lsst.ctrl.events::EventReceiver Class Reference

Receive events from the event bus. More...

#include <EventReceiver.h>

Public Member Functions
	EventReceiver (const pexPolicy::Policy &policy)
	Receives events based on Policy file contents. More...
	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 method 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 ()
	returns the topic for this EventReceiver 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
bool	_turnEventsOff
std::string	_topic
std::string	_selector

Detailed Description

Receive events from the event bus.

Definition at line 63 of file EventReceiver.h.

Constructor & Destructor Documentation

lsst.ctrl.events::EventReceiver::EventReceiver

(

const pexPolicy::Policy &

policy

)

Receives events based on Policy file contents.

Parameters

policy

the policy object to use when building the receiver

Exceptions

throws	lsst::pex::exceptions::NotFoundError if topicName isn't specified
throws	lsst::pex::exceptions::NotFoundError if hostName isn't specified
throws	lsst::pex::exceptions::RuntimeError if connection fails to initialize

Definition at line 73 of file EventReceiver.cc.

                                                          {
    //EventLibrary().initializeLibrary();
    int hostPort;

    try {
        _turnEventsOff = policy.getBool("turnEventsOff");
    } catch (pexPolicy::NameNotFound& e) {
        _turnEventsOff = false;
    }
    if (_turnEventsOff == true)
        return;

    if (!policy.exists("topicName")) {
        throw LSST_EXCEPT(pexExceptions::NotFoundError, "topicName not found in policy");
    }

    std::string topicName = policy.getString("topicName");
    try {
        _turnEventsOff = policy.getBool("turnEventsOff");
    } catch (pexPolicy::NameNotFound& e) {
        _turnEventsOff = false;
    }

    if (!policy.exists("hostName")) {
        throw LSST_EXCEPT(pexExceptions::NotFoundError, "hostName not found in policy");
    }

    std::string hostName = policy.getString("hostName");

    try {
        hostPort = policy.getInt("hostPort");
    } catch (pexPolicy::NameNotFound& e) {
        hostPort = EventBroker::DEFAULTHOSTPORT;
    }

    try {
        _selector = policy.getString("selector");
    } catch (pexPolicy::NameNotFound& e) {
        _selector = "";
    }
    init(hostName, topicName, _selector, hostPort);
}

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 123 of file EventReceiver.cc.

                                                                                                {
    _turnEventsOff = false;
    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 136 of file EventReceiver.cc.

                                                                                                                           {
    _turnEventsOff = false;
    init(hostName, topicName, selector, hostPort);
}

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

virtual

destructor method

Definition at line 241 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

(

)

returns the topic for this EventReceiver

Definition at line 235 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. Sets up use of local sockets or activemq, depending on how the policy file was configured.

Definition at line 144 of file EventReceiver.cc.

                                                                                                                       {

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

    if (_turnEventsOff == true)
        return;

    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.

Wait until an Event is received Note: Caller is responsible for deleting received Event.

Definition at line 199 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.

Wait to receive an event for a length of time. Note: Caller is responsible for deleting received Event.

Parameters

timeout

the length of time to waitm in milliseconds

Definition at line 208 of file EventReceiver.cc.

                                               {
    PropertySet::Ptr psp;

    if (_turnEventsOff == true)
        return NULL;

    
    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 85 of file EventReceiver.h.

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

private

Definition at line 94 of file EventReceiver.h.

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

private

Definition at line 91 of file EventReceiver.h.

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

private

Definition at line 103 of file EventReceiver.h.

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

private

Definition at line 88 of file EventReceiver.h.

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

private

Definition at line 100 of file EventReceiver.h.

bool lsst.ctrl.events::EventReceiver::_turnEventsOff

private

Definition at line 97 of file EventReceiver.h.

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

static

Definition at line 79 of file EventReceiver.h.

---

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

• /lsst/home/lsstsw/stack/Linux64/ctrl_events/master-gcf15f11bcc/include/lsst/ctrl/events/EventReceiver.h
• /lsst/home/lsstsw/stack/Linux64/ctrl_events/master-gcf15f11bcc/src/EventReceiver.cc