io.lettuce.core.protocol

Class Command<K,V,T>

java.lang.Object

io.lettuce.core.protocol.Command<K,V,T>

Type Parameters:

K - Key type.

V - Value type.

T - Command output type.

All Implemented Interfaces:

RedisCommand<K,V,T>

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

A Redis command with a command type, arguments and an optional output. All successfully executed commands will eventually return a CommandOutput object.

Author:

Will Glozer, Mark Paluch

Field Summary

Fields

Modifier and Type	Field and Description
protected CommandArgs<K,V>	args
protected Throwable	exception
protected CommandOutput<K,V,T>	output
protected static byte	ST_CANCELLED
protected static byte	ST_COMPLETED
protected static byte	ST_INITIAL
protected byte	status

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	cancel() Attempts to cancel execution of this command.
void	complete() Mark this command complete and notify all waiting threads.
boolean	completeExceptionally(Throwable throwable) Complete this command by attaching the given exception.
void	encode(ByteBuf buf) Encode and write this command to the supplied buffer using the new Unified Request Protocol.
T	get()
CommandArgs<K,V>	getArgs()
String	getError()
CommandOutput<K,V,T>	getOutput() Get the object that holds this command's output.
ProtocolKeyword	getType()
boolean	isCancelled() Returns true if this task was cancelled before it completed normally.
boolean	isDone() Returns true if this task completed.
void	setOutput(CommandOutput<K,V,T> output) Set a new output.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

ST_INITIAL

protected static final byte ST_INITIAL

See Also:

Constant Field Values

ST_COMPLETED

protected static final byte ST_COMPLETED

See Also:

Constant Field Values

ST_CANCELLED

protected static final byte ST_CANCELLED

See Also:

Constant Field Values

args

protected CommandArgs<K,V> args

output

protected CommandOutput<K,V,T> output

exception

protected Throwable exception

status

protected volatile byte status

Constructor Detail

Command

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

Create a new command with the supplied type.

Parameters:

type - Command type, must not be null.

output - Command output, can be null.

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, must not be null.

output - Command output, can be null.

args - Command args, can be null

Method Detail

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.

completeExceptionally

public boolean completeExceptionally(Throwable throwable)

Description copied from interface: RedisCommand

Complete this command by attaching the given exception.

Specified by:

completeExceptionally in interface RedisCommand<K,V,T>

Parameters:

throwable - the exception.

Returns:

true if this invocation caused this CompletableFuture to transition to a completed state, else false.

complete

public void complete()

Mark this command complete and notify all waiting threads.

Specified by:

complete in interface RedisCommand<K,V,T>

cancel

public void cancel()

Description copied from interface: RedisCommand

Attempts to cancel execution of this command. This attempt will fail if the task has already completed, has already been cancelled, or could not be cancelled for some other reason.

Specified by:

cancel 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.

getError

public String getError()

getArgs

public CommandArgs<K,V> getArgs()

Specified by:

getArgs in interface RedisCommand<K,V,T>

Returns:

the current command args.

get

public T get()

Returns:

the resut from the output.

toString

public String toString()

Overrides:

toString in class Object

setOutput

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

Description copied from interface: RedisCommand

Set a new output. Only possible as long as the command is not completed/cancelled.

Specified by:

setOutput in interface RedisCommand<K,V,T>

Parameters:

output - the new command output.

getType

public ProtocolKeyword getType()

Specified by:

getType in interface RedisCommand<K,V,T>

Returns:

the Redis command type like SADD, HMSET, QUIT.

isCancelled

public boolean isCancelled()

Description copied from interface: RedisCommand

Returns true if this task was cancelled before it completed normally.

Specified by:

isCancelled in interface RedisCommand<K,V,T>

Returns:

true if the command was cancelled before it completed normally.

isDone

public boolean isDone()

Description copied from interface: RedisCommand

Returns true if this task completed. Completion may be due to normal termination, an exception, or cancellation. In all of these cases, this method will return true.

Specified by:

isDone in interface RedisCommand<K,V,T>

Returns:

true if this task completed.