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Diffstat (limited to 'lib/asio/detail/chrono_time_traits.hpp')
-rw-r--r-- | lib/asio/detail/chrono_time_traits.hpp | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/lib/asio/detail/chrono_time_traits.hpp b/lib/asio/detail/chrono_time_traits.hpp new file mode 100644 index 0000000..d1528f7 --- /dev/null +++ b/lib/asio/detail/chrono_time_traits.hpp @@ -0,0 +1,190 @@ +// +// detail/chrono_time_traits.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under 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 ASIO_DETAIL_CHRONO_TIME_TRAITS_HPP +#define ASIO_DETAIL_CHRONO_TIME_TRAITS_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/cstdint.hpp" + +#include "asio/detail/push_options.hpp" + +namespace asio { +namespace detail { + +// Helper template to compute the greatest common divisor. +template <int64_t v1, int64_t v2> +struct gcd { enum { value = gcd<v2, v1 % v2>::value }; }; + +template <int64_t v1> +struct gcd<v1, 0> { enum { value = v1 }; }; + +// Adapts std::chrono clocks for use with a deadline timer. +template <typename Clock, typename WaitTraits> +struct chrono_time_traits +{ + // The clock type. + typedef Clock clock_type; + + // The duration type of the clock. + typedef typename clock_type::duration duration_type; + + // The time point type of the clock. + typedef typename clock_type::time_point time_type; + + // The period of the clock. + typedef typename duration_type::period period_type; + + // Get the current time. + static time_type now() + { + return clock_type::now(); + } + + // Add a duration to a time. + static time_type add(const time_type& t, const duration_type& d) + { + const time_type epoch; + if (t >= epoch) + { + if ((time_type::max)() - t < d) + return (time_type::max)(); + } + else // t < epoch + { + if (-(t - (time_type::min)()) > d) + return (time_type::min)(); + } + + return t + d; + } + + // Subtract one time from another. + static duration_type subtract(const time_type& t1, const time_type& t2) + { + const time_type epoch; + if (t1 >= epoch) + { + if (t2 >= epoch) + { + return t1 - t2; + } + else if (t2 == (time_type::min)()) + { + return (duration_type::max)(); + } + else if ((time_type::max)() - t1 < epoch - t2) + { + return (duration_type::max)(); + } + else + { + return t1 - t2; + } + } + else // t1 < epoch + { + if (t2 < epoch) + { + return t1 - t2; + } + else if (t1 == (time_type::min)()) + { + return (duration_type::min)(); + } + else if ((time_type::max)() - t2 < epoch - t1) + { + return (duration_type::min)(); + } + else + { + return -(t2 - t1); + } + } + } + + // Test whether one time is less than another. + static bool less_than(const time_type& t1, const time_type& t2) + { + return t1 < t2; + } + + // Implement just enough of the posix_time::time_duration interface to supply + // what the timer_queue requires. + class posix_time_duration + { + public: + explicit posix_time_duration(const duration_type& d) + : d_(d) + { + } + + int64_t ticks() const + { + return d_.count(); + } + + int64_t total_seconds() const + { + return duration_cast<1, 1>(); + } + + int64_t total_milliseconds() const + { + return duration_cast<1, 1000>(); + } + + int64_t total_microseconds() const + { + return duration_cast<1, 1000000>(); + } + + private: + template <int64_t Num, int64_t Den> + int64_t duration_cast() const + { + const int64_t num1 = period_type::num / gcd<period_type::num, Num>::value; + const int64_t num2 = Num / gcd<period_type::num, Num>::value; + + const int64_t den1 = period_type::den / gcd<period_type::den, Den>::value; + const int64_t den2 = Den / gcd<period_type::den, Den>::value; + + const int64_t num = num1 * den2; + const int64_t den = num2 * den1; + + if (num == 1 && den == 1) + return ticks(); + else if (num != 1 && den == 1) + return ticks() * num; + else if (num == 1 && period_type::den != 1) + return ticks() / den; + else + return ticks() * num / den; + } + + duration_type d_; + }; + + // Convert to POSIX duration type. + static posix_time_duration to_posix_duration(const duration_type& d) + { + return posix_time_duration(WaitTraits::to_wait_duration(d)); + } +}; + +} // namespace detail +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#endif // ASIO_DETAIL_CHRONO_TIME_TRAITS_HPP |