org.rocksdb

Class ComparatorOptions

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.ComparatorOptions

All Implemented Interfaces:

java.lang.AutoCloseable

public class ComparatorOptions
extends RocksObject

This class controls the behaviour of Java implementations of AbstractComparator Note that dispose() must be called before a ComparatorOptions instance becomes out-of-scope to release the allocated memory in C++.

Field Summary

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Fields inherited from class org.rocksdb.AbstractImmutableNativeReference

owningHandle_

Constructor Summary

Constructors

Constructor and Description
ComparatorOptions()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	disposeInternal(long handle)
int	maxReusedBufferSize() Maximum size of a buffer (in bytes) that will be reused.
ReusedSynchronisationType	reusedSynchronisationType() Get the synchronisation type used to guard the reused buffers.
ComparatorOptions	setMaxReusedBufferSize(int maxReusedBufferSize) Sets the maximum size of a buffer (in bytes) that will be reused.
ComparatorOptions	setReusedSynchronisationType(ReusedSynchronisationType reusedSynchronisationType) Set the synchronisation type used to guard the reused buffers.
ComparatorOptions	setUseDirectBuffer(boolean useDirectBuffer) Controls whether a direct byte buffer (i.e.
boolean	useDirectBuffer() Indicates if a direct byte buffer (i.e.

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

ComparatorOptions

public ComparatorOptions()

Method Detail

reusedSynchronisationType

public ReusedSynchronisationType reusedSynchronisationType()

Get the synchronisation type used to guard the reused buffers. Only used if maxReusedBufferSize() > 0 Default: ReusedSynchronisationType.ADAPTIVE_MUTEX

Returns:

the synchronisation type

setReusedSynchronisationType

public ComparatorOptions setReusedSynchronisationType(ReusedSynchronisationType reusedSynchronisationType)

Set the synchronisation type used to guard the reused buffers. Only used if maxReusedBufferSize() > 0 Default: ReusedSynchronisationType.ADAPTIVE_MUTEX

Parameters:

reusedSynchronisationType - the synchronisation type

Returns:

the reference to the current comparator options.

useDirectBuffer

public boolean useDirectBuffer()

Indicates if a direct byte buffer (i.e. outside of the normal garbage-collected heap) is used, as opposed to a non-direct byte buffer which is a wrapper around an on-heap byte[]. Default: true

Returns:

true if a direct byte buffer will be used, false otherwise

setUseDirectBuffer

public ComparatorOptions setUseDirectBuffer(boolean useDirectBuffer)

Controls whether a direct byte buffer (i.e. outside of the normal garbage-collected heap) is used, as opposed to a non-direct byte buffer which is a wrapper around an on-heap byte[]. Default: true

Parameters:

useDirectBuffer - true if a direct byte buffer should be used, false otherwise

Returns:

the reference to the current comparator options.

maxReusedBufferSize

public int maxReusedBufferSize()

Maximum size of a buffer (in bytes) that will be reused. Comparators will use 5 of these buffers, so the retained memory size will be 5 * max_reused_buffer_size. When a buffer is needed for transferring data to a callback, if it requires less than maxReuseBufferSize, then an existing buffer will be reused, else a new buffer will be allocated just for that callback. Default: 64 bytes

Returns:

the maximum size of a buffer which is reused, or 0 if reuse is disabled

setMaxReusedBufferSize

public ComparatorOptions setMaxReusedBufferSize(int maxReusedBufferSize)

Sets the maximum size of a buffer (in bytes) that will be reused. Comparators will use 5 of these buffers, so the retained memory size will be 5 * max_reused_buffer_size. When a buffer is needed for transferring data to a callback, if it requires less than maxReuseBufferSize, then an existing buffer will be reused, else a new buffer will be allocated just for that callback. Default: 64 bytes

Parameters:

maxReusedBufferSize - the maximum size for a buffer to reuse, or 0 to disable reuse

Returns:

the maximum size of a buffer which is reused

disposeInternal

protected final void disposeInternal(long handle)

Specified by:

disposeInternal in class RocksObject