return written bytes, add debug mode

git-svn-id: https://weed-fs.googlecode.com/svn/trunk@22 282b0af5-e82d-9cf1-ede4-77906d7719d0

weed-fs/src/pkg/storage/needle.go

@@ -47,7 +47,7 @@ func (n *Needle) ParsePath(fid string) {
 	}
 	n.Key, n.Cookie = ParseKeyHash(fid)
 }
-func (n *Needle) Append(w io.Writer) {
+func (n *Needle) Append(w io.Writer) (uint32){
 	header := make([]byte, 16)
 	Uint32toBytes(header[0:4], n.Cookie)
 	Uint64toBytes(header[4:12], n.Key)
@@ -58,6 +58,7 @@ func (n *Needle) Append(w io.Writer) {
 	rest := 8 - ((n.Size + 16 + 4) % 8)
 	Uint32toBytes(header[0:4], uint32(n.Checksum))
 	w.Write(header[0 : rest+4])
+	return n.Size
 }
 func (n *Needle) Read(r io.Reader, size uint32) {
 	bytes := make([]byte, size+16+4)

weed-fs/src/pkg/storage/store.go

@@ -83,8 +83,8 @@ func (s *Store) Close() {
 		v.Close()
 	}
 }
-func (s *Store) Write(i uint64, n *Needle) {
-	s.volumes[i].write(n)
+func (s *Store) Write(i uint64, n *Needle) (uint32){
+	return s.volumes[i].write(n)
 }
 func (s *Store) Read(i uint64, n *Needle) {
 	s.volumes[i].read(n)

weed-fs/src/pkg/storage/volume.go

@@ -48,15 +48,16 @@ func (v *Volume) Close() {
 	v.dataFile.Close()
 }
 
-func (v *Volume) write(n *Needle) {
+func (v *Volume) write(n *Needle) uint32{
 	counter := <-v.accessChannel
 	offset, _ := v.dataFile.Seek(0, 2)
-	n.Append(v.dataFile)
+	ret := n.Append(v.dataFile)
 	nv, ok := v.nm.get(n.Key)
 	if !ok || int64(nv.Offset)*8 < offset {
 		v.nm.put(n.Key, uint32(offset/8), n.Size)
 	}
 	v.accessChannel <- counter + 1
+	return ret
 }
 func (v *Volume) read(n *Needle) {
 	counter := <-v.accessChannel