mapnik/plugins/input/sqlite/sqlite_datasource.cpp

360 lines
10 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>
#include <boost/filesystem/operations.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;
std::string table_from_sql(std::string const& sql)
{
std::string table_name = boost::algorithm::to_lower_copy(sql);
boost::algorithm::replace_all(table_name,"\n"," ");
std::string::size_type idx = table_name.rfind("from");
if (idx!=std::string::npos)
{
idx=table_name.find_first_not_of(" ",idx+4);
if (idx != std::string::npos)
{
table_name=table_name.substr(idx);
}
idx=table_name.find_first_of(" ),");
if (idx != std::string::npos)
{
table_name = table_name.substr(0,idx);
}
}
return table_name;
}
sqlite_datasource::sqlite_datasource(parameters const& params, bool bind)
: 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","the_geom")),
key_field_(*params.get<std::string>("key_field","OGC_FID")),
row_offset_(*params_.get<int>("row_offset",0)),
row_limit_(*params_.get<int>("row_limit",0)),
desc_(*params.get<std::string>("type"), *params.get<std::string>("encoding","utf-8")),
format_(mapnik::wkbGeneric)
{
boost::optional<std::string> file = params.get<std::string>("file");
if (!file) throw datasource_exception("missing <file> parameter");
boost::optional<std::string> wkb = params.get<std::string>("wkb_format");
if (wkb)
{
if (*wkb == "spatialite")
format_ = mapnik::wkbSpatiaLite;
}
multiple_geometries_ = *params_.get<mapnik::boolean>("multiple_geometries",false);
use_spatial_index_ = *params_.get<mapnik::boolean>("use_spatial_index",true);
boost::optional<std::string> base = params.get<std::string>("base");
if (base)
dataset_name_ = *base + "/" + *file;
else
dataset_name_ = *file;
if (bind)
{
this->bind();
}
}
void sqlite_datasource::bind() const
{
if (is_bound_) return;
if (!boost::filesystem::exists(dataset_name_)) throw datasource_exception(dataset_name_ + " does not exist");
dataset_ = new sqlite_connection (dataset_name_);
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;
}
}
std::string table_name = table_from_sql(table_);
if (metadata_ != "" && ! extent_initialized_)
{
std::ostringstream s;
s << "select xmin, ymin, xmax, ymax from " << metadata_;
s << " where lower(f_table_name) = lower('" << table_name << "')";
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 lower(name) = lower('idx_" << table_name << "_" << geometry_field_ << "')";
boost::scoped_ptr<sqlite_resultset> rs (dataset_->execute_query (s.str()));
if (rs->is_valid () && rs->step_next())
{
use_spatial_index_ = rs->column_integer (0) == 1;
}
#ifdef MAPNIK_DEBUG
if (! use_spatial_index_)
clog << "cannot use the spatial index " << endl;
#endif
}
{
/*
XXX - This is problematic, if we do not have at least a row,
we cannot determine the right columns types and names
as all column_type are SQLITE_NULL
*/
std::string::size_type idx = table_.find(table_name);
std::ostringstream s;
s << "select * from (" << table_.substr(0,idx + table_name.length()) << ") 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;
}
}
}
}
is_bound_ = true;
}
sqlite_datasource::~sqlite_datasource()
{
if (is_bound_)
{
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
{
if (!is_bound_) bind();
return extent_;
}
layer_descriptor sqlite_datasource::get_descriptor() const
{
if (!is_bound_) bind();
return desc_;
}
featureset_ptr sqlite_datasource::features(query const& q) const
{
if (!is_bound_) bind();
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 ";
std::string query (table_);
if (use_spatial_index_)
{
std::string table_name = table_from_sql(query);
std::ostringstream spatial_sql;
spatial_sql << std::setprecision(16);
spatial_sql << " where rowid in (select pkid from idx_" << table_name << "_" << geometry_field_;
spatial_sql << " where xmax>=" << e.minx() << " and xmin<=" << e.maxx() ;
spatial_sql << " and ymax>=" << e.miny() << " and ymin<=" << e.maxy() << ")";
if (boost::algorithm::ifind_first(query,"where"))
{
boost::algorithm::ireplace_first(query, "where", spatial_sql.str() + " and");
}
else if (boost::algorithm::find_first(query,table_name))
{
boost::algorithm::ireplace_first(query, table_name , table_name + " " + spatial_sql.str());
}
}
s << query ;
if (row_limit_ > 0) {
s << " limit " << row_limit_;
}
if (row_offset_ > 0) {
s << " offset " << row_offset_;
}
#ifdef MAPNIK_DEBUG
std::cerr << 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(), format_, multiple_geometries_));
}
return featureset_ptr();
}
featureset_ptr sqlite_datasource::features_at_point(coord2d const& pt) const
{
if (!is_bound_) bind();
#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();
}