org.rocksdb

Class CompressionOptions

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.CompressionOptions

All Implemented Interfaces:

AutoCloseable

public class CompressionOptions
extends RocksObject

Options for Compression

Field Summary

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Fields inherited from class org.rocksdb.AbstractImmutableNativeReference

owningHandle_

Constructor Summary

Constructors

Constructor and Description
CompressionOptions()

Method Summary

Modifier and Type	Method and Description
protected void	disposeInternal(long handle)
boolean	enabled() Determine whether these compression options are used for the bottommost_compression_opts.
int	level()
int	maxDictBytes() Maximum size of dictionary used to prime the compression library.
CompressionOptions	setEnabled(boolean enabled) When the compression options are set by the user, it will be set to "true".
CompressionOptions	setLevel(int level)
CompressionOptions	setMaxDictBytes(int maxDictBytes) Maximum size of dictionary used to prime the compression library.
CompressionOptions	setStrategy(int strategy)
CompressionOptions	setWindowBits(int windowBits)
CompressionOptions	setZStdMaxTrainBytes(int zstdMaxTrainBytes) Maximum size of training data passed to zstd's dictionary trainer.
int	strategy()
int	windowBits()
int	zstdMaxTrainBytes() Maximum size of training data passed to zstd's dictionary trainer.

Methods inherited from class org.rocksdb.RocksObject

disposeInternal, getNativeHandle

Methods inherited from class org.rocksdb.AbstractImmutableNativeReference

close, disOwnNativeHandle, isOwningHandle

Methods inherited from class java.lang.Object

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

Constructor Detail

CompressionOptions

public CompressionOptions()

Method Detail

setWindowBits

public CompressionOptions setWindowBits(int windowBits)

windowBits

public int windowBits()

setLevel

public CompressionOptions setLevel(int level)

level

public int level()

setStrategy

public CompressionOptions setStrategy(int strategy)

strategy

public int strategy()

setMaxDictBytes

public CompressionOptions setMaxDictBytes(int maxDictBytes)

Maximum size of dictionary used to prime the compression library. Currently this dictionary will be constructed by sampling the first output file in a subcompaction when the target level is bottommost. This dictionary will be loaded into the compression library before compressing/uncompressing each data block of subsequent files in the subcompaction. Effectively, this improves compression ratios when there are repetitions across data blocks. A value of 0 indicates the feature is disabled. Default: 0.

Parameters:

maxDictBytes - Maximum bytes to use for the dictionary

Returns:

the reference to the current options

maxDictBytes

public int maxDictBytes()

Maximum size of dictionary used to prime the compression library.

Returns:

The maximum bytes to use for the dictionary

setZStdMaxTrainBytes

public CompressionOptions setZStdMaxTrainBytes(int zstdMaxTrainBytes)

Maximum size of training data passed to zstd's dictionary trainer. Using zstd's dictionary trainer can achieve even better compression ratio improvements than using setMaxDictBytes(int) alone. The training data will be used to generate a dictionary of maxDictBytes(). Default: 0.

Parameters:

zstdMaxTrainBytes - Maximum bytes to use for training ZStd.

Returns:

the reference to the current options

zstdMaxTrainBytes

public int zstdMaxTrainBytes()

Maximum size of training data passed to zstd's dictionary trainer.

Returns:

Maximum bytes to use for training ZStd

setEnabled

public CompressionOptions setEnabled(boolean enabled)

When the compression options are set by the user, it will be set to "true". For bottommost_compression_opts, to enable it, user must set enabled=true. Otherwise, bottommost compression will use compression_opts as default compression options. For compression_opts, if compression_opts.enabled=false, it is still used as compression options for compression process. Default: false.

Parameters:

enabled - true to use these compression options for the bottommost_compression_opts, false otherwise

Returns:

the reference to the current options

enabled

public boolean enabled()

Determine whether these compression options are used for the bottommost_compression_opts.

Returns:

true if these compression options are used for the bottommost_compression_opts, false otherwise

disposeInternal

protected final void disposeInternal(long handle)

Specified by:

disposeInternal in class RocksObject