boost/chrono/io/time_point_get.hpp
// (C) Copyright Howard Hinnant // (C) Copyright 2011 Vicente J. Botet Escriba // Use, modification and distribution are subject to the Boost Software License, // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt). // #ifndef BOOST_CHRONO_IO_TIME_POINT_GET_HPP #define BOOST_CHRONO_IO_TIME_POINT_GET_HPP #include <boost/chrono/config.hpp> #include <boost/chrono/detail/scan_keyword.hpp> #include <boost/chrono/io/time_point_units.hpp> #include <boost/chrono/io/duration_get.hpp> #include <boost/assert.hpp> #include <locale> #include <string> /** * Duration formatting facet for input. */ namespace boost { namespace chrono { template <class CharT, class InputIterator = std::istreambuf_iterator<CharT> > class time_point_get: public std::locale::facet { public: /** * Type of character the facet is instantiated on. */ typedef CharT char_type; /** * Type of iterator used to scan the character buffer. */ typedef InputIterator iter_type; /** * Construct a @c time_point_get facet. * @param refs * @Effects Construct a @c time_point_get facet. * If the @c refs argument is @c 0 then destruction of the object is * delegated to the @c locale, or locales, containing it. This allows * the user to ignore lifetime management issues. On the other had, * if @c refs is @c 1 then the object must be explicitly deleted; * the @c locale will not do so. In this case, the object can be * maintained across the lifetime of multiple locales. */ explicit time_point_get(size_t refs = 0) : std::locale::facet(refs) { } /** * @param s start input stream iterator * @param end end input stream iterator * @param ios a reference to a ios_base * @param err the ios_base state * @param d the duration * @param pattern begin of the formatting pattern * @param pat_end end of the formatting pattern * * Requires: [pattern,pat_end) shall be a valid range. * * Effects: The function starts by evaluating err = std::ios_base::goodbit. * It then enters a loop, reading zero or more characters from s at * each iteration. Unless otherwise specified below, the loop * terminates when the first of the following conditions holds: * - The expression pattern == pat_end evaluates to true. * - The expression err == std::ios_base::goodbit evaluates to false. * - The expression s == end evaluates to true, in which case the * function evaluates err = std::ios_base::eofbit | std::ios_base::failbit. * - The next element of pattern is equal to '%', followed by a conversion * specifier character, the functions @c get_duration or @c get_epoch are called depending on * whether the format is @c 'd' or @c 'e'. * If the number of elements in the range [pattern,pat_end) is not * sufficient to unambiguously determine whether the conversion * specification is complete and valid, the function evaluates * err = std::ios_base::failbit. Otherwise, the function evaluates * s = do_get(s, end, ios, err, d). If err == std::ios_base::goodbit holds after * the evaluation of the expression, the function increments pattern to * point just past the end of the conversion specification and continues * looping. * - The expression isspace(*pattern, ios.getloc()) evaluates to true, in * which case the function first increments pattern until * pattern == pat_end || !isspace(*pattern, ios.getloc()) evaluates to true, * then advances s until s == end || !isspace(*s, ios.getloc()) is true, * and finally resumes looping. * - The next character read from s matches the element pointed to by * pattern in a case-insensitive comparison, in which case the function * evaluates ++pattern, ++s and continues looping. Otherwise, the function * evaluates err = std::ios_base::failbit. * * Returns: s */ template <class Clock, class Duration> iter_type get(iter_type i, iter_type e, std::ios_base& is, std::ios_base::iostate& err, time_point<Clock, Duration> &tp, const char_type *pattern, const char_type *pat_end) const { if (std::has_facet<time_point_units<CharT> >(is.getloc())) { time_point_units<CharT> const &facet = std::use_facet<time_point_units<CharT> >(is.getloc()); return get(facet, i, e, is, err, tp, pattern, pat_end); } else { time_point_units_default<CharT> facet; return get(facet, i, e, is, err, tp, pattern, pat_end); } } template <class Clock, class Duration> iter_type get(time_point_units<CharT> const &facet, iter_type s, iter_type end, std::ios_base& ios, std::ios_base::iostate& err, time_point<Clock, Duration> &tp, const char_type *pattern, const char_type *pat_end) const { Duration d; bool duration_found = false, epoch_found = false; const std::ctype<char_type>& ct = std::use_facet<std::ctype<char_type> >(ios.getloc()); err = std::ios_base::goodbit; while (pattern != pat_end && err == std::ios_base::goodbit) { if (s == end) { err |= std::ios_base::eofbit; break; } if (ct.narrow(*pattern, 0) == '%') { if (++pattern == pat_end) { err |= std::ios_base::failbit; return s; } char cmd = ct.narrow(*pattern, 0); switch (cmd) { case 'd': { if (duration_found) { err |= std::ios_base::failbit; return s; } duration_found = true; s = get_duration(s, end, ios, err, d); if (err & (std::ios_base::badbit | std::ios_base::failbit)) { return s; } break; } case 'e': { if (epoch_found) { err |= std::ios_base::failbit; return s; } epoch_found = true; s = get_epoch<Clock> (facet, s, end, ios, err); if (err & (std::ios_base::badbit | std::ios_base::failbit)) { return s; } break; } default: BOOST_ASSERT(false && "Boost::Chrono internal error."); break; } ++pattern; } else if (ct.is(std::ctype_base::space, *pattern)) { for (++pattern; pattern != pat_end && ct.is(std::ctype_base::space, *pattern); ++pattern) ; for (; s != end && ct.is(std::ctype_base::space, *s); ++s) ; } else if (ct.toupper(*s) == ct.toupper(*pattern)) { ++s; ++pattern; } else { err |= std::ios_base::failbit; } } // Success! Store it. tp = time_point<Clock, Duration> (d); return s; } /** * * @param s an input stream iterator * @param ios a reference to a ios_base * @param d the duration * Stores the duration pattern from the @c duration_unit facet in let say @c str. Last as if * @code * return get(s, end, ios, err, ios, d, str.data(), str.data() + str.size()); * @codeend * @Returns An iterator pointing just beyond the last character that can be determined to be part of a valid name */ template <class Clock, class Duration> iter_type get(iter_type i, iter_type e, std::ios_base& is, std::ios_base::iostate& err, time_point<Clock, Duration> &tp) const { if (std::has_facet<time_point_units<CharT> >(is.getloc())) { time_point_units<CharT> const &facet = std::use_facet<time_point_units<CharT> >(is.getloc()); std::basic_string<CharT> str = facet.get_pattern(); return get(facet, i, e, is, err, tp, str.data(), str.data() + str.size()); } else { time_point_units_default<CharT> facet; std::basic_string<CharT> str = facet.get_pattern(); return get(facet, i, e, is, err, tp, str.data(), str.data() + str.size()); } } /** * As if * @code * return facet.get(s, end, ios, err, d); * @endcode * where @c facet is either the @c duration_get facet associated to the @c ios or an instance of the default @c duration_get facet. * * @Returns An iterator pointing just beyond the last character that can be determined to be part of a valid duration. */ template <typename Rep, typename Period> iter_type get_duration(iter_type i, iter_type e, std::ios_base& is, std::ios_base::iostate& err, duration<Rep, Period>& d) const { if (std::has_facet<duration_get<CharT> >(is.getloc())) { duration_get<CharT> const &facet = std::use_facet<duration_get<CharT> >(is.getloc()); return get_duration(facet, i, e, is, err, d); } else { duration_get<CharT> facet; return get_duration(facet, i, e, is, err, d); } } template <typename Rep, typename Period> iter_type get_duration(duration_get<CharT> const& facet, iter_type s, iter_type end, std::ios_base& ios, std::ios_base::iostate& err, duration<Rep, Period>& d) const { return facet.get(s, end, ios, err, d); } /** * * @Effects Let @c facet be the @c time_point_units facet associated to @c is or a new instance of the default @c time_point_units_default facet. * Let @c epoch be the epoch string associated to the Clock using this facet. * Scans @c i to match @c epoch or @c e is reached. * * If not match before the @c e is reached @c std::ios_base::failbit is set in @c err. * If @c e is reached @c std::ios_base::failbit is set in @c err. * * @Returns An iterator pointing just beyond the last character that can be determined to be part of a valid epoch. */ template <class Clock> iter_type get_epoch(iter_type i, iter_type e, std::ios_base& is, std::ios_base::iostate& err) const { if (std::has_facet<time_point_units<CharT> >(is.getloc())) { time_point_units<CharT> const &facet = std::use_facet<time_point_units<CharT> >(is.getloc()); return get_epoch<Clock>(facet, i, e, is, err); } else { time_point_units_default<CharT> facet; return get_epoch<Clock>(facet, i, e, is, err); } } template <class Clock> iter_type get_epoch(time_point_units<CharT> const &facet, iter_type i, iter_type e, std::ios_base&, std::ios_base::iostate& err) const { const std::basic_string<CharT> epoch = facet.template get_epoch<Clock> (); std::ptrdiff_t k = chrono_detail::scan_keyword(i, e, &epoch, &epoch + 1, //~ std::use_facet<std::ctype<CharT> >(ios.getloc()), err) - &epoch; if (k == 1) { err |= std::ios_base::failbit; return i; } return i; } /** * Unique identifier for this type of facet. */ static std::locale::id id; /** * @Effects Destroy the facet */ ~time_point_get() { } }; /** * Unique identifier for this type of facet. */ template <class CharT, class InputIterator> std::locale::id time_point_get<CharT, InputIterator>::id; } // chrono } // boost #endif // header