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Parser.cpp

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/*******************************************************************************
 * This file is part of openWNS (open Wireless Network Simulator)
 * _____________________________________________________________________________
 *
 * Copyright (C) 2004-2007
 * Chair of Communication Networks (ComNets)
 * Kopernikusstr. 16, D-52074 Aachen, Germany
 * phone: ++49-241-80-27910,
 * fax: ++49-241-80-22242
 * email: info@openwns.org
 * www: http://www.openwns.org
 * _____________________________________________________________________________
 *
 * openWNS is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 2 as published by the
 * Free Software Foundation;
 *
 * openWNS is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/

#include <WNS/Python.hpp>

#include <WNS/pyconfig/Parser.hpp>
#include <WNS/pyconfig/helper/Functions.hpp>

#include <WNS/Exception.hpp>
#include <WNS/Assure.hpp>

#include <sstream>
#include <iostream>

using namespace wns::pyconfig;

long Parser::serial = 0;

Parser::Parser() :
    View(),
    module_name()
{
    this->initPython();
} // Parser


Parser::Parser(const std::string& filename, const std::string& pathname) :
    View(),
    module_name()
{
    this->initPython();
    this->appendPath(pathname);
    this->load(filename);
} // Parser


Parser::~Parser()
{
} // ~Parser


void
Parser::load(const std::string &filename)
{
    assure(PyErr_Occurred() == false, "Dirty python context!");

    FILE* fp = fopen(filename.c_str(), "r");
    if(fp == NULL)
    {
        throw Exception(std::string("couldn't load ")
                + filename
                + ": "
                + strerror(errno));
    }

    PyObject* o = PyRun_File(fp,
                 filename.c_str(),
                 Py_file_input,
                 this->dict.obj_,
                 this->dict.obj_);
    fclose(fp);
    if(o == NULL)
    {
        std::cerr << "wns::pyconfig::Parser says:\n"
              << "Couldn't load config file '" << filename << "'.\n";

        showdown("Couldn't load config file '" + filename + "'");
    }

    Py_DECREF(o);
    this->viewExpression = filename;
} // load


void
Parser::loadString(const std::string &s)
{
    assure(PyErr_Occurred() == false, "Dirty python context!");

    PyObject* o = PyRun_String(s.c_str(),
                   Py_file_input,
                   this->dict.obj_,
                   this->dict.obj_);
    if(o == NULL)
    {
        std::cerr << "wns::pyconfig::Parser says:\n"
              << "Couldn't load config from string:\n"
              << s
              << "\n";

        showdown("Couldn't load from string.");
    }
    Py_DECREF(o);

    this->viewExpression = "<string>";
} // loadString


void
Parser::initPython()
{
    std::stringstream ss;
    ss << Parser::serial++;
    ss >> this->module_name;

    PyObject* module = PyImport_AddModule(const_cast<char*>(this->module_name.c_str()));
    if(module == NULL)
    {
        throw Exception("couldn't open configfile");    // FIXME(fds)
    }

    this->dict = Object(PyModule_GetDict(module));
    this->dict.incref();
    PyDict_SetItemString(this->dict.obj_, "__builtins__", PyImport_ImportModule("__builtin__"));
} // initPython


void
Parser::appendPath(const std::string& pathname)
{
    assure(PyErr_Occurred() == false, "Dirty python context!");

    std::stringstream ss;
    ss << "import sys\n"
       << "sys.path.append('" << pathname << "')\n";
    if(-1 == PyRun_SimpleString(ss.str().c_str()))
    {
        std::cerr << "wns::pyconfig::Parser says:\n"
              << "Couldn't add path '" + pathname + "' to sys.path.\n";

        showdown("Couldn't add path.");
    }
} // addPath


View
Parser::fromString(const std::string& s)
{
    return helper::createViewFromString(s);
} // fromString

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