public class ZlibEncoder extends OneToOneStrictEncoder implements LifeCycleAwareChannelHandler
ChannelBuffer
using the deflate algorithm.ChannelHandler.Sharable
Constructor and Description |
---|
ZlibEncoder()
Creates a new zlib encoder with the default compression level (
6 ),
default window bits (15 ), default memory level (8 ),
and the default wrapper (ZlibWrapper.ZLIB ). |
ZlibEncoder(byte[] dictionary)
Creates a new zlib encoder with the default compression level (
6 ),
default window bits (15 ), default memory level (8 ),
and the specified preset dictionary. |
ZlibEncoder(int compressionLevel)
Creates a new zlib encoder with the specified
compressionLevel ,
default window bits (15 ), default memory level (8 ),
and the default wrapper (ZlibWrapper.ZLIB ). |
ZlibEncoder(int compressionLevel,
byte[] dictionary)
Creates a new zlib encoder with the specified
compressionLevel ,
default window bits (15 ), default memory level (8 ),
and the specified preset dictionary. |
ZlibEncoder(int compressionLevel,
int windowBits,
int memLevel,
byte[] dictionary)
Creates a new zlib encoder with the specified
compressionLevel ,
the specified windowBits , the specified memLevel ,
and the specified preset dictionary. |
ZlibEncoder(ZlibWrapper wrapper)
Creates a new zlib encoder with the default compression level (
6 ),
default window bits (15 ), default memory level (8 ),
and the specified wrapper. |
ZlibEncoder(ZlibWrapper wrapper,
int compressionLevel)
Creates a new zlib encoder with the specified
compressionLevel ,
default window bits (15 ), default memory level (8 ),
and the specified wrapper. |
ZlibEncoder(ZlibWrapper wrapper,
int compressionLevel,
int windowBits,
int memLevel)
Creates a new zlib encoder with the specified
compressionLevel ,
the specified windowBits , the specified memLevel , and
the specified wrapper. |
Modifier and Type | Method and Description |
---|---|
void |
afterAdd(ChannelHandlerContext ctx) |
void |
afterRemove(ChannelHandlerContext ctx) |
void |
beforeAdd(ChannelHandlerContext ctx) |
void |
beforeRemove(ChannelHandlerContext ctx) |
ChannelFuture |
close() |
protected Object |
encode(ChannelHandlerContext ctx,
Channel channel,
Object msg)
Transforms the specified message into another message and return the
transformed message.
|
void |
handleDownstream(ChannelHandlerContext ctx,
ChannelEvent evt)
Handles the specified downstream event.
|
boolean |
isClosed() |
doEncode
public ZlibEncoder()
6
),
default window bits (15
), default memory level (8
),
and the default wrapper (ZlibWrapper.ZLIB
).CompressionException
- if failed to initialize zlibpublic ZlibEncoder(int compressionLevel)
compressionLevel
,
default window bits (15
), default memory level (8
),
and the default wrapper (ZlibWrapper.ZLIB
).compressionLevel
- 1
yields the fastest compression and 9
yields the
best compression. 0
means no compression. The default
compression level is 6
.CompressionException
- if failed to initialize zlibpublic ZlibEncoder(ZlibWrapper wrapper)
6
),
default window bits (15
), default memory level (8
),
and the specified wrapper.CompressionException
- if failed to initialize zlibpublic ZlibEncoder(ZlibWrapper wrapper, int compressionLevel)
compressionLevel
,
default window bits (15
), default memory level (8
),
and the specified wrapper.compressionLevel
- 1
yields the fastest compression and 9
yields the
best compression. 0
means no compression. The default
compression level is 6
.CompressionException
- if failed to initialize zlibpublic ZlibEncoder(ZlibWrapper wrapper, int compressionLevel, int windowBits, int memLevel)
compressionLevel
,
the specified windowBits
, the specified memLevel
, and
the specified wrapper.compressionLevel
- 1
yields the fastest compression and 9
yields the
best compression. 0
means no compression. The default
compression level is 6
.windowBits
- The base two logarithm of the size of the history buffer. The
value should be in the range 9
to 15
inclusive.
Larger values result in better compression at the expense of
memory usage. The default value is 15
.memLevel
- How much memory should be allocated for the internal compression
state. 1
uses minimum memory and 9
uses maximum
memory. Larger values result in better and faster compression
at the expense of memory usage. The default value is 8
CompressionException
- if failed to initialize zlibpublic ZlibEncoder(byte[] dictionary)
6
),
default window bits (15
), default memory level (8
),
and the specified preset dictionary. The wrapper is always
ZlibWrapper.ZLIB
because it is the only format that supports
the preset dictionary.dictionary
- the preset dictionaryCompressionException
- if failed to initialize zlibpublic ZlibEncoder(int compressionLevel, byte[] dictionary)
compressionLevel
,
default window bits (15
), default memory level (8
),
and the specified preset dictionary. The wrapper is always
ZlibWrapper.ZLIB
because it is the only format that supports
the preset dictionary.compressionLevel
- 1
yields the fastest compression and 9
yields the
best compression. 0
means no compression. The default
compression level is 6
.dictionary
- the preset dictionaryCompressionException
- if failed to initialize zlibpublic ZlibEncoder(int compressionLevel, int windowBits, int memLevel, byte[] dictionary)
compressionLevel
,
the specified windowBits
, the specified memLevel
,
and the specified preset dictionary. The wrapper is always
ZlibWrapper.ZLIB
because it is the only format that supports
the preset dictionary.compressionLevel
- 1
yields the fastest compression and 9
yields the
best compression. 0
means no compression. The default
compression level is 6
.windowBits
- The base two logarithm of the size of the history buffer. The
value should be in the range 9
to 15
inclusive.
Larger values result in better compression at the expense of
memory usage. The default value is 15
.memLevel
- How much memory should be allocated for the internal compression
state. 1
uses minimum memory and 9
uses maximum
memory. Larger values result in better and faster compression
at the expense of memory usage. The default value is 8
dictionary
- the preset dictionaryCompressionException
- if failed to initialize zlibpublic ChannelFuture close()
public boolean isClosed()
protected Object encode(ChannelHandlerContext ctx, Channel channel, Object msg) throws Exception
OneToOneEncoder
null
, unlike
you can in OneToOneDecoder.decode(ChannelHandlerContext, Channel, Object)
;
you must return something, at least ChannelBuffers.EMPTY_BUFFER
.encode
in class OneToOneEncoder
Exception
public void handleDownstream(ChannelHandlerContext ctx, ChannelEvent evt) throws Exception
ChannelDownstreamHandler
handleDownstream
in interface ChannelDownstreamHandler
handleDownstream
in class OneToOneEncoder
ctx
- the context object for this handlerevt
- the downstream event to process or interceptException
public void beforeAdd(ChannelHandlerContext ctx) throws Exception
beforeAdd
in interface LifeCycleAwareChannelHandler
Exception
public void afterAdd(ChannelHandlerContext ctx) throws Exception
afterAdd
in interface LifeCycleAwareChannelHandler
Exception
public void beforeRemove(ChannelHandlerContext ctx) throws Exception
beforeRemove
in interface LifeCycleAwareChannelHandler
Exception
public void afterRemove(ChannelHandlerContext ctx) throws Exception
afterRemove
in interface LifeCycleAwareChannelHandler
Exception
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