mapnik/plugins/input/osm/osm_datasource.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2011 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
 *
 *****************************************************************************/

// stl
#include <iostream>
#include <sstream>
#include <fstream>
#include <stdexcept>
#include <set>

// mapnik
#include <mapnik/geom_util.hpp>
#include <mapnik/query.hpp>

// boost
#include <boost/make_shared.hpp>

#include "osm_datasource.hpp"
#include "osm_featureset.hpp"
#include "dataset_deliverer.h"
#include "osmtagtypes.h"
#include "osmparser.h"

using mapnik::String;
using mapnik::Double;
using mapnik::Integer;
using mapnik::datasource_exception;
using mapnik::filter_in_box;
using mapnik::filter_at_point;
using mapnik::attribute_descriptor;

DATASOURCE_PLUGIN(osm_datasource)

osm_datasource::osm_datasource(const parameters& params, bool bind)
: datasource (params),
    type_(datasource::Vector),
    desc_(*params_.get<std::string>("type"), *params_.get<std::string>("encoding", "utf-8"))
{
    if (bind)
    {
        this->bind();
    }
}

void osm_datasource::bind() const
{
    if (is_bound_) return;

    osm_data_ = NULL;
    std::string osm_filename = *params_.get<std::string>("file", "");
    std::string parser = *params_.get<std::string>("parser", "libxml2");
    std::string url = *params_.get<std::string>("url", "");
    std::string bbox = *params_.get<std::string>("bbox", "");

    bool do_process = false;

    // load the data
    // if we supplied a filename, load from file
    if (url != "" && bbox != "")
    {
        // otherwise if we supplied a url and a bounding box, load from the url
#ifdef MAPNIK_DEBUG
        std::clog << "Osm Plugin: loading_from_url: url=" << url << " bbox=" << bbox << std::endl;
#endif
        if ((osm_data_ = dataset_deliverer::load_from_url(url, bbox, parser)) == NULL)
        {
            throw datasource_exception("Error loading from URL");
        }

        do_process = true;
    }
    else if (osm_filename != "")
    {
        if ((osm_data_= dataset_deliverer::load_from_file(osm_filename, parser)) == NULL)
        {
            std::ostringstream s;
            s << "OSM Plugin: Error loading from file '" << osm_filename << "'";
            throw datasource_exception(s.str());
        }

        do_process = true;
    }

    if (do_process == true)
    {
        osm_tag_types tagtypes;
        tagtypes.add_type("maxspeed", mapnik::Integer);
        tagtypes.add_type("z_order", mapnik::Integer);

        osm_data_->rewind();

        // Need code to get the attributes of all the data
        std::set<std::string> keys = osm_data_->get_keys();

        // Add the attributes to the datasource descriptor - assume they are
        // all of type String
        for (std::set<std::string>::iterator i = keys.begin(); i != keys.end(); i++)
        {
            desc_.add_descriptor(attribute_descriptor(*i, tagtypes.get_type(*i)));
        }

        // Get the bounds of the data and set extent_ accordingly
        bounds b = osm_data_->get_bounds();
        extent_ =  box2d<double>(b.w, b.s, b.e, b.n);
    }

    // osm data is most likely a collection of geometry types
    desc_.set_geometry_type("collection");

    is_bound_ = true;
}

osm_datasource::~osm_datasource()
{
    // Do not do as is now static variable and cleaned up at exit
    //delete osm_data_;
}

std::string osm_datasource::name()
{
    return "osm";
}

int osm_datasource::type() const
{
    return type_;
}

layer_descriptor osm_datasource::get_descriptor() const
{
    return desc_;
}

featureset_ptr osm_datasource::features(const query& q) const
{
    if (! is_bound_) bind();

    filter_in_box filter(q.get_bbox());
    // so we need to filter osm features by bbox here...

    return boost::make_shared<osm_featureset<filter_in_box> >(filter,
                                                              osm_data_,
                                                              q.property_names(),
                                                              desc_.get_encoding());
}

featureset_ptr osm_datasource::features_at_point(coord2d const& pt) const
{
    if (! is_bound_) bind();

    filter_at_point filter(pt);
    // collect all attribute names
    std::vector<attribute_descriptor> const& desc_vector = desc_.get_descriptors();
    std::vector<attribute_descriptor>::const_iterator itr = desc_vector.begin();
    std::vector<attribute_descriptor>::const_iterator end = desc_vector.end();
    std::set<std::string> names;

    while (itr != end)
    {
        names.insert(itr->get_name());
        ++itr;
    }

    return boost::make_shared<osm_featureset<filter_at_point> >(filter,
                                                                osm_data_,
                                                                names,
                                                                desc_.get_encoding());
}

box2d<double> osm_datasource::envelope() const
{
    if (! is_bound_) bind();

    return extent_;
}