summaryrefslogtreecommitdiffstats
path: root/lib/asio/detail/chrono_time_traits.hpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/asio/detail/chrono_time_traits.hpp')
-rw-r--r--lib/asio/detail/chrono_time_traits.hpp190
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