simplify the file id format

git-svn-id: https://weed-fs.googlecode.com/svn/trunk@19 282b0af5-e82d-9cf1-ede4-77906d7719d0

weed-fs/src/pkg/directory/file_id.go

@@ -0,0 +1,44 @@
+package directory
+
+import (
+	"encoding/hex"
+	"storage"
+	"strconv"
+	"strings"
+)
+
+type FileId struct {
+	VolumeId uint32
+	Key      uint64
+	Hashcode uint32
+}
+
+func NewFileId(VolumeId uint32, Key uint64, Hashcode uint32) *FileId {
+	return &FileId{VolumeId: VolumeId, Key: Key, Hashcode: Hashcode}
+}
+
+func ParseFileId(path string) *FileId {
+	a := strings.Split(path, ",")
+	if len(a) != 2 {
+		return nil
+	}
+	vid_string, key_hash_string := a[0], a[1]
+	key_hash_bytes, khe := hex.DecodeString(key_hash_string)
+	key_hash_len := len(key_hash_bytes)
+	if khe != nil || key_hash_len <= 4 {
+		return nil
+	}
+	vid, _ := strconv.Atoui64(vid_string)
+	key := storage.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
+	hash := storage.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
+	return &FileId{VolumeId: uint32(vid), Key: key, Hashcode: hash}
+}
+func (n *FileId) String() string {
+	bytes := make([]byte, 12)
+	storage.Uint64toBytes(bytes[0:8], n.Key)
+	storage.Uint32toBytes(bytes[8:12], n.Hashcode)
+	nonzero_index := 0
+	for ; bytes[nonzero_index] == 0; nonzero_index++ {
+	}
+	return strconv.Uitoa64(uint64(n.VolumeId)) + "," + hex.EncodeToString(bytes[nonzero_index:])
+}

weed-fs/src/pkg/directory/file_id_test.go

@@ -0,0 +1,16 @@
+package directory
+
+import {
+    "testing"
+    "log"
+}
+func TestSerialDeserialization(t *testing.T) {
+    f1 := &FileId{VolumeId: 345, Key:8698, Hashcode: 23849095}
+    log.Println("vid", f1.VolumeId, "key", f1.Key, "hash", f1.Hashcode)
+
+    f2 := ParseFileId(t.String())
+
+    log.Println("vvid", f2.VolumeId, "vkey", f2.Key, "vhash", f2.Hashcode)
+
+    t.
+}

weed-fs/src/pkg/directory/volume_mapping.go

@@ -32,10 +32,10 @@ type Mapper struct {
 
 	lock          sync.Mutex
 	Machines      []*Machine
-	vid2machineId map[uint64]int
+	vid2machineId map[uint32]int
 	Writers       []int // transient array of Writers volume id
 
-	GlobalVolumeSequence uint64
+	GlobalVolumeSequence uint32
 
 	FileIdSequence uint64
 	fileIdCounter  uint64
@@ -49,7 +49,7 @@ func NewMapper(dirname string, filename string, capacity int) (m *Mapper) {
 	m = &Mapper{dir: dirname, fileName: filename, capacity: capacity}
 	log.Println("Loading volume id to maching mapping:", path.Join(m.dir, m.fileName+".map"))
 	dataFile, e := os.OpenFile(path.Join(m.dir, m.fileName+".map"), os.O_RDONLY, 0644)
-	m.vid2machineId = make(map[uint64]int)
+	m.vid2machineId = make(map[uint32]int)
 	m.Writers = *new([]int)
 	if e != nil {
 		log.Println("Mapping File Read", e)
@@ -86,10 +86,10 @@ func NewMapper(dirname string, filename string, capacity int) (m *Mapper) {
 	}
 	return
 }
-func (m *Mapper) PickForWrite() (vid uint64, server MachineInfo) {
+func (m *Mapper) PickForWrite() (string, MachineInfo) {
 	machine := m.Machines[m.Writers[rand.Intn(len(m.Writers))]]
-	vid = machine.Volumes[rand.Intn(len(machine.Volumes))].Id
-	return vid, machine.Server
+	vid := machine.Volumes[rand.Intn(len(machine.Volumes))].Id
+	return NewFileId(vid,m.NextFileId(),rand.Uint32()).String(), machine.Server
 }
 func (m *Mapper) NextFileId() uint64 {
     if m.fileIdCounter <= 0 {
@@ -99,10 +99,10 @@ func (m *Mapper) NextFileId() uint64 {
 	m.fileIdCounter--
 	return m.FileIdSequence - m.fileIdCounter
 }
-func (m *Mapper) Get(vid uint64) *Machine {
+func (m *Mapper) Get(vid uint32) *Machine {
 	return m.Machines[m.vid2machineId[vid]]
 }
-func (m *Mapper) Add(machine Machine) []uint64 {
+func (m *Mapper) Add(machine Machine) []uint32 {
 	log.Println("Adding existing", machine.Server.Url, len(machine.Volumes), "volumes to dir", len(m.Machines))
 	log.Println("Adding      new ", machine.Server.Url, machine.Capacity-len(machine.Volumes), "volumes to dir", len(m.Machines))
 	//check existing machine, linearly
@@ -121,7 +121,7 @@ func (m *Mapper) Add(machine Machine) []uint64 {
 	}
 
 	//generate new volumes
-	vids := new([]uint64)
+	vids := new([]uint32)
 	for vid, i := m.GlobalVolumeSequence, len(machine.Volumes); i < machine.Capacity; i, vid = i+1, vid+1 {
 		newVolume := storage.VolumeInfo{Id: vid, Size: 0}
 		machine.Volumes = append(machine.Volumes, newVolume)