1 files changed, 38 insertions, 2 deletions
diff --git a/weed/storage/backend/disk_file.go b/weed/storage/backend/disk_file.go
index 2b04c8df2..aee02e7be 100644
--- a/weed/storage/backend/disk_file.go
+++ b/weed/storage/backend/disk_file.go
@@ -1,6 +1,8 @@
 package backend
 
 import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util/buffered_writer"
 	"os"
 	"time"
 )
@@ -12,32 +14,64 @@ var (
 type DiskFile struct {
 	File         *os.File
 	fullFilePath string
+	bufWriterAt  *buffered_writer.TimedWriteBuffer
+	fileSize     int64
+	modTime      time.Time
 }
 
 func NewDiskFile(f *os.File) *DiskFile {
+	stat, e := f.Stat()
+	if e != nil {
+		glog.Fatalf("stat file %s: %v", f.Name(), e)
+	}
+
 	return &DiskFile{
 		fullFilePath: f.Name(),
 		File:         f,
+		bufWriterAt:  buffered_writer.NewTimedWriteBuffer(f, 1*1024*1024, 200*time.Millisecond, stat.Size()),
+		fileSize:     stat.Size(),
+		modTime:      stat.ModTime(),
 	}
 }
 
 func (df *DiskFile) ReadAt(p []byte, off int64) (n int, err error) {
+	n, _ = df.bufWriterAt.ReadAt(p, off)
+	if len(p) == n {
+		return
+	}
 	return df.File.ReadAt(p, off)
 }
 
 func (df *DiskFile) WriteAt(p []byte, off int64) (n int, err error) {
-	return df.File.WriteAt(p, off)
+	n, err = df.bufWriterAt.WriteAt(p, off)
+	if err == nil {
+		waterMark := off + int64(n)
+		if waterMark > df.fileSize {
+			df.fileSize = waterMark
+			df.modTime = time.Now()
+		}
+	}
+	return
 }
 
 func (df *DiskFile) Truncate(off int64) error {
-	return df.File.Truncate(off)
+	err := df.File.Truncate(off)
+	if err == nil {
+		df.fileSize = off
+		df.modTime = time.Now()
+	}
+	return err
 }
 
 func (df *DiskFile) Close() error {
+	df.bufWriterAt.Close()
 	return df.File.Close()
 }
 
 func (df *DiskFile) GetStat() (datSize int64, modTime time.Time, err error) {
+	if df.fileSize != 0 {
+		return df.fileSize, df.modTime, nil
+	}
 	stat, e := df.File.Stat()
 	if e == nil {
 		return stat.Size(), stat.ModTime(), nil
@@ -50,5 +84,7 @@ func (df *DiskFile) Name() string {
 }
 
 func (df *DiskFile) Sync() error {
+	df.fileSize = 0
+	df.bufWriterAt.Flush()
 	return df.File.Sync()
 }