Package net.jpountz.lz4

Class LZ4FastDecompressor

java.lang.Object

net.jpountz.lz4.LZ4FastDecompressor

All Implemented Interfaces:

LZ4Decompressor

public abstract class LZ4FastDecompressor
extends Object
implements LZ4Decompressor

LZ4 decompressor that requires the size of the original input to be known. Use LZ4SafeDecompressor if you only know the size of the compressed stream.

From lz4-java 1.6.0, it is deprecated to use a JNI-binding instance of this class; i.e., an instasnce returned by LZ4Factory.fastDecompressor() of LZ4Factory.nativeInstance(). Please see LZ4Factory.nativeInstance() for details.

Instances of this class are thread-safe.

See Also:

• LZ4Factory.nativeInstance()

Constructor Summary

Constructors

Constructor	Description
LZ4FastDecompressor()

Method Summary

Modifier and Type	Method	Description
final int	decompress(byte[] src, byte[] dest)	Convenience method, equivalent to calling decompress(src, dest, dest.length).
final int	decompress(byte[] src, byte[] dest, int destLen)	Convenience method, equivalent to calling decompress(src, 0, dest, 0, destLen).
final byte[]	decompress(byte[] src, int destLen)	Convenience method, equivalent to calling decompress(src, 0, destLen).
abstract int	decompress(byte[] src, int srcOff, byte[] dest, int destOff, int destLen)	Decompresses src[srcOff:] into dest[destOff:destOff+destLen] and returns the number of bytes read from src.
final byte[]	decompress(byte[] src, int srcOff, int destLen)	Convenience method which returns src[srcOff:?] decompressed.
abstract int	decompress(ByteBuffer src, int srcOff, ByteBuffer dest, int destOff, int destLen)	Decompresses src[srcOff:] into dest[destOff:destOff+destLen] and returns the number of bytes read from src.
final void	decompress(ByteBuffer src, ByteBuffer dest)	Decompresses src into dest.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

LZ4FastDecompressor

public LZ4FastDecompressor()

Method Details

decompress

public abstract int decompress(byte[] src,
 int srcOff,
 byte[] dest,
 int destOff,
 int destLen)

Decompresses src[srcOff:] into dest[destOff:destOff+destLen] and returns the number of bytes read from src. destLen must be exactly the size of the decompressed data.

Specified by:

decompress in interface LZ4Decompressor

Parameters:

src - the compressed data

srcOff - the start offset in src

dest - the destination buffer to store the decompressed data

destOff - the start offset in dest

destLen - the exact size of the original input

Returns:

the number of bytes read to restore the original input

decompress

public abstract int decompress(ByteBuffer src,
 int srcOff,
 ByteBuffer dest,
 int destOff,
 int destLen)

Decompresses src[srcOff:] into dest[destOff:destOff+destLen] and returns the number of bytes read from src. destLen must be exactly the size of the decompressed data. The positions and limits of the ByteBuffers remain unchanged.

Parameters:

src - the compressed data

srcOff - the start offset in src

dest - the destination buffer to store the decompressed data

destOff - the start offset in dest

destLen - the exact size of the original input

Returns:

the number of bytes read to restore the original input

decompress

public final int decompress(byte[] src,
 byte[] dest,
 int destLen)

Convenience method, equivalent to calling decompress(src, 0, dest, 0, destLen).

Parameters:

src - the compressed data

dest - the destination buffer to store the decompressed data

destLen - the exact size of the original input

Returns:

the number of bytes read to restore the original input

decompress

public final int decompress(byte[] src,
 byte[] dest)

Convenience method, equivalent to calling decompress(src, dest, dest.length).

Parameters:

src - the compressed data

dest - the destination buffer to store the decompressed data

Returns:

the number of bytes read to restore the original input

decompress

public final byte[] decompress(byte[] src,
 int srcOff,
 int destLen)

Convenience method which returns src[srcOff:?] decompressed.

Warning: this method has an important overhead due to the fact that it needs to allocate a buffer to decompress into.

Here is how this method is implemented:

 final byte[] decompressed = new byte[destLen];
 decompress(src, srcOff, decompressed, 0, destLen);
 return decompressed;
 

Parameters:

src - the compressed data

srcOff - the start offset in src

destLen - the exact size of the original input

Returns:

the decompressed data

decompress

public final byte[] decompress(byte[] src,
 int destLen)

Convenience method, equivalent to calling decompress(src, 0, destLen).

Parameters:

src - the compressed data

destLen - the exact size of the original input

Returns:

the decompressed data

decompress

public final void decompress(ByteBuffer src,
 ByteBuffer dest)

Decompresses src into dest. dest's Buffer.remaining() must be exactly the size of the decompressed data. This method moves the positions of the buffers.

Parameters:

src - the compressed data

dest - the destination buffer to store the decompressed data

toString

public String toString()

Overrides:

toString in class Object