com.fr.third.jgroups.protocols

类 COMPRESS

java.lang.Object

com.fr.third.jgroups.stack.Protocol

com.fr.third.jgroups.protocols.COMPRESS

public class COMPRESS
extends Protocol

Compresses the payload of a message. Goal is to reduce the number of messages sent across the wire. Should ideally be layered somewhere above a fragmentation protocol (e.g. FRAG).

作者:

Bela Ban

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	COMPRESS.CompressHeader

字段概要

字段

限定符和类型	字段和说明
protected int	compression_level
protected java.util.concurrent.BlockingQueue<java.util.zip.Deflater>	deflater_pool
protected java.util.concurrent.BlockingQueue<java.util.zip.Inflater>	inflater_pool
protected long	min_size
protected int	pool_size

从类继承的字段 com.fr.third.jgroups.stack.Protocol

down_prot, ergonomics, id, log, name, stack, stats, up_prot

构造器概要

构造器

构造器和说明
COMPRESS()

方法概要

方法

限定符和类型	方法和说明
void	destroy() This method is called on a Channel.close().
java.lang.Object	down(Event evt) We compress the payload if it is larger than min_size.
void	init() Called after instance has been created (null constructor) and before protocol is started.
protected Message	uncompress(Message msg, int original_size) Returns a new message as a result of uncompressing msg, or null if msg couldn't be uncompressed
java.lang.Object	up(Event evt) If there is no header, we pass the message up.
void	up(MessageBatch batch) Sends up a multiple messages in a MessageBatch.

从类继承的方法 com.fr.third.jgroups.stack.Protocol

accept, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, resetStats, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, start, statsEnabled, stop

从类继承的方法 java.lang.Object

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

字段详细资料

compression_level

protected int compression_level

min_size

protected long min_size

pool_size

protected int pool_size

deflater_pool

protected java.util.concurrent.BlockingQueue<java.util.zip.Deflater> deflater_pool

inflater_pool

protected java.util.concurrent.BlockingQueue<java.util.zip.Inflater> inflater_pool

构造器详细资料

COMPRESS

public COMPRESS()

方法详细资料

init

public void init()
          throws java.lang.Exception

从类复制的说明: Protocol

Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.

覆盖:

init 在类中 Protocol

抛出:

java.lang.Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor will throw an exception

destroy

public void destroy()

从类复制的说明: Protocol

This method is called on a Channel.close(). Does some cleanup; after the call the VM will terminate

覆盖:

destroy 在类中 Protocol

down

public java.lang.Object down(Event evt)

We compress the payload if it is larger than min_size. In this case we add a header containing the original size before compression. Otherwise we add no header.
Note that we compress either the entire buffer (if offset/length are not used), or a subset (if offset/length are used)

覆盖:

down 在类中 Protocol

参数:

evt -

up

public java.lang.Object up(Event evt)

If there is no header, we pass the message up. Otherwise we uncompress the payload to its original size.

覆盖:

up 在类中 Protocol

参数:

evt -

up

public void up(MessageBatch batch)

从类复制的说明: Protocol

Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(Message)), and - if true - calls Protocol.up(Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.getMatchingMessages(short, boolean)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

覆盖:

up 在类中 Protocol

参数:

batch - The message batch

uncompress

protected Message uncompress(Message msg,
                 int original_size)

Returns a new message as a result of uncompressing msg, or null if msg couldn't be uncompressed