com.lambdaworks.redis.protocol

Class Command<K,V,T>

java.lang.Object

com.google.common.util.concurrent.AbstractFuture<T>

com.lambdaworks.redis.protocol.Command<K,V,T>

Type Parameters:

K - Key type.

V - Value type.

T - Command output type.

All Implemented Interfaces:

ListenableFuture<T>, RedisCommand<K,V,T>, RedisFuture<T>, Future<T>

public class Command<K,V,T>
extends AbstractFuture<T>
implements RedisCommand<K,V,T>

A redis command and its result. All successfully executed commands will eventually return a CommandOutput object.

Author:

Will Glozer

Field Summary

Fields

Modifier and Type	Field and Description
protected CommandArgs<K,V>	args
protected CountDownLatch	latch
protected CommandOutput<K,V,T>	output

Constructor Summary

Constructors

Constructor and Description
Command(ProtocolKeyword type, CommandOutput<K,V,T> output, CommandArgs<K,V> args) Create a new command with the supplied type and args.
Command(ProtocolKeyword type, CommandOutput<K,V,T> output, CommandArgs<K,V> args, boolean multi) Create a new command with the supplied type and args.

Method Summary

Modifier and Type	Method and Description
boolean	await(long timeout, TimeUnit unit) Wait up to the specified time for the command output to become available.
void	complete() Mark this command complete and notify all waiting threads.
void	encode(ByteBuf buf) Encode and write this command to the supplied buffer using the new Unified Request Protocol.
T	get() Get the command output and if the command hasn't completed yet, wait until it does.
T	get(long timeout, TimeUnit unit) Get the command output and if the command hasn't completed yet, wait up to the specified time until it does.
CommandArgs<K,V>	getArgs()
String	getError()
Throwable	getException()
CommandOutput<K,V,T>	getOutput() Get the object that holds this command's output.
ProtocolKeyword	getType()
protected void	interruptTask()
boolean	isCancelled() Check if the command has been cancelled.
boolean	isDone() Check if the command has completed.
boolean	isMulti()
boolean	setException(Throwable exception) Subclasses should invoke this method to set the result of the computation to an error, throwable.
void	setMulti(boolean multi)
void	setOutput(CommandOutput<K,V,T> output)
String	toString()
protected static void	writeInt(ByteBuf buf, int value) Write the textual value of a positive integer to the supplied buffer.

Methods inherited from class com.google.common.util.concurrent.AbstractFuture

addListener, cancel, set, wasInterrupted

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.common.util.concurrent.ListenableFuture

addListener

Methods inherited from interface java.util.concurrent.Future

cancel

Field Detail

args

protected CommandArgs<K,V> args

output

protected CommandOutput<K,V,T> output

latch

protected CountDownLatch latch

Constructor Detail

Command

public Command(ProtocolKeyword type,
               CommandOutput<K,V,T> output,
               CommandArgs<K,V> args)

Create a new command with the supplied type and args.

Parameters:

type - Command type.

output - Command output.

args - Command args, if any.

Command

public Command(ProtocolKeyword type,
               CommandOutput<K,V,T> output,
               CommandArgs<K,V> args,
               boolean multi)

Create a new command with the supplied type and args.

Parameters:

type - Command type.

output - Command output.

args - Command args, if any.

multi - Flag indicating if MULTI active.

Method Detail

setMulti

public void setMulti(boolean multi)

isMulti

public boolean isMulti()

interruptTask

protected void interruptTask()

Overrides:

interruptTask in class AbstractFuture<T>

isCancelled

public boolean isCancelled()

Check if the command has been cancelled.

Specified by:

isCancelled in interface Future<T>

Overrides:

isCancelled in class AbstractFuture<T>

Returns:

True if the command was cancelled.

isDone

public boolean isDone()

Check if the command has completed.

Specified by:

isDone in interface Future<T>

Overrides:

isDone in class AbstractFuture<T>

Returns:

true if the command has completed.

get

public T get()
      throws ExecutionException

Get the command output and if the command hasn't completed yet, wait until it does.

Specified by:

get in interface Future<T>

Overrides:

get in class AbstractFuture<T>

Returns:

The command output.

Throws:

ExecutionException

get

public T get(long timeout,
             TimeUnit unit)
      throws TimeoutException,
             ExecutionException

Get the command output and if the command hasn't completed yet, wait up to the specified time until it does.

Specified by:

get in interface Future<T>

Overrides:

get in class AbstractFuture<T>

Parameters:

timeout - Maximum time to wait for a result.

unit - Unit of time for the timeout.

Returns:

The command output.

Throws:

TimeoutException - if the wait timed out.

ExecutionException

await

public boolean await(long timeout,
                     TimeUnit unit)

Wait up to the specified time for the command output to become available.

Specified by:

await in interface RedisFuture<T>

Parameters:

timeout - Maximum time to wait for a result.

unit - Unit of time for the timeout.

Returns:

true if the output became available.

getOutput

public CommandOutput<K,V,T> getOutput()

Get the object that holds this command's output.

Specified by:

getOutput in interface RedisCommand<K,V,T>

Returns:

The command output object.

complete

public void complete()

Mark this command complete and notify all waiting threads.

Specified by:

complete in interface RedisCommand<K,V,T>

encode

public void encode(ByteBuf buf)

Encode and write this command to the supplied buffer using the new Unified Request Protocol.

Specified by:

encode in interface RedisCommand<K,V,T>

Parameters:

buf - Buffer to write to.

writeInt

protected static void writeInt(ByteBuf buf,
                               int value)

Write the textual value of a positive integer to the supplied buffer.

Parameters:

buf - Buffer to write to.

value - Value to write.

getError

public String getError()

Specified by:

getError in interface RedisFuture<T>

Returns:

error text, if any error occured.

getArgs

public CommandArgs<K,V> getArgs()

Specified by:

getArgs in interface RedisCommand<K,V,T>

Returns:

the current command args

toString

public String toString()

Overrides:

toString in class Object

setOutput

public void setOutput(CommandOutput<K,V,T> output)

getException

public Throwable getException()

setException

public boolean setException(Throwable exception)

Description copied from interface: RedisCommand

Subclasses should invoke this method to set the result of the computation to an error, throwable. This will set the state of the future to COMPLETED and invoke the listeners if the state was successfully changed.

Specified by:

setException in interface RedisCommand<K,V,T>

Overrides:

setException in class AbstractFuture<T>

Parameters:

exception - the exception that the task failed with.

Returns:

true if the state was successfully changed.

getType

public ProtocolKeyword getType()

Specified by:

getType in interface RedisCommand<K,V,T>

Returns:

the redis command type like SADD, HMSET, QUIT.