org.lsst.ccs.gconsole.agent.command

Class CommandSender

java.lang.Object

org.lsst.ccs.gconsole.agent.command.CommandSender

public class CommandSender
extends Object

Utility class for sending commands to remote subsystems and processing responses. The sender can be configured by calling its setter methods. This class is thread-safe, all methods can be called on any thread.

Author:

onoprien

Constructor Summary

Constructors

Constructor and Description
CommandSender(org.lsst.ccs.messaging.AgentMessagingLayer messenger, Executor callbackExecutor, Executor workerExecutor, org.lsst.ccs.utilities.scheduler.Scheduler timer) Creates an instance of CommandSender.

Method Summary

Modifier and Type	Method and Description
CommandTask	execute(CommandHandle handle, Duration timeout, String command, Object... args) Sends a command to a remote subsystem.
CommandTask	execute(CommandHandle handle, String command, Object... args) Sends a command to a remote subsystem with the default timeout.
CommandTask	execute(Duration timeout, String command, Object... args) Sends a command to a remote subsystem, using the default CommandHandle of this sender to process responses.
CommandTask	execute(String command, Object... args) Sends a command to a remote subsystem with the default timeout and the default callback handle.
void	setCommandHandle(CommandHandle defaultCommandHandle) Sets the default command handle for this sender.
void	setTimeout(Duration defaultTimeout) Sets the default command timeout for this sender.

Methods inherited from class java.lang.Object

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

Constructor Detail

CommandSender

public CommandSender(org.lsst.ccs.messaging.AgentMessagingLayer messenger,
                     Executor callbackExecutor,
                     Executor workerExecutor,
                     org.lsst.ccs.utilities.scheduler.Scheduler timer)

Creates an instance of CommandSender.

Parameters:

messenger - Messaging access point. If null, the environment messaging access will be used.

callbackExecutor - Executor for running CommandHandle methods. If null, a dedicated single-threaded executor will be created.

workerExecutor - Executor for running potentially time-consuming tasks. If null, a dedicated executor will be created.

timer - Scheduling executor for timing commands.

Method Detail

setTimeout

public void setTimeout(Duration defaultTimeout)

Sets the default command timeout for this sender. The specified timeout will be used for command execution requests that do not provide their own timeout values. If this method has never been called, the default timeout value is 10 seconds.

Parameters:

defaultTimeout - Default timeout. Zero duration means the command will never time out. Negative duration means its absolute value will be used and the custom timeout suggested by the target subsystem through an ACK will be ignored.

Throws:

IllegalArgumentException - If the supplied value is null.

setCommandHandle

public void setCommandHandle(CommandHandle defaultCommandHandle)

Sets the default command handle for this sender. The specified handle will be used for command execution requests that do not provide their own handle. If this method has never been called, the default handle does nothing.

Parameters:

defaultCommandHandle - Default command handle.

execute

public CommandTask execute(CommandHandle handle,
                           Duration timeout,
                           String command,
                           Object... args)

Sends a command to a remote subsystem.

This method returns immediately, without waiting for the command to be processed by the messaging service or the target subsystem. Synchronous command execution can be done by calling get() or getResult() on the CommandTask returned by this method.

Parameters:

handle - Handle for processing the command responses. May be null if no processing is required.

timeout - Timeout. Cannot be null. Zero duration means the command will never time out. Negative duration means its absolute value will be used and the custom timeout suggested by the target subsystem through an ACK will be ignored.

command - Command in subsystem/path format.

args - Command arguments.

Returns:

CommandTask created to process the command. Can be used to wait for the response or cancel the command processing.

execute

public CommandTask execute(Duration timeout,
                           String command,
                           Object... args)

Sends a command to a remote subsystem, using the default CommandHandle of this sender to process responses. If no default handle has been set, responses will be ignored.

This method returns immediately, without waiting for the command to be processed by the messaging service or the target subsystem. Synchronous command execution can be done by calling get() or getResult() on the CommandTask returned by this method.

Parameters:

timeout - Timeout. Cannot be null. Zero duration means the command will never time out. Negative duration means its absolute value will be used and the custom timeout suggested by the target subsystem through an ACK will be ignored.

command - Command in subsystem/path format.

args - Command arguments.

Returns:

CommandTask created to process the command. Can be used to wait for the response or cancel the command processing.

execute

public CommandTask execute(CommandHandle handle,
                           String command,
                           Object... args)

Sends a command to a remote subsystem with the default timeout. If no default timeout has been set for this sender, the timeout is 10 seconds, unless the target subsystem returns a custom timeout with ACK.

This method returns immediately, without waiting for the command to be processed by the messaging service or the target subsystem. Synchronous command execution can be done by calling get() or getResult() on the CommandTask returned by this method.

Parameters:

handle - Handle for processing the command responses. Cannot be null. If no processing is required, use CommandHandle.NONE.

command - Command in subsystem/path format.

args - Command arguments.

Returns:

CommandTask created to process the command. Can be used to wait for the response or cancel the command processing.

execute

public CommandTask execute(String command,
                           Object... args)

Sends a command to a remote subsystem with the default timeout and the default callback handle. The default timeout is 10 seconds, unless the target subsystem returns a custom timeout with ACK. If no default handle has been set, responses will be ignored.

This method returns immediately, without waiting for the command to be processed by the messaging service or the target subsystem. Synchronous command execution can be done by calling get() or getResult() on the CommandTask returned by this method.

Parameters:

command - Command in subsystem/path format.

args - Command arguments.

Returns:

CommandTask created to process the command. Can be used to wait for the response or cancel the command processing.