PyBind11ProcessDesc.cc

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#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/ParameterSet/interface/ProcessDesc.h"
#include "FWCore/PyDevParameterSet/interface/PyBind11ProcessDesc.h"
#include "FWCore/PyDevParameterSet/src/initializePyBind11Module.h"
#include "FWCore/PyDevParameterSet/interface/PyBind11Wrapper.h"
#include <pybind11/embed.h>
#include <pybind11/pybind11.h>

#include <sstream>
#include <iostream>

namespace cmspython3 {
  PyBind11ProcessDesc::PyBind11ProcessDesc() : theProcessPSet(), theMainModule(), theOwnsInterpreter(false) {}

  PyBind11ProcessDesc::PyBind11ProcessDesc(std::string const& config)
      : theProcessPSet(), theMainModule(), theOwnsInterpreter(true) {
    pybind11::initialize_interpreter();
    edm::python3::initializePyBind11Module();
    prepareToRead();
    read(config);
  }

  PyBind11ProcessDesc::PyBind11ProcessDesc(std::string const& config, int argc, char* argv[])
      : theProcessPSet(),
        theMainModule(),
        theOwnsInterpreter(true)

  {
    pybind11::initialize_interpreter();
    edm::python3::initializePyBind11Module();
    prepareToRead();
    {
#if PY_MAJOR_VERSION >= 3
      typedef std::unique_ptr<wchar_t[], decltype(&PyMem_RawFree)> WArgUPtr;
      std::vector<WArgUPtr> v_argv;
      std::vector<wchar_t*> vp_argv;
      v_argv.reserve(argc);
      vp_argv.reserve(argc);
      for (int i = 0; i < argc; i++) {
        v_argv.emplace_back(Py_DecodeLocale(argv[i], nullptr), &PyMem_RawFree);
        vp_argv.emplace_back(v_argv.back().get());
      }

      wchar_t** argvt = vp_argv.data();
#else
      char** argvt = argv;
#endif

      PySys_SetArgv(argc, argvt);
    }
    read(config);
  }

  PyBind11ProcessDesc::~PyBind11ProcessDesc() {
    if (theOwnsInterpreter) {
      theMainModule = pybind11::object();
      pybind11::finalize_interpreter();
    }
  }

  void PyBind11ProcessDesc::prepareToRead() {
    //  pybind11::scoped_interpreter guard{};
    theMainModule = pybind11::module::import("__main__");
    theMainModule.attr("processDesc") = this;
    theMainModule.attr("processPSet") = &theProcessPSet;
  }

  void PyBind11ProcessDesc::read(std::string const& config) {
    try {
      // if it ends with py, it's a file
      if (config.substr(config.size() - 3) == ".py") {
        readFile(config);
      } else {
        readString(config);
      }
    } catch (pybind11::error_already_set const& e) {
      cmspython3::pythonToCppException("Configuration", e.what());
    }
  }

  void PyBind11ProcessDesc::readFile(std::string const& fileName) {
    pybind11::eval_file(fileName);
    std::string command("process.fillProcessDesc(processPSet)");
    pybind11::exec(command);
  }

  void PyBind11ProcessDesc::readString(std::string const& pyConfig) {
    std::string command = pyConfig;
    command += "\nprocess.fillProcessDesc(processPSet)";
    pybind11::exec(command.c_str());
  }

  std::unique_ptr<edm::ParameterSet> PyBind11ProcessDesc::parameterSet() const {
    return std::make_unique<edm::ParameterSet>(theProcessPSet.pset());
  }

  std::string PyBind11ProcessDesc::dump() const {
    std::ostringstream os;
    os << theProcessPSet.dump();
    return os.str();
  }

  // For backward compatibility only.  Remove when no longer used.
  std::unique_ptr<edm::ProcessDesc> PyBind11ProcessDesc::processDesc() const {
    return std::make_unique<edm::ProcessDesc>(parameterSet());
  }
}  // namespace cmspython3