Package org.apache.flink.runtime.io.compression

Class Lz4BlockCompressor

java.lang.Object

org.apache.flink.runtime.io.compression.Lz4BlockCompressor

All Implemented Interfaces:

BlockCompressor

public class Lz4BlockCompressor
extends Object
implements BlockCompressor

Encode data into LZ4 format (not compatible with the LZ4 Frame format). It reads from and writes to byte arrays provided from the outside, thus reducing copy time.

This class is copied and modified from LZ4BlockOutputStream.

Constructor Summary

Constructors

Constructor	Description
Lz4BlockCompressor()

Method Summary

Modifier and Type	Method	Description
int	compress(byte[] src, int srcOff, int srcLen, byte[] dst, int dstOff)	Compress data read from src, and write the compressed data to dst.
int	compress(ByteBuffer src, int srcOff, int srcLen, ByteBuffer dst, int dstOff)	Compress source data read from (Buffer.position() + srcOff), and write the compressed data to dst.
int	getMaxCompressedSize(int srcSize)	Get the max compressed size for a given original size.

Methods inherited from class java.lang.Object

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

Constructor Details

Lz4BlockCompressor

public Lz4BlockCompressor()

Method Details

getMaxCompressedSize

public int getMaxCompressedSize(int srcSize)

Description copied from interface: BlockCompressor

Get the max compressed size for a given original size.

Specified by:

getMaxCompressedSize in interface BlockCompressor

compress

public int compress(ByteBuffer src,
 int srcOff,
 int srcLen,
 ByteBuffer dst,
 int dstOff)
             throws BufferCompressionException

Description copied from interface: BlockCompressor

Compress source data read from (Buffer.position() + srcOff), and write the compressed data to dst.

Specified by:

compress in interface BlockCompressor

Parameters:

src - Uncompressed data to read from

srcOff - The start offset of uncompressed data

srcLen - The length of data which want to be compressed

dst - The target to write compressed data

dstOff - The start offset to write the compressed data

Returns:

Length of compressed data

Throws:

BufferCompressionException - if exception thrown when compressing

compress

public int compress(byte[] src,
 int srcOff,
 int srcLen,
 byte[] dst,
 int dstOff)
             throws BufferCompressionException

Description copied from interface: BlockCompressor

Compress data read from src, and write the compressed data to dst.

Specified by:

compress in interface BlockCompressor

Parameters:

src - Uncompressed data to read from

srcOff - The start offset of uncompressed data

srcLen - The length of data which want to be compressed

dst - The target to write compressed data

dstOff - The start offset to write the compressed data

Returns:

Length of compressed data

Throws:

BufferCompressionException - if exception thrown when compressing