mapnik/plugins/input/csv/csv_index_featureset.cpp
2015-09-25 17:50:24 +01:00

104 lines
3.7 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
*
*****************************************************************************/
// mapnik
#include "csv_index_featureset.hpp"
#include <mapnik/debug.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/util/utf_conv_win.hpp>
#include <mapnik/util/trim.hpp>
#include <mapnik/util/spatial_index.hpp>
#include <mapnik/geometry.hpp>
// stl
#include <string>
#include <vector>
#include <deque>
#include <fstream>
csv_index_featureset::csv_index_featureset(std::string const& filename,
mapnik::filter_in_box const& filter,
detail::geometry_column_locator const& locator,
std::string const& separator,
std::vector<std::string> const& headers,
mapnik::context_ptr const& ctx)
: separator_(separator),
headers_(headers),
ctx_(ctx),
locator_(locator),
tr_("utf8"),
in_(filename.c_str(), std::ios::binary)
{
if (!in_) throw mapnik::datasource_exception("CSV Plugin: can't open file " + filename);
std::string indexname = filename + ".index";
std::ifstream index(indexname.c_str(), std::ios::binary);
if (!index) throw mapnik::datasource_exception("CSV Plugin: can't open index file " + indexname);
mapnik::util::spatial_index<value_type,
mapnik::filter_in_box,
std::ifstream>::query(filter, index, positions_);
std::sort(positions_.begin(), positions_.end(),
[](value_type const& lhs, value_type const& rhs) { return lhs.first < rhs.first;});
itr_ = positions_.begin();
}
csv_index_featureset::~csv_index_featureset() {}
mapnik::feature_ptr csv_index_featureset::parse_feature(std::string const& str)
{
auto values = csv_utils::parse_line(str, separator_);
auto geom = detail::extract_geometry(values, locator_);
if (!geom.is<mapnik::geometry::geometry_empty>())
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_, ++feature_id_));
feature->set_geometry(std::move(geom));
detail::process_properties(*feature, headers_, values, locator_, tr_);
return feature;
}
return mapnik::feature_ptr();
}
mapnik::feature_ptr csv_index_featureset::next()
{
/*
if (row_limit_ && count_ >= row_limit_)
{
return feature_ptr();
}
*/
while( itr_ != positions_.end())
{
auto pos = *itr_++;
in_.seekg(pos.first, std::ios::beg);
std::unique_ptr<char[]> buf(new char[pos.second]);
in_.read(buf.get(),pos.second);
std::string line(buf.get(), pos.second);
auto feature = parse_feature(line);
if (feature) return feature;
}
return mapnik::feature_ptr();
}