net.jpountz.lz4

Class LZ4Compressor

java.lang.Object

net.jpountz.lz4.LZ4Compressor

public abstract class LZ4Compressor
extends java.lang.Object

LZ4 compressor.

Instances of this class are thread-safe.

Constructor Summary

Constructors

Constructor and Description
LZ4Compressor()

Method Summary

Modifier and Type	Method and Description
byte[]	compress(byte[] src) Convenience method, equivalent to calling compress(src, 0, src.length).
int	compress(byte[] src, byte[] dest) Convenience method, equivalent to calling compress(src, 0, src.length, dest, 0).
byte[]	compress(byte[] src, int srcOff, int srcLen) Convenience method which returns src[srcOff:srcOff+srcLen] compressed.
int	compress(byte[] src, int srcOff, int srcLen, byte[] dest, int destOff) Convenience method, equivalent to calling compress(src, srcOff, srcLen, dest, destOff, dest.length - destOff).
abstract int	compress(byte[] src, int srcOff, int srcLen, byte[] dest, int destOff, int maxDestLen) Compress src[srcOff:srcOff+srcLen] into dest[destOff:destOff+destLen] and return the compressed length.
void	compress(java.nio.ByteBuffer src, java.nio.ByteBuffer dest) Compress src into dest.
abstract int	compress(java.nio.ByteBuffer src, int srcOff, int srcLen, java.nio.ByteBuffer dest, int destOff, int maxDestLen) Compress src[srcOff:srcOff+srcLen] into dest[destOff:destOff+destLen] and return the compressed length.
int	maxCompressedLength(int length) Return the maximum compressed length for an input of size length.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LZ4Compressor

public LZ4Compressor()

Method Detail

maxCompressedLength

public final int maxCompressedLength(int length)

Return the maximum compressed length for an input of size length.

compress

public abstract int compress(byte[] src,
                             int srcOff,
                             int srcLen,
                             byte[] dest,
                             int destOff,
                             int maxDestLen)

Compress src[srcOff:srcOff+srcLen] into dest[destOff:destOff+destLen] and return the compressed length. This method will throw a LZ4Exception if this compressor is unable to compress the input into less than maxDestLen bytes. To prevent this exception to be thrown, you should make sure that maxDestLen >= maxCompressedLength(srcLen).

Returns:

the compressed size

Throws:

LZ4Exception - if maxDestLen is too small

compress

public abstract int compress(java.nio.ByteBuffer src,
                             int srcOff,
                             int srcLen,
                             java.nio.ByteBuffer dest,
                             int destOff,
                             int maxDestLen)

Compress src[srcOff:srcOff+srcLen] into dest[destOff:destOff+destLen] and return the compressed length. This method will throw a LZ4Exception if this compressor is unable to compress the input into less than maxDestLen bytes. To prevent this exception to be thrown, you should make sure that maxDestLen >= maxCompressedLength(srcLen). ByteBuffer positions remain unchanged.

Returns:

the compressed size

Throws:

LZ4Exception - if maxDestLen is too small

compress

public final int compress(byte[] src,
                          int srcOff,
                          int srcLen,
                          byte[] dest,
                          int destOff)

Convenience method, equivalent to calling compress(src, srcOff, srcLen, dest, destOff, dest.length - destOff).

compress

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

Convenience method, equivalent to calling compress(src, 0, src.length, dest, 0).

compress

public final byte[] compress(byte[] src,
                             int srcOff,
                             int srcLen)

Convenience method which returns src[srcOff:srcOff+srcLen] compressed.

Warning: this method has an important overhead due to the fact that it needs to allocate a buffer to compress into, and then needs to resize this buffer to the actual compressed length.

Here is how this method is implemented:

 final int maxCompressedLength = maxCompressedLength(srcLen);
 final byte[] compressed = new byte[maxCompressedLength];
 final int compressedLength = compress(src, srcOff, srcLen, compressed, 0);
 return Arrays.copyOf(compressed, compressedLength);
 

compress

public final byte[] compress(byte[] src)

Convenience method, equivalent to calling compress(src, 0, src.length).

compress

public final void compress(java.nio.ByteBuffer src,
                           java.nio.ByteBuffer dest)

Compress src into dest. Calling this method will update the positions of both ByteBuffers.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object