org.jlab.coda.hipo

Class Compressor

java.lang.Object

org.jlab.coda.hipo.Compressor

public class Compressor
extends java.lang.Object

Singleton class used to provide data compression and decompression in a variety of formats.

Author:

gavalian, timmer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Compressor.ByteBufferBackedInputStream Use this class when decompressing GZIP data from a ByteBuffer.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Compressor() Constructor to defeat instantiation.

Method Summary

Modifier and Type	Method and Description
static byte[]	compressGZIP(byte[] ungzipped) GZIP compression.
static byte[]	compressGZIP(byte[] ungzipped, int offset, int length) GZIP compression.
static int	compressLZ4(byte[] src, int srcOff, int srcSize, byte[] dst, int dstOff, int maxSize) Fastest LZ4 compression.
static int	compressLZ4(java.nio.ByteBuffer src, int srcSize, java.nio.ByteBuffer dst, int maxSize) Fastest LZ4 compression.
static int	compressLZ4(java.nio.ByteBuffer src, int srcOff, int srcSize, java.nio.ByteBuffer dst, int dstOff, int maxSize) Fastest LZ4 compression.
static int	compressLZ4Best(byte[] src, int srcOff, int srcSize, byte[] dst, int dstOff, int maxSize) Highest LZ4 compression.
static int	compressLZ4Best(java.nio.ByteBuffer src, int srcSize, java.nio.ByteBuffer dst, int maxSize) Highest LZ4 compression.
static int	compressLZ4Best(java.nio.ByteBuffer src, int srcOff, int srcSize, java.nio.ByteBuffer dst, int dstOff, int maxSize) Highest LZ4 compression.
static byte[]	getCompressedBuffer(CompressionType compressionType, byte[] buffer) Returns compressed buffer.
static Compressor	getInstance() Get the single instance of this class.
static int	getMaxCompressedLength(CompressionType compressionType, int uncompressedLength) Returns the maximum number of bytes needed to compress the given length of uncompressed data.
static byte[]	getUnCompressedBuffer(CompressionType compressionType, byte[] compressedBuffer) Returns uncompressed buffer.
static byte[]	uncompressGZIP(byte[] gzipped) GZIP decompression.
static byte[]	uncompressGZIP(byte[] gzipped, int off, int length) GZIP decompression.
static byte[]	uncompressGZIP(java.nio.ByteBuffer gzipped) GZIP decompression.
static int	uncompressLZ4(byte[] src, int srcOff, int srcSize, byte[] dst, int dstOff) LZ4 decompression.
static byte[]	uncompressLZ4(byte[] src, int srcOff, int srcSize, int maxDestLen) LZ4 decompression.
static int	uncompressLZ4(java.nio.ByteBuffer src, int srcSize, java.nio.ByteBuffer dst) LZ4 decompression.
static int	uncompressLZ4(java.nio.ByteBuffer src, int srcOff, int srcSize, java.nio.ByteBuffer dst) LZ4 decompression.

Methods inherited from class java.lang.Object

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

Constructor Detail

Compressor

protected Compressor()

Constructor to defeat instantiation.

Method Detail

getInstance

public static Compressor getInstance()

Get the single instance of this class.

Returns:

single instance of this class.

getMaxCompressedLength

public static int getMaxCompressedLength(CompressionType compressionType,
                                         int uncompressedLength)

Returns the maximum number of bytes needed to compress the given length of uncompressed data. Depends on compression type. Unknown for gzip.

Parameters:

compressionType - type of data compression to do (0=none, 1=lz4 fast, 2=lz4 best, 3=gzip). Default to none.

uncompressedLength - uncompressed data length in bytes.

Returns:

maximum compressed length in bytes or -1 if unknown.

getCompressedBuffer

public static byte[] getCompressedBuffer(CompressionType compressionType,
                                         byte[] buffer)

Returns compressed buffer. Depends on compression type.

Parameters:

compressionType - type of data compression to do (0=none, 1=lz4 fast, 2=lz4 best, 3=gzip). Default to none.

buffer - uncompressed buffer.

Returns:

compressed buffer.

getUnCompressedBuffer

public static byte[] getUnCompressedBuffer(CompressionType compressionType,
                                           byte[] compressedBuffer)
                                    throws net.jpountz.lz4.LZ4Exception

Returns uncompressed buffer. Depends on compression type.

Parameters:

compressionType - type of data compression to undo (0=none, 1=lz4 fast, 2=lz4 best, 3=gzip). Default to none.

compressedBuffer - uncompressed array.

Returns:

uncompressed array.

Throws:

net.jpountz.lz4.LZ4Exception - if not enough room in allocated array (3x compressed) to hold LZ4 uncompressed data.

compressGZIP

public static byte[] compressGZIP(byte[] ungzipped)

GZIP compression. Returns compressed byte array.

Parameters:

ungzipped - uncompressed data.

Returns:

compressed data.

compressGZIP

public static byte[] compressGZIP(byte[] ungzipped,
                                  int offset,
                                  int length)

GZIP compression. Returns compressed byte array.

Parameters:

ungzipped - uncompressed data.

offset - offset into ungzipped array

length - length of valid data in bytes

Returns:

compressed data.

uncompressGZIP

public static byte[] uncompressGZIP(byte[] gzipped)

GZIP decompression. Returns uncompressed byte array.

Parameters:

gzipped - compressed data.

Returns:

uncompressed data.

uncompressGZIP

public static byte[] uncompressGZIP(byte[] gzipped,
                                    int off,
                                    int length)

GZIP decompression. Returns uncompressed byte array.

Parameters:

gzipped - compressed data.

off - offset into gzipped array.

length - max number of bytes to read from gzipped.

Returns:

uncompressed data.

uncompressGZIP

public static byte[] uncompressGZIP(java.nio.ByteBuffer gzipped)

GZIP decompression. Returns uncompressed byte array.

Parameters:

gzipped - compressed data.

Returns:

uncompressed data.

compressLZ4

public static int compressLZ4(java.nio.ByteBuffer src,
                              int srcSize,
                              java.nio.ByteBuffer dst,
                              int maxSize)
                       throws HipoException

Fastest LZ4 compression. Returns length of compressed data in bytes.

Parameters:

src - source of uncompressed data.

srcSize - number of bytes to compress.

dst - destination buffer.

maxSize - maximum number of bytes to write in dst.

Returns:

length of compressed data in bytes.

Throws:

HipoException - if maxSize < max # of compressed bytes

compressLZ4

public static int compressLZ4(byte[] src,
                              int srcOff,
                              int srcSize,
                              byte[] dst,
                              int dstOff,
                              int maxSize)
                       throws HipoException

Fastest LZ4 compression. Returns length of compressed data in bytes.

Parameters:

src - source of uncompressed data.

srcOff - start offset in src.

srcSize - number of bytes to compress.

dst - destination array.

dstOff - start offset in dst.

maxSize - maximum number of bytes to write in dst.

Returns:

length of compressed data in bytes.

Throws:

HipoException - if maxSize < max # of compressed bytes

compressLZ4

public static int compressLZ4(java.nio.ByteBuffer src,
                              int srcOff,
                              int srcSize,
                              java.nio.ByteBuffer dst,
                              int dstOff,
                              int maxSize)
                       throws HipoException

Fastest LZ4 compression. Returns length of compressed data in bytes.

Parameters:

src - source of uncompressed data.

srcOff - start offset in src.

srcSize - number of bytes to compress.

dst - destination array.

dstOff - start offset in dst.

maxSize - maximum number of bytes to write in dst.

Returns:

length of compressed data in bytes.

Throws:

HipoException - if maxSize < max # of compressed bytes

compressLZ4Best

public static int compressLZ4Best(java.nio.ByteBuffer src,
                                  int srcSize,
                                  java.nio.ByteBuffer dst,
                                  int maxSize)
                           throws HipoException

Highest LZ4 compression. Returns length of compressed data in bytes.

Parameters:

src - source of uncompressed data.

srcSize - number of bytes to compress.

dst - destination buffer.

maxSize - maximum number of bytes to write in dst.

Returns:

length of compressed data in bytes.

Throws:

HipoException - if maxSize < max # of compressed bytes

compressLZ4Best

public static int compressLZ4Best(byte[] src,
                                  int srcOff,
                                  int srcSize,
                                  byte[] dst,
                                  int dstOff,
                                  int maxSize)
                           throws HipoException

Highest LZ4 compression. Returns length of compressed data in bytes.

Parameters:

src - source of uncompressed data.

srcOff - start offset in src.

srcSize - number of bytes to compress.

dst - destination array.

dstOff - start offset in dst.

maxSize - maximum number of bytes to write in dst.

Returns:

length of compressed data in bytes.

Throws:

HipoException - if maxSize < max # of compressed bytes

compressLZ4Best

public static int compressLZ4Best(java.nio.ByteBuffer src,
                                  int srcOff,
                                  int srcSize,
                                  java.nio.ByteBuffer dst,
                                  int dstOff,
                                  int maxSize)
                           throws HipoException

Highest LZ4 compression. Returns length of compressed data in bytes.

Parameters:

src - source of uncompressed data.

srcOff - start offset in src.

srcSize - number of bytes to compress.

dst - destination array.

dstOff - start offset in dst.

maxSize - maximum number of bytes to write in dst.

Returns:

length of compressed data in bytes.

Throws:

HipoException - if maxSize < max # of compressed bytes

uncompressLZ4

public static int uncompressLZ4(java.nio.ByteBuffer src,
                                int srcSize,
                                java.nio.ByteBuffer dst)
                         throws HipoException

LZ4 decompression. Returns original length of decompressed data in bytes.

Parameters:

src - source of compressed data.

srcSize - number of compressed bytes.

dst - destination array.

Returns:

original (uncompressed) input size.

Throws:

HipoException - if dst is too small to hold uncompressed data

uncompressLZ4

public static int uncompressLZ4(java.nio.ByteBuffer src,
                                int srcOff,
                                int srcSize,
                                java.nio.ByteBuffer dst)
                         throws HipoException

LZ4 decompression. Returns original length of decompressed data in bytes.

Parameters:

src - source of compressed data.

srcOff - start offset in src.

srcSize - number of compressed bytes.

dst - destination array.

Returns:

original (uncompressed) input size.

Throws:

HipoException - if dst is too small to hold uncompressed data

uncompressLZ4

public static int uncompressLZ4(byte[] src,
                                int srcOff,
                                int srcSize,
                                byte[] dst,
                                int dstOff)
                         throws HipoException

LZ4 decompression. Returns original length of decompressed data in bytes.

Parameters:

src - source of compressed data.

srcOff - start offset in src.

srcSize - number of compressed bytes.

dst - destination array.

dstOff - start offset in dst.

Returns:

original (uncompressed) input size.

Throws:

HipoException - if (dst.length - dstOff) is too small to hold uncompressed data

uncompressLZ4

public static byte[] uncompressLZ4(byte[] src,
                                   int srcOff,
                                   int srcSize,
                                   int maxDestLen)

LZ4 decompression. Returns an array containing the original decompressed data in bytes.

Parameters:

src - source of compressed data.

srcOff - start offset in src.

srcSize - number of compressed bytes.

maxDestLen - max available bytes to hold uncompressed data.

Returns:

original, uncompressed data. Length of array is length of valid data.