Module lettuce.core

Package io.lettuce.core.protocol

Class CommandHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.lettuce.core.protocol.CommandHandler

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler

Direct Known Subclasses:

PubSubCommandHandler

public class CommandHandler
extends ChannelDuplexHandler

A netty ChannelHandler responsible for writing redis commands and reading responses from the server.

Author:

Will Glozer, Mark Paluch, Jongyeol Choi, Grzegorz Szpak, Daniel Albuquerque, Gavin Cook, Anuraag Agrawal

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CommandHandler.LifecycleState

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor	Description
CommandHandler(ClientOptions clientOptions, ClientResources clientResources, Endpoint endpoint)	Initialize a new instance that handles commands from the supplied queue.

Method Summary

Modifier and Type	Method	Description
protected void	afterDecode(ChannelHandlerContext ctx, RedisCommand<?,?,?> command)	Hook method called after command completion.
protected boolean	canComplete(RedisCommand<?,?,?> command)	Decoding hook: Can the command be completed.
protected boolean	canDecode(ByteBuf buffer)	Decoding hook: Can the buffer be decoded to a command.
void	channelActive(ChannelHandlerContext ctx)
void	channelInactive(ChannelHandlerContext ctx)
void	channelRead(ChannelHandlerContext ctx, Object msg)
void	channelRegistered(ChannelHandlerContext ctx)
void	channelUnregistered(ChannelHandlerContext ctx)
protected void	complete(RedisCommand<?,?,?> command)	Decoding hook: Complete a command.
protected boolean	decode(ByteBuf buffer, CommandOutput<?,?,?> output)
protected boolean	decode(ByteBuf buffer, RedisCommand<?,?,?> command, CommandOutput<?,?,?> output)
protected void	decode(ChannelHandlerContext ctx, ByteBuf buffer)
Collection<RedisCommand<?,?,?>>	drainQueue()
void	exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
String	getChannelId()
protected CommandOutput<?,?,?>	getCommandOutput(RedisCommand<?,?,?> command)	Decoding hook: Retrieve CommandOutput for RedisCommand decoding.
Endpoint	getEndpoint()
Queue<RedisCommand<?,?,?>>	getStack()
protected CommandHandler.LifecycleState	getState()
boolean	isClosed()
protected boolean	isPushDecode(ByteBuf buffer)
protected void	notifyPushListeners(PushMessage notification)
protected void	setState(CommandHandler.LifecycleState lifecycleState)
void	userEventTriggered(ChannelHandlerContext ctx, Object evt)
void	write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)

Methods inherited from class io.netty.channel.ChannelDuplexHandler

bind, close, connect, deregister, disconnect, flush, read

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelReadComplete, channelWritabilityChanged

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

Constructor Details

CommandHandler

public CommandHandler(ClientOptions clientOptions,
ClientResources clientResources,
Endpoint endpoint)

Initialize a new instance that handles commands from the supplied queue.

Parameters:

clientOptions - client options for this connection, must not be null

clientResources - client resources for this connection, must not be null

endpoint - must not be null.

Method Details

getEndpoint

public Endpoint getEndpoint()

getStack

public Queue<RedisCommand<?,?,?>> getStack()

setState

protected void setState(CommandHandler.LifecycleState lifecycleState)

drainQueue

public Collection<RedisCommand<?,?,?>> drainQueue()

getState

protected CommandHandler.LifecycleState getState()

isClosed

public boolean isClosed()

channelRegistered

public void channelRegistered(ChannelHandlerContext ctx)
                       throws Exception

Specified by:

channelRegistered in interface ChannelInboundHandler

Overrides:

channelRegistered in class ChannelInboundHandlerAdapter

Throws:

Exception

See Also:

ChannelInboundHandlerAdapter.channelRegistered(io.netty.channel.ChannelHandlerContext)

channelUnregistered

public void channelUnregistered(ChannelHandlerContext ctx)
                         throws Exception

Specified by:

channelUnregistered in interface ChannelInboundHandler

Overrides:

channelUnregistered in class ChannelInboundHandlerAdapter

Throws:

Exception

See Also:

ChannelInboundHandlerAdapter.channelUnregistered(io.netty.channel.ChannelHandlerContext)

userEventTriggered

public void userEventTriggered(ChannelHandlerContext ctx,
Object evt)
                        throws Exception

Specified by:

userEventTriggered in interface ChannelInboundHandler

Overrides:

userEventTriggered in class ChannelInboundHandlerAdapter

Throws:

Exception

See Also:

ChannelInboundHandlerAdapter.userEventTriggered(io.netty.channel.ChannelHandlerContext, Object)

exceptionCaught

public void exceptionCaught(ChannelHandlerContext ctx,
Throwable cause)
                     throws Exception

Specified by:

exceptionCaught in interface ChannelHandler

Specified by:

exceptionCaught in interface ChannelInboundHandler

Overrides:

exceptionCaught in class ChannelInboundHandlerAdapter

Throws:

Exception

channelActive

public void channelActive(ChannelHandlerContext ctx)
                   throws Exception

Specified by:

channelActive in interface ChannelInboundHandler

Overrides:

channelActive in class ChannelInboundHandlerAdapter

Throws:

Exception

See Also:

ChannelInboundHandlerAdapter.channelActive(io.netty.channel.ChannelHandlerContext)

channelInactive

public void channelInactive(ChannelHandlerContext ctx)
                     throws Exception

Specified by:

channelInactive in interface ChannelInboundHandler

Overrides:

channelInactive in class ChannelInboundHandlerAdapter

Throws:

Exception

See Also:

ChannelInboundHandlerAdapter.channelInactive(io.netty.channel.ChannelHandlerContext)

write

public void write(ChannelHandlerContext ctx,
Object msg,
ChannelPromise promise)
           throws Exception

Specified by:

write in interface ChannelOutboundHandler

Overrides:

write in class ChannelDuplexHandler

Throws:

Exception

See Also:

ChannelDuplexHandler.write(io.netty.channel.ChannelHandlerContext, java.lang.Object, io.netty.channel.ChannelPromise)

channelRead

public void channelRead(ChannelHandlerContext ctx,
Object msg)
                 throws Exception

Specified by:

channelRead in interface ChannelInboundHandler

Overrides:

channelRead in class ChannelInboundHandlerAdapter

Throws:

Exception

See Also:

ChannelInboundHandlerAdapter.channelRead(io.netty.channel.ChannelHandlerContext, java.lang.Object)

decode

protected void decode(ChannelHandlerContext ctx,
ByteBuf buffer)
               throws InterruptedException

Throws:

InterruptedException

notifyPushListeners

protected void notifyPushListeners(PushMessage notification)

canDecode

protected boolean canDecode(ByteBuf buffer)

Decoding hook: Can the buffer be decoded to a command.

Parameters:

buffer -

Returns:

isPushDecode

protected boolean isPushDecode(ByteBuf buffer)

canComplete

protected boolean canComplete(RedisCommand<?,?,?> command)

Decoding hook: Can the command be completed.

Parameters:

command -

Returns:

complete

protected void complete(RedisCommand<?,?,?> command)

Decoding hook: Complete a command.

Parameters:

command -

See Also:

RedisCommand.complete()

getCommandOutput

protected CommandOutput<?,?,?> getCommandOutput(RedisCommand<?,?,?> command)

Decoding hook: Retrieve CommandOutput for RedisCommand decoding.

Parameters:

command -

Returns:

See Also:

RedisCommand.getOutput()

decode

protected boolean decode(ByteBuf buffer,
CommandOutput<?,?,?> output)

decode

protected boolean decode(ByteBuf buffer,
RedisCommand<?,?,?> command,
CommandOutput<?,?,?> output)

afterDecode

protected void afterDecode(ChannelHandlerContext ctx,
RedisCommand<?,?,?> command)

Hook method called after command completion.

Parameters:

ctx -

command -

getChannelId

public String getChannelId()

Returns:

the channel Id.

Since:

6.1