mapnik/plugins/input/postgis/postgis_datasource.cpp
2015-10-09 16:07:19 -07:00

1164 lines
42 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2015 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"
#include "asyncresultset.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>
#include <mapnik/value_types.hpp>
// boost
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Wunused-local-typedef"
#include <boost/algorithm/string.hpp>
#include <boost/tokenizer.hpp>
#include <boost/regex.hpp>
#pragma GCC diagnostic pop
// stl
#include <memory>
#include <string>
#include <algorithm>
#include <set>
#include <sstream>
#include <iomanip>
DATASOURCE_PLUGIN(postgis_datasource)
const double postgis_datasource::FMAX = std::numeric_limits<float>::max();
const std::string postgis_datasource::GEOMETRY_COLUMNS = "geometry_columns";
const std::string postgis_datasource::SPATIAL_REF_SYS = "spatial_ref_system";
using std::shared_ptr;
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<mapnik::value_integer>("cursor_size", 0)),
row_limit_(*params.get<mapnik::value_integer>("row_limit", 0)),
type_(datasource::Vector),
srid_(*params.get<mapnik::value_integer>("srid", 0)),
extent_initialized_(false),
simplify_geometries_(false),
desc_(postgis_datasource::name(), "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!"),
pool_max_size_(*params_.get<mapnik::value_integer>("max_size", 10)),
persist_connection_(*params.get<mapnik::boolean_type>("persist_connection", true)),
extent_from_subquery_(*params.get<mapnik::boolean_type>("extent_from_subquery", false)),
max_async_connections_(*params_.get<mapnik::value_integer>("max_async_connection", 1)),
asynchronous_request_(false),
// TODO - use for known tokens too: "(@\\w+|!\\w+!)"
pattern_(boost::regex("(@\\w+)",boost::regex::normal | boost::regbase::icase)),
// params below are for testing purposes only and may be removed at any time
intersect_min_scale_(*params.get<mapnik::value_integer>("intersect_min_scale", 0)),
intersect_max_scale_(*params.get<mapnik::value_integer>("intersect_max_scale", 0)),
key_field_as_attribute_(*params.get<mapnik::boolean_type>("key_field_as_attribute", true))
{
#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);
}
// NOTE: In multithread environment, pool_max_size_ should be
// max_async_connections_ * num_threads
if(max_async_connections_ > 1)
{
if(max_async_connections_ > pool_max_size_)
{
std::ostringstream err;
err << "PostGIS Plugin: Error: 'max_async_connections ("
<< max_async_connections_ << ") must be <= max_size(" << pool_max_size_ << ")";
throw mapnik::datasource_exception(err.str());
}
asynchronous_request_ = true;
}
boost::optional<mapnik::value_integer> initial_size = params.get<mapnik::value_integer>("initial_size", 1);
boost::optional<mapnik::boolean_type> autodetect_key_field = params.get<mapnik::boolean_type>("autodetect_key_field", false);
boost::optional<mapnik::boolean_type> estimate_extent = params.get<mapnik::boolean_type>("estimate_extent", false);
estimate_extent_ = estimate_extent && *estimate_extent;
boost::optional<mapnik::boolean_type> simplify_opt = params.get<mapnik::boolean_type>("simplify_geometries", false);
simplify_geometries_ = simplify_opt && *simplify_opt;
ConnectionManager::instance().registerPool(creator_, *initial_size, pool_max_size_);
CnxPool_ptr pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (!conn) return;
if (conn->isOK())
{
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);
}
// NOTE: geometry_table_ how should ideally be a table name, but
// there are known edge cases where this will break down and
// geometry_table_ may even be empty: https://github.com/mapnik/mapnik/issues/2718
// 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 (!geometry_table_.empty() && (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");
// only accept srid from geometry_tables if
// user has not provided as option
if (srid_ == 0)
{
const char* srid_c = rs->getValue("srid");
if (srid_c != nullptr)
{
int result = 0;
const char * end = srid_c + std::strlen(srid_c);
if (mapnik::util::string2int(srid_c, end, 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 'geometry_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)
{
std::ostringstream s;
s << "SELECT ST_SRID(\"" << geometryColumn_ << "\") AS srid FROM ";
if (!geometry_table_.empty())
{
if (!schema_.empty())
{
s << schema_ << '.';
}
s << geometry_table_;
}
else
{
s << populate_tokens(table_);
}
s << " 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 != nullptr)
{
int result = 0;
const char * end = srid_c + std::strlen(srid_c);
if (mapnik::util::string2int(srid_c, end, 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;
if (key_field_as_attribute_)
{
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();
}
// Close explicitly the connection so we can 'fork()' without sharing open connections
conn->close();
// Finally, add unique metadata to layer descriptor
mapnik::parameters & extra_params = desc_.get_extra_parameters();
// explicitly make copies of values due to https://github.com/mapnik/mapnik/issues/2651
extra_params["srid"] = srid_;
if (!key_field_.empty())
{
extra_params["key_field"] = key_field_;
}
}
}
postgis_datasource::~postgis_datasource()
{
if (! persist_connection_)
{
CnxPool_ptr pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
try {
shared_ptr<Connection> conn = pool->borrowObject();
if (conn)
{
conn->close();
}
} catch (mapnik::datasource_exception const& ex) {
// happens when borrowObject tries to
// create a new connection and fails.
// In turn, new connection would be needed
// when our broke and was thus no good to
// be borrowed
// See https://github.com/mapnik/mapnik/issues/2191
}
}
}
}
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_))
{
boost::algorithm::replace_all(populated_sql, pixel_width_token_, "0");
}
if (boost::algorithm::icontains(sql, pixel_height_token_))
{
boost::algorithm::replace_all(populated_sql, pixel_height_token_, "0");
}
std::string copy2 = populated_sql;
std::list<std::string> l;
boost::regex_split(std::back_inserter(l), copy2, pattern_);
if (!l.empty())
{
for (auto const & token: l)
{
boost::algorithm::replace_all(populated_sql, token, "null");
}
}
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,
mapnik::attributes const& vars) 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);
}
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;
}
populated_sql += s.str();
}
std::string copy2 = populated_sql;
std::list<std::string> l;
boost::regex_split(std::back_inserter(l), copy2, pattern_);
if (!l.empty())
{
for (auto const & token: l)
{
auto itr = vars.find(token.substr(1,std::string::npos));
if (itr != vars.end())
{
boost::algorithm::replace_all(populated_sql, token, itr->second.to_string());
}
else
{
boost::algorithm::replace_all(populated_sql, token, "null");
}
}
}
return populated_sql;
}
std::shared_ptr<IResultSet> postgis_datasource::get_resultset(std::shared_ptr<Connection> &conn, std::string const& sql, CnxPool_ptr const& pool, processor_context_ptr ctx) const
{
if (!ctx)
{
// ! asynchronous_request_
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 std::make_shared<CursorResultSet>(conn, cursor_name, cursor_fetch_size_);
}
else
{
// no cursor
return conn->executeQuery(sql, 1);
}
}
else
{ // asynchronous requests
std::shared_ptr<postgis_processor_context> pgis_ctxt = std::static_pointer_cast<postgis_processor_context>(ctx);
if (conn)
{
// lauch async req & create asyncresult with conn
conn->executeAsyncQuery(sql, 1);
return std::make_shared<AsyncResultSet>(pgis_ctxt, pool, conn, sql);
}
else
{
// create asyncresult with null connection
std::shared_ptr<AsyncResultSet> res = std::make_shared<AsyncResultSet>(pgis_ctxt, pool, conn, sql);
pgis_ctxt->add_request(res);
return res;
}
}
}
processor_context_ptr postgis_datasource::get_context(feature_style_context_map & ctx) const
{
if (!asynchronous_request_)
{
return processor_context_ptr();
}
std::string ds_name(name());
feature_style_context_map::const_iterator itr = ctx.find(ds_name);
if (itr != ctx.end())
{
return itr->second;
}
else
{
return ctx.emplace(ds_name,std::make_shared<postgis_processor_context>()).first->second;
}
}
featureset_ptr postgis_datasource::features(query const& q) const
{
// if the driver is in asynchronous mode, return the appropriate fetaures
if (asynchronous_request_ )
{
return features_with_context(q,std::make_shared<postgis_processor_context>());
}
else
{
return features_with_context(q,processor_context_ptr());
}
}
featureset_ptr postgis_datasource::features_with_context(query const& q,processor_context_ptr proc_ctx) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "postgis_datasource::features_with_context");
#endif
box2d<double> const& box = q.get_bbox();
double scale_denom = q.scale_denominator();
CnxPool_ptr pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn;
if ( asynchronous_request_ )
{
// limit use to num_async_request_ => if reached don't borrow the last connexion object
std::shared_ptr<postgis_processor_context> pgis_ctxt = std::static_pointer_cast<postgis_processor_context>(proc_ctx);
if ( pgis_ctxt->num_async_requests_ < max_async_connections_ )
{
conn = pool->borrowObject();
pgis_ctxt->num_async_requests_++;
}
}
else
{
// Always get a connection in synchronous mode
conn = pool->borrowObject();
if(!conn )
{
throw mapnik::datasource_exception("Postgis Plugin: Null connection");
}
}
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 / std::get<0>(q.resolution());
const double px_gh = 1.0 / std::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 = std::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_);
if (key_field_as_attribute_)
{
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, q.variables());
s << " FROM " << table_with_bbox;
if (row_limit_ > 0)
{
s << " LIMIT " << row_limit_;
}
std::shared_ptr<IResultSet> rs = get_resultset(conn, s.str(), pool, proc_ctx);
return std::make_shared<postgis_featureset>(rs, ctx, desc_.get_encoding(), !key_field_.empty(), key_field_as_attribute_);
}
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
CnxPool_ptr pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (!conn) return featureset_ptr();
if (conn->isOK())
{
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 = std::make_shared<mapnik::context_type>();
auto const& desc = desc_.get_descriptors();
if (!key_field_.empty())
{
mapnik::sql_utils::quote_attr(s, key_field_);
if (key_field_as_attribute_)
{
ctx->push(key_field_);
}
for (auto const& attr_info : desc)
{
std::string const& name = attr_info.get_name();
if (name != key_field_)
{
mapnik::sql_utils::quote_attr(s, name);
ctx->push(name);
}
}
}
else
{
for (auto const& attr_info : desc)
{
std::string const& name = attr_info.get_name();
mapnik::sql_utils::quote_attr(s, name);
ctx->push(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, mapnik::attributes());
s << " FROM " << table_with_bbox;
if (row_limit_ > 0)
{
s << " LIMIT " << row_limit_;
}
std::shared_ptr<IResultSet> rs = get_resultset(conn, s.str(), pool);
return std::make_shared<postgis_featureset>(rs, ctx, desc_.get_encoding(), !key_field_.empty(), key_field_as_attribute_);
}
}
return featureset_ptr();
}
box2d<double> postgis_datasource::envelope() const
{
if (extent_initialized_)
{
return extent_;
}
CnxPool_ptr pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (!conn) return extent_;
if (conn->isOK())
{
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;
CnxPool_ptr pool = ConnectionManager::instance().getPool(creator_.id());
if (pool)
{
shared_ptr<Connection> conn = pool->borrowObject();
if (!conn) return result;
if (conn->isOK())
{
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_geometry_t::LineString);
return result;
}
else if (boost::algorithm::contains(g_type, "point"))
{
result.reset(mapnik::datasource_geometry_t::Point);
return result;
}
else if (boost::algorithm::contains(g_type, "polygon"))
{
result.reset(mapnik::datasource_geometry_t::Polygon);
return result;
}
else // geometry
{
g_type = "";
}
}
}
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_geometry_t::LineString);
}
else if (boost::algorithm::icontains(data, "point"))
{
g_type = "point";
result.reset(mapnik::datasource_geometry_t::Point);
}
else if (boost::algorithm::icontains(data, "polygon"))
{
g_type = "polygon";
result.reset(mapnik::datasource_geometry_t::Polygon);
}
else // geometry
{
result.reset(mapnik::datasource_geometry_t::Collection);
return result;
}
if (! prev_type.empty() && g_type != prev_type)
{
result.reset(mapnik::datasource_geometry_t::Collection);
return result;
}
prev_type = g_type;
}
}
}
}
return result;
}