org.apache.hadoop.io.compress.zlib
Class BuiltInZlibDeflater

java.lang.Object
  extended by java.util.zip.Deflater
      extended by org.apache.hadoop.io.compress.zlib.BuiltInZlibDeflater
All Implemented Interfaces:
Compressor

public class BuiltInZlibDeflater
extends Deflater
implements Compressor

A wrapper around java.util.zip.Deflater to make it conform to org.apache.hadoop.io.compress.Compressor interface.


Field Summary
 
Fields inherited from class java.util.zip.Deflater
BEST_COMPRESSION, BEST_SPEED, DEFAULT_COMPRESSION, DEFAULT_STRATEGY, DEFLATED, FILTERED, HUFFMAN_ONLY, NO_COMPRESSION
 
Constructor Summary
BuiltInZlibDeflater()
           
BuiltInZlibDeflater(int level)
           
BuiltInZlibDeflater(int level, boolean nowrap)
           
 
Method Summary
 int compress(byte[] b, int off, int len)
          Fills specified buffer with compressed data.
 void reinit(Configuration conf)
          reinit the compressor with the given configuration.
 
Methods inherited from class java.util.zip.Deflater
deflate, deflate, end, finalize, finish, finished, getAdler, getBytesRead, getBytesWritten, getTotalIn, getTotalOut, needsInput, reset, setDictionary, setDictionary, setInput, setInput, setLevel, setStrategy
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.apache.hadoop.io.compress.Compressor
end, finish, finished, getBytesRead, getBytesWritten, needsInput, reset, setDictionary, setInput
 

Constructor Detail

BuiltInZlibDeflater

public BuiltInZlibDeflater(int level,
                           boolean nowrap)

BuiltInZlibDeflater

public BuiltInZlibDeflater(int level)

BuiltInZlibDeflater

public BuiltInZlibDeflater()
Method Detail

compress

public int compress(byte[] b,
                    int off,
                    int len)
             throws IOException
Description copied from interface: Compressor
Fills specified buffer with compressed data. Returns actual number of bytes of compressed data. A return value of 0 indicates that needsInput() should be called in order to determine if more input data is required.

Specified by:
compress in interface Compressor
Parameters:
b - Buffer for the compressed data
off - Start offset of the data
len - Size of the buffer
Returns:
The actual number of bytes of compressed data.
Throws:
IOException

reinit

public void reinit(Configuration conf)
reinit the compressor with the given configuration. It will reset the compressor's compression level and compression strategy. Different from ZlibCompressor, BuiltInZlibDeflater only support three kind of compression strategy: FILTERED, HUFFMAN_ONLY and DEFAULT_STRATEGY. It will use DEFAULT_STRATEGY as default if the configured compression strategy is not supported.

Specified by:
reinit in interface Compressor
Parameters:
conf - Configuration from which new setting are fetched


Copyright © 2009 The Apache Software Foundation