org.mapdb

Class StoreWAL

java.lang.Object

org.mapdb.Store

org.mapdb.StoreDirect

org.mapdb.StoreCached

org.mapdb.StoreWAL

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Engine

public class StoreWAL
extends StoreCached

Write-Ahead-Log

Nested Class Summary

Nested classes/interfaces inherited from class org.mapdb.StoreDirect

StoreDirect.Snapshot

Nested classes/interfaces inherited from class org.mapdb.Store

Store.Cache, Store.LongLongMap, Store.LongObjectMap<V>, Store.LongObjectObjectMap<V1,V2>, Store.LongQueue, Store.MemoryBarrierLessLock, Store.ReadWriteSingleLock

Nested classes/interfaces inherited from interface org.mapdb.Engine

Engine.CloseOnJVMShutdown, Engine.ReadOnly, Engine.ReadOnlyWrapper

Field Summary

Fields inherited from class org.mapdb.Store

LOCKING_STRATEGY_NOLOCK, LOCKING_STRATEGY_READWRITELOCK, LOCKING_STRATEGY_WRITELOCK, NOLOCK

Fields inherited from interface org.mapdb.Engine

CLOSED_ENGINE, RECID_CLASS_CATALOG, RECID_FIRST, RECID_LAST_RESERVED, RECID_NAME_CATALOG, RECID_RECORD_CHECK

Constructor Summary

Constructors

Constructor and Description
StoreWAL(java.lang.String fileName)
StoreWAL(java.lang.String fileName, Volume.VolumeFactory volumeFactory, Store.Cache cache, int lockScale, int lockingStrategy, boolean checksum, boolean compress, byte[] password, boolean readonly, boolean snapshotEnable, boolean fileLockDisable, DataIO.HeartbeatFileLock fileLockHeartbeat, java.util.concurrent.ScheduledExecutorService executor, long startSize, long sizeIncrement, boolean recidReuseDisable, long executorScheduledRate, int writeQueueSize)

Method Summary

Modifier and Type	Method and Description
boolean	canRollback()
void	close() Close store/cache.
void	commit() Makes all changes made since the previous commit/rollback permanent.
void	compact()
void	initOpen()
void	rollback() Undoes all changes made in the current transaction.

Methods inherited from class org.mapdb.StoreCached

compareAndSwap, put, update

Methods inherited from class org.mapdb.StoreDirect

backup, backupRestore, clearCache, fileLoad, getCurrSize, getFreeSize, init, preallocate, snapshot

Methods inherited from class org.mapdb.Store

canSnapshot, delete, forDB, forEngine, get, getWrappedEngine, isClosed, isReadOnly, metricsCollect

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StoreWAL

public StoreWAL(java.lang.String fileName)

StoreWAL

public StoreWAL(java.lang.String fileName,
                Volume.VolumeFactory volumeFactory,
                Store.Cache cache,
                int lockScale,
                int lockingStrategy,
                boolean checksum,
                boolean compress,
                byte[] password,
                boolean readonly,
                boolean snapshotEnable,
                boolean fileLockDisable,
                DataIO.HeartbeatFileLock fileLockHeartbeat,
                java.util.concurrent.ScheduledExecutorService executor,
                long startSize,
                long sizeIncrement,
                boolean recidReuseDisable,
                long executorScheduledRate,
                int writeQueueSize)

Method Detail

initOpen

public void initOpen()

rollback

public void rollback()
              throws java.lang.UnsupportedOperationException

Description copied from interface: Engine

Undoes all changes made in the current transaction. If transactions are disabled it throws UnsupportedOperationException.

Specified by:

rollback in interface Engine

Overrides:

rollback in class StoreDirect

Throws:

java.lang.UnsupportedOperationException - if transactions are disabled

commit

public void commit()

Description copied from interface: Engine

Makes all changes made since the previous commit/rollback permanent. In transactional mode (on by default) it means creating journal file and replaying it to storage. In other modes it may flush disk caches or do nothing at all (check your config options)

Specified by:

commit in interface Engine

Overrides:

commit in class StoreDirect

canRollback

public boolean canRollback()

Specified by:

canRollback in interface Engine

Overrides:

canRollback in class StoreDirect

Returns:

true if engine supports rollback

close

public void close()

Description copied from interface: Engine

Close store/cache. This method must be called before JVM exits to flush all caches and prevent store corruption. Also it releases resources used by MapDB (disk, memory..).

Engine can no longer be used after this method was called. If Engine is used after closing, it may throw any exception including NullPointerException

There is an configuration option DBMaker.Maker.closeOnJvmShutdown() which uses shutdown hook to automatically close Engine when JVM shutdowns.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface Engine

Overrides:

close in class StoreDirect

compact

public void compact()

Specified by:

compact in interface Engine

Overrides:

compact in class StoreDirect