Package org.apache.hadoop.io.compress.zlib

Class BuiltInZlibDeflater

java.lang.Object

java.util.zip.Deflater

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, FULL_FLUSH, HUFFMAN_ONLY, NO_COMPRESSION, NO_FLUSH, SYNC_FLUSH

Constructor Summary

Constructors

Constructor	Description
BuiltInZlibDeflater()
BuiltInZlibDeflater(int level)
BuiltInZlibDeflater(int level, boolean nowrap)

Method Summary

Modifier and Type	Method	Description
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, deflate, deflate, deflate, end, finish, finished, getAdler, getBytesRead, getBytesWritten, getTotalIn, getTotalOut, needsInput, reset, setDictionary, setDictionary, setDictionary, setInput, setInput, setInput, setLevel, setStrategy

Methods inherited from class java.lang.Object

clone, equals, finalize, 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 Details

BuiltInZlibDeflater

public BuiltInZlibDeflater(int level,
 boolean nowrap)

BuiltInZlibDeflater

public BuiltInZlibDeflater(int level)

BuiltInZlibDeflater

public BuiltInZlibDeflater()

Method Details

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 - raised on errors performing I/O.

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