mapnik/plugins/input/postgis/postgis_datasource.cpp

709 lines
26 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 $
// mapnik
#include <mapnik/global.hpp>
#include <mapnik/ptree_helpers.hpp>
#include <mapnik/sql_utils.hpp>
#include "connection_manager.hpp"
#include "postgis_datasource.hpp"
#include "postgis_featureset.hpp"
// boost
#include <boost/algorithm/string.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/tokenizer.hpp>
#include <boost/format.hpp>
#include <boost/make_shared.hpp>
// stl
#include <string>
#include <algorithm>
#include <set>
#include <sstream>
#include <iomanip>
#define FMAX std::numeric_limits<double>::max()
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 boost::lexical_cast;
using boost::bad_lexical_cast;
using boost::shared_ptr;
using mapnik::PoolGuard;
using mapnik::attribute_descriptor;
postgis_datasource::postgis_datasource(parameters const& params, bool bind)
: datasource(params),
table_(*params_.get<std::string>("table","")),
schema_(""),
geometry_table_(*params_.get<std::string>("geometry_table","")),
geometry_field_(*params_.get<std::string>("geometry_field","")),
key_field_(*params_.get<std::string>("key_field","")),
cursor_fetch_size_(*params_.get<int>("cursor_size",0)),
row_limit_(*params_.get<int>("row_limit",0)),
type_(datasource::Vector),
srid_(*params_.get<int>("srid",0)),
extent_initialized_(false),
desc_(*params_.get<std::string>("type"),"utf-8"),
creator_(params.get<std::string>("host"),
params.get<std::string>("port"),
params.get<std::string>("dbname"),
params.get<std::string>("user"),
params.get<std::string>("password"),
params.get<std::string>("connect_timeout","4")),
bbox_token_("!bbox!"),
scale_denom_token_("!scale_denominator!"),
persist_connection_(*params_.get<mapnik::boolean>("persist_connection",true)),
extent_from_subquery_(*params_.get<mapnik::boolean>("extent_from_subquery",false)),
// params below are for testing purposes only (will likely be removed at any time)
intersect_min_scale_(*params_.get<int>("intersect_min_scale",0)),
intersect_max_scale_(*params_.get<int>("intersect_max_scale",0))
//show_queries_(*params_.get<mapnik::boolean>("show_queries",false))
{
if (table_.empty()) throw mapnik::datasource_exception("Postgis Plugin: missing <table> parameter");
multiple_geometries_ = *params_.get<mapnik::boolean>("multiple_geometries",false);
boost::optional<std::string> ext = params_.get<std::string>("extent");
if (ext) extent_initialized_ = extent_.from_string(*ext);
if (bind)
{
this->bind();
}
}
void postgis_datasource::bind() const
{
if (is_bound_) return;
boost::optional<int> initial_size = params_.get<int>("initial_size",1);
boost::optional<int> max_size = params_.get<int>("max_size",10);
ConnectionManager *mgr=ConnectionManager::instance();
mgr->registerPool(creator_, *initial_size, *max_size);
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (conn && conn->isOK())
{
is_bound_ = true;
PoolGuard<shared_ptr<Connection>,
shared_ptr<Pool<Connection,ConnectionCreator> > > guard(conn,pool);
desc_.set_encoding(conn->client_encoding());
if(geometry_table_.empty())
{
geometry_table_ = mapnik::table_from_sql(table_);
}
std::string::size_type idx = geometry_table_.find_last_of('.');
if (idx!=std::string::npos)
{
schema_ = geometry_table_.substr(0,idx);
geometry_table_ = geometry_table_.substr(idx+1);
}
else
{
geometry_table_ = geometry_table_.substr(0);
}
// If we do not know both the geometry_field and the srid
// then first attempt to fetch the geometry name from a geometry_columns entry.
// This will return no records if we are querying a bogus table returned
// from the simplistic table parsing in table_from_sql() or if
// the table parameter references a table, view, or subselect not
// registered in the geometry columns.
geometryColumn_ = geometry_field_;
if (!geometryColumn_.length() > 0 || srid_ == 0)
{
std::ostringstream s;
s << "SELECT f_geometry_column, srid FROM ";
s << GEOMETRY_COLUMNS <<" WHERE f_table_name='" << mapnik::unquote_sql(geometry_table_) <<"'";
if (schema_.length() > 0)
s << " AND f_table_schema='" << mapnik::unquote_sql(schema_) << "'";
if (geometry_field_.length() > 0)
s << " AND f_geometry_column='" << mapnik::unquote_sql(geometry_field_) << "'";
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % s.str();
}
*/
shared_ptr<ResultSet> rs=conn->executeQuery(s.str());
if (rs->next())
{
geometryColumn_ = rs->getValue("f_geometry_column");
if (srid_ == 0)
{
try
{
srid_ = lexical_cast<int>(rs->getValue("srid"));
}
catch (bad_lexical_cast &ex)
{
std::clog << "Postgis Plugin: SRID=" << rs->getValue("srid") << " " << ex.what() << std::endl;
}
}
}
rs->close();
// If we still do not know the srid then we can try to fetch
// it from the 'table_' parameter, which should work even if it is
// a subselect as long as we know the geometry_field to query
if (geometryColumn_.length() && srid_ <= 0)
{
s.str("");
s << "SELECT ST_SRID(\"" << geometryColumn_ << "\") AS srid FROM ";
s << populate_tokens(table_) << " WHERE \"" << geometryColumn_ << "\" IS NOT NULL LIMIT 1;";
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % s.str();
}
*/
shared_ptr<ResultSet> rs=conn->executeQuery(s.str());
if (rs->next())
{
try
{
srid_ = lexical_cast<int>(rs->getValue("srid"));
}
catch (bad_lexical_cast &ex)
{
std::clog << "Postgis Plugin: SRID=" << rs->getValue("srid") << " " << ex.what() << std::endl;
}
}
rs->close();
}
}
if (srid_ == 0)
{
srid_ = -1;
std::clog << "Postgis Plugin: SRID warning, using srid=-1" << std::endl;
}
// At this point the geometry_field may still not be known
// but we'll catch that where more useful...
#ifdef MAPNIK_DEBUG
std::clog << "Postgis Plugin: using SRID=" << srid_ << std::endl;
std::clog << "Postgis Plugin: using geometry_column=" << geometryColumn_ << std::endl;
#endif
// collect attribute desc
std::ostringstream s;
s << "SELECT * FROM " << populate_tokens(table_) << " LIMIT 0";
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % s.str();
}
*/
shared_ptr<ResultSet> rs=conn->executeQuery(s.str());
int count = rs->getNumFields();
bool found_key_field = false;
for (int i=0;i<count;++i)
{
std::string fld_name=rs->getFieldName(i);
int type_oid = rs->getTypeOID(i);
// validate type of key_field
if (!found_key_field && !key_field_.empty() && fld_name == key_field_)
{
found_key_field = true;
if (type_oid == 20 || type_oid == 21 || type_oid == 23)
{
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer));
}
else
{
std::ostringstream error_s;
error_s << "invalid type '";
std::ostringstream type_s;
type_s << "SELECT oid, typname FROM pg_type WHERE oid = " << type_oid;
shared_ptr<ResultSet> rs_oid = conn->executeQuery(type_s.str());
if (rs_oid->next())
{
error_s << rs_oid->getValue("typname")
<< "' (oid:" << rs_oid->getValue("oid") << ")";
}
else
{
error_s << "oid:" << type_oid << "'";
}
rs_oid->close();
error_s << " for key_field '" << fld_name << "' - "
<< "must be an integer primary key";
rs->close();
throw mapnik::datasource_exception( error_s.str() );
}
}
else
{
switch (type_oid)
{
case 16: // bool
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Boolean));
break;
case 20: // int8
case 21: // int2
case 23: // int4
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Integer));
break;
case 700: // float4
case 701: // float8
case 1700: // numeric ??
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double));
case 1042: // bpchar
case 1043: // varchar
case 25: // text
desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::String));
break;
default: // should not get here
#ifdef MAPNIK_DEBUG
s.str("");
s << "SELECT oid, typname FROM pg_type WHERE oid = " << type_oid;
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % s.str();
}
*/
shared_ptr<ResultSet> rs_oid = conn->executeQuery(s.str());
if (rs_oid->next())
{
std::clog << "Postgis Plugin: unknown type = " << rs_oid->getValue("typname")
<< " (oid:" << rs_oid->getValue("oid") << ")" << std::endl;
}
else
{
std::clog << "Postgis Plugin: unknown oid type =" << type_oid << std::endl;
}
rs_oid->close();
#endif
break;
}
}
}
rs->close();
}
}
}
std::string postgis_datasource::name()
{
return "postgis";
}
int postgis_datasource::type() const
{
return type_;
}
layer_descriptor postgis_datasource::get_descriptor() const
{
if (!is_bound_) bind();
return desc_;
}
std::string postgis_datasource::sql_bbox(box2d<double> const& env) const
{
std::ostringstream b;
if (srid_ > 0)
b << "ST_SetSRID(";
b << "'BOX3D(";
b << std::setprecision(16);
b << env.minx() << " " << env.miny() << ",";
b << env.maxx() << " " << env.maxy() << ")'::box3d";
if (srid_ > 0)
b << ", " << srid_ << ")";
return b.str();
}
std::string postgis_datasource::populate_tokens(const std::string& sql) const
{
std::string populated_sql = sql;
if ( boost::algorithm::icontains(sql,bbox_token_) )
{
box2d<double> max_env(-1 * FMAX,-1 * FMAX,FMAX,FMAX);
std::string max_box = sql_bbox(max_env);
boost::algorithm::replace_all(populated_sql,bbox_token_,max_box);
}
if ( boost::algorithm::icontains(sql,scale_denom_token_) )
{
std::string max_denom = lexical_cast<std::string>(FMAX);
boost::algorithm::replace_all(populated_sql,scale_denom_token_,max_denom);
}
return populated_sql;
}
std::string postgis_datasource::populate_tokens(const std::string& sql, double const& scale_denom, box2d<double> const& env) const
{
std::string populated_sql = sql;
std::string box = sql_bbox(env);
if ( boost::algorithm::icontains(populated_sql,scale_denom_token_) )
{
std::string max_denom = lexical_cast<std::string>(scale_denom);
boost::algorithm::replace_all(populated_sql,scale_denom_token_,max_denom);
}
if ( boost::algorithm::icontains(populated_sql,bbox_token_) )
{
boost::algorithm::replace_all(populated_sql,bbox_token_,box);
return populated_sql;
}
else
{
std::ostringstream s;
if (intersect_min_scale_ > 0 && (scale_denom <= intersect_min_scale_ ))
{
s << " WHERE ST_Intersects(\"" << geometryColumn_ << "\"," << box << ")";
}
else if (intersect_max_scale_ > 0 && (scale_denom >= intersect_max_scale_ ))
{
// do no bbox restriction
}
else
{
s << " WHERE \"" << geometryColumn_ << "\" && " << box;
}
return populated_sql + s.str();
}
}
boost::shared_ptr<IResultSet> postgis_datasource::get_resultset(boost::shared_ptr<Connection> const &conn, const std::string &sql) const
{
if (cursor_fetch_size_ > 0)
{
// cursor
std::ostringstream csql;
std::string cursor_name = conn->new_cursor_name();
csql << "DECLARE " << cursor_name << " BINARY INSENSITIVE NO SCROLL CURSOR WITH HOLD FOR " << sql << " FOR READ ONLY";
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % csql.str();
}
*/
if (!conn->execute(csql.str()))
throw mapnik::datasource_exception("Postgis Plugin: error creating cursor for data select." );
return boost::make_shared<CursorResultSet>(conn, cursor_name, cursor_fetch_size_);
}
else
{
// no cursor
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % sql;
}
*/
return conn->executeQuery(sql,1);
}
}
featureset_ptr postgis_datasource::features(const query& q) const
{
if (!is_bound_) bind();
box2d<double> const& box = q.get_bbox();
double scale_denom = q.scale_denominator();
ConnectionManager *mgr=ConnectionManager::instance();
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (conn && conn->isOK())
{
PoolGuard<shared_ptr<Connection>,shared_ptr<Pool<Connection,ConnectionCreator> > > guard(conn,pool);
if (!geometryColumn_.length() > 0)
{
std::ostringstream s_error;
s_error << "geometry name lookup failed for table '";
if (schema_.length() > 0)
{
s_error << schema_ << ".";
}
s_error << geometry_table_
<< "'. Please manually provide the 'geometry_field' parameter or add an entry "
<< "in the geometry_columns for '";
if (schema_.length() > 0)
{
s_error << schema_ << ".";
}
s_error << geometry_table_ << "'.";
throw mapnik::datasource_exception("Postgis Plugin: " + s_error.str());
}
std::ostringstream s;
s << "SELECT ST_AsBinary(\"" << geometryColumn_ << "\") AS geom";
if (!key_field_.empty())
mapnik::quote_attr(s,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)
{
mapnik::quote_attr(s,*pos);
++pos;
}
std::string table_with_bbox = populate_tokens(table_,scale_denom,box);
s << " from " << table_with_bbox;
if (row_limit_ > 0) {
s << " LIMIT " << row_limit_;
}
boost::shared_ptr<IResultSet> rs = get_resultset(conn, s.str());
unsigned num_attr = props.size();
if (!key_field_.empty())
++num_attr;
return boost::make_shared<postgis_featureset>(rs,desc_.get_encoding(),multiple_geometries_,!key_field_.empty(),num_attr);
}
else
{
throw mapnik::datasource_exception("Postgis Plugin: bad connection");
}
}
return featureset_ptr();
}
featureset_ptr postgis_datasource::features_at_point(coord2d const& pt) const
{
if (!is_bound_) bind();
ConnectionManager *mgr=ConnectionManager::instance();
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
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;
if (!geometryColumn_.length() > 0)
{
std::ostringstream s_error;
s_error << "PostGIS: geometry name lookup failed for table '";
if (schema_.length() > 0)
{
s_error << schema_ << ".";
}
s_error << "." << geometry_table_
<< "'. Please manually provide the 'geometry_field' parameter or add an entry "
<< "in the geometry_columns for '";
if (schema_.length() > 0)
{
s_error << schema_ << ".";
}
s_error << geometry_table_ << "'.";
throw mapnik::datasource_exception(s_error.str());
}
s << "SELECT AsBinary(\"" << geometryColumn_ << "\") AS geom";
if (!key_field_.empty())
mapnik::quote_attr(s,key_field_);
std::vector<attribute_descriptor>::const_iterator itr = desc_.get_descriptors().begin();
std::vector<attribute_descriptor>::const_iterator end = desc_.get_descriptors().end();
unsigned size=0;
while (itr != end)
{
mapnik::quote_attr(s,itr->get_name());
++itr;
++size;
}
box2d<double> box(pt.x,pt.y,pt.x,pt.y);
std::string table_with_bbox = populate_tokens(table_,FMAX,box);
s << " from " << table_with_bbox;
if (row_limit_ > 0) {
s << " LIMIT " << row_limit_;
}
boost::shared_ptr<IResultSet> rs = get_resultset(conn, s.str());
return boost::make_shared<postgis_featureset>(rs,desc_.get_encoding(),multiple_geometries_,!key_field_.empty(),size);
}
}
return featureset_ptr();
}
box2d<double> postgis_datasource::envelope() const
{
if (extent_initialized_) return extent_;
if (!is_bound_) bind();
ConnectionManager *mgr=ConnectionManager::instance();
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
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;
boost::optional<mapnik::boolean> estimate_extent = params_.get<mapnik::boolean>("estimate_extent",false);
if (!geometryColumn_.length() > 0)
{
std::ostringstream s_error;
s_error << "PostGIS: unable to query the layer extent of table '";
if (schema_.length() > 0)
{
s_error << schema_ << ".";
}
s_error << geometry_table_ << "' because we cannot determine the geometry field name."
<< "\nPlease provide either an 'extent' parameter to skip this query, "
<< "a 'geometry_field' and/or 'geometry_table' parameter, or add a "
<< "record to the 'geometry_columns' for your table.";
throw mapnik::datasource_exception("Postgis Plugin: " + s_error.str());
}
if (estimate_extent && *estimate_extent)
{
s << "SELECT ST_XMin(ext),ST_YMin(ext),ST_XMax(ext),ST_YMax(ext)"
<< " FROM (SELECT ST_Estimated_Extent('";
if (schema_.length() > 0)
{
s << mapnik::unquote_sql(schema_) << "','";
}
s << mapnik::unquote_sql(geometry_table_) << "','"
<< mapnik::unquote_sql(geometryColumn_) << "') as ext) as tmp";
}
else
{
s << "SELECT ST_XMin(ext),ST_YMin(ext),ST_XMax(ext),ST_YMax(ext)"
<< " FROM (SELECT ST_Extent(" <<geometryColumn_<< ") as ext from ";
if (extent_from_subquery_)
{
// if a subselect limits records then calculating the extent upon the
// subquery will be faster and the bounds will be more accurate
s << populate_tokens(table_) << ") as tmp";
}
else
{
if (schema_.length() > 0)
{
s << schema_ << ".";
}
// but if the subquery does not limit records then querying the
// actual table will be faster as indexes can be used
s << geometry_table_ << ") as tmp";
}
}
/*
if (show_queries_)
{
std::clog << boost::format("PostGIS: sending query: %s\n") % s.str();
}
*/
shared_ptr<ResultSet> 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);
extent_initialized_ = true;
}
catch (bad_lexical_cast &ex)
{
std::clog << boost::format("Postgis Plugin: warning: could not determine extent from query: %s\nError was: '%s'\n") % s.str() % ex.what() << std::endl;
}
}
rs->close();
}
}
return extent_;
}
postgis_datasource::~postgis_datasource()
{
if (is_bound_ && !persist_connection_)
{
ConnectionManager *mgr=ConnectionManager::instance();
shared_ptr<Pool<Connection,ConnectionCreator> > pool=mgr->getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (conn)
{
conn->close();
}
}
}
}