mapnik/plugins/input/ogr/ogr_datasource.cpp

315 lines
9.3 KiB
C++

/*****************************************************************************
*
* 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 <iostream>
#include <fstream>
#include <stdexcept>
#include "ogr_datasource.hpp"
#include "ogr_featureset.hpp"
#include "ogr_index_featureset.hpp"
// mapnik
#include <mapnik/ptree_helpers.hpp>
#include <mapnik/geom_util.hpp>
// boost
#include <boost/algorithm/string.hpp>
using std::clog;
using std::endl;
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(ogr_datasource)
using mapnik::Envelope;
using mapnik::coord2d;
using mapnik::query;
using mapnik::featureset_ptr;
using mapnik::layer_descriptor;
using mapnik::attribute_descriptor;
using mapnik::datasource_exception;
using mapnik::filter_in_box;
using mapnik::filter_at_point;
ogr_datasource::ogr_datasource(parameters const& params, bool bind)
: datasource(params),
extent_(),
type_(datasource::Vector),
desc_(*params.get<std::string>("type"), *params.get<std::string>("encoding","utf-8")),
indexed_(false)
{
OGRRegisterAll();
boost::optional<std::string> file = params.get<std::string>("file");
if (!file) throw datasource_exception("missing <file> parameter");
multiple_geometries_ = *params_.get<mapnik::boolean>("multiple_geometries",false);
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 ogr_datasource::bind() const
{
if (is_bound_) return;
// open ogr driver
dataset_ = OGRSFDriverRegistrar::Open ((dataset_name_).c_str(), FALSE);
if (!dataset_)
{
std::string err = CPLGetLastErrorMsg();
if( err.size() == 0 )
{
throw datasource_exception("Connection failed: " + dataset_name_ + " was not found or is not a supported format");
} else {
throw datasource_exception(err);
}
}
// initialize layer
boost::optional<std::string> layer = params_.get<std::string>("layer");
if (!layer)
{
std::string s ("missing <layer> parameter, available layers are: ");
unsigned num_layers = dataset_->GetLayerCount();
for (unsigned i = 0; i < num_layers; ++i )
{
OGRLayer *ogr_layer = dataset_->GetLayer(i);
OGRFeatureDefn* def = ogr_layer->GetLayerDefn();
if (def != 0) {
s += " '";
s += def->GetName();
s += "' ";
} else {
s += "No layers found!";
}
}
throw datasource_exception(s);
}
layerName_ = *layer;
layer_ = dataset_->GetLayerByName (layerName_.c_str());
if (! layer_) throw datasource_exception("cannot find <layer> in dataset");
// initialize envelope
OGREnvelope envelope;
layer_->GetExtent (&envelope);
extent_.init (envelope.MinX, envelope.MinY, envelope.MaxX, envelope.MaxY);
// scan for index file
size_t breakpoint = dataset_name_.find_last_of (".");
if (breakpoint == std::string::npos) breakpoint = dataset_name_.length();
index_name_ = dataset_name_.substr(0, breakpoint) + ".index";
std::ifstream index_file (index_name_.c_str(), std::ios::in | std::ios::binary);
if (index_file)
{
indexed_=true;
index_file.close();
}
// deal with attributes descriptions
OGRFeatureDefn* def = layer_->GetLayerDefn ();
if (def != 0)
{
int fld_count = def->GetFieldCount ();
for (int i = 0; i < fld_count; i++)
{
OGRFieldDefn* fld = def->GetFieldDefn (i);
std::string fld_name = fld->GetNameRef ();
OGRFieldType type_oid = fld->GetType ();
switch (type_oid)
{
case OFTInteger:
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer));
break;
case OFTReal:
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double));
break;
case OFTString:
case OFTWideString: // deprecated
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
break;
case OFTBinary:
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Object));
break;
case OFTIntegerList:
case OFTRealList:
case OFTStringList:
case OFTWideStringList: // deprecated !
#ifdef MAPNIK_DEBUG
clog << "unhandled type_oid=" << type_oid << endl;
#endif
break;
case OFTDate:
case OFTTime:
case OFTDateTime: // unhandled !
#ifdef MAPNIK_DEBUG
clog << "unhandled type_oid=" << type_oid << endl;
#endif
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Object));
break;
default: // unknown
#ifdef MAPNIK_DEBUG
clog << "unknown type_oid=" << type_oid << endl;
#endif
break;
}
}
}
is_bound_ = true;
}
ogr_datasource::~ogr_datasource()
{
if (is_bound_)
{
OGRDataSource::DestroyDataSource (dataset_);
}
}
std::string ogr_datasource::name()
{
return "ogr";
}
int ogr_datasource::type() const
{
return type_;
}
Envelope<double> ogr_datasource::envelope() const
{
if (!is_bound_) bind();
return extent_;
}
layer_descriptor ogr_datasource::get_descriptor() const
{
if (!is_bound_) bind();
return desc_;
}
featureset_ptr ogr_datasource::features(query const& q) const
{
if (!is_bound_) bind();
if (dataset_ && layer_)
{
#if 0
std::ostringstream s;
s << "select ";
std::set<std::string> const& props=q.property_names();
std::set<std::string>::const_iterator pos=props.begin();
std::set<std::string>::const_iterator end=props.end();
while (pos != end)
{
s <<",\""<<*pos<<"\"";
++pos;
}
s << " from " << layerName_ ;
// execute existing SQL
OGRLayer* layer = dataset_->ExecuteSQL (s.str(), poly);
// layer must be freed
dataset_->ReleaseResultSet (layer);
#endif
if (indexed_)
{
filter_in_box filter(q.get_bbox());
return featureset_ptr(new ogr_index_featureset<filter_in_box> (*dataset_,
*layer_,
filter,
index_name_,
desc_.get_encoding(),
multiple_geometries_));
}
else
{
return featureset_ptr(new ogr_featureset (*dataset_,
*layer_,
q.get_bbox(),
desc_.get_encoding(),
multiple_geometries_));
}
}
return featureset_ptr();
}
featureset_ptr ogr_datasource::features_at_point(coord2d const& pt) const
{
if (!is_bound_) bind();
if (dataset_ && layer_)
{
if (indexed_)
{
filter_at_point filter(pt);
return featureset_ptr(new ogr_index_featureset<filter_at_point> (*dataset_,
*layer_,
filter,
index_name_,
desc_.get_encoding(),
multiple_geometries_));
}
else
{
OGRPoint point;
point.setX (pt.x);
point.setY (pt.y);
return featureset_ptr(new ogr_featureset (*dataset_,
*layer_,
point,
desc_.get_encoding(),
multiple_geometries_));
}
}
return featureset_ptr();
}