vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/chrono/io/duration_get.hpp

594 lines
21 KiB
C++

// (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_DURATION_GET_HPP
#define BOOST_CHRONO_IO_DURATION_GET_HPP
#include <boost/chrono/config.hpp>
#include <string>
#include <boost/type_traits/is_scalar.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/type_traits/is_signed.hpp>
#include <boost/mpl/if.hpp>
#include <boost/integer/common_factor_rt.hpp>
#include <boost/chrono/detail/scan_keyword.hpp>
#include <boost/chrono/detail/no_warning/signed_unsigned_cmp.hpp>
#include <boost/chrono/process_cpu_clocks.hpp>
#include <boost/assert.hpp>
#include <locale>
/**
* Duration formatting facet for input.
*/
namespace boost
{
namespace chrono
{
namespace detail
{
template <class Rep, bool = is_scalar<Rep>::value>
struct duration_io_intermediate
{
typedef Rep type;
};
template <class Rep>
struct duration_io_intermediate<Rep, true>
{
typedef typename mpl::if_c<is_floating_point<Rep>::value, long double, typename mpl::if_c<
is_signed<Rep>::value, long long, unsigned long long>::type>::type type;
};
template <class Rep>
struct duration_io_intermediate<process_times<Rep>, false>
{
typedef process_times<typename duration_io_intermediate<Rep>::type> type;
};
template <typename intermediate_type>
typename enable_if<is_integral<intermediate_type> , bool>::type reduce(intermediate_type& r,
unsigned long long& den, std::ios_base::iostate& err)
{
typedef typename common_type<intermediate_type, unsigned long long>::type common_type_t;
// Reduce r * num / den
common_type_t t = integer::gcd<common_type_t>(common_type_t(r), common_type_t(den));
r /= t;
den /= t;
if (den != 1)
{
// Conversion to Period is integral and not exact
err |= std::ios_base::failbit;
return false;
}
return true;
}
template <typename intermediate_type>
typename disable_if<is_integral<intermediate_type> , bool>::type reduce(intermediate_type&, unsigned long long&,
std::ios_base::iostate&)
{
return true;
}
}
/**
* @c duration_get is used to parse a character sequence, extracting
* components of a duration into a class duration.
* Each get member parses a format as produced by a corresponding format specifier to time_put<>::put.
* If the sequence being parsed matches the correct format, the
* corresponding member of the class duration argument are set to the
* value used to produce the sequence;
* otherwise either an error is reported or unspecified values are assigned.
* In other words, user confirmation is required for reliable parsing of
* user-entered durations, but machine-generated formats can be parsed
* reliably. This allows parsers to be aggressive about interpreting user
* variations on standard formats.
*
* If the end iterator is reached during parsing of the get() member
* function, the member sets std::ios_base::eofbit in err.
*/
template <class CharT, class InputIterator = std::istreambuf_iterator<CharT> >
class duration_get: public std::locale::facet
{
public:
/**
* Type of character the facet is instantiated on.
*/
typedef CharT char_type;
/**
* Type of character string passed to member functions.
*/
typedef std::basic_string<CharT> string_type;
/**
* Type of iterator used to scan the character buffer.
*/
typedef InputIterator iter_type;
/**
* Construct a @c duration_get facet.
* @param refs
* @Effects Construct a @c duration_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 duration_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, format.
* 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 = get_value(s, end, ios, err, r) when the conversion specification is 'v' and
* s = get_value(s, end, ios, err, rt) when the conversion specification is 'u'.
* 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.
*
* Once r and rt are retrieved,
* Returns: s
*/
template <typename Rep, typename Period>
iter_type get(iter_type s, iter_type end, std::ios_base& ios, std::ios_base::iostate& err,
duration<Rep, Period> &d, const char_type *pattern, const char_type *pat_end) const
{
if (std::has_facet<duration_units<CharT> >(ios.getloc()))
{
duration_units<CharT> const&facet = std::use_facet<duration_units<CharT> >(ios.getloc());
return get(facet, s, end, ios, err, d, pattern, pat_end);
}
else
{
duration_units_default<CharT> facet;
return get(facet, s, end, ios, err, d, pattern, pat_end);
}
}
template <typename Rep, typename Period>
iter_type get(duration_units<CharT> const&facet, iter_type s, iter_type end, std::ios_base& ios,
std::ios_base::iostate& err, duration<Rep, Period> &d, const char_type *pattern, const char_type *pat_end) const
{
typedef typename detail::duration_io_intermediate<Rep>::type intermediate_type;
intermediate_type r;
rt_ratio rt;
bool value_found = false, unit_found = false;
const std::ctype<char_type>& ct = std::use_facet<std::ctype<char_type> >(ios.getloc());
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 'v':
{
if (value_found)
{
err |= std::ios_base::failbit;
return s;
}
value_found = true;
s = get_value(s, end, ios, err, r);
if (err & (std::ios_base::badbit | std::ios_base::failbit))
{
return s;
}
break;
}
case 'u':
{
if (unit_found)
{
err |= std::ios_base::failbit;
return s;
}
unit_found = true;
s = get_unit(facet, s, end, ios, err, rt);
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;
return s;
}
}
unsigned long long num = rt.num;
unsigned long long den = rt.den;
// r should be multiplied by (num/den) / Period
// Reduce (num/den) / Period to lowest terms
unsigned long long gcd_n1_n2 = integer::gcd<unsigned long long>(num, Period::num);
unsigned long long gcd_d1_d2 = integer::gcd<unsigned long long>(den, Period::den);
num /= gcd_n1_n2;
den /= gcd_d1_d2;
unsigned long long n2 = Period::num / gcd_n1_n2;
unsigned long long d2 = Period::den / gcd_d1_d2;
if (num > (std::numeric_limits<unsigned long long>::max)() / d2 || den
> (std::numeric_limits<unsigned long long>::max)() / n2)
{
// (num/den) / Period overflows
err |= std::ios_base::failbit;
return s;
}
num *= d2;
den *= n2;
typedef typename common_type<intermediate_type, unsigned long long>::type common_type_t;
// num / den is now factor to multiply by r
if (!detail::reduce(r, den, err)) return s;
if (chrono::detail::gt(r, ( (duration_values<common_type_t>::max)() / num)))
{
// Conversion to Period overflowed
err |= std::ios_base::failbit;
return s;
}
common_type_t t = r * num;
t /= den;
if (t > duration_values<common_type_t>::zero())
{
Rep pt = t;
if ( (duration_values<Rep>::max)() < pt)
{
// Conversion to Period overflowed
err |= std::ios_base::failbit;
return s;
}
}
// Success! Store it.
r = Rep(t);
d = duration<Rep, Period> (r);
return s;
}
/**
*
* @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
* 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 <typename Rep, typename Period>
iter_type get(iter_type s, iter_type end, std::ios_base& ios, std::ios_base::iostate& err,
duration<Rep, Period> & d) const
{
if (std::has_facet<duration_units<CharT> >(ios.getloc()))
{
duration_units<CharT> const&facet = std::use_facet<duration_units<CharT> >(ios.getloc());
std::basic_string<CharT> str = facet.get_pattern();
return get(facet, s, end, ios, err, d, str.data(), str.data() + str.size());
}
else
{
duration_units_default<CharT> facet;
std::basic_string<CharT> str = facet.get_pattern();
return get(facet, s, end, ios, err, d, str.data(), str.data() + str.size());
}
}
/**
*
* @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 r a reference to the duration representation.
* @Effects As if
* @code
* return std::use_facet<std::num_get<cahr_type, iter_type> >(ios.getloc()).get(s, end, ios, err, r);
* @endcode
*
* @Returns An iterator pointing just beyond the last character that can be determined to be part of a valid name
*/
template <typename Rep>
iter_type get_value(iter_type s, iter_type end, std::ios_base& ios, std::ios_base::iostate& err, Rep& r) const
{
return std::use_facet<std::num_get<CharT, iter_type> >(ios.getloc()).get(s, end, ios, err, r);
}
template <typename Rep>
iter_type get_value(iter_type s, iter_type end, std::ios_base& ios, std::ios_base::iostate& err, process_times<Rep>& r) const
{
if (s == end) {
err |= std::ios_base::eofbit;
return s;
} else if (*s != '{') { // mandatory '{'
err |= std::ios_base::failbit;
return s;
}
++s;
s = std::use_facet<std::num_get<CharT, iter_type> >(ios.getloc()).get(s, end, ios, err, r.real);
if (s == end) {
err |= std::ios_base::eofbit;
return s;
} else if (*s != ';') { // mandatory ';'
err |= std::ios_base::failbit;
return s;
}
++s;
s = std::use_facet<std::num_get<CharT, iter_type> >(ios.getloc()).get(s, end, ios, err, r.user);
if (s == end) {
err |= std::ios_base::eofbit;
return s;
} else if (*s != ';') { // mandatory ';'
err |= std::ios_base::failbit;
return s;
}
++s;
s = std::use_facet<std::num_get<CharT, iter_type> >(ios.getloc()).get(s, end, ios, err, r.system);
if (s == end) {
err |= std::ios_base::eofbit;
return s;
} else if (*s != '}') { // mandatory '}'
err |= std::ios_base::failbit;
return s;
}
return s;
}
/**
*
* @param s start input stream iterator
* @param e end input stream iterator
* @param ios a reference to a ios_base
* @param err the ios_base state
* @param rt a reference to the duration run-time ratio.
* @Returns An iterator pointing just beyond the last character that can be determined to be part of a valid name
*/
iter_type get_unit(iter_type i, iter_type e, std::ios_base& is, std::ios_base::iostate& err, rt_ratio &rt) const
{
if (std::has_facet<duration_units<CharT> >(is.getloc()))
{
return get_unit(std::use_facet<duration_units<CharT> >(is.getloc()), i, e, is, err, rt);
}
else
{
duration_units_default<CharT> facet;
return get_unit(facet, i, e, is, err, rt);
}
}
iter_type get_unit(duration_units<CharT> const &facet, iter_type i, iter_type e, std::ios_base& is,
std::ios_base::iostate& err, rt_ratio &rt) const
{
if (*i == '[')
{
// parse [N/D]s or [N/D]second or [N/D]seconds format
++i;
i = std::use_facet<std::num_get<CharT, iter_type> >(is.getloc()).get(i, e, is, err, rt.num);
if ( (err & std::ios_base::failbit) != 0)
{
return i;
}
if (i == e)
{
err |= std::ios_base::failbit;
return i;
}
CharT x = *i++;
if (x != '/')
{
err |= std::ios_base::failbit;
return i;
}
i = std::use_facet<std::num_get<CharT, iter_type> >(is.getloc()).get(i, e, is, err, rt.den);
if ( (err & std::ios_base::failbit) != 0)
{
return i;
}
if (i == e)
{
err |= std::ios_base::failbit;
return i;
}
if (*i != ']')
{
err |= std::ios_base::failbit;
return i;
}
++i;
if (i == e)
{
err |= std::ios_base::failbit;
return i;
}
// parse s or second or seconds
return do_get_n_d_valid_unit(facet, i, e, is, err);
}
else
{
return do_get_valid_unit(facet, i, e, is, err, rt);
}
}
/**
* Unique identifier for this type of facet.
*/
static std::locale::id id;
/**
* @Effects Destroy the facet
*/
~duration_get()
{
}
protected:
/**
* Extracts the run-time ratio associated to the duration when it is given in prefix form.
*
* This is an extension point of this facet so that we can take in account other periods that can have a useful
* translation in other contexts, as e.g. days and weeks.
*
* @param facet the duration_units facet
* @param i start input stream iterator.
* @param e end input stream iterator.
* @param ios a reference to a ios_base.
* @param err the ios_base state.
* @return @c s
*/
iter_type do_get_n_d_valid_unit(duration_units<CharT> const &facet, iter_type i, iter_type e,
std::ios_base&, std::ios_base::iostate& err) const
{
// parse SI name, short or long
const string_type* units = facet.get_n_d_valid_units_start();
const string_type* units_end = facet.get_n_d_valid_units_end();
const string_type* k = chrono_detail::scan_keyword(i, e, units, units_end,
//~ std::use_facet<std::ctype<CharT> >(loc),
err);
if (err & (std::ios_base::badbit | std::ios_base::failbit))
{
return i;
}
if (!facet.match_n_d_valid_unit(k))
{
err |= std::ios_base::failbit;
}
return i;
}
/**
* Extracts the run-time ratio associated to the duration when it is given in prefix form.
*
* This is an extension point of this facet so that we can take in account other periods that can have a useful
* translation in other contexts, as e.g. days and weeks.
*
* @param facet the duration_units facet
* @param i start input stream iterator.
* @param e end input stream iterator.
* @param ios a reference to a ios_base.
* @param err the ios_base state.
* @param rt a reference to the duration run-time ratio.
* @Effects
* @Returns An iterator pointing just beyond the last character that can be determined to be part of a valid name.
*/
iter_type do_get_valid_unit(duration_units<CharT> const &facet, iter_type i, iter_type e,
std::ios_base&, std::ios_base::iostate& err, rt_ratio &rt) const
{
// parse SI name, short or long
const string_type* units = facet.get_valid_units_start();
const string_type* units_end = facet.get_valid_units_end();
err = std::ios_base::goodbit;
const string_type* k = chrono_detail::scan_keyword(i, e, units, units_end,
//~ std::use_facet<std::ctype<CharT> >(loc),
err);
if (err & (std::ios_base::badbit | std::ios_base::failbit))
{
return i;
}
if (!facet.match_valid_unit(k, rt))
{
err |= std::ios_base::failbit;
}
return i;
}
};
/**
* Unique identifier for this type of facet.
*/
template <class CharT, class InputIterator>
std::locale::id duration_get<CharT, InputIterator>::id;
} // chrono
}
// boost
#endif // header