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/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2011 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
*
*****************************************************************************/
#include "connection_manager.hpp"
#include "postgis_datasource.hpp"
#include "postgis_featureset.hpp"
// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/global.hpp>
#include <mapnik/boolean.hpp>
#include <mapnik/sql_utils.hpp>
#include <mapnik/util/conversions.hpp>
#include <mapnik/timer.hpp>
// boost
#include <boost/algorithm/string.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>
DATASOURCE_PLUGIN(postgis_datasource)
const double postgis_datasource::FMAX = std::numeric_limits<double>::max();
const std::string postgis_datasource::GEOMETRY_COLUMNS = "geometry_columns";
const std::string postgis_datasource::SPATIAL_REF_SYS = "spatial_ref_system";
using boost::shared_ptr;
using mapnik::PoolGuard;
using mapnik::attribute_descriptor;
postgis_datasource::postgis_datasource(parameters const& params)
: 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),
simplify_geometries_(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!"),
pixel_width_token_("!pixel_width!"),
pixel_height_token_("!pixel_height!"),
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))
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "postgis_datasource::init");
#endif
if (table_.empty())
{
throw mapnik::datasource_exception("Postgis Plugin: missing <table> parameter");
}
boost::optional<std::string> ext = params.get<std::string>("extent");
if (ext && !ext->empty())
{
extent_initialized_ = extent_.from_string(*ext);
}
boost::optional<int> initial_size = params.get<int>("initial_size", 1);
boost::optional<int> max_size = params.get<int>("max_size", 10);
boost::optional<mapnik::boolean> autodetect_key_field = params.get<mapnik::boolean>("autodetect_key_field", false);
boost::optional<mapnik::boolean> estimate_extent = params.get<mapnik::boolean>("estimate_extent", false);
estimate_extent_ = estimate_extent && *estimate_extent;
boost::optional<mapnik::boolean> simplify_opt = params.get<mapnik::boolean>("simplify_geometries", false);
simplify_geometries_ = simplify_opt && *simplify_opt;
ConnectionManager::instance().registerPool(creator_, *initial_size, *max_size);
shared_ptr< Pool<Connection,ConnectionCreator> > pool = ConnectionManager::instance().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);
desc_.set_encoding(conn->client_encoding());
if (geometry_table_.empty())
{
geometry_table_ = mapnik::sql_utils::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_.empty() || srid_ == 0)
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats2__(std::clog, "postgis_datasource::init(get_srid_and_geometry_column)");
#endif
std::ostringstream s;
try
{
s << "SELECT f_geometry_column, srid FROM "
<< GEOMETRY_COLUMNS <<" WHERE f_table_name='"
<< mapnik::sql_utils::unquote_double(geometry_table_)
<< "'";
if (! schema_.empty())
{
s << " AND f_table_schema='"
<< mapnik::sql_utils::unquote_double(schema_)
<< "'";
}
if (! geometry_field_.empty())
{
s << " AND f_geometry_column='"
<< mapnik::sql_utils::unquote_double(geometry_field_)
<< "'";
}
shared_ptr<ResultSet> rs = conn->executeQuery(s.str());
if (rs->next())
{
geometryColumn_ = rs->getValue("f_geometry_column");
if (srid_ == 0)
{
const char* srid_c = rs->getValue("srid");
if (srid_c != NULL)
{
int result = 0;
if (mapnik::util::string2int(srid_c, result))
{
srid_ = result;
}
}
}
}
rs->close();
}
catch (mapnik::datasource_exception const& ex) {
// let this pass on query error and use the fallback below
MAPNIK_LOG_WARN(postgis) << "postgis_datasource: metadata query failed: " << ex.what();
}
// 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_.empty() && srid_ <= 0)
{
s.str("");
s << "SELECT ST_SRID(\"" << geometryColumn_ << "\") AS srid FROM "
<< populate_tokens(table_) << " WHERE \"" << geometryColumn_ << "\" IS NOT NULL LIMIT 1;";
shared_ptr<ResultSet> rs = conn->executeQuery(s.str());
if (rs->next())
{
const char* srid_c = rs->getValue("srid");
if (srid_c != NULL)
{
int result = 0;
if (mapnik::util::string2int(srid_c, result))
{
srid_ = result;
}
}
}
rs->close();
}
}
// detect primary key
if (*autodetect_key_field && key_field_.empty())
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats2__(std::clog, "postgis_datasource::bind(get_primary_key)");
#endif
std::ostringstream s;
s << "SELECT a.attname, a.attnum, t.typname, t.typname in ('int2','int4','int8') "
"AS is_int FROM pg_class c, pg_attribute a, pg_type t, pg_namespace n, pg_index i "
"WHERE a.attnum > 0 AND a.attrelid = c.oid "
"AND a.atttypid = t.oid AND c.relnamespace = n.oid "
"AND c.oid = i.indrelid AND i.indisprimary = 't' "
"AND t.typname !~ '^geom' AND c.relname ="
<< " '" << mapnik::sql_utils::unquote_double(geometry_table_) << "' "
//"AND a.attnum = ANY (i.indkey) " // postgres >= 8.1
<< "AND (i.indkey[0]=a.attnum OR i.indkey[1]=a.attnum OR i.indkey[2]=a.attnum "
"OR i.indkey[3]=a.attnum OR i.indkey[4]=a.attnum OR i.indkey[5]=a.attnum "
"OR i.indkey[6]=a.attnum OR i.indkey[7]=a.attnum OR i.indkey[8]=a.attnum "
"OR i.indkey[9]=a.attnum) ";
if (! schema_.empty())
{
s << "AND n.nspname='"
<< mapnik::sql_utils::unquote_double(schema_)
<< "' ";
}
s << "ORDER BY a.attnum";
shared_ptr<ResultSet> rs_key = conn->executeQuery(s.str());
if (rs_key->next())
{
unsigned int result_rows = rs_key->size();
if (result_rows == 1)
{
bool is_int = (std::string(rs_key->getValue(3)) == "t");
if (is_int)
{
const char* key_field_string = rs_key->getValue(0);
if (key_field_string)
{
key_field_ = std::string(key_field_string);
MAPNIK_LOG_DEBUG(postgis) << "postgis_datasource: auto-detected key field of '"
<< key_field_ << "' on table '" << geometry_table_ << "'";
}
}
else
{
// throw for cases like a numeric primary key, which is invalid
// as it should be floating point (int numerics are useless)
std::ostringstream err;
err << "PostGIS Plugin: Error: '"
<< rs_key->getValue(0)
<< "' on table '"
<< geometry_table_
<< "' is not a valid integer primary key field\n";
throw mapnik::datasource_exception(err.str());
}
}
else if (result_rows > 1)
{
std::ostringstream err;
err << "PostGIS Plugin: Error: '"
<< "multi column primary key detected but is not supported";
throw mapnik::datasource_exception(err.str());
}
}
rs_key->close();
}
// if a globally unique key field/primary key is required
// but still not known at this point, then throw
if (*autodetect_key_field && key_field_.empty())
{
throw mapnik::datasource_exception(std::string("PostGIS Plugin: Error: primary key required")
+ " but could not be detected for table '" +
geometry_table_ + "', please supply 'key_field' option to specify field to use for primary key");
}
if (srid_ == 0)
{
srid_ = -1;
MAPNIK_LOG_DEBUG(postgis) << "postgis_datasource: Table " << table_ << " is using SRID=" << srid_;
}
// At this point the geometry_field may still not be known
// but we'll catch that where more useful...
MAPNIK_LOG_DEBUG(postgis) << "postgis_datasource: Using SRID=" << srid_;
MAPNIK_LOG_DEBUG(postgis) << "postgis_datasource: Using geometry_column=" << geometryColumn_;
// collect attribute desc
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats2__(std::clog, "postgis_datasource::bind(get_column_description)");
#endif
std::ostringstream s;
s << "SELECT * FROM " << populate_tokens(table_) << " LIMIT 0";
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_)
{
if (type_oid == 20 || type_oid == 21 || type_oid == 23)
{
found_key_field = true;
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));
break;
case 1042: // bpchar
case 1043: // varchar
case 25: // text
case 705: // literal
desc_.add_descriptor(attribute_descriptor(fld_name, mapnik::String));
break;
default: // should not get here
#ifdef MAPNIK_LOG
s.str("");
s << "SELECT oid, typname FROM pg_type WHERE oid = " << type_oid;
shared_ptr<ResultSet> rs_oid = conn->executeQuery(s.str());
if (rs_oid->next())
{
std::string typname(rs_oid->getValue("typname"));
if (typname != "geometry")
{
MAPNIK_LOG_WARN(postgis) << "postgis_datasource: Unknown type=" << typname
<< " (oid:" << rs_oid->getValue("oid") << ")";
}
}
else
{
MAPNIK_LOG_WARN(postgis) << "postgis_datasource: Unknown type_oid=" << type_oid;
}
rs_oid->close();
#endif
break;
}
}
}
rs->close();
}
}
}
postgis_datasource::~postgis_datasource()
{
if (! persist_connection_)
{
shared_ptr< Pool<Connection,ConnectionCreator> > pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (conn)
{
conn->close();
}
}
}
}
const char * postgis_datasource::name()
{
return "postgis";
}
mapnik::datasource::datasource_t postgis_datasource::type() const
{
return type_;
}
layer_descriptor postgis_datasource::get_descriptor() const
{
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(std::string const& sql) const
{
std::string populated_sql = sql;
if (boost::algorithm::icontains(sql, bbox_token_))
{
box2d<double> max_env(-1.0 * FMAX, -1.0 * FMAX, FMAX, FMAX);
const 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::ostringstream ss;
ss << FMAX;
boost::algorithm::replace_all(populated_sql, scale_denom_token_, ss.str());
}
if (boost::algorithm::icontains(sql, pixel_width_token_))
{
std::ostringstream ss;
ss << 0;
boost::algorithm::replace_all(populated_sql, pixel_width_token_, ss.str());
}
if (boost::algorithm::icontains(sql, pixel_height_token_))
{
std::ostringstream ss;
ss << 0;
boost::algorithm::replace_all(populated_sql, pixel_height_token_, ss.str());
}
return populated_sql;
}
std::string postgis_datasource::populate_tokens(std::string const& sql, double scale_denom, box2d<double> const& env, double pixel_width, double pixel_height) const
{
std::string populated_sql = sql;
std::string box = sql_bbox(env);
if (boost::algorithm::icontains(populated_sql, scale_denom_token_))
{
std::ostringstream ss;
ss << scale_denom;
boost::algorithm::replace_all(populated_sql, scale_denom_token_, ss.str());
}
if (boost::algorithm::icontains(sql, pixel_width_token_))
{
std::ostringstream ss;
ss << pixel_width;
boost::algorithm::replace_all(populated_sql, pixel_width_token_, ss.str());
}
if (boost::algorithm::icontains(sql, pixel_height_token_))
{
std::ostringstream ss;
ss << pixel_height;
boost::algorithm::replace_all(populated_sql, pixel_height_token_, ss.str());
}
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, std::string const& 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 (! conn->execute(csql.str()))
{
// TODO - better error
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
return conn->executeQuery(sql, 1);
}
}
featureset_ptr postgis_datasource::features(const query& q) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "postgis_datasource::features");
#endif
box2d<double> const& box = q.get_bbox();
double scale_denom = q.scale_denominator();
shared_ptr< Pool<Connection,ConnectionCreator> > pool = ConnectionManager::instance().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_.empty())
{
std::ostringstream s_error;
s_error << "PostGIS: geometry name lookup failed for table '";
if (! schema_.empty())
{
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_.empty())
{
s_error << schema_ << ".";
}
s_error << geometry_table_ << "'.";
throw mapnik::datasource_exception(s_error.str());
}
std::ostringstream s;
const double px_gw = 1.0 / boost::get<0>(q.resolution());
const double px_gh = 1.0 / boost::get<1>(q.resolution());
s << "SELECT ST_AsBinary(";
if (simplify_geometries_) {
s << "ST_Simplify(";
}
s << "\"" << geometryColumn_ << "\"";
if (simplify_geometries_) {
// 1/20 of pixel seems to be a good compromise to avoid
// drop of collapsed polygons.
// See https://github.com/mapnik/mapnik/issues/1639
const double tolerance = std::min(px_gw, px_gh) / 20.0;
s << ", " << tolerance << ")";
}
s << ") AS geom";
mapnik::context_ptr ctx = boost::make_shared<mapnik::context_type>();
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();
if (! key_field_.empty())
{
mapnik::sql_utils::quote_attr(s, key_field_);
ctx->push(key_field_);
for (; pos != end; ++pos)
{
if (*pos != key_field_)
{
mapnik::sql_utils::quote_attr(s, *pos);
ctx->push(*pos);
}
}
}
else
{
for (; pos != end; ++pos)
{
mapnik::sql_utils::quote_attr(s, *pos);
ctx->push(*pos);
}
}
std::string table_with_bbox = populate_tokens(table_, scale_denom, box, px_gw, px_gh);
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, ctx, desc_.get_encoding(), !key_field_.empty());
}
else
{
std::string err_msg = "Postgis Plugin:";
if (conn)
{
err_msg += conn->status();
}
else
{
err_msg += " Null connection";
}
throw mapnik::datasource_exception(err_msg);
}
}
return featureset_ptr();
}
featureset_ptr postgis_datasource::features_at_point(coord2d const& pt, double tol) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "postgis_datasource::features_at_point");
#endif
shared_ptr< Pool<Connection,ConnectionCreator> > pool = ConnectionManager::instance().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_.empty())
{
std::ostringstream s_error;
s_error << "PostGIS: geometry name lookup failed for table '";
if (! schema_.empty())
{
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_.empty())
{
s_error << schema_ << ".";
}
s_error << geometry_table_ << "'.";
throw mapnik::datasource_exception(s_error.str());
}
std::ostringstream s;
s << "SELECT ST_AsBinary(\"" << geometryColumn_ << "\") AS geom";
mapnik::context_ptr ctx = boost::make_shared<mapnik::context_type>();
std::vector<attribute_descriptor>::const_iterator itr = desc_.get_descriptors().begin();
std::vector<attribute_descriptor>::const_iterator end = desc_.get_descriptors().end();
if (! key_field_.empty())
{
mapnik::sql_utils::quote_attr(s, key_field_);
ctx->push(key_field_);
for (; itr != end; ++itr)
{
if (itr->get_name() != key_field_)
{
mapnik::sql_utils::quote_attr(s, itr->get_name());
ctx->push(itr->get_name());
}
}
}
else
{
for (; itr != end; ++itr)
{
mapnik::sql_utils::quote_attr(s, itr->get_name());
ctx->push(itr->get_name());
}
}
box2d<double> box(pt.x - tol, pt.y - tol, pt.x + tol, pt.y + tol);
std::string table_with_bbox = populate_tokens(table_, FMAX, box, 0, 0);
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, ctx, desc_.get_encoding(), !key_field_.empty());
}
}
return featureset_ptr();
}
box2d<double> postgis_datasource::envelope() const
{
if (extent_initialized_)
{
return extent_;
}
shared_ptr< Pool<Connection,ConnectionCreator> > pool = ConnectionManager::instance().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_.empty())
{
std::ostringstream s_error;
s_error << "PostGIS: unable to query the layer extent of table '";
if (! schema_.empty())
{
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_)
{
s << "SELECT ST_XMin(ext),ST_YMin(ext),ST_XMax(ext),ST_YMax(ext)"
<< " FROM (SELECT ST_Estimated_Extent('";
if (! schema_.empty())
{
s << mapnik::sql_utils::unquote_double(schema_) << "','";
}
s << mapnik::sql_utils::unquote_double(geometry_table_) << "','"
<< mapnik::sql_utils::unquote_double(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_.empty())
{
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";
}
}
shared_ptr<ResultSet> rs = conn->executeQuery(s.str());
if (rs->next() && ! rs->isNull(0))
{
double lox, loy, hix, hiy;
if (mapnik::util::string2double(rs->getValue(0), lox) &&
mapnik::util::string2double(rs->getValue(1), loy) &&
mapnik::util::string2double(rs->getValue(2), hix) &&
mapnik::util::string2double(rs->getValue(3), hiy))
{
extent_.init(lox, loy, hix, hiy);
extent_initialized_ = true;
}
else
{
MAPNIK_LOG_DEBUG(postgis) << "postgis_datasource: Could not determine extent from query: " << s.str();
}
}
rs->close();
}
}
return extent_;
}
boost::optional<mapnik::datasource::geometry_t> postgis_datasource::get_geometry_type() const
{
boost::optional<mapnik::datasource::geometry_t> result;
shared_ptr< Pool<Connection,ConnectionCreator> > pool = ConnectionManager::instance().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;
std::string g_type;
try
{
s << "SELECT lower(type) as type FROM "
<< GEOMETRY_COLUMNS <<" WHERE f_table_name='"
<< mapnik::sql_utils::unquote_double(geometry_table_)
<< "'";
if (! schema_.empty())
{
s << " AND f_table_schema='"
<< mapnik::sql_utils::unquote_double(schema_)
<< "'";
}
if (! geometry_field_.empty())
{
s << " AND f_geometry_column='"
<< mapnik::sql_utils::unquote_double(geometry_field_)
<< "'";
}
shared_ptr<ResultSet> rs = conn->executeQuery(s.str());
if (rs->next())
{
g_type = rs->getValue("type");
if (boost::algorithm::contains(g_type, "line"))
{
result.reset(mapnik::datasource::LineString);
return result;
}
else if (boost::algorithm::contains(g_type, "point"))
{
result.reset(mapnik::datasource::Point);
return result;
}
else if (boost::algorithm::contains(g_type, "polygon"))
{
result.reset(mapnik::datasource::Polygon);
return result;
}
else // geometry
{
result.reset(mapnik::datasource::Collection);
return result;
}
}
}
catch (mapnik::datasource_exception const& ex) {
// let this pass on query error and use the fallback below
MAPNIK_LOG_WARN(postgis) << "postgis_datasource: metadata query failed: " << ex.what();
}
// fallback to querying first several features
if (g_type.empty() && ! geometryColumn_.empty())
{
s.str("");
std::string prev_type("");
s << "SELECT ST_GeometryType(\""
<< geometryColumn_ << "\") AS geom"
<< " FROM " << populate_tokens(table_);
if (row_limit_ > 0 && row_limit_ < 5)
{
s << " LIMIT " << row_limit_;
}
else
{
s << " LIMIT 5";
}
shared_ptr<ResultSet> rs = conn->executeQuery(s.str());
while (rs->next() && ! rs->isNull(0))
{
const char* data = rs->getValue(0);
if (boost::algorithm::icontains(data, "line"))
{
g_type = "linestring";
result.reset(mapnik::datasource::LineString);
}
else if (boost::algorithm::icontains(data, "point"))
{
g_type = "point";
result.reset(mapnik::datasource::Point);
}
else if (boost::algorithm::icontains(data, "polygon"))
{
g_type = "polygon";
result.reset(mapnik::datasource::Polygon);
}
else // geometry
{
result.reset(mapnik::datasource::Collection);
return result;
}
if (! prev_type.empty() && g_type != prev_type)
{
result.reset(mapnik::datasource::Collection);
return result;
}
prev_type = g_type;
}
}
}
}
return result;
}
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