org.rocksdb

Class WriteBatch

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.AbstractWriteBatch

org.rocksdb.WriteBatch

All Implemented Interfaces:

java.lang.AutoCloseable, WriteBatchInterface

public class WriteBatch
extends AbstractWriteBatch

WriteBatch holds a collection of updates to apply atomically to a DB. The updates are applied in the order in which they are added to the WriteBatch. For example, the value of "key" will be "v3" after the following batch is written: batch.put("key", "v1"); batch.remove("key"); batch.put("key", "v2"); batch.put("key", "v3"); Multiple threads can invoke const methods on a WriteBatch without external synchronization, but if any of the threads may call a non-const method, all threads accessing the same WriteBatch must use external synchronization.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WriteBatch.Handler Handler callback for iterating over the contents of a batch.
static class	WriteBatch.SavePoint A structure for describing the save point in the Write Batch.

Field Summary

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Fields inherited from class org.rocksdb.AbstractImmutableNativeReference

owningHandle_

Constructor Summary

Constructors

Constructor and Description
WriteBatch() Constructs a WriteBatch instance.
WriteBatch(byte[] serialized) Constructs a WriteBatch instance from a serialized representation as returned by data().
WriteBatch(int reserved_bytes) Constructs a WriteBatch instance with a given size.

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	data() Retrieve the serialized version of this batch.
protected void	disposeInternal(long handle)
long	getDataSize() Retrieve data size of the batch.
WriteBatch.SavePoint	getWalTerminationPoint() Gets the WAL termination point.
WriteBatch	getWriteBatch() Get the underlying Write Batch.
boolean	hasBeginPrepare() Returns true if MarkBeginPrepare will be called during Iterate.
boolean	hasCommit() Returns true if MarkCommit will be called during Iterate.
boolean	hasDelete() Returns true if Delete will be called during Iterate.
boolean	hasDeleteRange() Returns true if DeleteRange will be called during Iterate.
boolean	hasEndPrepare() Returns true if MarkEndPrepare will be called during Iterate.
boolean	hasMerge() Returns true if Merge will be called during Iterate.
boolean	hasPut() Returns true if Put will be called during Iterate.
boolean	hasRollback() Returns true if MarkRollback will be called during Iterate.
boolean	hasSingleDelete() Returns true if SingleDelete will be called during Iterate.
void	iterate(WriteBatch.Handler handler) Support for iterating over the contents of a batch.
void	markWalTerminationPoint() Marks this point in the WriteBatch as the last record to be inserted into the WAL, provided the WAL is enabled.

Methods inherited from class org.rocksdb.AbstractWriteBatch

clear, count, delete, delete, deleteRange, deleteRange, merge, merge, popSavePoint, put, put, put, put, putLogData, remove, remove, remove, remove, rollbackToSavePoint, setMaxBytes, setSavePoint, singleDelete, singleDelete

Methods inherited from class org.rocksdb.RocksObject

disposeInternal

Methods inherited from class org.rocksdb.AbstractImmutableNativeReference

close, disOwnNativeHandle, isOwningHandle

Methods inherited from class org.rocksdb.AbstractNativeReference

dispose, finalize

Methods inherited from class java.lang.Object

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

Constructor Detail

WriteBatch

public WriteBatch()

Constructs a WriteBatch instance.

WriteBatch

public WriteBatch(int reserved_bytes)

Constructs a WriteBatch instance with a given size.

Parameters:

reserved_bytes - reserved size for WriteBatch

WriteBatch

public WriteBatch(byte[] serialized)

Constructs a WriteBatch instance from a serialized representation as returned by data().

Parameters:

serialized - the serialized representation.

Method Detail

iterate

public void iterate(WriteBatch.Handler handler)
             throws RocksDBException

Support for iterating over the contents of a batch.

Parameters:

handler - A handler that is called back for each update present in the batch

Throws:

RocksDBException - If we cannot iterate over the batch

data

public byte[] data()
            throws RocksDBException

Retrieve the serialized version of this batch.

Returns:

the serialized representation of this write batch.

Throws:

RocksDBException - if an error occurs whilst retrieving the serialized batch data.

getDataSize

public long getDataSize()

Retrieve data size of the batch.

Returns:

the serialized data size of the batch.

hasPut

public boolean hasPut()

Returns true if Put will be called during Iterate.

Returns:

true if Put will be called during Iterate.

hasDelete

public boolean hasDelete()

Returns true if Delete will be called during Iterate.

Returns:

true if Delete will be called during Iterate.

hasSingleDelete

public boolean hasSingleDelete()

Returns true if SingleDelete will be called during Iterate.

Returns:

true if SingleDelete will be called during Iterate.

hasDeleteRange

public boolean hasDeleteRange()

Returns true if DeleteRange will be called during Iterate.

Returns:

true if DeleteRange will be called during Iterate.

hasMerge

public boolean hasMerge()

Returns true if Merge will be called during Iterate.

Returns:

true if Merge will be called during Iterate.

hasBeginPrepare

public boolean hasBeginPrepare()

Returns true if MarkBeginPrepare will be called during Iterate.

Returns:

true if MarkBeginPrepare will be called during Iterate.

hasEndPrepare

public boolean hasEndPrepare()

Returns true if MarkEndPrepare will be called during Iterate.

Returns:

true if MarkEndPrepare will be called during Iterate.

hasCommit

public boolean hasCommit()

Returns true if MarkCommit will be called during Iterate.

Returns:

true if MarkCommit will be called during Iterate.

hasRollback

public boolean hasRollback()

Returns true if MarkRollback will be called during Iterate.

Returns:

true if MarkRollback will be called during Iterate.

getWriteBatch

public WriteBatch getWriteBatch()

Description copied from interface: WriteBatchInterface

Get the underlying Write Batch.

Specified by:

getWriteBatch in interface WriteBatchInterface

Overrides:

getWriteBatch in class AbstractWriteBatch

Returns:

the underlying WriteBatch.

markWalTerminationPoint

public void markWalTerminationPoint()

Marks this point in the WriteBatch as the last record to be inserted into the WAL, provided the WAL is enabled.

getWalTerminationPoint

public WriteBatch.SavePoint getWalTerminationPoint()

Gets the WAL termination point. See markWalTerminationPoint()

Returns:

the WAL termination point

disposeInternal

protected final void disposeInternal(long handle)

Specified by:

disposeInternal in class RocksObject