PyWrap/src/PyWrap.cc

#define PY_SSIZE_T_CLEAN
#include <stdexcept>
#include "PyWrap.h"
#include <iostream>
#include <string>
#include <map>
#include <boost/python/numpy.hpp>
#include "PyHelper.hpp"

namespace pywrap {
    namespace np = boost::python::numpy;
    PyWrap* PyWrap::wrapper = nullptr;
    std::mutex PyWrap::mutex;

    PyWrap* PyWrap::GetInstance()
    {
        std::lock_guard<std::mutex> lock(mutex);
        if (wrapper == nullptr) {
            std::cout << "Creando instancia" << std::endl;
            wrapper = new PyWrap();
            std::cout << "Instancia creada" << std::endl;
        }
        return wrapper;
    }

    PyWrap::PyWrap()
    {
        PyStatus status = initPython();
        if (PyStatus_Exception(status)) {
            throw std::runtime_error("Error initializing Python");
        }
        np::initialize();
    }

    PyWrap::~PyWrap()
    {
        for (const auto& item : moduleClassMap) {
            Py_DECREF(std::get<0>(item.second));
            Py_DECREF(std::get<1>(item.second));
            Py_DECREF(std::get<2>(item.second));
        }
        Py_Finalize();
    }

    void PyWrap::importClass(const std::string& moduleName, const std::string& className)
    {
        std::cout << "Importando clase" << std::endl;
        auto result = moduleClassMap.find({ moduleName, className });
        if (result != moduleClassMap.end()) {
            return;
        }
        std::cout << "No estaba en el mapa" << std::endl;
        PyObject* module = PyImport_ImportModule(moduleName.c_str());
        if (PyErr_Occurred()) {
            errorAbort("Could't import module " + moduleName);
        }
        PyObject* classObject = PyObject_GetAttrString(module, className.c_str());
        if (PyErr_Occurred()) {
            errorAbort("Couldn't find class " + className);
        }
        PyObject* instance = PyObject_CallObject(classObject, NULL);
        if (PyErr_Occurred()) {
            errorAbort("Couldn't create instance of class " + className);
        }
        moduleClassMap[{moduleName, className}] = { module, classObject, instance };
        std::cout << "Clase importada" << std::endl;
    }

    void PyWrap::clean(const std::string& moduleName, const std::string& className)
    {
        std::cout << "Limpiando" << std::endl;
        auto result = moduleClassMap.find({ moduleName, className });
        if (result == moduleClassMap.end()) {
            return;
        }
        std::cout << "--> Limpiando" << std::endl;
        Py_DECREF(std::get<0>(result->second));
        Py_DECREF(std::get<1>(result->second));
        Py_DECREF(std::get<2>(result->second));
        moduleClassMap.erase(result);
        std::cout << "Limpieza terminada" << std::endl;
    }


    void PyWrap::errorAbort(const std::string& message)
    {
        std::cout << message << std::endl;
        PyErr_Print();
        exit(1);
    }
    PyObject* PyWrap::getClass(const std::string& moduleName, const std::string& className)
    {
        auto item = moduleClassMap.find({ moduleName, className });
        if (item == moduleClassMap.end()) {
            errorAbort("Module " + moduleName + " and class " + className + " not found");
        }
        std::cout << "Clase encontrada" << std::endl;
        return std::get<2>(item->second);
    }
    std::string PyWrap::callMethodString(const std::string& moduleName, const std::string& className, const std::string& method)
    {
        std::cout << "Llamando método " << method << std::endl;
        PyObject* instance = getClass(moduleName, className);
        PyObject* result;
        if (!(result = PyObject_CallMethod(instance, method.c_str(), NULL)))
            errorAbort("Couldn't call method " + method);

        std::string value = PyUnicode_AsUTF8(result);
        std::cout << "Result: " << value << std::endl;
        Py_DECREF(result);
        return value;
    }
    std::string PyWrap::version(const std::string& moduleName, const std::string& className)
    {
        return callMethodString(moduleName, className, "version");
    }

    void PyWrap::fit(const std::string& moduleName, const std::string& className, PyObject* X, PyObject* y)
    {
        std::cout << "Llamando método fit" << std::endl;
        PyObject* instance = getClass(moduleName, className);
        PyObject* result;
        std::string method = "fit";
        if (!(result = PyObject_CallMethodObjArgs(instance, PyUnicode_FromString(method.c_str()), X, y, NULL)))
            errorAbort("Couldn't call method fit");
        Py_DECREF(result);
    }
    PyObject* PyWrap::predict(const std::string& moduleName, const std::string& className, PyObject* X)
    {
        std::cout << "Llamando método predict" << std::endl;
        PyObject* instance = getClass(moduleName, className);
        PyObject* result;
        std::string method = "predict";
        if (!(result = PyObject_CallMethodObjArgs(instance, PyUnicode_FromString(method.c_str()), X, NULL)))
            errorAbort("Couldn't call method predict");
        return result; // The caller has to decref the result
    }
    double PyWrap::score(const std::string& moduleName, const std::string& className, PyObject* X, PyObject* y)
    {
        std::cout << "Llamando método score" << std::endl;
        PyObject* instance = getClass(moduleName, className);
        PyObject* result;
        std::string method = "score";
        if (!(result = PyObject_CallMethodObjArgs(instance, PyUnicode_FromString(method.c_str()), X, y, NULL)))
            errorAbort("Couldn't call method score");
        return PyFloat_AsDouble(result);
    }
    // void PyWrap::doCommand2()
// {
//     PyObject* list = Py_BuildValue("[s]", "Stree");
//     // PyObject* module = PyImport_ImportModuleEx("stree", NULL, NULL, list);
//     PyObject* module = PyImport_ImportModule("stree");
//     if (PyErr_Occurred()) {
//         PyErr_Print();
//         cout << "Fails to obtain the module.\n";
//         return;
//     }
//     cout << "Antes de empezar" << endl;
//     if (module != nullptr) {
//         cout << "Lo consiguió!!!" << endl;
//         // dict is a borrowed reference.
//         auto pdict = PyModule_GetDict(module);
//         if (pdict == nullptr) {
//             cout << "Fails to get the dictionary.\n";
//             return;
//         }
//         Py_DECREF(module);
//         PyObject* pKeys = PyDict_Keys(pdict);
//         PyObject* pValues = PyDict_Values(pdict);
//         map<string, string> my_map;
//         cout << "size: " << PyDict_Size(pdict) << endl;
//         char* cstr_key = new char[100];
//         char* cstr_value = new char[500];
//         for (Py_ssize_t i = 0; i < PyDict_Size(pdict); ++i) {
//             PyArg_Parse(PyList_GetItem(pKeys, i), "s", &cstr_key);
//             PyArg_Parse(PyList_GetItem(pValues, i), "s", &cstr_value);
//             //cout << cstr<< "  "<< cstr2 <<endl;
//             my_map.emplace(cstr_key, cstr_value);
//         }
//         for (auto x : my_map) {
//             cout << x.first << " : " << x.second << endl;
//         }
//         // Builds the name of a callable class
//         const char* class_name = "Stree";
//         auto python_class = PyDict_GetItemString(pdict, class_name);
//         // if (PyErr_Occurred()) {
//         //     PyErr_Print();
//         //     cout << "Fails to obtain the class.\n";
//         //     return;
//         // }
//         if (python_class == nullptr) {
//             cout << "Fails to get the Python class.\n";
//             return;
//         }
//         Py_DECREF(pdict);
//         cout << "Clase: " << python_class << endl;
//         PyObject* object;
//         // Creates an instance of the class
//         if (PyCallable_Check(python_class)) {
//             cout << "Es callable" << endl;
//             object = PyObject_CallObject(python_class, NULL);
//             Py_DECREF(python_class);
//         } else {
//             std::cout << "Cannot instantiate the Python class" << endl;
//             Py_DECREF(python_class);
//             return;
//         }
//         if (PyErr_Occurred()) {
//             PyErr_Print();
//             cout << "Fails to create the Python object.\n";
//             return;
//         }
//         auto val = PyObject_CallMethod(object, "version", NULL);
//         if (val != nullptr) {
//             cout << "Valor: " << val << endl;
//         } else {
//             cout << "No se pudo ejecutar" << endl;
//         }

//     } else {
//         cout << "No lo consiguió :(" << endl;
//     }
//     Py_RunMain();
// }

    PyStatus PyWrap::initPython()
    {
        PyStatus status;
        PyConfig config;
        PyConfig_InitPythonConfig(&config);
        config.isolated = 0;
        status = PyConfig_Read(&config);
        if (PyStatus_Exception(status)) {
            errorAbort("Error reading config");
        }
        status = Py_InitializeFromConfig(&config);
        PyConfig_Clear(&config);
        return status;
    }
}