Basic buffered filelogger

filelogger.go

@@ -8,8 +8,27 @@ import (
 )
 
 type FileLogger struct {
-	w *os.File
-	l sync.Mutex
+	w        *os.File
+	l        sync.Mutex
+	buffer   chan []byte
+	buffered bool
+}
+
+func (f *FileLogger) flush() {
+	f.l.Lock()
+	defer func() {
+		f.w.Sync()
+		f.l.Unlock()
+	}()
+
+	if !f.buffered {
+		return
+	}
+
+	for msg := range f.buffer {
+		// TODO: errors?
+		f.w.Write(msg)
+	}
 }
 
 func (f *FileLogger) Write(p []byte) (n int, err error) {
@@ -17,6 +36,15 @@ func (f *FileLogger) Write(p []byte) (n int, err error) {
 		return 0, fmt.Errorf("No file handle available")
 	}
 
+	if f.buffered {
+		if len(f.buffer) == cap(f.buffer) {
+			f.flush()
+		}
+
+		f.buffer <- p
+		return len(p), nil
+	}
+
 	f.l.Lock()
 	defer func() {
 		f.w.Sync()
@@ -31,18 +59,30 @@ func (f *FileLogger) Close() error {
 		return nil
 	}
 
-	f.l.Lock()
-	defer f.l.Unlock()
+	f.flush()
 
 	return f.w.Close()
 }
 
-func NewFileLogger(file string) (ret io.WriteCloser, err error) {
+func newFileLogger(file string, buffer int) (ret io.WriteCloser, err error) {
 	rret := &FileLogger{}
+	rret.buffered = false
 
 	if rret.w, err = os.OpenFile(file, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644); err != nil {
 		return nil, err
 	}
+	if buffer > 0 {
+		rret.buffer = make(chan []byte, buffer)
+		rret.buffered = true
+	}
 
 	return rret, nil
 }
+
+func NewFileLogger(file string) (ret io.WriteCloser, err error) {
+	return newFileLogger(file, 0)
+}
+
+func NewBufferedFileLogger(file string, buffer int) (ret io.WriteCloser, err error) {
+	return newFileLogger(file, buffer)
+}