diff options
Diffstat (limited to 'go/storage/volume_super_block.go')
| -rw-r--r-- | go/storage/volume_super_block.go | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/go/storage/volume_super_block.go b/go/storage/volume_super_block.go index 95f7c30bb..35030b93e 100644 --- a/go/storage/volume_super_block.go +++ b/go/storage/volume_super_block.go @@ -2,6 +2,7 @@ package storage import ( "code.google.com/p/weed-fs/go/glog" + "code.google.com/p/weed-fs/go/util" "fmt" "os" ) @@ -10,9 +11,16 @@ const ( SuperBlockSize = 8 ) +/* +* Super block currently has 8 bytes allocated for each volume. +* Byte 0: version, 1 or 2 +* Byte 1: Replica Placement strategy, 000, 001, 002, 010, etc +* Byte 2 and byte 3: Time to live in minutes + */ type SuperBlock struct { version Version ReplicaPlacement *ReplicaPlacement + Ttl uint16 } func (s *SuperBlock) Version() Version { @@ -22,6 +30,7 @@ func (s *SuperBlock) Bytes() []byte { header := make([]byte, SuperBlockSize) header[0] = byte(s.version) header[1] = s.ReplicaPlacement.Byte() + util.Uint16toBytes(header[2:4], s.Ttl) return header } @@ -61,5 +70,6 @@ func ParseSuperBlock(header []byte) (superBlock SuperBlock, err error) { if superBlock.ReplicaPlacement, err = NewReplicaPlacementFromByte(header[1]); err != nil { err = fmt.Errorf("cannot read replica type: %s", err.Error()) } + superBlock.Ttl = util.BytesToUint16(header[2:4]) return } |