org.yamcs.commanding

Class CommandQueueManager

java.lang.Object

com.google.common.util.concurrent.AbstractService

org.yamcs.commanding.CommandQueueManager

All Implemented Interfaces:

com.google.common.util.concurrent.Service, ParameterConsumer, SystemParametersProducer

public class CommandQueueManager
extends com.google.common.util.concurrent.AbstractService
implements ParameterConsumer, SystemParametersProducer

Author:

nm Implements the management of the control queues for one processor: - for each command that is sent, based on the sender it finds the queue where the command should go - depending on the queue state the command can be immediately sent, stored in the queue or rejected - when the command is immediately sent or rejected, the command queue monitor is not notified - if the command has transmissionConstraints with timeout > 0, the command can sit in the queue even if the queue is not blocked Note: the update of the command monitors is done in the same thread. That means that if the connection to one of the monitors is lost, there may be a delay of a few seconds. As the monitoring clients will be priviledged users most likely connected in the same LAN, I don't consider this to be an issue.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

com.google.common.util.concurrent.Service.Listener, com.google.common.util.concurrent.Service.State

Constructor Summary

Constructors

Constructor and Description
CommandQueueManager(CommandingManager commandingManager) Constructs a Command Queue Manager.

Method Summary

Modifier and Type	Method and Description
CommandQueue	addCommand(AuthenticationToken authToken, PreparedCommand pc) Called from the CommandingImpl to add a command to the queue First the command is added to the command history Depending on the status of the queue, the command is rejected by setting the CommandFailed in the command history added to the queue or directly sent using the command releaser
void	addToCommandHistory(Commanding.CommandId commandId, String key, String value)
void	doStart() called at processor startup, subscribe all parameters required for checking command constraints
void	doStop()
String	getChannelName()
String	getInstance()
CommandQueue	getQueue(AuthenticationToken authToken, PreparedCommand pc)
CommandQueue	getQueue(String name)
Collection<CommandQueue>	getQueues()
Collection<ParameterValue>	getSystemParameters() return the next bunch of parameter values.
void	registerListener(CommandQueueListener cqm) Called from a queue monitor to register itself in order to be notified when new commands are added/removed from the queue.
PreparedCommand	rejectCommand(Commanding.CommandId commandId, String username) Called by external clients to remove a command from the queue
PreparedCommand	rejectCommand(UUID uuid, String username)
boolean	removeListener(CommandQueueListener cqm)
PreparedCommand	sendCommand(Commanding.CommandId commandId, boolean rebuild) Called from external client to release a command from the queue
PreparedCommand	sendCommand(UUID uuid, boolean rebuild)
CommandQueue	setQueueState(String queueName, Commanding.QueueState newState) Called from external clients to change the state of the queue
void	updateItems(int subscriptionId, List<ParameterValue> items)

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

addListener, awaitRunning, awaitRunning, awaitTerminated, awaitTerminated, failureCause, isRunning, notifyFailed, notifyStarted, notifyStopped, startAsync, state, stopAsync, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

CommandQueueManager

public CommandQueueManager(CommandingManager commandingManager)
                    throws ConfigurationException

Constructs a Command Queue Manager.

Parameters:

commandingManager -

Throws:

ConfigurationException - in case there is an error in the configuration file. Note: if the configuration file doesn't exist, this exception is not thrown.

Method Detail

doStart

public void doStart()

called at processor startup, subscribe all parameters required for checking command constraints

Specified by:

doStart in class com.google.common.util.concurrent.AbstractService

doStop

public void doStop()

Specified by:

doStop in class com.google.common.util.concurrent.AbstractService

getQueues

public Collection<CommandQueue> getQueues()

getQueue

public CommandQueue getQueue(String name)

addCommand

public CommandQueue addCommand(AuthenticationToken authToken,
                               PreparedCommand pc)
                        throws InvalidAuthenticationToken

Called from the CommandingImpl to add a command to the queue First the command is added to the command history Depending on the status of the queue, the command is rejected by setting the CommandFailed in the command history added to the queue or directly sent using the command releaser

Parameters:

authToken -

pc -

Returns:

the queue the command was added to

Throws:

InvalidAuthenticationToken

addToCommandHistory

public void addToCommandHistory(Commanding.CommandId commandId,
                                String key,
                                String value)

getQueue

public CommandQueue getQueue(AuthenticationToken authToken,
                             PreparedCommand pc)
                      throws InvalidAuthenticationToken

Parameters:

authToken -

pc -

Returns:

the queue where the command should be placed.

Throws:

InvalidAuthenticationToken

rejectCommand

public PreparedCommand rejectCommand(Commanding.CommandId commandId,
                                     String username)

Called by external clients to remove a command from the queue

Parameters:

commandId -

username - - the username rejecting the command

Returns:

the command removed from the queeu

rejectCommand

public PreparedCommand rejectCommand(UUID uuid,
                                     String username)

sendCommand

public PreparedCommand sendCommand(Commanding.CommandId commandId,
                                   boolean rebuild)

Called from external client to release a command from the queue

Parameters:

commandId -

rebuild - - if to rebuild the command binary from the source

Returns:

the prepared command sent

sendCommand

public PreparedCommand sendCommand(UUID uuid,
                                   boolean rebuild)

setQueueState

public CommandQueue setQueueState(String queueName,
                                  Commanding.QueueState newState)

Called from external clients to change the state of the queue

Parameters:

queueName - the queue whose state has to be set

newState - the new state of the queue

Returns:

the queue whose state has been changed or null if no queue by the name exists

registerListener

public void registerListener(CommandQueueListener cqm)

Called from a queue monitor to register itself in order to be notified when new commands are added/removed from the queue.

Parameters:

cqm - the callback which will be called with updates

removeListener

public boolean removeListener(CommandQueueListener cqm)

getInstance

public String getInstance()

getChannelName

public String getChannelName()

updateItems

public void updateItems(int subscriptionId,
                        List<ParameterValue> items)

Specified by:

updateItems in interface ParameterConsumer

getSystemParameters

public Collection<ParameterValue> getSystemParameters()

Description copied from interface: SystemParametersProducer

return the next bunch of parameter values. The values must contain a reference to a Parameter (i.e. parameter definition) and that Parameter does not need to be coming from the XtceDB - the provider can just make it up on the fly.

Specified by:

getSystemParameters in interface SystemParametersProducer