http://www.h2database.com: H2 Database Engine
  • Thomas Mueller 
/*
 * Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
 * and the EPL 1.0 (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.compress;



Each data compression algorithm must implement this interface.

/**
 * Each data compression algorithm must implement this interface.
 */
public interface Compressor {

    
No compression is used.

/**
     * No compression is used.
     */
    int NO = 0;

    
The LZF compression algorithm is used

/**
     * The LZF compression algorithm is used
     */
    int LZF = 1;

    
The DEFLATE compression algorithm is used.

/**
     * The DEFLATE compression algorithm is used.
     */
    int DEFLATE = 2;

    
Get the compression algorithm type.

Returns:the type
/**
     * Get the compression algorithm type.
     *
     * @return the type
     */
    int getAlgorithm();

    
Compress a number of bytes.

Params:
  • in – the input data
  • inLen – the number of bytes to compress
  • out – the output area
  • outPos – the offset at the output array
Returns:the end position
/**
     * Compress a number of bytes.
     *
     * @param in the input data
     * @param inLen the number of bytes to compress
     * @param out the output area
     * @param outPos the offset at the output array
     * @return the end position
     */
    int compress(byte[] in, int inLen, byte[] out, int outPos);

    
Expand a number of compressed bytes.

Params:
  • in – the compressed data
  • inPos – the offset at the input array
  • inLen – the number of bytes to read
  • out – the output area
  • outPos – the offset at the output array
  • outLen – the size of the uncompressed data
/**
     * Expand a number of compressed bytes.
     *
     * @param in the compressed data
     * @param inPos the offset at the input array
     * @param inLen the number of bytes to read
     * @param out the output area
     * @param outPos the offset at the output array
     * @param outLen the size of the uncompressed data
     */
    void expand(byte[] in, int inPos, int inLen, byte[] out, int outPos,
            int outLen);

    
Set the compression options. This may include settings for
higher performance but less compression.

Params:
  • options – the options
/**
     * Set the compression options. This may include settings for
     * higher performance but less compression.
     *
     * @param options the options
     */
    void setOptions(String options);
}