Issue #896, first implementation of ZMQ Publisher class

#ifndef __PYZMQPUBLISHER_HPP__

#define __PYZMQPUBLISHER_HPP__

#include "ZMQPublisher.hpp"

#include <boost/python.hpp>

namespace py = boost::python;

/**

 * Wrapper for the above ZMQPublisher class in order to be used with boost_python.

 */

class PyZMQPublisher : public ZMQPublisher

{

public:

    using ZMQPublisher::ZMQPublisher;

    /**

     * Re-definition of the base protected publish method as public.

     * We cannot use "using" because it won't work with boost_python.

     * @param payload, a json-ified string.

     */

    void publish(const std::string& payload) override;

};

/**

 * Python module definition.

 */

BOOST_PYTHON_MODULE(libPyZMQPublisher)

{

    /**

     * Expose DEFAULT_ADDRESS and DEFAULT_PORT to the Python module.

     */

    py::object scope = py::scope();

    scope.attr("DEFAULT_ADDRESS") = DEFAULT_ADDRESS;

    scope.attr("DEFAULT_PORT") = DEFAULT_PORT;

    /**

     * Python PyZMQPublisher class definition. It is a wrapper of the PyZMQPublisher class defined above.

     * Unlike the PyZMQPublisher class, the "publish" method is exposed as a private method "__publish".

     * The actual "publish" method is defined inside the actual python module in order to convert a python dict() to a json-ified string.

     * Take a look there for more info.

     */

    py::class_<PyZMQPublisher>("PyZMQPublisher", py::init<const std::string, const std::string, const unsigned int>())

        .def("__publish", &PyZMQPublisher::publish)

        .def_readonly("topic", &ZMQPublisher::topic);

}

#endif /*__PYZMQPUBLISHER_HPP__*/

#ifndef __ZMQDICTIONARY_HPP__

#define __ZMQDICTIONARY_HPP__

#include <json.hpp>

using ZMQDictionary = nlohmann::json;

#endif /*__ZMQDICTIONARY_HPP__*/

#ifndef __ZMQPUBLISHER_HPP__

#define __ZMQPUBLISHER_HPP__

#include <zmq.hpp>

#include <zmq_addon.hpp>

#include "ZMQDictionary.hpp"

#define DEFAULT_ADDRESS std::string("127.0.0.1")

#define DEFAULT_PORT    16001

/**

 * This class implements a publisher object over a ZeroMQ socket, single topic only.

 * It exposes a publish method which sends a dictionary of key, value format over the ZMQ socket.

 */

class ZMQPublisher

{

public:

    /**

     * Constructors. Initializes the ZMQPublisher object with the given topic, address and port.

     */

    ZMQPublisher(const std::string& topic, const std::string address, const unsigned int port);

    ZMQPublisher(const std::string& topic) : ZMQPublisher(topic, DEFAULT_ADDRESS, DEFAULT_PORT) {};

    ZMQPublisher(const std::string& topic, const std::string address) : ZMQPublisher(topic, address, DEFAULT_PORT) {};

    ZMQPublisher(const std::string& topic, const unsigned int port) : ZMQPublisher(topic, DEFAULT_ADDRESS, port) {};

    /**

     * Destructor.

     */

    ~ZMQPublisher();

    /**

     * Public publisher method. This method accepts a ZMQDictionary object reference,

     * it converts it to a json-ified string and calls the protected publisher method.

     * @param dictionary, a json-like dictionary containing tuples of key, value format.

     */

    virtual void publish(const ZMQDictionary& dictionary);

    /**

     * Name of the topic on which the messages will be sent.

     */

    const std::string topic;

protected:

    /**

     * Protected publisher method. This method sends a tuple (topic, payload) over the ZMQ socket.

     * @param payload, a json-ified string.

     */

    virtual void publish(const std::string& payload);

private:

    /**

     * ZMQ constant buffer which references the topic name.

     */

    const zmq::const_buffer m_topic;

    /**

     * ZMQ context shared pointer. We use a pointer since the context must not be destroyed for communications to work properly.

     */

    std::shared_ptr<zmq::context_t> m_context;

    /**

     * ZMQ socket shared pointer. We use a pointer since the socket must not be destroyed for communications to work properly.

     */

    std::shared_ptr<zmq::socket_t> m_socket;

};

#endif /*__ZMQPUBLISHER_HPP__*/

#*******************************************************************************

# This Makefile follows VLT Standards (see Makefile(5) for more).

#*******************************************************************************

# REMARKS

#    None

#------------------------------------------------------------------------

#

# user definable C-compilation flags

#USER_CFLAGS = 

#

# additional include and library search paths

#USER_INC =

USER_LIB = /usr/local/lib64/libzmq.so

#

# MODULE CODE DESCRIPTION:

# ------------------------

# As a general rule:  public file are "cleaned" and "installed"  

#                     local (_L) are not "installed".

#

# C programs (public and local)

# -----------------------------

EXECUTABLES =

EXECUTABLES_L =

PY_PACKAGES = ZMQPublisher

#PY_SCRIPTS =

#

# <brief description of xxxxx program>

#

# Includes (.h) files (public only)

# ---------------------------------

INCLUDES = ZMQDictionary.hpp ZMQPublisher.hpp PyZMQPublisher.hpp

#

# Libraries (public and local)

# ----------------------------

LIBRARIES = ZMQPublisher PyZMQPublisher

LIBRARIES_L =

ZMQPublisher_OBJECTS = ZMQPublisher

PyZMQPublisher_OBJECTS = PyZMQPublisher

PyZMQPublisher_LIBS = ZMQPublisher boost_python3

#

# list of all possible C-sources (used to create automatic dependencies)

# ------------------------------

CSOURCENAMES = \

	$(foreach exe, $(EXECUTABLES) $(EXECUTABLES_L), $($(exe)_OBJECTS)) \

	$(foreach rtos, $(RTAI_MODULES) , $($(rtos)_OBJECTS)) \

	$(foreach lib, $(LIBRARIES) $(LIBRARIES_L), $($(lib)_OBJECTS))

#

#>>>>> END OF standard rules

#

# INCLUDE STANDARDS

# -----------------

MAKEDIRTMP := $(shell searchFile include/acsMakefile)

ifneq ($(MAKEDIRTMP),\#error\#)

   MAKEDIR := $(MAKEDIRTMP)/include

   include $(MAKEDIR)/acsMakefile

endif

#

# TARGETS

# -------

all:	do_all

	@echo " . . . 'all' done" 

clean : clean_all 

	@echo " . . . clean done"

clean_dist : clean_all clean_dist_all 

	@echo " . . . clean_dist done"

man   : do_man 

	@echo " . . . man page(s) done"

install : install_all

	@echo " . . . installation done"

#___oOo___

#include "PyZMQPublisher.hpp"

void PyZMQPublisher::publish(const std::string& payload)

{

    ZMQPublisher::publish(payload);

}