mapnik/plugins/input/postgis/postgis.cpp
2006-10-09 09:45:45 +00:00

222 lines
7.6 KiB
C++

/*****************************************************************************
*
* 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
*
*****************************************************************************/
//$Id: postgis.cc 44 2005-04-22 18:53:54Z pavlenko $
#include "postgis.hpp"
#include <string>
#include <algorithm>
#include <set>
#include <sstream>
#include "connection_manager.hpp"
DATASOURCE_PLUGIN(postgis_datasource)
const std::string postgis_datasource::GEOMETRY_COLUMNS="geometry_columns";
const std::string postgis_datasource::SPATIAL_REF_SYS="spatial_ref_system";
using std::clog;
using std::clog;
using std::endl;
using boost::lexical_cast;
using boost::bad_lexical_cast;
using boost::shared_ptr;
postgis_datasource::postgis_datasource(const parameters& params)
: datasource (params),
table_(params.get("table")),
type_(datasource::Vector),
desc_(params.get("name")),
creator_(params.get("host"),
params.get("dbname"),
params.get("user"),
params.get("password"))
{
ConnectionManager *mgr=ConnectionManager::instance();
mgr->registerPool(creator_,10,20);
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
const shared_ptr<Connection>& conn = pool->borrowObject();
if (conn && conn->isOK())
{
PoolGuard<shared_ptr<Connection>,shared_ptr<Pool<Connection,ConnectionCreator> > > guard(conn,pool);
std::string table_name=table_from_sql(table_);
std::ostringstream s;
s << "select f_geometry_column,srid,type from ";
s << GEOMETRY_COLUMNS <<" where f_table_name='"<<table_name<<"'";
shared_ptr<ResultSet> rs=conn->executeQuery(s.str());
if (rs->next())
{
try
{
srid_ = lexical_cast<int>(rs->getValue("srid"));
desc_.set_srid(srid_);
}
catch (bad_lexical_cast &ex)
{
clog << ex.what() << endl;
}
geometryColumn_=rs->getValue("f_geometry_column");
std::string postgisType=rs->getValue("type");
}
rs->close();
s.str("");
s << "select xmin(ext),ymin(ext),xmax(ext),ymax(ext)";
s << " from (select estimated_extent('"<<table_name<<"','"<<geometryColumn_<<"') as ext) as tmp";
rs=conn->executeQuery(s.str());
if (rs->next())
{
try
{
double lox=lexical_cast<double>(rs->getValue(0));
double loy=lexical_cast<double>(rs->getValue(1));
double hix=lexical_cast<double>(rs->getValue(2));
double hiy=lexical_cast<double>(rs->getValue(3));
extent_.init(lox,loy,hix,hiy);
}
catch (bad_lexical_cast &ex)
{
clog << ex.what() << endl;
}
}
rs->close();
// collect attribute desc
s.str("");
s << "select * from "<<table_<<" limit 1";
rs=conn->executeQuery(s.str());
if (rs->next())
{
int count = rs->getNumFields();
for (int i=0;i<count;++i)
{
std::string fld_name=rs->getFieldName(i);
int length = rs->getFieldLength(i);
int type_oid = rs->getTypeOID(i);
switch (type_oid)
{
case 17285: // geometry
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Geometry));
break;
case 21: // int2
case 23: // int4
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer,false,length));
break;
case 701: // float8
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double,false,length));
case 1042: // bpchar
case 1043: // varchar
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
break;
default: // shouldn't get here
clog << "unknown type_oid="<<type_oid<<endl;
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
break;
}
}
}
}
}
}
std::string postgis_datasource::name_="postgis";
std::string postgis_datasource::name()
{
return name_;
}
int postgis_datasource::type() const
{
return type_;
}
layer_descriptor const& postgis_datasource::get_descriptor() const
{
return desc_;
}
std::string postgis_datasource::table_from_sql(const std::string& sql)
{
std::string table_name(sql);
transform(table_name.begin(),table_name.end(),table_name.begin(),tolower);
std::string::size_type idx=table_name.rfind("from");
if (idx!=std::string::npos)
{
idx=table_name.find_first_not_of(" ",idx+4);
table_name=table_name.substr(idx);
idx=table_name.find_first_of(" )");
return table_name.substr(0,idx);
}
return table_name;
}
featureset_ptr postgis_datasource::features(const query& q) const
{
Featureset *fs=0;
Envelope<double> const& box=q.get_bbox();
ConnectionManager *mgr=ConnectionManager::instance();
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
const shared_ptr<Connection>& conn = pool->borrowObject();
if (conn && conn->isOK())
{
PoolGuard<shared_ptr<Connection>,shared_ptr<Pool<Connection,ConnectionCreator> > > guard(conn,pool);
std::ostringstream s;
s << "select asbinary("<<geometryColumn_<<") as geom";
std::set<std::string> const& props=q.property_names();
std::set<std::string>::const_iterator pos=props.begin();
while (pos!=props.end())
{
s <<",\""<<*pos<<"\"";
++pos;
}
s << " from " << table_<<" where "<<geometryColumn_<<" && setSRID('BOX3D(";
s << box.minx() << " " << box.miny() << ",";
s << box.maxx() << " " << box.maxy() << ")'::box3d,"<<srid_<<")";
clog << s.str() << endl;
shared_ptr<ResultSet> rs=conn->executeQuery(s.str(),1);
fs=new postgis_featureset(rs,props.size());
}
}
return featureset_ptr(fs);
}
const Envelope<double>& postgis_datasource::envelope() const
{
return extent_;
}
postgis_datasource::~postgis_datasource() {}