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authorchris.lu@gmail.com <chris.lu@gmail.com@282b0af5-e82d-9cf1-ede4-77906d7719d0>2011-12-16 14:51:26 +0000
committerchris.lu@gmail.com <chris.lu@gmail.com@282b0af5-e82d-9cf1-ede4-77906d7719d0>2011-12-16 14:51:26 +0000
commit23ecd7bb33e8c22b07f630fb963cbdc5c072adad (patch)
tree6408c31e48fde5cb2dcf34266504dff3a014388f
parent02f4e7b82c5763efb6932bcc3f97dc549b66e4a9 (diff)
downloadseaweedfs-23ecd7bb33e8c22b07f630fb963cbdc5c072adad.tar.xz
seaweedfs-23ecd7bb33e8c22b07f630fb963cbdc5c072adad.zip
split into server and clients
git-svn-id: https://weed-fs.googlecode.com/svn/trunk@9 282b0af5-e82d-9cf1-ede4-77906d7719d0
-rw-r--r--weed-fs/src/cmd/gstore.go145
-rw-r--r--weed-fs/src/cmd/weedc.go73
-rw-r--r--weed-fs/src/cmd/weeds.go80
-rw-r--r--weed-fs/src/pkg/directory/volume_mapping.go17
-rw-r--r--weed-fs/src/pkg/storage/needle.go67
-rw-r--r--weed-fs/src/pkg/storage/needle_map.go53
-rw-r--r--weed-fs/src/pkg/storage/store.go69
-rw-r--r--weed-fs/src/pkg/storage/util.go50
-rw-r--r--weed-fs/src/pkg/storage/volume.go66
9 files changed, 466 insertions, 154 deletions
diff --git a/weed-fs/src/cmd/gstore.go b/weed-fs/src/cmd/gstore.go
deleted file mode 100644
index 5f92d3950..000000000
--- a/weed-fs/src/cmd/gstore.go
+++ /dev/null
@@ -1,145 +0,0 @@
-package main
-
-import (
- "store"
- "directory"
- "flag"
- "fmt"
- "http"
- "json"
- "log"
- "mime"
- "rand"
- "strconv"
- "strings"
- "time"
-)
-
-var (
- port = flag.Int("port", 8080, "http listen port")
- chunkFolder = flag.String("dir", "/tmp", "data directory to store files")
- chunkCount = flag.Int("chunks", 5, "data chunks to store files")
- chunkEnabled = flag.Bool("data", false, "act as a store server")
- chunkServer = flag.String("cserver", "localhost:8080", "chunk server to store data")
- publicServer = flag.String("pserver", "localhost:8080", "public server to serve data read")
- metaServer = flag.String("mserver", "localhost:8080", "metadata server to store mappings")
-
- metaEnabled = flag.Bool("meta", false, "act as a directory server")
- metaFolder = flag.String("mdir", "/tmp", "data directory to store mappings")
-)
-
-type Haystack struct {
- store *store.Store
- directory *directory.Mapper
-}
-
-func storeHandler(w http.ResponseWriter, r *http.Request) {
- switch r.Method {
- case "GET":
- server.GetHandler(w, r)
- case "DELETE":
- server.DeleteHandler(w, r)
- case "POST":
- server.PostHandler(w, r)
- }
-}
-func (s *Haystack) GetHandler(w http.ResponseWriter, r *http.Request) {
- n := new(store.Needle)
- path := r.URL.Path
- sepIndex := strings.Index(path[1:], "/") + 1
- volumeId, _ := strconv.Atoui64(path[1:sepIndex])
- dotIndex := strings.LastIndex(path, ".")
- n.ParsePath(path[sepIndex+1 : dotIndex])
- ext := path[dotIndex:]
-
- s.store.Read(volumeId, n)
- w.Header().Set("Content-Type", mime.TypeByExtension(ext))
- w.Write(n.Data)
-}
-func (s *Haystack) PostHandler(w http.ResponseWriter, r *http.Request) {
- volumeId, _ := strconv.Atoui64(r.FormValue("volumeId"))
- s.store.Write(volumeId, store.NewNeedle(r))
- w.Header().Set("Content-Type", "text/plain")
- fmt.Fprint(w, "volumeId=", volumeId, "\n")
-}
-func (s *Haystack) DeleteHandler(w http.ResponseWriter, r *http.Request) {
-
-}
-func dirReadHandler(w http.ResponseWriter, r *http.Request) {
- volumeId, _ := strconv.Atoui64(r.FormValue("volumeId"))
- machineList := server.directory.Get((uint32)(volumeId))
- x := rand.Intn(len(machineList))
- machine := machineList[x]
- bytes, _ := json.Marshal(machine)
- callback := r.FormValue("callback")
- w.Header().Set("Content-Type", "application/javascript")
- if callback == "" {
- w.Write(bytes)
- } else {
- w.Write([]uint8(callback))
- w.Write([]uint8("("))
- w.Write(bytes)
- w.Write([]uint8(")"))
- }
-}
-func dirWriteHandler(w http.ResponseWriter, r *http.Request) {
- machineList := server.directory.PickForWrite()
- bytes, _ := json.Marshal(machineList)
- callback := r.FormValue("callback")
- w.Header().Set("Content-Type", "application/javascript")
- if callback == "" {
- w.Write(bytes)
- } else {
- w.Write([]uint8(callback))
- w.Write([]uint8("("))
- w.Write(bytes)
- w.Write([]uint8(")"))
- }
-}
-func dirJoinHandler(w http.ResponseWriter, r *http.Request) {
- s := r.FormValue("server")
- publicServer := r.FormValue("publicServer")
- volumes := make([]store.VolumeStat, 0)
- json.Unmarshal([]byte(r.FormValue("volumes")), volumes)
- server.directory.Add(directory.NewMachine(s, publicServer), volumes)
-}
-func dirStatusHandler(w http.ResponseWriter, r *http.Request) {
- w.Header().Set("Content-Type", "text/plain")
- bytes, _ := json.Marshal(server.directory)
- fmt.Fprint(w, bytes)
-}
-
-var server *Haystack
-
-func main() {
- flag.Parse()
- bothEnabled := false
- if !*chunkEnabled && !*metaEnabled {
- bothEnabled = true
- log.Println("Act as both a store server and a directory server")
- }
- server = new(Haystack)
- if *chunkEnabled || bothEnabled {
- log.Println("data stored in", *chunkFolder)
- server.store = store.NewStore(*chunkServer, *publicServer, *chunkFolder)
- defer server.store.Close()
- http.HandleFunc("/", storeHandler)
- }
- if *metaEnabled || bothEnabled {
- server.directory = directory.NewMapper(*metaFolder, "directory")
- defer server.directory.Save()
- http.HandleFunc("/dir/read", dirReadHandler)
- http.HandleFunc("/dir/write", dirWriteHandler)
- http.HandleFunc("/dir/join", dirJoinHandler)
- http.HandleFunc("/dir/status", dirStatusHandler)
- }
- go func() {
- time.Sleep(3000 * 1000)
- server.store.Join(*metaServer)
- log.Println("store joined at", *metaServer)
- }()
-
- log.Println("Serving at http://127.0.0.1:" + strconv.Itoa(*port))
- http.ListenAndServe(":"+strconv.Itoa(*port), nil)
-
-}
diff --git a/weed-fs/src/cmd/weedc.go b/weed-fs/src/cmd/weedc.go
new file mode 100644
index 000000000..94032a971
--- /dev/null
+++ b/weed-fs/src/cmd/weedc.go
@@ -0,0 +1,73 @@
+package main
+
+import (
+ "storage"
+ "flag"
+ "fmt"
+ "http"
+ "log"
+ "mime"
+ "strconv"
+ "strings"
+)
+
+var (
+ port = flag.Int("port", 8080, "http listen port")
+ chunkFolder = flag.String("dir", "/tmp", "data directory to store files")
+ chunkCount = flag.Int("chunks", 5, "data chunks to store files")
+ publicServer = flag.String("pserver", "localhost:8080", "public server to serve data read")
+ metaServer = flag.String("mserver", "localhost:9333", "metadata server to store mappings")
+
+ store *storage.Store
+)
+
+
+func storeHandler(w http.ResponseWriter, r *http.Request) {
+ switch r.Method {
+ case "GET":
+ GetHandler(w, r)
+ case "DELETE":
+ DeleteHandler(w, r)
+ case "POST":
+ PostHandler(w, r)
+ }
+}
+func GetHandler(w http.ResponseWriter, r *http.Request) {
+ n := new(storage.Needle)
+ path := r.URL.Path
+ sepIndex := strings.Index(path[1:], "/") + 1
+ volumeId, _ := strconv.Atoui64(path[1:sepIndex])
+ dotIndex := strings.LastIndex(path, ".")
+ n.ParsePath(path[sepIndex+1 : dotIndex])
+ ext := path[dotIndex:]
+
+ store.Read(volumeId, n)
+ w.Header().Set("Content-Type", mime.TypeByExtension(ext))
+ w.Write(n.Data)
+}
+func PostHandler(w http.ResponseWriter, r *http.Request) {
+ volumeId, _ := strconv.Atoui64(r.FormValue("volumeId"))
+ store.Write(volumeId, storage.NewNeedle(r))
+ w.Header().Set("Content-Type", "text/plain")
+ fmt.Fprint(w, "volumeId=", volumeId, "\n")
+}
+func DeleteHandler(w http.ResponseWriter, r *http.Request) {
+
+}
+
+func main() {
+ flag.Parse()
+ store = storage.NewStore(*port, *publicServer, *chunkFolder)
+ defer store.Close()
+ http.HandleFunc("/", storeHandler)
+
+ store.Join(*metaServer)
+ log.Println("store joined at", *metaServer)
+
+ log.Println("Start storage service at http://127.0.0.1:" + strconv.Itoa(*port))
+ e := http.ListenAndServe(":"+strconv.Itoa(*port), nil)
+ if e!=nil {
+ log.Fatalf("Fail to start:",e.String())
+ }
+
+}
diff --git a/weed-fs/src/cmd/weeds.go b/weed-fs/src/cmd/weeds.go
new file mode 100644
index 000000000..ad423b71e
--- /dev/null
+++ b/weed-fs/src/cmd/weeds.go
@@ -0,0 +1,80 @@
+package main
+
+import (
+ "storage"
+ "directory"
+ "flag"
+ "fmt"
+ "http"
+ "json"
+ "log"
+ "rand"
+ "strconv"
+)
+
+var (
+ port = flag.Int("port", 9333, "http listen port")
+ metaFolder = flag.String("mdir", "/tmp", "data directory to store mappings")
+ mapper *directory.Mapper
+)
+
+func dirReadHandler(w http.ResponseWriter, r *http.Request) {
+ volumeId, _ := strconv.Atoui64(r.FormValue("volumeId"))
+ machineList := mapper.Get((uint32)(volumeId))
+ x := rand.Intn(len(machineList))
+ machine := machineList[x]
+ bytes, _ := json.Marshal(machine)
+ callback := r.FormValue("callback")
+ w.Header().Set("Content-Type", "application/javascript")
+ if callback == "" {
+ w.Write(bytes)
+ } else {
+ w.Write([]uint8(callback))
+ w.Write([]uint8("("))
+ w.Write(bytes)
+ w.Write([]uint8(")"))
+ }
+}
+func dirWriteHandler(w http.ResponseWriter, r *http.Request) {
+ machineList := mapper.PickForWrite()
+ bytes, _ := json.Marshal(machineList)
+ callback := r.FormValue("callback")
+ w.Header().Set("Content-Type", "application/javascript")
+ if callback == "" {
+ w.Write(bytes)
+ } else {
+ w.Write([]uint8(callback))
+ w.Write([]uint8("("))
+ w.Write(bytes)
+ w.Write([]uint8(")"))
+ }
+}
+func dirJoinHandler(w http.ResponseWriter, r *http.Request) {
+ s := r.FormValue("server")
+ publicServer := r.FormValue("publicServer")
+ volumes := make([]storage.VolumeStat, 0)
+ json.Unmarshal([]byte(r.FormValue("volumes")), volumes)
+ mapper.Add(directory.NewMachine(s, publicServer), volumes)
+}
+func dirStatusHandler(w http.ResponseWriter, r *http.Request) {
+ w.Header().Set("Content-Type", "text/plain")
+ bytes, _ := json.Marshal(mapper)
+ fmt.Fprint(w, bytes)
+}
+
+func main() {
+ flag.Parse()
+ mapper = directory.NewMapper(*metaFolder, "directory")
+ defer mapper.Save()
+ http.HandleFunc("/dir/read", dirReadHandler)
+ http.HandleFunc("/dir/write", dirWriteHandler)
+ http.HandleFunc("/dir/join", dirJoinHandler)
+ http.HandleFunc("/dir/status", dirStatusHandler)
+
+ log.Println("Start directory service at http://127.0.0.1:" + strconv.Itoa(*port))
+ e := http.ListenAndServe(":"+strconv.Itoa(*port), nil)
+ if e!=nil {
+ log.Fatalf("Fail to start:",e.String())
+ }
+
+}
diff --git a/weed-fs/src/pkg/directory/volume_mapping.go b/weed-fs/src/pkg/directory/volume_mapping.go
index 95ec57d2e..459d7f2b1 100644
--- a/weed-fs/src/pkg/directory/volume_mapping.go
+++ b/weed-fs/src/pkg/directory/volume_mapping.go
@@ -6,13 +6,19 @@ import (
"path"
"rand"
"log"
- "store"
+ "storage"
)
type Machine struct {
Server string //<server name/ip>[:port]
PublicServer string
}
+type Mapper struct {
+ dir string
+ FileName string
+ Id2Machine map[uint32][]*Machine
+ LastId uint32
+}
func NewMachine(server, publicServer string) (m *Machine) {
m = new(Machine)
@@ -20,13 +26,6 @@ func NewMachine(server, publicServer string) (m *Machine) {
return
}
-type Mapper struct {
- dir string
- FileName string
- Id2Machine map[uint32][]*Machine
- LastId uint32
-}
-
func NewMapper(dirname string, filename string) (m *Mapper) {
m = new(Mapper)
m.dir = dirname
@@ -51,7 +50,7 @@ func (m *Mapper) PickForWrite() []*Machine {
func (m *Mapper) Get(vid uint32) []*Machine {
return m.Id2Machine[vid]
}
-func (m *Mapper) Add(machine *Machine, volumes []store.VolumeStat) {
+func (m *Mapper) Add(machine *Machine, volumes []storage.VolumeStat) {
log.Println("Adding store node", machine.Server)
for _, v := range volumes {
existing := m.Id2Machine[uint32(v.Id)]
diff --git a/weed-fs/src/pkg/storage/needle.go b/weed-fs/src/pkg/storage/needle.go
new file mode 100644
index 000000000..7fde63953
--- /dev/null
+++ b/weed-fs/src/pkg/storage/needle.go
@@ -0,0 +1,67 @@
+package storage
+
+import (
+ "io"
+ "io/ioutil"
+ "http"
+ "log"
+ "strconv"
+ "strings"
+)
+
+type Needle struct{
+ Cookie uint8 "random number to mitigate brute force lookups"
+ Key uint64 "file id"
+ AlternateKey uint32 "supplemental id"
+ Size uint32 "Data size"
+ Data []byte "The actual file data"
+ Checksum int32 "CRC32 to check integrity"
+ Padding []byte "Aligned to 8 bytes"
+}
+func NewNeedle(r *http.Request)(n *Needle){
+ n = new(Needle)
+ form,fe:=r.MultipartReader()
+ if fe!=nil {
+ log.Fatalf("MultipartReader [ERROR] %s\n", fe)
+ }
+ part,_:=form.NextPart()
+ data,_:=ioutil.ReadAll(part)
+ n.Data = data
+
+ n.ParsePath(r.URL.Path[1:strings.LastIndex(r.URL.Path,".")])
+
+ return
+}
+func (n *Needle) ParsePath(path string){
+ a := strings.Split(path,"_")
+ log.Println("cookie",a[0],"key",a[1],"altKey",a[2])
+ cookie,_ := strconv.Atoi(a[0])
+ n.Cookie = uint8(cookie)
+ n.Key,_ = strconv.Atoui64(a[1])
+ altKey,_ := strconv.Atoui64(a[2])
+ n.AlternateKey = uint32(altKey)
+}
+func (n *Needle) Append(w io.Writer){
+ header := make([]byte,17)
+ header[0] = n.Cookie
+ uint64toBytes(header[1:9],n.Key)
+ uint32toBytes(header[9:13],n.AlternateKey)
+ n.Size = uint32(len(n.Data))
+ uint32toBytes(header[13:17],n.Size)
+ w.Write(header)
+ w.Write(n.Data)
+ rest := 8-((n.Size+17+4)%8)
+ uint32toBytes(header[0:4],uint32(n.Checksum))
+ w.Write(header[0:rest+4])
+}
+func (n *Needle) Read(r io.Reader, size uint32){
+ bytes := make([]byte,size+17+4)
+ r.Read(bytes)
+ n.Cookie = bytes[0]
+ n.Key = bytesToUint64(bytes[1:9])
+ n.AlternateKey = bytesToUint32(bytes[9:13])
+ n.Size = bytesToUint32(bytes[13:17])
+ n.Data = bytes[17:17+size]
+ n.Checksum = int32(bytesToUint32(bytes[17+size:17+size+4]))
+}
+
diff --git a/weed-fs/src/pkg/storage/needle_map.go b/weed-fs/src/pkg/storage/needle_map.go
new file mode 100644
index 000000000..9669536ac
--- /dev/null
+++ b/weed-fs/src/pkg/storage/needle_map.go
@@ -0,0 +1,53 @@
+package storage
+
+import (
+ "os"
+)
+
+type NeedleKey struct{
+ Key uint64 "file id"
+ AlternateKey uint32 "supplemental id"
+}
+func (k *NeedleKey) String() string {
+ var tmp [12]byte
+ for i :=uint(0);i<8;i++{
+ tmp[i] = byte(k.Key >> (8*i));
+ }
+ for i :=uint(0);i<4;i++{
+ tmp[i+8] = byte(k.AlternateKey >> (8*i));
+ }
+ return string(tmp[:])
+}
+
+type NeedleValue struct{
+ Offset uint32 "Volume offset" //since aligned to 8 bytes, range is 4G*8=32G
+ Size uint32 "Size of the data portion"
+}
+
+type NeedleMap struct{
+ m map[string]*NeedleValue //mapping NeedleKey(Key,AlternateKey) to NeedleValue
+}
+func NewNeedleMap() (nm *NeedleMap){
+ nm = new(NeedleMap)
+ nm.m = make(map[string]*NeedleValue)
+ return
+}
+func (nm *NeedleMap) load(file *os.File){
+}
+func makeKey(key uint64, altKey uint32) string {
+ var tmp [12]byte
+ for i :=uint(0);i<8;i++{
+ tmp[i] = byte(key >> (8*i));
+ }
+ for i :=uint(0);i<4;i++{
+ tmp[i+8] = byte(altKey >> (8*i));
+ }
+ return string(tmp[:])
+}
+func (nm *NeedleMap) put(key uint64, altKey uint32, offset uint32, size uint32){
+ nm.m[makeKey(key,altKey)] = &NeedleValue{Offset:offset, Size:size}
+}
+func (nm *NeedleMap) get(key uint64, altKey uint32) (element *NeedleValue, ok bool){
+ element, ok = nm.m[makeKey(key,altKey)]
+ return
+}
diff --git a/weed-fs/src/pkg/storage/store.go b/weed-fs/src/pkg/storage/store.go
new file mode 100644
index 000000000..201f50528
--- /dev/null
+++ b/weed-fs/src/pkg/storage/store.go
@@ -0,0 +1,69 @@
+package storage
+
+import (
+ "log"
+ "io/ioutil"
+ "json"
+ "strings"
+ "strconv"
+ "url"
+)
+
+type Store struct {
+ volumes map[uint64]*Volume
+ dir string
+ Port int
+ PublicServer string
+}
+type VolumeStat struct {
+ Id uint64 "id"
+ Status int "status" //0:read, 1:write
+}
+
+func NewStore(port int, publicServer, dirname string) (s *Store) {
+ s = new(Store)
+ s.Port, s.PublicServer, s.dir = port, publicServer, dirname
+ s.volumes = make(map[uint64]*Volume)
+
+ counter := uint64(0)
+ files, _ := ioutil.ReadDir(dirname)
+ for _, f := range files {
+ if f.IsDirectory() || !strings.HasSuffix(f.Name, ".dat") {
+ continue
+ }
+ id, err := strconv.Atoui64(f.Name[:-4])
+ if err == nil {
+ continue
+ }
+ s.volumes[counter] = NewVolume(s.dir, id)
+ counter++
+ }
+ log.Println("Store started on dir:", dirname, "with", counter, "existing volumes")
+ return
+}
+
+func (s *Store) Join(mserver string) {
+ stats := make([]*VolumeStat, len(s.volumes))
+ for k, _ := range s.volumes {
+ s := new(VolumeStat)
+ s.Id, s.Status = k, 1
+ stats = append(stats, s)
+ }
+ bytes, _ := json.Marshal(stats)
+ values := make(url.Values)
+ values.Add("port", strconv.Itoa(s.Port))
+ values.Add("publicServer", s.PublicServer)
+ values.Add("volumes", string(bytes))
+ post("http://"+mserver+"/dir/join", values)
+}
+func (s *Store) Close() {
+ for _, v := range s.volumes {
+ v.Close()
+ }
+}
+func (s *Store) Write(i uint64, n *Needle) {
+ s.volumes[i].write(n)
+}
+func (s *Store) Read(i uint64, n *Needle) {
+ s.volumes[i].read(n)
+}
diff --git a/weed-fs/src/pkg/storage/util.go b/weed-fs/src/pkg/storage/util.go
new file mode 100644
index 000000000..3315dbe01
--- /dev/null
+++ b/weed-fs/src/pkg/storage/util.go
@@ -0,0 +1,50 @@
+package storage
+
+import (
+ "http"
+ "io/ioutil"
+ "url"
+ "log"
+)
+
+func bytesToUint64(b []byte)(v uint64){
+ for i :=uint(7);i>0;i-- {
+ v += uint64(b[i])
+ v <<= 8
+ }
+ v+=uint64(b[0])
+ return
+}
+func bytesToUint32(b []byte)(v uint32){
+ for i :=uint(3);i>0;i-- {
+ v += uint32(b[i])
+ v <<= 8
+ }
+ v+=uint32(b[0])
+ return
+}
+func uint64toBytes(b []byte, v uint64){
+ for i :=uint(0);i<8;i++ {
+ b[i] = byte(v>>(i*8))
+ }
+}
+func uint32toBytes(b []byte, v uint32){
+ for i :=uint(0);i<4;i++ {
+ b[i] = byte(v>>(i*8))
+ }
+}
+
+func post(url string, values url.Values)string{
+ r, err := http.PostForm(url, values)
+ if err != nil {
+ log.Println("post:", err)
+ return ""
+ }
+ defer r.Body.Close()
+ b, err := ioutil.ReadAll(r.Body)
+ if err != nil {
+ log.Println("post:", err)
+ return ""
+ }
+ return string(b)
+} \ No newline at end of file
diff --git a/weed-fs/src/pkg/storage/volume.go b/weed-fs/src/pkg/storage/volume.go
new file mode 100644
index 000000000..6b6db1ba2
--- /dev/null
+++ b/weed-fs/src/pkg/storage/volume.go
@@ -0,0 +1,66 @@
+package storage
+
+import (
+ "os"
+ "path"
+ "strconv"
+ "log"
+)
+
+type Volume struct {
+ Id uint64
+ dir string
+ dataFile, indexFile *os.File
+ nm *NeedleMap
+
+ accessChannel chan int
+}
+
+func NewVolume(dirname string, id uint64) (v *Volume) {
+ var e os.Error
+ v = new(Volume)
+ v.dir = dirname
+ v.Id = id
+ fileName := strconv.Uitoa64(v.Id)
+ log.Println("file", v.dir, "/", fileName)
+ v.dataFile, e = os.OpenFile(path.Join(v.dir,fileName+".dat"), os.O_RDWR|os.O_CREATE, 0644)
+ if e != nil {
+ log.Fatalf("New Volume [ERROR] %s\n", e)
+ }
+ v.indexFile, e = os.OpenFile(path.Join(v.dir,fileName+".idx"), os.O_RDWR|os.O_CREATE, 0644)
+ if e != nil {
+ log.Fatalf("New Volume [ERROR] %s\n", e)
+ }
+ v.nm = NewNeedleMap()
+ v.nm.load(v.indexFile)
+
+ v.accessChannel = make(chan int, 1)
+ v.accessChannel <- 0
+
+ return
+}
+func (v *Volume) Close() {
+ close(v.accessChannel)
+ v.dataFile.Close()
+ v.indexFile.Close()
+}
+
+func (v *Volume) write(n *Needle) {
+ counter := <-v.accessChannel
+ offset, _ := v.dataFile.Seek(0, 2)
+ n.Append(v.dataFile)
+ nv, ok := v.nm.get(n.Key, n.AlternateKey)
+ if !ok || int64(nv.Offset)*8 < offset {
+ v.nm.put(n.Key, n.AlternateKey, uint32(offset/8), n.Size)
+ }
+ v.accessChannel <- counter + 1
+}
+func (v *Volume) read(n *Needle) {
+ counter := <-v.accessChannel
+ nv, ok := v.nm.get(n.Key, n.AlternateKey)
+ if ok && nv.Offset > 0 {
+ v.dataFile.Seek(int64(nv.Offset)*8, 0)
+ n.Read(v.dataFile, nv.Size)
+ }
+ v.accessChannel <- counter + 1
+}