mapnik/plugins/input/shape/shape.cpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 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
 *
 *****************************************************************************/

#include <iostream>
#include <fstream>
#include <stdexcept>

#include <mapnik/geom_util.hpp>


#include "shape_featureset.hpp"
#include "shape_index_featureset.hpp"

#include "shape.hpp"

DATASOURCE_PLUGIN(shape_datasource)

shape_datasource::shape_datasource(const parameters &params)
    : datasource (params) ,
      shape_name_(params.get("file")),
      type_(datasource::Vector),
      file_length_(0),
      indexed_(false),
      desc_(params.get("name"))
{
    try
    {
        shape_io shape(shape_name_);
        init(shape);
        for (int i=0;i<shape.dbf().num_fields();++i)
        {
            field_descriptor const& fd=shape.dbf().descriptor(i);
            std::string fld_name=fd.name_;
            switch (fd.type_)
            {
            case 'C':
            case 'D':
            case 'M':
            case 'L':		
                desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
                break;
            case 'N':
            case 'F':
                {
                    if (fd.dec_>0)
                    {   
                        desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double,false,8));
                    }
                    else
                    {
                        desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer,false,4));
                    }
                    break;
                }
            default:
#ifdef MAPNIK_DEBUG                
                std::clog << "unknown type "<<fd.type_<<"\n";
#endif 
                break;
            }
        }
    }
    catch  (datasource_exception& ex)
    {
        std::clog<<ex.what()<<std::endl;
        throw;
    }
}


shape_datasource::~shape_datasource()
{
}

const std::string shape_datasource::name_="shape";

void  shape_datasource::init(shape_io& shape)
{
    //first read header from *.shp
    int file_code=shape.shp().read_xdr_integer();
    if (file_code!=9994)
    {
        //invalid
        throw datasource_exception("wrong file code");
    }
    shape.shp().skip(5*4);
    file_length_=shape.shp().read_xdr_integer();
    int version=shape.shp().read_ndr_integer();
    if (version!=1000)
    {
        //invalid version number
        throw datasource_exception("invalid version number");
    }
    int shape_type=shape.shp().read_ndr_integer();
    shape.shp().read_envelope(extent_);
    shape.shp().skip(4*8);

    // check if we have an index file around
    std::string index_name(shape_name_+".index");
    std::ifstream file(index_name.c_str(),std::ios::in | std::ios::binary);
    if (file)
    {
        indexed_=true;
        file.close();
    }

#ifdef MAPNIK_DEBUG
    std::clog << extent_ << std::endl;
    std::clog << "file_length=" << file_length_ << std::endl;
    std::clog << "shape_type=" << shape_type << std::endl;
#endif

}

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

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

std::string shape_datasource::name()
{
    return name_;
}

featureset_ptr shape_datasource::features(const query& q) const
{
    filter_in_box filter(q.get_bbox());
    if (indexed_)
    {
        return featureset_ptr
            (new shape_index_featureset<filter_in_box>(filter,shape_name_,q.property_names()));
    }
    else
    {
        return featureset_ptr
            (new shape_featureset<filter_in_box>(filter,shape_name_,q.property_names(),file_length_));
    }
}

featureset_ptr shape_datasource::features_at_point(coord2d const& pt) const
{
    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;
    }
    
    if (indexed_)
    {
        return featureset_ptr
            (new shape_index_featureset<filter_at_point>(filter,shape_name_,names));
    }
    else
    {
        return featureset_ptr
            (new shape_featureset<filter_at_point>(filter,shape_name_,names,file_length_));
    }
}

Envelope<double> shape_datasource::envelope() const
{
    return extent_;
}