mapnik/utils/mapnik-index/process_csv_file.cpp
2016-02-25 11:58:38 +01:00

253 lines
9.2 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 "process_csv_file.hpp"
#include "../../plugins/input/csv/csv_getline.hpp"
#include "../../plugins/input/csv/csv_utils.hpp"
#include <mapnik/datasource.hpp>
#include <mapnik/geometry_envelope.hpp>
#include <mapnik/util/utf_conv_win.hpp>
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
#pragma GCC diagnostic push
#include <mapnik/warning_ignore.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/streams/bufferstream.hpp>
#pragma GCC diagnostic pop
#include <mapnik/mapped_memory_cache.hpp>
#endif
#include <fstream>
#include <iostream>
#include <sstream>
namespace mapnik { namespace detail {
template <typename T>
std::pair<bool,box2d<double>> process_csv_file(T & boxes, std::string const& filename, std::string const& manual_headers, char separator, char quote)
{
mapnik::box2d<double> extent;
#if defined(MAPNIK_MEMORY_MAPPED_FILE)
using file_source_type = boost::interprocess::ibufferstream;
file_source_type csv_file;
mapnik::mapped_region_ptr mapped_region;
boost::optional<mapnik::mapped_region_ptr> memory =
mapnik::mapped_memory_cache::instance().find(filename, true);
if (memory)
{
mapped_region = *memory;
csv_file.buffer(static_cast<char*>(mapped_region->get_address()),mapped_region->get_size());
}
else
{
std::clog << "Error : cannot mmap " << filename << std::endl;
return std::make_pair(false, extent);
}
#else
#if defined(_WINDOWS)
std::ifstream csv_file(mapnik::utf8_to_utf16(filename),std::ios_base::in | std::ios_base::binary);
#else
std::ifstream csv_file(filename.c_str(),std::ios_base::in | std::ios_base::binary);
#endif
if (!csv_file.is_open())
{
std::clog << "Error : cannot open " << filename << std::endl;
return std::make_pair(false, extent);
}
#endif
auto file_length = ::detail::file_length(csv_file);
// set back to start
csv_file.seekg(0, std::ios::beg);
char newline;
bool has_newline;
char detected_quote;
char detected_separator;
std::tie(newline, has_newline, detected_separator, detected_quote) = ::detail::autodect_csv_flavour(csv_file, file_length);
if (quote == 0) quote = detected_quote;
if (separator == 0) separator = detected_separator;
// set back to start
csv_file.seekg(0, std::ios::beg);
std::string csv_line;
csv_utils::getline_csv(csv_file, csv_line, newline, quote);
csv_file.seekg(0, std::ios::beg);
int line_number = 0;
::detail::geometry_column_locator locator;
std::vector<std::string> headers;
std::clog << "Parsing CSV using SEPARATOR=" << separator << " QUOTE=" << quote << std::endl;
if (!manual_headers.empty())
{
std::size_t index = 0;
headers = csv_utils::parse_line(manual_headers, separator, quote);
for (auto const& header : headers)
{
::detail::locate_geometry_column(header, index++, locator);
headers.push_back(header);
}
}
else // parse first line as headers
{
while (csv_utils::getline_csv(csv_file,csv_line,newline, quote))
{
try
{
headers = csv_utils::parse_line(csv_line, separator, quote);
// skip blank lines
if (headers.size() > 0 && headers[0].empty()) ++line_number;
else
{
std::size_t index = 0;
for (auto & header : headers)
{
mapnik::util::trim(header);
if (header.empty())
{
// create a placeholder for the empty header
std::ostringstream s;
s << "_" << index;
header = s.str();
}
else
{
::detail::locate_geometry_column(header, index, locator);
}
++index;
}
++line_number;
break;
}
}
catch (std::exception const& ex)
{
std::string s("CSV index: error parsing headers: ");
s += ex.what();
std::clog << s << std::endl;
return std::make_pair(false, extent);
}
}
}
std::size_t num_headers = headers.size();
if (!::detail::valid(locator, num_headers))
{
std::clog << "CSV index: could not detect column(s) with the name(s) of wkt, geojson, x/y, or "
<< "latitude/longitude in:\n"
<< csv_line
<< "\n - this is required for reading geometry data"
<< std::endl;
return std::make_pair(false, extent);
}
auto pos = csv_file.tellg();
// handle rare case of a single line of data and user-provided headers
// where a lack of a newline will mean that csv_utils::getline_csv returns false
bool is_first_row = false;
if (!has_newline)
{
csv_file.setstate(std::ios::failbit);
pos = 0;
if (!csv_line.empty())
{
is_first_row = true;
}
}
while (is_first_row || csv_utils::getline_csv(csv_file, csv_line, newline, quote))
{
++line_number;
auto record_offset = pos;
auto record_size = csv_line.length();
pos = csv_file.tellg();
is_first_row = false;
// skip blank lines
if (record_size <= 10)
{
std::string trimmed = csv_line;
boost::trim_if(trimmed, boost::algorithm::is_any_of("\",'\r\n "));
if (trimmed.empty())
{
std::clog << "CSV index: empty row encountered at line: " << line_number << std::endl;
continue;
}
}
try
{
auto const* start_line = csv_line.data();
auto const* end_line = start_line + csv_line.size();
auto values = csv_utils::parse_line(start_line, end_line, separator, quote, num_headers);
unsigned num_fields = values.size();
if (num_fields != num_headers)
{
std::ostringstream s;
s << "CSV Plugin: # of columns(" << num_fields << ")";
if (num_fields > num_headers)
{
s << " > ";
}
else
{
s << " < ";
}
s << "# of headers(" << num_headers << ") parsed";
throw mapnik::datasource_exception(s.str());
}
auto geom = ::detail::extract_geometry(values, locator);
if (!geom.is<mapnik::geometry::geometry_empty>())
{
auto box = mapnik::geometry::envelope(geom);
if (!extent.valid()) extent = box;
else extent.expand_to_include(box);
boxes.emplace_back(std::move(box), make_pair(record_offset, record_size));
}
else
{
std::ostringstream s;
s << "CSV Index: expected geometry column: could not parse row "
<< line_number << " "
<< values[locator.index] << "'";
throw mapnik::datasource_exception(s.str());
}
}
catch (mapnik::datasource_exception const& ex )
{
std::clog << ex.what() << " at line: " << line_number << std::endl;
}
catch (std::exception const& ex)
{
std::ostringstream s;
s << "CSV Index: unexpected error parsing line: " << line_number
<< " - found " << headers.size() << " with values like: " << csv_line << "\n"
<< " and got error like: " << ex.what();
std::clog << s.str() << std::endl;
}
}
return std::make_pair(true, extent);;
}
using box_type = mapnik::box2d<double>;
using item_type = std::pair<box_type, std::pair<std::size_t, std::size_t>>;
using boxes_type = std::vector<item_type>;
template std::pair<bool,box2d<double>> process_csv_file(boxes_type&, std::string const&, std::string const&, char, char);
}}