org.rocksdb

Class WriteBatch

java.lang.Object

org.rocksdb.RocksObject

org.rocksdb.AbstractWriteBatch

org.rocksdb.WriteBatch

All Implemented Interfaces:

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.

Field Summary

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Constructor Summary

Constructors

Constructor and Description
WriteBatch() Constructs a WriteBatch instance.
WriteBatch(int reserved_bytes) Constructs a WriteBatch instance with a given size.

Method Summary

Methods

Modifier and Type	Method and Description
void	iterate(WriteBatch.Handler handler) Support for iterating over the contents of a batch.

Methods inherited from class org.rocksdb.AbstractWriteBatch

clear, count, disposeInternal, merge, merge, put, put, putLogData, remove, remove

Methods inherited from class org.rocksdb.RocksObject

disOwnNativeHandle, dispose, finalize, isInitialized, isOwningNativeHandle

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

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