org.apache.zookeeper.server.persistence

Interface SnapShot

All Known Implementing Classes:

FileSnap

public interface SnapShot

snapshot interface for the persistence layer. implement this interface for implementing snapshots.

Method Summary

Modifier and Type	Method and Description
void	close() free resources from this snapshot immediately
long	deserialize(DataTree dt, Map<Long,Integer> sessions) deserialize a data tree from the last valid snapshot and return the last zxid that was deserialized
File	findMostRecentSnapshot() find the most recent snapshot file
SnapshotInfo	getLastSnapshotInfo() get information of the last saved/restored snapshot
void	serialize(DataTree dt, Map<Long,Integer> sessions, File name, boolean fsync) persist the datatree and the sessions into a persistence storage

Method Detail

deserialize

long deserialize(DataTree dt,
                 Map<Long,Integer> sessions)
          throws IOException

deserialize a data tree from the last valid snapshot and return the last zxid that was deserialized

Parameters:

dt - the datatree to be deserialized into

sessions - the sessions to be deserialized into

Returns:

the last zxid that was deserialized from the snapshot

Throws:

IOException

serialize

void serialize(DataTree dt,
               Map<Long,Integer> sessions,
               File name,
               boolean fsync)
        throws IOException

persist the datatree and the sessions into a persistence storage

Parameters:

dt - the datatree to be serialized

sessions - the session timeouts to be serialized

name - the object name to store snapshot into

fsync - sync the snapshot immediately after write

Throws:

IOException

findMostRecentSnapshot

File findMostRecentSnapshot()
                     throws IOException

find the most recent snapshot file

Returns:

the most recent snapshot file

Throws:

IOException

getLastSnapshotInfo

SnapshotInfo getLastSnapshotInfo()

get information of the last saved/restored snapshot

Returns:

info of last snapshot

close

void close()
    throws IOException

free resources from this snapshot immediately

Throws:

IOException