Add 4 FileWriters implementions

always_new_file_writer.go

@@ -0,0 +1,42 @@
+package log
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"time"
+)
+
+// AlwaysNewFileWriter create new log for every process
+type AlwaysNewFileWriter struct {
+	Name string
+	file *os.File
+}
+
+func (w *AlwaysNewFileWriter) Write(p []byte) (n int, err error) {
+	if w.file == nil {
+		w.openFile()
+	}
+
+	return w.file.Write(p)
+}
+
+func (w *AlwaysNewFileWriter) openFile() (err error) {
+	name := fmt.Sprintf("%s.%s", w.Name, time.Now().Format("20060102_150405"))
+
+	// remove symbol link if exist
+	os.Remove(w.Name)
+
+	// create symbol
+	err = os.Symlink(path.Base(name), w.Name)
+	if err != nil {
+		return err
+	}
+
+	w.file, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

always_new_file_writer_test.go

@@ -0,0 +1,16 @@
+package log
+
+import (
+	"testing"
+)
+
+func TestAlwaysNewFileWriter(t *testing.T) {
+	log := New(&AlwaysNewFileWriter{
+		Name: "/tmp/test.log",
+	})
+	log.SetTimeLayout("15:04:05.999")
+	log.SetName("main")
+	for i := 0; i < 100; i++ {
+		log.Info("i = %d", i)
+	}
+}

composite_writers.go

@@ -0,0 +1,14 @@
+package log
+
+import (
+	"io"
+)
+
+type CompositeWriters []io.Writer
+
+func (ws *CompositeWriters) Write(p []byte) (n int, err error) {
+	for _, w := range *ws {
+		n, err = w.Write(p)
+	}
+	return
+}

composite_writers_test.go

@@ -0,0 +1,20 @@
+package log
+
+import (
+	"os"
+	"testing"
+)
+
+func TestCompositeWriters(t *testing.T) {
+	log := New(&CompositeWriters{
+		os.Stdout,
+		&DailyFileWriter{
+			Name: "/tmp/test.log",
+		},
+	})
+	log.SetTimeLayout("15:04:05.999")
+	log.SetName("main")
+	for i := 0; i < 5; i++ {
+		log.Info("i = %d", i)
+	}
+}

daily_file_writer.go

@@ -0,0 +1,51 @@
+package log
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"time"
+)
+
+// DailyFileWriter create new log for every day
+type DailyFileWriter struct {
+	Name        string
+	file        *os.File
+	nextDayTime int64
+}
+
+func (w *DailyFileWriter) Write(p []byte) (n int, err error) {
+	now := time.Now()
+
+	if w.file == nil {
+		w.openFile(&now)
+	} else if now.Unix() >= w.nextDayTime {
+		w.file.Close()
+		w.openFile(&now)
+	}
+
+	return w.file.Write(p)
+}
+
+func (w *DailyFileWriter) openFile(now *time.Time) (err error) {
+	name := fmt.Sprintf("%s.%s", w.Name, now.Format("2006-01-02"))
+
+	// remove symbol link if exist
+	os.Remove(w.Name)
+
+	// create symbol
+	err = os.Symlink(path.Base(name), w.Name)
+	if err != nil {
+		return err
+	}
+
+	w.file, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
+	if err != nil {
+		return err
+	}
+
+	year, month, day := now.Date()
+	w.nextDayTime = time.Date(year, month, day+1, 0, 0, 0, 0, now.Location()).Unix()
+
+	return nil
+}

daily_file_writer_test.go

@@ -0,0 +1,16 @@
+package log
+
+import (
+	"testing"
+)
+
+func TestDailyFileWriter(t *testing.T) {
+	log := New(&DailyFileWriter{
+		Name: "/tmp/test.log",
+	})
+	log.SetTimeLayout("15:04:05.999")
+	log.SetName("main")
+	for i := 0; i < 100; i++ {
+		log.Info("i = %d", i)
+	}
+}

fixed_size_file_writer.go

@@ -0,0 +1,106 @@
+package log
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"path"
+)
+
+// FixedSizeFileWriter create new log if log size exceed
+type FixedSizeFileWriter struct {
+	Name     string
+	MaxSize  int64
+	MaxCount int
+
+	file        *os.File
+	currentSize int64
+}
+
+func (w *FixedSizeFileWriter) Write(p []byte) (n int, err error) {
+	if w.file == nil {
+		w.openCurrentFile()
+	} else if w.currentSize > w.MaxSize {
+		w.file.Close()
+		w.openNextFile()
+	}
+
+	w.currentSize += int64(len(p))
+
+	return w.file.Write(p)
+}
+
+func (w *FixedSizeFileWriter) openCurrentFile() error {
+	name, err := os.Readlink(w.Name)
+	if err != nil {
+		name = w.getAvailableFileName()
+
+		// create a symlink
+		err = os.Symlink(path.Base(name), w.Name)
+		if err != nil {
+			return err
+		}
+	} else {
+		// convert to abs path
+		name = path.Join(path.Dir(w.Name), name)
+	}
+
+	w.file, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
+	if err != nil {
+		return err
+	}
+
+	stat, err := w.file.Stat()
+	if err != nil {
+		return err
+	}
+	w.currentSize = stat.Size()
+
+	return nil
+}
+
+func (w *FixedSizeFileWriter) openNextFile() (err error) {
+	name := w.getAvailableFileName()
+
+	// remove symbol link
+	err = os.Remove(w.Name)
+	if err != nil {
+		return err
+	}
+
+	// create symbol
+	err = os.Symlink(path.Base(name), w.Name)
+	if err != nil {
+		return err
+	}
+
+	w.file, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return err
+	}
+
+	w.currentSize = 0
+
+	return nil
+}
+
+// get available file or oldest file
+func (w *FixedSizeFileWriter) getAvailableFileName() string {
+	var oldestTime int64 = math.MaxInt64
+	var oldestName string
+
+	for i := 0; i < w.MaxCount; i++ {
+		name := fmt.Sprintf("%s.%d", w.Name, i)
+		stat, err := os.Stat(name)
+		if err != nil {
+			return name
+		}
+
+		if fTime := stat.ModTime().Unix(); fTime < oldestTime {
+			oldestTime = fTime
+			oldestName = name
+		}
+	}
+
+	return oldestName
+}

fixed_size_file_writer_test.go

@@ -0,0 +1,18 @@
+package log
+
+import (
+	"testing"
+)
+
+func TestFixedSizeFileWriter(t *testing.T) {
+	log := New(&FixedSizeFileWriter{
+		Name:     "/tmp/test.log",
+		MaxSize:  1024 * 3,
+		MaxCount: 5,
+	})
+	log.SetTimeLayout("15:04:05.999")
+	log.SetName("main")
+	for i := 0; i < 100; i++ {
+		log.Info("i = %d", i)
+	}
+}