lsst.ctrl.events::EventTransmitter Class Reference

Transmit events to the event bus. More...

#include <EventTransmitter.h>

Public Member Functions
	EventTransmitter (const pexPolicy::Policy &policy)
	Configures an EventTransmitter based on Policy contents. More...
	EventTransmitter (const std::string &hostName, const std::string &topicName, int hostPort=EventBroker::DEFAULTHOSTPORT)
	Transmits events to the specified host and topic. More...
	~EventTransmitter ()
	Destructor for EventTransmitter. More...
std::string	getTopicName ()
	get the topic name of this EventTransmitter More...
void	publishEvent (Event &event)

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

Private Attributes
cms::Connection *	_connection
cms::Session *	_session
cms::Destination *	_destination
cms::MessageProducer *	_producer
std::string	_brokerUri
activemq::commands::ActiveMQTopic *	_topic
std::string	_topicName
bool	_turnEventsOff

Detailed Description

Transmit events to the event bus.

Definition at line 67 of file EventTransmitter.h.

Constructor & Destructor Documentation

lsst.ctrl.events::EventTransmitter::EventTransmitter

(

const pexPolicy::Policy &

policy

)

Configures an EventTransmitter based on Policy contents.

The Policy object is checked for four keywords:

topicName - the name of the topic to send to hostName - the name of the host hosting the event broker hostPort - the port the event broker is listening on turnEventsOff - turn off event transmission

Defaults are:

turnEventsOff = false hostPort = EventSystem::DEFAULTHOSTPORT

The dependencies for these keywords are as follows:

1) If turnEventsOff is specified as true, no further checking is done, and no events will be transmitted.

2) If no topicName is specified, a NotFound exception is thrown

Parameters

policy

the policy object to use when building the receiver

Exceptions

throws	NotFoundError if expected keywords are missing in Policy object
throws	RuntimeError if connection to transport mechanism fails

Definition at line 94 of file EventTransmitter.cc.

                                                                 {
    int hostPort;

    EventLibrary().initializeLibrary();

    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");
    }
    _topicName = policy.getString("topicName");

    std::string hostName;
    try {
        hostName = policy.getString("hostName");
    } catch (pexPolicy::NameNotFound& e) {
        throw LSST_EXCEPT(pexExceptions::NotFoundError, "hostName not found in policy");
    }

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

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

Transmits events to the specified host and topic.

Parameters

hostName	the machine hosting the message broker
topicName	the topic to transmit events to
hostPort	the port number which the message broker is listening to

Exceptions

throws	RuntimeError if local socket can't be created
throws	RuntimeError if connect to local socket fails
throws	RuntimeError if connect to remote ActiveMQ host fails

Definition at line 136 of file EventTransmitter.cc.

                                                                                                       {
    EventLibrary().initializeLibrary();

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

lsst.ctrl.events::EventTransmitter::~EventTransmitter

(

)

Destructor for EventTransmitter.

Definition at line 226 of file EventTransmitter.cc.

                                    {

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

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

    // Close open resources.
    try {
        if( _session != NULL )
            _session->close();
        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::EventTransmitter::getTopicName

(

)

get the topic name of this EventTransmitter

Definition at line 220 of file EventTransmitter.cc.

                                         {
    return _topicName;
}

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

private

private initialization method for configuring EventTransmitter

Definition at line 145 of file EventTransmitter.cc.

                                                                                                {
    _connection = NULL;
    _session = NULL;
    // _destination = NULL;
    _producer = NULL;
    _topicName = topicName;
    _topic = NULL;

    if (_turnEventsOff == true)
        return;

    // set up a connection to the ActiveMQ server for message transmission
    try {
        std::stringstream ss;

        ss << hostPort;

        /*
         * Create a ConnectionFactory to connect to hostName, and
         * create a topic for this.
         */
        string brokerUri = "tcp://"+hostName+":"+ss.str()+"?wireFormat=openwire&transport.useAsyncSend=true";

        activemq::core::ActiveMQConnectionFactory* connectionFactory =
            new activemq::core::ActiveMQConnectionFactory( brokerUri );

        _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 );
       
        // Create the destination topic
        //_destination = _session->createTopic( topicName );

        // Create Topic
        _topic = new activemq::commands::ActiveMQTopic(_topicName);
        

        // Create a MessageProducer from the Session to the Topic or Queue
        _producer = _session->createProducer(NULL);
        _producer->setDeliveryMode( cms::DeliveryMode::NON_PERSISTENT );
    } catch ( cms::CMSException& e ) {
        throw LSST_EXCEPT(pexExceptions::RuntimeError, std::string("Trouble creating EventTransmitter: ") + e.getMessage());
    }
}

void lsst.ctrl.events::EventTransmitter::publishEvent

(

Event &

event

)

Definition at line 202 of file EventTransmitter.cc.

                                                {
    long long pubtime;
    cms::TextMessage* message = _session->createTextMessage();

    event.marshall(message);

    message->setStringProperty("TOPIC", _topicName);

    // wait until the last moment to timestamp publication time
    pubtime = dafBase::DateTime::now().nsecs();
    message->setLongProperty("PUBTIME", pubtime);

    _producer->send(_topic, message);
    delete message;
}

Member Data Documentation

std::string lsst.ctrl.events::EventTransmitter::_brokerUri

private

Definition at line 95 of file EventTransmitter.h.

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

private

Definition at line 83 of file EventTransmitter.h.

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

private

Definition at line 89 of file EventTransmitter.h.

cms::MessageProducer* lsst.ctrl.events::EventTransmitter::_producer

private

Definition at line 92 of file EventTransmitter.h.

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

private

Definition at line 86 of file EventTransmitter.h.

activemq::commands::ActiveMQTopic* lsst.ctrl.events::EventTransmitter::_topic

private

Definition at line 97 of file EventTransmitter.h.

std::string lsst.ctrl.events::EventTransmitter::_topicName

private

Definition at line 98 of file EventTransmitter.h.

bool lsst.ctrl.events::EventTransmitter::_turnEventsOff

private

Definition at line 101 of file EventTransmitter.h.

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

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