...interface{}) {
 	if len(timeFormat) > 0 {
-		fmt.Fprintf(out, time.Now().Format(timeFormat)+" ")
+		log.Printf(time.Now().Format(timeFormat)+" "+format, args...)
+	} else {
+		log.Printf(format, args...)
 	}
 }
 

utils/log_test.go

@@ -2,6 +2,7 @@ package utils
 
 import (
 	"bytes"
+	"log"
 	"os"
 	"time"
 
@@ -12,16 +13,20 @@ import (
 var _ = Describe("Log", func() {
 	var (
 		b *bytes.Buffer
+
+		initialTimeFormat string
 	)
 
 	BeforeEach(func() {
 		b = bytes.NewBuffer([]byte{})
-		out = b
+		log.SetOutput(b)
+		initialTimeFormat = timeFormat
 	})
 
 	AfterEach(func() {
-		out = os.Stdout
+		log.SetOutput(os.Stdout)
 		SetLogLevel(LogLevelNothing)
+		timeFormat = initialTimeFormat
 	})
 
 	It("log level nothing", func() {