event.cc

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// gstreamer
#include "gstreamerJSONFactory.h"
#include "gstreamerConventions.h"
 
// c++
#include <sstream>
 
// Implementation summary:
// Start and finalize one JSON event object using the ordered event publish sequence.
 
bool GstreamerJsonFactory::startEventImpl(const std::shared_ptr<GEventDataCollection>& event_data) {
    if (!ofile.is_open()) { log->error(ERR_CANTOPENOUTPUT, SFUNCTION_NAME, "Error: can't access ", filename()); }
    if (!event_data) {
        log->error(ERR_PUBLISH_ERROR, "event_data is null in GstreamerJsonFactory::startEventImpl");
        return false;
    }
    if (!event_data->getHeader()) {
        log->error(ERR_PUBLISH_ERROR, "event header is null in GstreamerJsonFactory::startEventImpl");
        return false;
    }
 
    // Ensure the top-level JSON document is initialized for event output.
    ensureFileInitializedForType("event");
 
    // Reset all per-event assembly state.
    is_building_event = true;
    current_event.str(std::string());
    current_event.clear();
    current_event_has_header       = false;
    current_event_has_any_detector = false;
    current_event_has_generated    = false;
 
    // Cache the event number early so it is available to the root event object.
    event_number = event_data->getHeader()->getG4LocalEvn();
 
    current_event << "{";
    current_event << "\"event_number\": " << event_number;
 
    // Open the header object now. publishEventHeaderImpl() fills its contents.
    current_event << ", \"header\": {";
    return true;
}
 
bool GstreamerJsonFactory::endEventImpl(const std::shared_ptr<GEventDataCollection>& event_data) {
    if (!is_building_event) {
        log->error(ERR_PUBLISH_ERROR, "endEventImpl called without an active event in GstreamerJsonFactory");
        return false;
    }
 
    // If the caller skipped the header step, emit a minimal fallback so the JSON remains valid.
    if (!current_event_has_header) {
        current_event << "\"timestamp\": \"\", \"thread_id\": -1";
    }
 
    // Detector publishers leave the "detectors" object open so digitized data
    // can be appended after true-information banks without rewriting strings.
    if (current_event_has_any_detector) {
        current_event << "}";
    }
    current_event << "}";
 
    // Keep the event schema predictable even when no detector banks were published.
    if (!current_event_has_any_detector) {
        current_event << ", \"detectors\": {}";
    }
 
    current_event << "}";
 
    writeTopLevelEntry(current_event.str());
 
    is_building_event = false;
 
    (void)event_data;
    return true;
}
 
bool GstreamerJsonFactory::publishEventGeneratedParticlesImpl(const std::string& bankName,
                                                              const GGeneratedParticleBank& particles) {
    if (!is_building_event) {
        log->error(ERR_PUBLISH_ERROR,
                   "publishEventGeneratedParticlesImpl called without an active event in GstreamerJsonFactory");
        return false;
    }
 
    if (!current_event_has_generated) {
        current_event << ", \"generated\": {";
        current_event_has_generated = true;
    }
    else {
        current_event << ", ";
    }
 
    current_event << "\"" << jsonEscape(bankName) << "\": [";
 
    bool wrote_first_particle = false;
    for (const auto& particle : particles) {
        if (wrote_first_particle) { current_event << ", "; }
        wrote_first_particle = true;
 
        current_event << "{"
                      << "\"name\": \"" << jsonEscape(particle.name) << "\""
                      << ", \"pid\": " << particle.pid
                      << ", \"type\": " << particle.type
                      << ", \"multiplicity\": " << particle.multiplicity
                      << ", \"p\": " << particle.p
                      << ", \"theta\": " << particle.theta
                      << ", \"phi\": " << particle.phi
                      << ", \"vx\": " << particle.vx
                      << ", \"vy\": " << particle.vy
                      << ", \"vz\": " << particle.vz
                      << "}";
    }
 
    current_event << "]";
    if (bankName == "generated_tracked") {
        current_event << "}";
    }
 
    return true;
}