lsst.ctrl.events::EventReceiver Class Reference

Receive events from the event bus. More...

#include <EventReceiver.h>

Public Member Functions
	EventReceiver (const std::string &hostName, const std::string &topicName, int hostPort=EventBroker::DEFAULTHOSTPORT)
	Receives events from the specified host and topic. More...
	EventReceiver (const std::string &hostName, const std::string &topicName, const std::string &selector, int hostPort=EventBroker::DEFAULTHOSTPORT)
	Receives events from the specified host and topic. More...
virtual	~EventReceiver ()
	destructor More...
Event *	receiveEvent ()
	Wait until an Event is received. More...
Event *	receiveEvent (long timeout)
	wait for a length of time for an event to be received. More...
std::string	getTopicName ()
	get topic name More...

Static Public Attributes
static const long	infiniteTimeout = -1

Private Member Functions
void	init (const std::string &hostName, const std::string &topicName, const std::string &selector, int hostPort)

Private Attributes
cms::Connection *	_connection
cms::Session *	_session
cms::Destination *	_destination
cms::MessageConsumer *	_consumer
std::string	_topic
std::string	_selector

Detailed Description

Receive events from the event bus.

Definition at line 59 of file EventReceiver.h.

Constructor & Destructor Documentation

lsst.ctrl.events::EventReceiver::EventReceiver	(	const std::string &	hostName,
		const std::string &	topicName,
		int	hostPort = EventBroker::DEFAULTHOSTPORT
	)

Receives events from the specified host and topic.

Parameters

hostName	the machine hosting the message broker
topicName	the topic to receive events from
hostPort	the port the message broker is listening on

Exceptions

throws

lsst::pex::exceptions::RuntimeError if connection fails to initialize

Definition at line 60 of file EventReceiver.cc.

                                                                                                {
    init(hostName, topicName, "", hostPort);
}

lsst.ctrl.events::EventReceiver::EventReceiver	(	const std::string &	hostName,
		const std::string &	topicName,
		const std::string &	selector,
		int	hostPort = EventBroker::DEFAULTHOSTPORT
	)

Receives events from the specified host and topic.

Parameters

hostName	the machine hosting the message broker
topicName	the topic to receive events from
selector	the message selector expression to use. A selector value of "" is equivalent to no selector.
hostPort	the port the message broker is listening on

Exceptions

throws

lsst::pex::exceptions::RuntimeError if connection fails to initialize

Definition at line 64 of file EventReceiver.cc.

                                                                                                                           {
    init(hostName, topicName, selector, hostPort);
}

lsst.ctrl.events::EventReceiver::~EventReceiver ( )

virtual

destructor

Definition at line 147 of file EventReceiver.cc.

                              {

    // Destroy resources.
    try {
        if( _destination != NULL )
            delete _destination;
    } catch ( cms::CMSException& e ) {
        e.printStackTrace();
    }
    _destination = NULL;

    try {
        if( _consumer != NULL )
            delete _consumer;
    } catch ( cms::CMSException& e ) {
        e.printStackTrace();
    }
    _consumer = NULL;

    // Close open resources.
    try {
        if( _session != NULL )
            _session->close();
    } catch ( cms::CMSException& e ) {
        e.printStackTrace();
    }
    try {
        if( _connection != NULL )
            _connection->close();
    } catch ( cms::CMSException& e ) {
        e.printStackTrace();
    }

    try {
        if( _session != NULL )
            delete _session;
    } catch ( cms::CMSException& e ) {
        e.printStackTrace();
    }
    _session = NULL;

    try {
        if( _connection != NULL )
            delete _connection;
    } catch ( cms::CMSException& e ) {
        e.printStackTrace();
    }
    _connection = NULL;
}

Member Function Documentation

std::string lsst.ctrl.events::EventReceiver::getTopicName

(

)

get topic name

Returns

the topic name used by this EventReceiver

Definition at line 143 of file EventReceiver.cc.

                                      {
    return _topic;
}

void lsst.ctrl.events::EventReceiver::init ( const std::string &  hostName, const std::string &  topicName, const std::string &  selector, int  hostPort  )

private

private method for initialization of EventReceiver.

Definition at line 70 of file EventReceiver.cc.

                                                                                                                       {

    EventLibrary().initializeLibrary();
    _connection = NULL;
    _session = NULL;
    _destination = NULL;
    _consumer = NULL;
    _topic = topicName;
    _selector = selector;

    try {
        std::stringstream ss;

        ss << hostPort;

        string jmsURL = "tcp://"+hostName+":"+ss.str()+"?wireFormat=openwire";

        activemqCore::ActiveMQConnectionFactory* connectionFactory =
            new activemqCore::ActiveMQConnectionFactory( jmsURL );

        _connection = 0;
        try {
            _connection = connectionFactory->createConnection();
            _connection->start();
            delete connectionFactory;
        }
        catch (cms::CMSException& e) {
            delete connectionFactory;
            std::string msg("Failed to connect to broker: ");
            msg += e.getMessage();
            msg += " (is broker running?)";
            throw LSST_EXCEPT(pexExceptions::RuntimeError, msg);
        }

        _session = _connection->createSession( cms::Session::AUTO_ACKNOWLEDGE );

        _destination = _session->createTopic( topicName );

        if (_selector == "")
            _consumer = _session->createConsumer( _destination );
        else
            _consumer = _session->createConsumer( _destination, selector );

    } catch ( cms::CMSException& e ) {
        throw LSST_EXCEPT(pexExceptions::RuntimeError, std::string("Trouble creating EventReceiver: ") + e.getMessage());
    }
}

Event * lsst.ctrl.events::EventReceiver::receiveEvent

(

)

Wait until an Event is received.

Note

Caller is responsible for deleting received Event.

Definition at line 118 of file EventReceiver.cc.

                                   {
    return receiveEvent(infiniteTimeout);
}

Event * lsst.ctrl.events::EventReceiver::receiveEvent

(

long

timeout

)

wait for a length of time for an event to be received.

Parameters

timeout

the length of time to wait in milliseconds; value of -1 waits indefinately.

Note

Caller is responsible for deleting received Event.

Definition at line 122 of file EventReceiver.cc.

                                               {
    PropertySet::Ptr psp;

    cms::TextMessage* textMessage;
    try {
        cms::Message* msg = _consumer->receive(timeout);
        if (msg == NULL) return NULL;
        textMessage = dynamic_cast<cms::TextMessage* >(msg);
        if (textMessage == NULL)
            throw LSST_EXCEPT(pexExceptions::RuntimeError, "Unexpected JMS Message type");
    } catch (activemq::exceptions::ActiveMQException& e) {
        throw LSST_EXCEPT(pexExceptions::RuntimeError, e.getMessage());
    }

 
    Event* event = EventFactory().createEvent(textMessage);
    delete textMessage;

    return event;
}

Member Data Documentation

cms::Connection* lsst.ctrl.events::EventReceiver::_connection

private

Definition at line 110 of file EventReceiver.h.

cms::MessageConsumer* lsst.ctrl.events::EventReceiver::_consumer

private

Definition at line 119 of file EventReceiver.h.

cms::Destination* lsst.ctrl.events::EventReceiver::_destination

private

Definition at line 116 of file EventReceiver.h.

std::string lsst.ctrl.events::EventReceiver::_selector

private

Definition at line 125 of file EventReceiver.h.

cms::Session* lsst.ctrl.events::EventReceiver::_session

private

Definition at line 113 of file EventReceiver.h.

std::string lsst.ctrl.events::EventReceiver::_topic

private

Definition at line 122 of file EventReceiver.h.

const long lsst.ctrl.events::EventReceiver::infiniteTimeout = -1

static

Definition at line 104 of file EventReceiver.h.

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The documentation for this class was generated from the following files:

• /home/lsstsw/stack/Linux64/ctrl_events/10.0-6-g462a451+1/include/lsst/ctrl/events/EventReceiver.h
• /home/lsstsw/stack/Linux64/ctrl_events/10.0-6-g462a451+1/src/EventReceiver.cc