org.h2.tools
Class CompressTool

java.lang.Object
  org.h2.tools.CompressTool

public class CompressTool
extends java.lang.Object

A tool to losslessly compress data, and expand the compressed data again.

Method Summary

int	compress(byte[] in, int len, Compressor compress, byte[] out) INTERNAL
byte[]	compress(byte[] in, java.lang.String algorithm) Compressed the data using the specified algorithm.
byte[]	expand(byte[] in) Expands the compressed data.
void	expand(byte[] in, byte[] out, int outPos) INTERNAL
int	getCompressAlgorithm(java.lang.String algorithm) INTERNAL
static CompressTool	getInstance() Get a new instance.
static java.io.InputStream	wrapInputStream(java.io.InputStream in, java.lang.String compressionAlgorithm, java.lang.String entryName) INTERNAL
static java.io.OutputStream	wrapOutputStream(java.io.OutputStream out, java.lang.String compressionAlgorithm, java.lang.String entryName) INTERNAL

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static CompressTool getInstance()

Get a new instance. Each instance uses a separate buffer, so multiple instances can be used concurrently. However each instance alone is not multithreading safe.

Returns:

a new instance

compress

public byte[] compress(byte[] in,
                       java.lang.String algorithm)
                throws java.sql.SQLException

Compressed the data using the specified algorithm. If no algorithm is supplied, LZF is used

Parameters:

in - the byte array with the original data

algorithm - the algorithm (LZF, DEFLATE)

Returns:

the compressed data

Throws:

java.sql.SQLException - if a error occurs

compress

public int compress(byte[] in,
                    int len,
                    Compressor compress,
                    byte[] out)

INTERNAL

expand

public byte[] expand(byte[] in)
              throws java.sql.SQLException

Expands the compressed data.

Parameters:

in - the byte array with the compressed data

Returns:

the uncompressed data

Throws:

java.sql.SQLException - if a error occurs

expand

public void expand(byte[] in,
                   byte[] out,
                   int outPos)
            throws java.sql.SQLException

INTERNAL

Throws:

java.sql.SQLException

getCompressAlgorithm

public int getCompressAlgorithm(java.lang.String algorithm)
                         throws java.sql.SQLException

INTERNAL

Throws:

java.sql.SQLException

wrapOutputStream

public static java.io.OutputStream wrapOutputStream(java.io.OutputStream out,
                                                    java.lang.String compressionAlgorithm,
                                                    java.lang.String entryName)
                                             throws java.sql.SQLException

INTERNAL

Throws:

java.sql.SQLException

wrapInputStream

public static java.io.InputStream wrapInputStream(java.io.InputStream in,
                                                  java.lang.String compressionAlgorithm,
                                                  java.lang.String entryName)
                                           throws java.sql.SQLException

INTERNAL

Throws:

java.sql.SQLException