mapnik/plugins/input/rasterlite/rasterlite_datasource.cpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2007 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
 *
 *****************************************************************************/
// $Id$

#include "rasterlite_datasource.hpp"
#include "rasterlite_featureset.hpp"

// boost
#include <boost/filesystem/operations.hpp>

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

using mapnik::datasource;
using mapnik::parameters;

DATASOURCE_PLUGIN(rasterlite_datasource)

using mapnik::box2d;
using mapnik::coord2d;
using mapnik::query;
using mapnik::featureset_ptr;
using mapnik::layer_descriptor;
using mapnik::datasource_exception;



/*
 * Opens a GDALDataset and returns a pointer to it.
 * Caller is responsible for calling GDALClose on it
 */
inline void *rasterlite_datasource::open_dataset() const
{
   void *dataset = rasterliteOpen (dataset_name_.c_str(), table_name_.c_str());
   
   if (! dataset) throw datasource_exception("Rasterlite Plugin: Error opening dataset");

   if (rasterliteIsError (dataset))
   {
      std::string error (rasterliteGetLastError(dataset));

	  rasterliteClose (dataset);
   
      throw datasource_exception(error);
   }

   return dataset;
}



rasterlite_datasource::rasterlite_datasource(parameters const& params, bool bind)
   : datasource(params),
     desc_(*params.get<std::string>("type"),"utf-8")
{
#ifdef MAPNIK_DEBUG
   std::clog << "\nRasterlite Plugin: Initializing...\n";
#endif

   boost::optional<std::string> file = params.get<std::string>("file");
   if (!file) throw datasource_exception("missing <file> parameter");

   boost::optional<std::string> table = params.get<std::string>("table");
   if (!table) throw datasource_exception("missing <table> parameter");

   table_name_ = *table;

   boost::optional<std::string> base = params.get<std::string>("base");
   if (base)
      dataset_name_ = *base + "/" + *file;
   else
      dataset_name_ = *file;

   if (bind)
   {
      this->bind();
   }
}

void rasterlite_datasource::bind() const
{
   if (is_bound_) return;   
    
   if (!boost::filesystem::exists(dataset_name_)) throw datasource_exception(dataset_name_ + " does not exist");

   void *dataset = open_dataset();
   
   double x0, y0, x1, y1;
   if (rasterliteGetExtent (dataset, &x0, &y0, &x1, &y1) != RASTERLITE_OK)
   {
      std::string error (rasterliteGetLastError(dataset));

	  rasterliteClose (dataset);
   
      throw datasource_exception(error);
   }

   extent_.init(x0,y0,x1,y1);
   
#ifdef MAPNIK_DEBUG
   int srid, auth_srid;
   const char *auth_name;
   const char *ref_sys_name;
   const char *proj4text;

   int tile_count;
   double pixel_x_size, pixel_y_size;
   int levels = rasterliteGetLevels (dataset);

   if (rasterliteGetSrid(dataset, &srid, &auth_name, &auth_srid, &ref_sys_name, &proj4text) != RASTERLITE_OK)
   { 
      std::string error (rasterliteGetLastError(dataset));

	  rasterliteClose (dataset);
   
      throw datasource_exception(error);
   }

   std::clog << "Rasterlite Plugin: Data Source=" << rasterliteGetTablePrefix(dataset) << "\n";
   std::clog << "Rasterlite Plugin: SRID=" << srid << "\n";
   std::clog << "Rasterlite Plugin: Authority=" << auth_name << "\n";
   std::clog << "Rasterlite Plugin: AuthSRID=" << auth_srid << "\n";
   std::clog << "Rasterlite Plugin: RefSys Name=" << ref_sys_name << "\n";
   std::clog << "Rasterlite Plugin: Proj4Text=" << proj4text << "\n";
   std::clog << "Rasterlite Plugin: Extent(" << x0 << "," << y0 << " " << x1 << "," << y1 << ")\n";
   std::clog << "Rasterlite Plugin: Levels=" << levels << "\n";
   
   for (int i = 0; i < levels; i++)
   {
     if (rasterliteGetResolution(dataset, i, &pixel_x_size, &pixel_y_size, &tile_count) == RASTERLITE_OK)
     {
       std::clog << "Rasterlite Plugin: Level=" << i
           << " x=" << pixel_x_size << " y=" << pixel_y_size << " tiles=" << tile_count << "\n";
     }
   }
#endif

   rasterliteClose(dataset);
   
   is_bound_ = true;
}

rasterlite_datasource::~rasterlite_datasource() {}

int rasterlite_datasource::type() const
{
   return datasource::Raster;
}

std::string rasterlite_datasource::name()
{
   return "rasterlite";
}

box2d<double> rasterlite_datasource::envelope() const
{
   if (!is_bound_) bind();
   
   return extent_;
}

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

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

   rasterlite_query gq = q;
   return featureset_ptr(new rasterlite_featureset(open_dataset(), gq));
}

featureset_ptr rasterlite_datasource::features_at_point(coord2d const& pt) const
{
   if (!is_bound_) bind();
   
   rasterlite_query gq = pt;
   return featureset_ptr(new rasterlite_featureset(open_dataset(), gq));
}