mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2024-12-02 16:39:16 +08:00
45 lines
1.3 KiB
Go
45 lines
1.3 KiB
Go
|
package super_block
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
|
||
|
|
"github.com/golang/protobuf/proto"
|
||
|
|
|
||
|
|
"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
|
||
|
|
"github.com/chrislusf/seaweedfs/weed/storage/backend"
|
||
|
|
"github.com/chrislusf/seaweedfs/weed/storage/needle"
|
||
|
|
"github.com/chrislusf/seaweedfs/weed/util"
|
||
|
|
)
|
||
|
|
|
||
|
|
// ReadSuperBlock reads from data file and load it into volume's super block
|
||
|
|
func ReadSuperBlock(datBackend backend.BackendStorageFile) (superBlock SuperBlock, err error) {
|
||
|
|
|
||
|
|
header := make([]byte, SuperBlockSize)
|
||
|
|
if _, e := datBackend.ReadAt(header, 0); e != nil {
|
||
|
|
err = fmt.Errorf("cannot read volume %s super block: %v", datBackend.Name(), e)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
superBlock.Version = needle.Version(header[0])
|
||
|
|
if superBlock.ReplicaPlacement, err = NewReplicaPlacementFromByte(header[1]); err != nil {
|
||
|
|
err = fmt.Errorf("cannot read replica type: %s", err.Error())
|
||
|
|
return
|
||
|
|
}
|
||
|
|
superBlock.Ttl = needle.LoadTTLFromBytes(header[2:4])
|
||
|
|
superBlock.CompactionRevision = util.BytesToUint16(header[4:6])
|
||
|
|
superBlock.ExtraSize = util.BytesToUint16(header[6:8])
|
||
|
|
|
||
|
|
if superBlock.ExtraSize > 0 {
|
||
|
|
// read more
|
||
|
|
extraData := make([]byte, int(superBlock.ExtraSize))
|
||
|
|
superBlock.Extra = &master_pb.SuperBlockExtra{}
|
||
|
|
err = proto.Unmarshal(extraData, superBlock.Extra)
|
||
|
|
if err != nil {
|
||
|
|
err = fmt.Errorf("cannot read volume %s super block extra: %v", datBackend.Name(), err)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return
|
||
|
|
}
|