org.snf4j.core.codec.zip

Class GzipEncoder

java.lang.Object

org.snf4j.core.codec.zip.ZlibCodec

org.snf4j.core.codec.zip.ZlibEncoder

org.snf4j.core.codec.zip.GzipEncoder

All Implemented Interfaces:

ICodec<byte[],ByteBuffer>, IEncoder<byte[],ByteBuffer>, IEventDrivenCodec

public class GzipEncoder
extends ZlibEncoder

Compresses an array of bytes using the gzip compression as specified in RFC 1952. It generates the simplest gzip header with FLG=0, MTIME=0, XFL=0 and OS=255.

Author:

SNF4J.ORG

Nested Class Summary

Nested classes/interfaces inherited from class org.snf4j.core.codec.zip.ZlibCodec

ZlibCodec.Mode

Field Summary

Fields inherited from class org.snf4j.core.codec.zip.ZlibEncoder

deflater

Constructor Summary

Constructors

Constructor and Description
GzipEncoder() Creates a new gzip encoder with the default compression level (6).
GzipEncoder(int level) Creates a new gzip encoder with the specified compression level.

Method Summary

Modifier and Type	Method and Description
protected int	deflateBound(int len) Returns upper bound on the compressed size.
protected void	postFinish(ISession session, ByteBuffer out) Generates the gzip footer.
protected void	preDeflate(ISession session, byte[] in, ByteBuffer out) Generates the gzip header.
protected void	preFinish(ISession session, ByteBuffer out) Generates the gzip header if the compression was finished without compressing any data.

Methods inherited from class org.snf4j.core.codec.zip.ZlibEncoder

added, encode, event, finish, isFinished, removed

Methods inherited from class org.snf4j.core.codec.zip.ZlibCodec

getInboundType, getOutboundType

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.snf4j.core.codec.ICodec

getInboundType, getOutboundType

Constructor Detail

GzipEncoder

public GzipEncoder()

Creates a new gzip encoder with the default compression level (6).

GzipEncoder

public GzipEncoder(int level)

Creates a new gzip encoder with the specified compression level.

Parameters:

level - the compression level (0 - 9). 1 yields the fastest compression and 9 yields the best compression. 0 means no compression. The default compression level is 6.

Throws:

IllegalArgumentException - if the compression level is out of range

Method Detail

deflateBound

protected int deflateBound(int len)

Description copied from class: ZlibEncoder

Returns upper bound on the compressed size.

Overrides:

deflateBound in class ZlibEncoder

Parameters:

len - the length of the uncompressed data.

Returns:

the upper bound

preDeflate

protected void preDeflate(ISession session,
                          byte[] in,
                          ByteBuffer out)

Generates the gzip header.

Overrides:

preDeflate in class ZlibEncoder

Parameters:

session - the session object the encoder is associated with

in - the uncompressed input data

out - the output buffer

preFinish

protected void preFinish(ISession session,
                         ByteBuffer out)

Generates the gzip header if the compression was finished without compressing any data.

Overrides:

preFinish in class ZlibEncoder

Parameters:

session - the session object the encoder is associated with

out - the output buffer

postFinish

protected void postFinish(ISession session,
                          ByteBuffer out)

Generates the gzip footer.

Overrides:

postFinish in class ZlibEncoder

Parameters:

session - the session object the encoder is associated with

out - the output buffer