Streamlining DAOD_PHYSLITE Output ($3340) · Snippets

Below code also can't properly set up different compression level or algorithm

#include "MyCompressionAlg/MyCompressionAlg.h"
#include "xAODParticleEvent/ParticleContainer.h"
#include "xAODParticleEvent/ParticleAuxContainer.h"
#include "GaudiKernel/EventContext.h"
#include "TFile.h"

DECLARE_COMPONENT(MyCompressionAlg)

MyCompressionAlg::MyCompressionAlg(const std::string& name, ISvcLocator* svcLoc)
    : AthReentrantAlgorithm(name, svcLoc) {}

StatusCode MyCompressionAlg::initialize() {
    ATH_CHECK(m_inputKey.initialize());
    ATH_CHECK(m_outputKey.initialize());

    // Retrieve compression settings from job options (if provided)
    if (!m_compressionAlgorithm.value().empty()) {
        ATH_MSG_INFO("Using compression algorithm: " << m_compressionAlgorithm.value());
    }
    if (m_compressionLevel > 0) {
        ATH_MSG_INFO("Using compression level: " << m_compressionLevel);
    }

    return StatusCode::SUCCESS;
}

StatusCode MyCompressionAlg::execute(const EventContext& ctx) const {
    SG::ReadHandle<xAOD::ParticleContainer> inputParticles(m_inputKey, ctx);
    if (!inputParticles.isValid()) {
        ATH_MSG_ERROR("Failed to retrieve " << m_inputKey.key());
        return StatusCode::FAILURE;
    }

    SG::WriteHandle<xAOD::ParticleContainer> outputParticles(m_outputKey, ctx);
    auto outputContainer = std::make_unique<xAOD::ParticleContainer>();
    auto outputAuxContainer = std::make_unique<xAOD::ParticleAuxContainer>();
    outputContainer->setStore(outputAuxContainer.get());

    for (const xAOD::Particle* particle : *inputParticles) {
        xAOD::Particle* newParticle = new xAOD::Particle();
        outputContainer->push_back(newParticle);

        *newParticle = *particle;
    }

    // Set compression settings on the auxiliary store
    TFile* file = dynamic_cast<TFile*>(outputAuxContainer->getOutputFile());
    if (file) {
        int rootCompressionAlgorithm = 0; // Default ROOT algorithm (ZLIB)
        if (m_compressionAlgorithm.value() == "LZMA") {
            rootCompressionAlgorithm = 2; // LZMA
        } else if (m_compressionAlgorithm.value() == "LZ4") {
            rootCompressionAlgorithm = 4; // LZ4
        }

        file->SetCompressionAlgorithm(rootCompressionAlgorithm);
        file->SetCompressionLevel(m_compressionLevel);

        ATH_MSG_INFO("Applied compression settings: Algorithm = " << rootCompressionAlgorithm
                      << ", Level = " << m_compressionLevel);
    } else {
        ATH_MSG_WARNING("Output TFile not available for setting compression.");
    }

    ATH_CHECK(outputParticles.record(std::move(outputContainer), std::move(outputAuxContainer)));

    return StatusCode::SUCCESS;
}

StatusCode MyCompressionAlg::finalize() {
    return StatusCode::SUCCESS;
}