Package org.apache.cassandra.io.compress

Class LZ4Compressor

java.lang.Object

org.apache.cassandra.io.compress.LZ4Compressor

All Implemented Interfaces:

ICompressor

public class LZ4Compressor
extends Object
implements ICompressor

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.io.compress.ICompressor

ICompressor.Uses

Field Summary

Fields

Modifier and Type	Field	Description
static final String	LZ4_COMPRESSOR_TYPE
static final String	LZ4_FAST_COMPRESSOR
static final String	LZ4_HIGH_COMPRESSION_LEVEL
static final String	LZ4_HIGH_COMPRESSOR

Method Summary

Modifier and Type	Method	Description
void	compress(ByteBuffer input, ByteBuffer output)	Compression for ByteBuffers.
static LZ4Compressor	create(Map<String,String> args)
int	initialCompressedBufferLength(int chunkLength)
BufferType	preferredBufferType()	Returns the preferred (most efficient) buffer type for this compressor.
Set<ICompressor.Uses>	recommendedUses()	Hints to Cassandra which uses this compressor is recommended for.
Set<String>	supportedOptions()
boolean	supports(BufferType bufferType)	Checks if the given buffer would be supported by the compressor.
int	uncompress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset)
void	uncompress(ByteBuffer input, ByteBuffer output)	Decompression for DirectByteBuffers.
static Integer	validateCompressionLevel(String compressionLevel)
static String	validateCompressorType(String compressorType)

Methods inherited from class java.lang.Object

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

Field Details

LZ4_FAST_COMPRESSOR

public static final String LZ4_FAST_COMPRESSOR

See Also:

• Constant Field Values

LZ4_HIGH_COMPRESSOR

public static final String LZ4_HIGH_COMPRESSOR

See Also:

• Constant Field Values

LZ4_HIGH_COMPRESSION_LEVEL

public static final String LZ4_HIGH_COMPRESSION_LEVEL

See Also:

• Constant Field Values

LZ4_COMPRESSOR_TYPE

public static final String LZ4_COMPRESSOR_TYPE

See Also:

• Constant Field Values

Method Details

create

public static LZ4Compressor create(Map<String,String> args)
                            throws ConfigurationException

Throws:

ConfigurationException

initialCompressedBufferLength

public int initialCompressedBufferLength(int chunkLength)

Specified by:

initialCompressedBufferLength in interface ICompressor

compress

public void compress(ByteBuffer input,
 ByteBuffer output)
              throws IOException

Description copied from interface: ICompressor

Compression for ByteBuffers. The data between input.position() and input.limit() is compressed and placed into output starting from output.position(). Positions in both buffers are moved to reflect the bytes read and written. Limits are not changed.

Specified by:

compress in interface ICompressor

Throws:

IOException

uncompress

public int uncompress(byte[] input,
 int inputOffset,
 int inputLength,
 byte[] output,
 int outputOffset)
               throws IOException

Specified by:

uncompress in interface ICompressor

Throws:

IOException

uncompress

public void uncompress(ByteBuffer input,
 ByteBuffer output)
                throws IOException

Description copied from interface: ICompressor

Decompression for DirectByteBuffers. The data between input.position() and input.limit() is uncompressed and placed into output starting from output.position(). Positions in both buffers are moved to reflect the bytes read and written. Limits are not changed.

Specified by:

uncompress in interface ICompressor

Throws:

IOException

supportedOptions

public Set<String> supportedOptions()

Specified by:

supportedOptions in interface ICompressor

validateCompressorType

public static String validateCompressorType(String compressorType)
                                     throws ConfigurationException

Throws:

ConfigurationException

validateCompressionLevel

public static Integer validateCompressionLevel(String compressionLevel)
                                        throws ConfigurationException

Throws:

ConfigurationException

preferredBufferType

public BufferType preferredBufferType()

Description copied from interface: ICompressor

Returns the preferred (most efficient) buffer type for this compressor.

Specified by:

preferredBufferType in interface ICompressor

supports

public boolean supports(BufferType bufferType)

Description copied from interface: ICompressor

Checks if the given buffer would be supported by the compressor. If a type is supported, the compressor must be able to use it in combination with all other supported types. Direct and memory-mapped buffers must be supported by all compressors.

Specified by:

supports in interface ICompressor

recommendedUses

public Set<ICompressor.Uses> recommendedUses()

Description copied from interface: ICompressor

Hints to Cassandra which uses this compressor is recommended for. For example a compression algorithm which gets good compression ratio may trade off too much compression speed to be useful in certain compression heavy use cases such as flushes or mutation hints. Note that Cassandra may ignore these recommendations, it is not a strict contract.

Specified by:

recommendedUses in interface ICompressor