mapnik/plugins/input/sqlite/sqlite_datasource.cpp
2009-02-16 22:06:41 +00:00

271 lines
8.1 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 "sqlite_datasource.hpp"
#include "sqlite_featureset.hpp"
// mapnik
#include <mapnik/ptree_helpers.hpp>
// boost
#include <boost/algorithm/string.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/tokenizer.hpp>
using std::clog;
using std::endl;
using boost::lexical_cast;
using boost::bad_lexical_cast;
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(sqlite_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;
sqlite_datasource::sqlite_datasource(parameters const& params)
: datasource(params),
extent_(),
extent_initialized_(false),
type_(datasource::Vector),
table_(*params.get<std::string>("table","")),
metadata_(*params.get<std::string>("metadata","")),
geometry_field_(*params.get<std::string>("geometry_field","geom")),
key_field_(*params.get<std::string>("key_field","PK_UID")),
desc_(*params.get<std::string>("type"), *params.get<std::string>("encoding","utf-8"))
{
boost::optional<std::string> file = params.get<std::string>("file");
if (!file) throw datasource_exception("missing <file> paramater");
multiple_geometries_ = *params_.get<mapnik::boolean>("multiple_geometries",false);
use_spatial_index_ = *params_.get<mapnik::boolean>("use_spatial_index",true);
dataset_ = new sqlite_connection (*file);
boost::optional<std::string> ext = params_.get<std::string>("extent");
if (ext)
{
boost::char_separator<char> sep(",");
boost::tokenizer<boost::char_separator<char> > tok(*ext,sep);
unsigned i = 0;
bool success = false;
double d[4];
for (boost::tokenizer<boost::char_separator<char> >::iterator beg=tok.begin();
beg!=tok.end();++beg)
{
try
{
d[i] = boost::lexical_cast<double>(*beg);
}
catch (boost::bad_lexical_cast & ex)
{
std::clog << ex.what() << "\n";
break;
}
if (i==3)
{
success = true;
break;
}
++i;
}
if (success)
{
extent_.init(d[0],d[1],d[2],d[3]);
extent_initialized_ = true;
}
}
if (metadata_ != "" && ! extent_initialized_)
{
std::ostringstream s;
s << "select xmin, ymin, xmax, ymax from " << metadata_;
s << " where lower(f_table_name) = lower('" << table_ << "')";
boost::scoped_ptr<sqlite_resultset> rs (dataset_->execute_query (s.str()));
if (rs->is_valid () && rs->step_next())
{
double xmin = rs->column_double (0);
double ymin = rs->column_double (1);
double xmax = rs->column_double (2);
double ymax = rs->column_double (3);
extent_.init (xmin,ymin,xmax,ymax);
extent_initialized_ = true;
}
}
if (use_spatial_index_)
{
std::ostringstream s;
s << "select count (*) from sqlite_master";
s << " where name = 'idx_" << table_ << "_" << geometry_field_ << "'";
boost::scoped_ptr<sqlite_resultset> rs (dataset_->execute_query (s.str()));
if (rs->is_valid () && rs->step_next())
{
if (rs->column_integer (0) == 0)
{
#ifdef MAPNIK_DEBUG
clog << "cannot use the spatial index " << endl;
#endif
use_spatial_index_ = false;
}
}
}
{
/*
XXX - This is problematic, if we don't have at least a row,
we cannot determine the right columns types and names
as all column_type are SQLITE_NULL
*/
std::ostringstream s;
s << "select * from " << table_ << " limit 1";
boost::scoped_ptr<sqlite_resultset> rs (dataset_->execute_query (s.str()));
if (rs->is_valid () && rs->step_next())
{
for (int i = 0; i < rs->column_count (); ++i)
{
const int type_oid = rs->column_type (i);
const char* fld_name = rs->column_name (i);
switch (type_oid)
{
case SQLITE_INTEGER:
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer));
break;
case SQLITE_FLOAT:
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double));
break;
case SQLITE_TEXT:
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
break;
case SQLITE_NULL:
case SQLITE_BLOB:
break;
default:
#ifdef MAPNIK_DEBUG
clog << "unknown type_oid="<<type_oid<<endl;
#endif
break;
}
}
}
}
}
sqlite_datasource::~sqlite_datasource()
{
delete dataset_;
}
std::string const sqlite_datasource::name_="sqlite";
std::string sqlite_datasource::name()
{
return name_;
}
int sqlite_datasource::type() const
{
return type_;
}
Envelope<double> sqlite_datasource::envelope() const
{
return extent_;
}
layer_descriptor sqlite_datasource::get_descriptor() const
{
return desc_;
}
featureset_ptr sqlite_datasource::features(query const& q) const
{
if (dataset_)
{
mapnik::Envelope<double> const& e = q.get_bbox();
std::ostringstream s;
s << "select " << geometry_field_ << "," << key_field_;
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 " << table_;
if (use_spatial_index_)
{
s << std::setprecision(16);
s << " where rowid in (select pkid from idx_" << table_ << "_" << geometry_field_;
s << " where xmax>=" << e.minx() << " and xmin<=" << e.maxx() ;
s << " and ymax>=" << e.miny() << " and ymin<=" << e.maxy() << ")";
}
#ifdef MAPNIK_DEBUG
std::cerr << "executing sql: " << s.str() << "\n";
#endif
boost::shared_ptr<sqlite_resultset> rs (dataset_->execute_query (s.str()));
return featureset_ptr (new sqlite_featureset(rs, desc_.get_encoding(), multiple_geometries_));
}
return featureset_ptr();
}
featureset_ptr sqlite_datasource::features_at_point(coord2d const& pt) const
{
#if 0
if (dataset_ && layer_)
{
OGRPoint point;
point.setX (pt.x);
point.setY (pt.y);
layer_->SetSpatialFilter (&point);
return featureset_ptr(new ogr_featureset(*dataset_, *layer_, desc_.get_encoding(), multiple_geometries_));
}
#endif
return featureset_ptr();
}