If there's some template for writing a client to access event data, that would be 
very useful (and you can probably just ignore the context I gave below in that 
case).


Some context:

Quite a while ago, I wrote the attached "data pipeline" client whose job was to 
listen for events, copy their data, and pipe them to a python script. I believe I 
just stole bits and pieces from mdump.cxx to accomplish this. Later I wrote the 
attached wrapper class "MidasConnector.cpp" and a main.cpp to generalize
data_pipeline.cxx a bit. There were a lot of iterations to the code where I had the 
below problems; so don't take the logic in the attached code as the exact code that 
caused the issues below.

However, I'm unable to resolve a couple issues:

1. If a timeout is set, everything will work until that timeout is reached. Then 
regardless of what kind of logic I tried to implement (retry receiving event, 
disconnect and reconnect client, etc.) the client would refuse to receive more data.

2. When I ctrl-C main, it hangs; this is expected because it's stuck in a while 
loop. But because I can't set a timeout I have to ctrl-C twice; this would 
occasionally corrupt the ODB which was not ideal. I was able to get around this with 
some impractical solution involving ncurses I believe.


Thanks,
Jack

#include "event_processor/EventProcessor.h"
#include "data_transmitter/DataTransmitter.h"
#include "midas_connector/MidasConnector.h"
#include "json.hpp"
#include <fstream>

INT hBufEvent1;
INT hBufEvent2;

// Function to initialize MIDAS and open an event buffer
bool initializeMidas(MidasConnector& midasConnector, const nlohmann::json& config) {
    // Set the MidasConnector properties based on the config
    midasConnector.setEventId(config["eventId"].get<short>());
    midasConnector.setTriggerMask(config["triggerMask"].get<short>());
    midasConnector.setSamplingType(config["samplingType"].get<int>());
    midasConnector.setBufferSize(config["bufferSize"].get<int>());
    midasConnector.setBufferName(config["bufferName"].get<std::string>().c_str());
    midasConnector.setBufferSize(config["bufferSize"].get<int>());

    // Call the ConnectToExperiment method
    if (!midasConnector.ConnectToExperiment()) {
        return false;
    }

    // Call the OpenEventBuffer method
    if (!midasConnector.OpenEventBuffer()) {
        return false;
    }

    // Set the buffer cache size if requested
    midasConnector.SetCacheSize(config["cacheSize"].get<int>());

    // Place a request for a specific event id
    if (!midasConnector.RequestEvent()) {
        return false;
    }

    return true;
}

int main() {
    // Read configuration from a JSON file
    nlohmann::json config;
    std::ifstream configFile("config.json");
    configFile >> config;
    configFile.close();

    // Initialize MidasConnector and connect to the MIDAS experiment
    MidasConnector midasConnector(config["clientName"].get<std::string>().c_str());
    if (!initializeMidas(midasConnector, config)) {
        printf("Error: Failed to initialize MIDAS.\n");
        return 1;
    }

    // Read the maximum event size from the JSON configuration
    INT max_event_size = config["maxEventSize"].get<int>();

    // Allocate memory for storing event data dynamically
    void* event_data = malloc(max_event_size);

    // Initialize EventProcessor with detector mapping file and verbosity flag
    EventProcessor eventProcessor(config["detectorMappingFile"].get<std::string>(), config["verbose"].get<bool>());

    // Initialize DataTransmitter with the ZeroMQ address
    DataTransmitter dataPublisher(config["zmqAddress"].get<std::string>());

    // Connect to the ZeroMQ server
    if (!dataPublisher.bind()) {
        // Handle connection error
        printf("Error: Failed to bind to port %s.\n", config["zmqAddress"].get<std::string>().c_str());
        return 1;
    } else {
        printf("Connected to the ZeroMQ server.\n");
    }


    // Event processing loop
    while (true) {

        midasConnector.ReceiveEvent(event_data, max_event_size);

        //Prcoess data once we have it
        eventProcessor.processEvent(event_data, max_event_size);

        // Serialize the event data with EventProcessor and store it in serializedData
        std::string serializedData = eventProcessor.getSerializedData();

        // Send the serialized data to the ZeroMQ server with DataTransmitter
        if (!dataPublisher.publish(serializedData)) {
            // Handle send error
            printf("Error: Failed to send serialized data.\n");
        }
    }

    // Cleanup and finalize your application
    midasConnector.DisconnectFromExperiment(); // Disconnect from the MIDAS experiment

    return 0;
}