2 files changed, 65 insertions, 0 deletions
diff --git a/weed/storage/backend/backend.go b/weed/storage/backend/backend.go
new file mode 100644
index 000000000..ae0f84216
--- /dev/null
+++ b/weed/storage/backend/backend.go
@@ -0,0 +1,15 @@
+package backend
+
+import (
+	"io"
+	"time"
+)
+
+type DataStorageBackend interface {
+	io.ReaderAt
+	io.WriterAt
+	Truncate(off int64) error
+	io.Closer
+	GetStat() (datSize int64, modTime time.Time, err error)
+	String() string
+}
diff --git a/weed/storage/backend/disk_file.go b/weed/storage/backend/disk_file.go
new file mode 100644
index 000000000..7c8616cf6
--- /dev/null
+++ b/weed/storage/backend/disk_file.go
@@ -0,0 +1,50 @@
+package backend
+
+import (
+	"os"
+	"time"
+)
+
+var (
+	_ DataStorageBackend = &DiskFile{}
+)
+
+type DiskFile struct {
+	File         *os.File
+	fullFilePath string
+}
+
+func NewDiskFile(fullFilePath string, f *os.File) *DiskFile {
+	return &DiskFile{
+		fullFilePath: fullFilePath,
+		File:         f,
+	}
+}
+
+func (df *DiskFile) ReadAt(p []byte, off int64) (n int, err error) {
+	return df.File.ReadAt(p, off)
+}
+
+func (df *DiskFile) WriteAt(p []byte, off int64) (n int, err error) {
+	return df.File.WriteAt(p, off)
+}
+
+func (df *DiskFile) Truncate(off int64) error {
+	return df.File.Truncate(off)
+}
+
+func (df *DiskFile) Close() error {
+	return df.File.Close()
+}
+
+func (df *DiskFile) GetStat() (datSize int64, modTime time.Time, err error) {
+	stat, e := df.File.Stat()
+	if e == nil {
+		return stat.Size(), stat.ModTime(), nil
+	}
+	return 0, time.Time{}, err
+}
+
+func (df *DiskFile) String() string {
+	return df.fullFilePath
+}