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cleaner code, better error handling

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This commit is contained in:
Chris Lu
2012-11-20 01:45:36 -08:00
parent e00d8dc536
commit 5dc509c6e4
1 changed files with 31 additions and 11 deletions
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42
weed-fs/src/pkg/storage/volume.go
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@@ -2,6 +2,7 @@ package storage
import ( import (
"errors" "errors"
"fmt"
"log" "log"
"os" "os"
"path" "path"
@@ -10,6 +11,7 @@ import (
const ( const (
SuperBlockSize = 8 SuperBlockSize = 8
Version = 1
) )
type Volume struct { type Volume struct {
@@ -20,6 +22,8 @@ type Volume struct {
replicaType ReplicationType replicaType ReplicationType
version uint8
accessLock sync.Mutex accessLock sync.Mutex
} }
@@ -28,23 +32,26 @@ func NewVolume(dirname string, id VolumeId, replicationType ReplicationType) (v
v.load() v.load()
return return
} }
func (v *Volume) load() { func (v *Volume) load() error {
var e error var e error
fileName := path.Join(v.dir, v.Id.String()) fileName := path.Join(v.dir, v.Id.String())
v.dataFile, e = os.OpenFile(fileName+".dat", os.O_RDWR|os.O_CREATE, 0644) v.dataFile, e = os.OpenFile(fileName+".dat", os.O_RDWR|os.O_CREATE, 0644)
if e != nil { if e != nil {
log.Fatalf("New Volume [ERROR] %s\n", e) return fmt.Errorf("cannot create Volume Data %s.dat: %s", fileName, e)
} }
if v.replicaType == CopyNil { if v.replicaType == CopyNil {
v.readSuperBlock() if e = v.readSuperBlock(); e != nil {
return e
}
} else { } else {
v.maybeWriteSuperBlock() v.maybeWriteSuperBlock()
} }
indexFile, ie := os.OpenFile(fileName+".idx", os.O_RDWR|os.O_CREATE, 0644) indexFile, ie := os.OpenFile(fileName+".idx", os.O_RDWR|os.O_CREATE, 0644)
if ie != nil { if ie != nil {
log.Fatalf("Write Volume Index [ERROR] %s\n", ie) return fmt.Errorf("cannot create Volume Data %s.dat: %s", fileName, e)
} }
v.nm = LoadNeedleMap(indexFile) v.nm = LoadNeedleMap(indexFile)
return nil
} }
func (v *Volume) Size() int64 { func (v *Volume) Size() int64 {
stat, e := v.dataFile.Stat() stat, e := v.dataFile.Stat()
@@ -61,17 +68,23 @@ func (v *Volume) maybeWriteSuperBlock() {
stat, _ := v.dataFile.Stat() stat, _ := v.dataFile.Stat()
if stat.Size() == 0 { if stat.Size() == 0 {
header := make([]byte, SuperBlockSize) header := make([]byte, SuperBlockSize)
header[0] = 1 header[0] = Version
header[1] = v.replicaType.Byte() header[1] = v.replicaType.Byte()
v.dataFile.Write(header) v.dataFile.Write(header)
} }
} }
func (v *Volume) readSuperBlock() { func (v *Volume) readSuperBlock() error {
v.dataFile.Seek(0, 0) v.dataFile.Seek(0, 0)
header := make([]byte, SuperBlockSize) header := make([]byte, SuperBlockSize)
if _, error := v.dataFile.Read(header); error == nil { if _, e := v.dataFile.Read(header); e != nil {
v.replicaType, _ = NewReplicationTypeFromByte(header[1]) return fmt.Errorf("cannot read superblock: %s", e)
} }
v.version = header[0]
var err error
if v.replicaType, err = NewReplicationTypeFromByte(header[1]); err != nil {
return fmt.Errorf("cannot read replica type: %s", err)
}
return nil
} }
func (v *Volume) NeedToReplicate() bool { func (v *Volume) NeedToReplicate() bool {
return v.replicaType.GetCopyCount() > 1 return v.replicaType.GetCopyCount() > 1
@@ -123,9 +136,16 @@ func (v *Volume) commitCompact() (int, error) {
v.accessLock.Lock() v.accessLock.Lock()
defer v.accessLock.Unlock() defer v.accessLock.Unlock()
v.dataFile.Close() v.dataFile.Close()
os.Rename(path.Join(v.dir, v.Id.String()+".cpd"), path.Join(v.dir, v.Id.String()+".dat")) var e error
os.Rename(path.Join(v.dir, v.Id.String()+".cpx"), path.Join(v.dir, v.Id.String()+".idx")) if e = os.Rename(path.Join(v.dir, v.Id.String()+".cpd"), path.Join(v.dir, v.Id.String()+".dat")); e != nil {
v.load() return 0, e
}
if e = os.Rename(path.Join(v.dir, v.Id.String()+".cpx"), path.Join(v.dir, v.Id.String()+".idx")); e != nil {
return 0, e
}
if e = v.load(); e != nil {
return 0, e
}
return 0, nil return 0, nil
} }