mapnik/plugins/input/ogr/ogr_index_featureset.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
 *
 *****************************************************************************/

// mapnik
#include <mapnik/global.hpp>
#include <mapnik/debug.hpp>
#include <mapnik/datasource.hpp>
#include <mapnik/box2d.hpp>
#include <mapnik/geometry.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/feature_layer_desc.hpp>
#include <mapnik/wkb.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/mapped_memory_cache.hpp>
#include <mapnik/feature_factory.hpp>

// boost
#include <boost/interprocess/streams/bufferstream.hpp>

// ogr
#include "ogr_index_featureset.hpp"
#include "ogr_converter.hpp"
#include "ogr_index.hpp"
#include "ogr_feature_ptr.hpp"

using mapnik::query;
using mapnik::box2d;
using mapnik::Feature;
using mapnik::feature_ptr;
using mapnik::geometry_utils;
using mapnik::transcoder;
using mapnik::feature_factory;

template <typename filterT>
ogr_index_featureset<filterT>::ogr_index_featureset(mapnik::context_ptr const & ctx,
                                                    OGRLayer & layer,
                                                    filterT const& filter,
                                                    std::string const& index_file,
                                                    std::string const& encoding)
    : ctx_(ctx),
      layer_(layer),
      layerdef_(layer.GetLayerDefn()),
      filter_(filter),
      tr_(new transcoder(encoding)),
      fidcolumn_(layer_.GetFIDColumn())
{

    boost::optional<mapnik::mapped_region_ptr> memory = mapnik::mapped_memory_cache::instance().find(index_file.c_str(),true);
    if (memory)
    {
        boost::interprocess::ibufferstream file(static_cast<char*>((*memory)->get_address()),(*memory)->get_size());
        ogr_index<filterT,boost::interprocess::ibufferstream >::query(filter,file,ids_);
    }

    std::sort(ids_.begin(),ids_.end());

    MAPNIK_LOG_DEBUG(ogr) << "ogr_index_featureset: Query size=" << ids_.size();

    itr_ = ids_.begin();

    // reset reading
    layer_.ResetReading();
}

template <typename filterT>
ogr_index_featureset<filterT>::~ogr_index_featureset() {}

template <typename filterT>
feature_ptr ogr_index_featureset<filterT>::next()
{
    if (itr_ != ids_.end())
    {
        int pos = *itr_++;
        layer_.SetNextByIndex (pos);

        ogr_feature_ptr feat (layer_.GetNextFeature());
        if ((*feat) != NULL)
        {
            // ogr feature ids start at 0, so add one to stay
            // consistent with other mapnik datasources that start at 1
            int feature_id = ((*feat)->GetFID() + 1);
            feature_ptr feature(feature_factory::create(ctx_,feature_id));

            OGRGeometry* geom=(*feat)->GetGeometryRef();
            if (geom && !geom->IsEmpty())
            {
                ogr_converter::convert_geometry (geom, feature);
            }
            else
            {
                MAPNIK_LOG_DEBUG(ogr) << "ogr_index_featureset: Feature with null geometry=" << (*feat)->GetFID();
            }

            int fld_count = layerdef_->GetFieldCount();
            for (int i = 0; i < fld_count; i++)
            {
                OGRFieldDefn* fld = layerdef_->GetFieldDefn (i);
                OGRFieldType type_oid = fld->GetType ();
                std::string fld_name = fld->GetNameRef ();

                switch (type_oid)
                {
                case OFTInteger:
                {
                    feature->put(fld_name,(*feat)->GetFieldAsInteger (i));
                    break;
                }

                case OFTReal:
                {
                    feature->put(fld_name,(*feat)->GetFieldAsDouble (i));
                    break;
                }

                case OFTString:
                case OFTWideString:     // deprecated !
                {
                    UnicodeString ustr = tr_->transcode((*feat)->GetFieldAsString (i));
                    feature->put(fld_name,ustr);
                    break;
                }

                case OFTIntegerList:
                case OFTRealList:
                case OFTStringList:
                case OFTWideStringList: // deprecated !
                {
                    MAPNIK_LOG_WARN(ogr) << "ogr_index_featureset: Unhandled type_oid=" << type_oid;
                    break;
                }

                case OFTBinary:
                {
                    MAPNIK_LOG_WARN(ogr) << "ogr_index_featureset: Unhandled type_oid=" << type_oid;
                    //feature->put(name,feat->GetFieldAsBinary (i, size));
                    break;
                }

                case OFTDate:
                case OFTTime:
                case OFTDateTime:       // unhandled !
                {
                    MAPNIK_LOG_WARN(ogr) << "ogr_index_featureset: Unhandled type_oid=" << type_oid;
                    break;
                }
                }
            }
            return feature;
        }
    }

    return feature_ptr();
}

template class ogr_index_featureset<mapnik::filter_in_box>;
template class ogr_index_featureset<mapnik::filter_at_point>;