add version type

weed-fs/src/cmd/weed/fix.go

@@ -15,8 +15,8 @@ func init() {
 
 var cmdFix = &Command{
   UsageLine: "fix -dir=/tmp -volumeId=234 -debug=1",
-  Short:     "run weed tool fix on data file if corrupted",
-  Long: `Fix runs the WeedFS fix command on the .dat volume file.
+  Short:     "run weed tool fix on index file if corrupted",
+  Long: `Fix runs the WeedFS fix command to re-create the index .idx file.
 
   `,
 }

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

@@ -17,8 +17,13 @@ import (
 type Needle struct {
 	Cookie uint32 "random number to mitigate brute force lookups"
 	Id     uint64 "needle id"
-	Size     uint32 "Data size"
+	Size   uint32 "sum of DataSize,Data,NameSize,Name,MimeSize,Mime"
+	//	DataSize uint32 "Data size"
 	Data []byte "The actual file data"
+	//	NameSize uint16
+	//	Name     []byte "maximum 256 characters"
+	//	MimeSize uint16
+	//	Mime     []byte "maximum 256 characters"
 	Checksum CRC    "CRC32 to check integrity"
 	Padding  []byte "Aligned to 8 bytes"
 }
@@ -97,7 +102,7 @@ func (n *Needle) Append(w io.Writer) uint32 {
 	w.Write(header[0 : rest+4])
 	return n.Size
 }
-func (n *Needle) Read(r io.Reader, size uint32) (int, error) {
+func (n *Needle) Read(r io.Reader, size uint32, version Version) (int, error) {
 	bytes := make([]byte, size+16+4)
 	ret, e := r.Read(bytes)
 	n.Cookie = util.BytesToUint32(bytes[0:4])

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

@@ -9,9 +9,11 @@ import (
 	"sync"
 )
 
+type Version uint8
+
 const (
 	SuperBlockSize = 8
-	Version        = 1
+	CurrentVersion = Version(1)
 )
 
 type Volume struct {
@@ -21,8 +23,7 @@ type Volume struct {
 	nm       *NeedleMap
 
 	replicaType ReplicationType
-
-	version uint8
+	version     Version
 
 	accessLock sync.Mutex
 }
@@ -68,7 +69,7 @@ func (v *Volume) maybeWriteSuperBlock() {
 	stat, _ := v.dataFile.Stat()
 	if stat.Size() == 0 {
 		header := make([]byte, SuperBlockSize)
-		header[0] = Version
+		header[0] = byte(CurrentVersion)
 		header[1] = v.replicaType.Byte()
 		v.dataFile.Write(header)
 	}
@@ -79,7 +80,7 @@ func (v *Volume) readSuperBlock() error {
 	if _, e := v.dataFile.Read(header); e != nil {
 		return fmt.Errorf("cannot read superblock: %s", e)
 	}
-	v.version = header[0]
+	v.version = Version(header[0])
 	var err error
 	if v.replicaType, err = NewReplicationTypeFromByte(header[1]); err != nil {
 		return fmt.Errorf("cannot read replica type: %s", err)
@@ -120,7 +121,7 @@ func (v *Volume) read(n *Needle) (int, error) {
 	nv, ok := v.nm.Get(n.Id)
 	if ok && nv.Offset > 0 {
 		v.dataFile.Seek(int64(nv.Offset)*8, 0)
-		return n.Read(v.dataFile, nv.Size)
+		return n.Read(v.dataFile, nv.Size, v.version)
 	}
 	return -1, errors.New("Not Found")
 }