mapnik/plugins/input/csv/csv_index_featureset.hpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2015 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#ifndef CSV_INDEX_FEATURESET_HPP
#define CSV_INDEX_FEATURESET_HPP

#include <mapnik/feature.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/geom_util.hpp>
#include "csv_utils.hpp"
#include "csv_datasource.hpp"
#include <fstream>

using value_type = std::pair<std::size_t, std::size_t>;
namespace std {
template <typename InputStream>
InputStream & operator>>(InputStream & in, value_type & value)
{
    in.read(reinterpret_cast<char*>(&value), sizeof(value_type));
    return in;
}
}


class csv_index_featureset : public mapnik::Featureset
{
    using locator_type = detail::geometry_column_locator;
public:

    csv_index_featureset(std::string const& filename,
                         mapnik::filter_in_box const& filter,
                         locator_type const& locator,
                         std::string const& separator,
                         std::vector<std::string> const& headers,
                         mapnik::context_ptr const& ctx);
    ~csv_index_featureset();
    mapnik::feature_ptr next();
private:
    mapnik::feature_ptr parse_feature(std::string const& str);
    std::string const& separator_;
    std::vector<std::string> headers_;
    mapnik::context_ptr ctx_;
    mapnik::value_integer feature_id_ = 0;
    detail::geometry_column_locator const& locator_;
    mapnik::transcoder tr_;
    std::ifstream in_;
    std::vector<value_type> positions_;
    std::vector<value_type>::iterator itr_;
};


#endif // CSV_INDEX_FEATURESET_HPP