comparison win32-mingw/include/kj/time.h @ 135:38d1c0e7850b

Headers for KJ/Capnp Win32

+// Copyright (c) 2014 Google Inc. (contributed by Remy Blank <[e-mail]>)
+// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
+// Licensed under the MIT License:
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#ifndef KJ_TIME_H_
+#define KJ_TIME_H_
+
+#if defined(__GNUC__) && !KJ_HEADER_WARNINGS
+#pragma GCC system_header
+#endif
+
+#include "async.h"
+#include "units.h"
+#include <inttypes.h>
+
+namespace kj {
+namespace _ {  // private
+
+class NanosecondLabel;
+class TimeLabel;
+class DateLabel;
+
+}  // namespace _ (private)
+
+using Duration = Quantity<int64_t, _::NanosecondLabel>;
+// A time value, in microseconds.
+
+constexpr Duration NANOSECONDS = unit<Duration>();
+constexpr Duration MICROSECONDS = 1000 * NANOSECONDS;
+constexpr Duration MILLISECONDS = 1000 * MICROSECONDS;
+constexpr Duration SECONDS = 1000 * MILLISECONDS;
+constexpr Duration MINUTES = 60 * SECONDS;
+constexpr Duration HOURS = 60 * MINUTES;
+constexpr Duration DAYS = 24 * HOURS;
+
+using TimePoint = Absolute<Duration, _::TimeLabel>;
+// An absolute time measured by some particular instance of `Timer`.  `Time`s from two different
+// `Timer`s may be measured from different origins and so are not necessarily compatible.
+
+using Date = Absolute<Duration, _::DateLabel>;
+// A point in real-world time, measured relative to the Unix epoch (Jan 1, 1970 00:00:00 UTC).
+
+constexpr Date UNIX_EPOCH = origin<Date>();
+// The `Date` representing Jan 1, 1970 00:00:00 UTC.
+
+class Timer {
+  // Interface to time and timer functionality.
+  //
+  // Each `Timer` may have a different origin, and some `Timer`s may in fact tick at a different
+  // rate than real time (e.g. a `Timer` could represent CPU time consumed by a thread).  However,
+  // all `Timer`s are monotonic: time will never appear to move backwards, even if the calendar
+  // date as tracked by the system is manually modified.
+
+public:
+  virtual TimePoint now() = 0;
+  // Returns the current value of a clock that moves steadily forward, independent of any
+  // changes in the wall clock. The value is updated every time the event loop waits,
+  // and is constant in-between waits.
+
+  virtual Promise<void> atTime(TimePoint time) = 0;
+  // Returns a promise that returns as soon as now() >= time.
+
+  virtual Promise<void> afterDelay(Duration delay) = 0;
+  // Equivalent to atTime(now() + delay).
+
+  template <typename T>
+  Promise<T> timeoutAt(TimePoint time, Promise<T>&& promise) KJ_WARN_UNUSED_RESULT;
+  // Return a promise equivalent to `promise` but which throws an exception (and cancels the
+  // original promise) if it hasn't completed by `time`. The thrown exception is of type
+  // "OVERLOADED".
+
+  template <typename T>
+  Promise<T> timeoutAfter(Duration delay, Promise<T>&& promise) KJ_WARN_UNUSED_RESULT;
+  // Return a promise equivalent to `promise` but which throws an exception (and cancels the
+  // original promise) if it hasn't completed after `delay` from now. The thrown exception is of
+  // type "OVERLOADED".
+
+private:
+  static kj::Exception makeTimeoutException();
+};
+
+// =======================================================================================
+// inline implementation details
+
+template <typename T>
+Promise<T> Timer::timeoutAt(TimePoint time, Promise<T>&& promise) {
+  return promise.exclusiveJoin(atTime(time).then([]() -> kj::Promise<T> {
+    return makeTimeoutException();
+  }));
+}
+
+template <typename T>
+Promise<T> Timer::timeoutAfter(Duration delay, Promise<T>&& promise) {
+  return promise.exclusiveJoin(afterDelay(delay).then([]() -> kj::Promise<T> {
+    return makeTimeoutException();
+  }));
+}
+
+}  // namespace kj
+
+#endif  // KJ_TIME_H_