osrm-backend/util/xml_renderer.hpp
Daniel J. Hofmann f9f0ffb64d Remove hand written conversion code and replace with stdlib features.
With C++11 the stdlib gains:

- `std::stoi` function family to convert from `std::string` to integral type

- `std::to_string` to convert from number types to `std::string`

The only reason for hand-writing the conversion code therefore is
performance. I benchmarked an `osrm-extract` with the hand-written code
against one with the stdlib conversion features and could not find any
significant difference (we switch back and forth between C++ and Lua,
shaving off a few us in conversion doesn't gain us much).

Formatting arithmetic types in the default format with given precision
requires streams, but is doable in a few lines of idiomatic stdlib code.

For this, there is now the following function template available:

    template <Arithmetic T, int Precision = 6>
    inline std::string to_string_with_precision(const T);

that requires integral or floating point types and returns a formatted
string in the defaukt format with the given precision applied.

In addition this completely rips out Boost.Spirit from the `casts.hpp`
header, resulting in faster compile times.

Boom!

References:

- http://en.cppreference.com/w/cpp/string/basic_string/stol
- http://en.cppreference.com/w/cpp/string/basic_string/to_string
- http://www.kumobius.com/2013/08/c-string-to-int/
2015-09-29 16:15:54 +02:00

138 lines
4.4 KiB
C++

/*
Copyright (c) 2014, Project OSRM contributors
All rights reserved.
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list
of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this
list of conditions and the following disclaimer in the documentation and/or
other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef XML_RENDERER_HPP
#define XML_RENDERER_HPP
#include "cast.hpp"
#include <osrm/json_container.hpp>
namespace osrm
{
namespace json
{
struct XMLToArrayRenderer : mapbox::util::static_visitor<>
{
explicit XMLToArrayRenderer(std::vector<char> &_out) : out(_out) {}
void operator()(const String &string) const
{
out.push_back('\"');
out.insert(out.end(), string.value.begin(), string.value.end());
out.push_back('\"');
}
void operator()(const Number &number) const
{
const std::string number_string = cast::to_string_with_precision(number.value);
out.insert(out.end(), number_string.begin(), number_string.end());
}
void operator()(const Object &object) const
{
for (auto &&each : object.values)
{
if (each.first.at(0) != '_')
{
out.push_back('<');
out.insert(out.end(), each.first.begin(), each.first.end());
}
else
{
out.push_back(' ');
out.insert(out.end(), ++(each).first.begin(), each.first.end());
out.push_back('=');
}
mapbox::util::apply_visitor(XMLToArrayRenderer(out), each.second);
if (each.first.at(0) != '_')
{
out.push_back('/');
out.push_back('>');
}
}
}
void operator()(const Array &array) const
{
for (auto &&each : array.values)
{
mapbox::util::apply_visitor(XMLToArrayRenderer(out), each);
}
}
void operator()(const True &) const
{
const std::string temp("true");
out.insert(out.end(), temp.begin(), temp.end());
}
void operator()(const False &) const
{
const std::string temp("false");
out.insert(out.end(), temp.begin(), temp.end());
}
void operator()(const Null &) const
{
const std::string temp("null");
out.insert(out.end(), temp.begin(), temp.end());
}
private:
std::vector<char> &out;
};
template <class JSONObject> inline void xml_render(std::vector<char> &out, const JSONObject &object)
{
Value value = object;
mapbox::util::apply_visitor(XMLToArrayRenderer(out), value);
}
template <class JSONObject> inline void gpx_render(std::vector<char> &out, const JSONObject &object)
{
// add header
const std::string header{
"<?xml version=\"1.0\" encoding=\"UTF-8\"?><gpx creator=\"OSRM Routing Engine\""
" version=\"1.1\" xmlns=\"http://www.topografix.com/GPX/1/1\" xmlns:xsi=\"http:"
"//www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://www.topogr"
"afix.com/GPX/1/1 gpx.xsd\"><metadata><copyright author=\"Project OSRM\"><lice"
"nse>Data (c) OpenStreetMap contributors (ODbL)</license></copyright></metadat"
"a><rte>"};
out.insert(out.end(), header.begin(), header.end());
xml_render(out, object);
const std::string footer{"</rte></gpx>"};
out.insert(out.end(), footer.begin(), footer.end());
}
} // namespace json
} // namespace osrm
#endif // XML_RENDERER_HPP