Revert "Add Chromium-style TimeDelta, Time and TimeTicks classes, and a new ElapsedTimer class."

src/time/time.h

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#ifndef V8_TIME_TIME_H_
-#define V8_TIME_TIME_H_
-
-#include <ctime>
-#include <limits>
-
-#include "allocation.h"
-
-// Forward declarations.
-extern "C" {
-struct _FILETIME;
-struct timeval;
-}
-
-namespace v8 {
-namespace internal {
-
-class Time;
-class TimeTicks;
-
-// -----------------------------------------------------------------------------
-// TimeDelta
-//
-// This class represents a duration of time, internally represented in
-// microseonds.
-
-class TimeDelta V8_FINAL BASE_EMBEDDED {
- public:
-  TimeDelta() : delta_(0) {}
-
-  // Converts units of time to TimeDeltas.
-  static TimeDelta FromDays(int days);
-  static TimeDelta FromHours(int hours);
-  static TimeDelta FromMinutes(int minutes);
-  static TimeDelta FromSeconds(int64_t seconds);
-  static TimeDelta FromMilliseconds(int64_t milliseconds);
-  static TimeDelta FromMicroseconds(int64_t microseconds) {
-    return TimeDelta(microseconds);
-  }
-  static TimeDelta FromNanoseconds(int64_t nanoseconds);
-
-  // Returns the time delta in some unit. The F versions return a floating
-  // point value, the "regular" versions return a rounded-down value.
-  //
-  // InMillisecondsRoundedUp() instead returns an integer that is rounded up
-  // to the next full millisecond.
-  int InDays() const;
-  int InHours() const;
-  int InMinutes() const;
-  double InSecondsF() const;
-  int64_t InSeconds() const;
-  double InMillisecondsF() const;
-  int64_t InMilliseconds() const;
-  int64_t InMillisecondsRoundedUp() const;
-  int64_t InMicroseconds() const { return delta_; }
-  int64_t InNanoseconds() const;
-
-  TimeDelta& operator=(const TimeDelta& other) {
-    delta_ = other.delta_;
-    return *this;
-  }
-
-  // Computations with other deltas.
-  TimeDelta operator+(const TimeDelta& other) const {
-    return TimeDelta(delta_ + other.delta_);
-  }
-  TimeDelta operator-(const TimeDelta& other) const {
-    return TimeDelta(delta_ - other.delta_);
-  }
-
-  TimeDelta& operator+=(const TimeDelta& other) {
-    delta_ += other.delta_;
-    return *this;
-  }
-  TimeDelta& operator-=(const TimeDelta& other) {
-    delta_ -= other.delta_;
-    return *this;
-  }
-  TimeDelta operator-() const {
-    return TimeDelta(-delta_);
-  }
-
-  double TimesOf(const TimeDelta& other) const {
-    return static_cast<double>(delta_) / static_cast<double>(other.delta_);
-  }
-  double PercentOf(const TimeDelta& other) const {
-    return TimesOf(other) * 100.0;
-  }
-
-  // Computations with ints, note that we only allow multiplicative operations
-  // with ints, and additive operations with other deltas.
-  TimeDelta operator*(int64_t a) const {
-    return TimeDelta(delta_ * a);
-  }
-  TimeDelta operator/(int64_t a) const {
-    return TimeDelta(delta_ / a);
-  }
-  TimeDelta& operator*=(int64_t a) {
-    delta_ *= a;
-    return *this;
-  }
-  TimeDelta& operator/=(int64_t a) {
-    delta_ /= a;
-    return *this;
-  }
-  int64_t operator/(const TimeDelta& other) const {
-    return delta_ / other.delta_;
-  }
-
-  // Comparison operators.
-  bool operator==(const TimeDelta& other) const {
-    return delta_ == other.delta_;
-  }
-  bool operator!=(const TimeDelta& other) const {
-    return delta_ != other.delta_;
-  }
-  bool operator<(const TimeDelta& other) const {
-    return delta_ < other.delta_;
-  }
-  bool operator<=(const TimeDelta& other) const {
-    return delta_ <= other.delta_;
-  }
-  bool operator>(const TimeDelta& other) const {
-    return delta_ > other.delta_;
-  }
-  bool operator>=(const TimeDelta& other) const {
-    return delta_ >= other.delta_;
-  }
-
- private:
-  // Constructs a delta given the duration in microseconds. This is private
-  // to avoid confusion by callers with an integer constructor. Use
-  // FromSeconds, FromMilliseconds, etc. instead.
-  explicit TimeDelta(int64_t delta) : delta_(delta) {}
-
-  // Delta in microseconds.
-  int64_t delta_;
-};
-
-
-// -----------------------------------------------------------------------------
-// Time
-//
-// This class represents an absolute point in time, internally represented as
-// microseconds (s/1,000,000) since 00:00:00 UTC, January 1, 1970.
-
-class Time V8_FINAL BASE_EMBEDDED {
- public:
-  static const int64_t kMillisecondsPerSecond = 1000;
-  static const int64_t kMicrosecondsPerMillisecond = 1000;
-  static const int64_t kMicrosecondsPerSecond = kMicrosecondsPerMillisecond *
-                                                kMillisecondsPerSecond;
-  static const int64_t kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60;
-  static const int64_t kMicrosecondsPerHour = kMicrosecondsPerMinute * 60;
-  static const int64_t kMicrosecondsPerDay = kMicrosecondsPerHour * 24;
-  static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7;
-  static const int64_t kNanosecondsPerMicrosecond = 1000;
-  static const int64_t kNanosecondsPerSecond = kNanosecondsPerMicrosecond *
-                                               kMicrosecondsPerSecond;
-
-  // Contains the NULL time. Use Time::Now() to get the current time.
-  Time() : us_(0) {}
-
-  // Returns true if the time object has not been initialized.
-  bool IsNull() const { return us_ == 0; }
-
-  // Returns true if the time object is the maximum time.
-  bool IsMax() const { return us_ == std::numeric_limits<int64_t>::max(); }
-
-  // Returns the current time. Watch out, the system might adjust its clock
-  // in which case time will actually go backwards. We don't guarantee that
-  // times are increasing, or that two calls to Now() won't be the same.
-  static Time Now();
-
-  // Returns the current time. Same as Now() except that this function always
-  // uses system time so that there are no discrepancies between the returned
-  // time and system time even on virtual environments including our test bot.
-  // For timing sensitive unittests, this function should be used.
-  static Time NowFromSystemTime();
-
-  // Returns the time for epoch in Unix-like system (Jan 1, 1970).
-  static Time UnixEpoch() { return Time(0); }
-
-  // Returns the maximum time, which should be greater than any reasonable time
-  // with which we might compare it.
-  static Time Max() { return Time(std::numeric_limits<int64_t>::max()); }
-
-  // Converts to/from POSIX time values.
-  static Time FromTimeval(struct timeval tv);
-  struct timeval ToTimeval() const;
-
-  // Converts to/from Windows file times.
-  static Time FromFiletime(struct _FILETIME ft);
-  struct _FILETIME ToFiletime() const;
-
-  // Converts to/from the Javascript convention for times, a number of
-  // milliseconds since the epoch:
-  static Time FromJsTime(double ms_since_epoch);
-  double ToJsTime() const;
-
-  Time& operator=(const Time& other) {
-    us_ = other.us_;
-    return *this;
-  }
-
-  // Compute the difference between two times.
-  TimeDelta operator-(const Time& other) const {
-    return TimeDelta::FromMicroseconds(us_ - other.us_);
-  }
-
-  // Modify by some time delta.
-  Time& operator+=(const TimeDelta& delta) {
-    us_ += delta.InMicroseconds();
-    return *this;
-  }
-  Time& operator-=(const TimeDelta& delta) {
-    us_ -= delta.InMicroseconds();
-    return *this;
-  }
-
-  // Return a new time modified by some delta.
-  Time operator+(const TimeDelta& delta) const {
-    return Time(us_ + delta.InMicroseconds());
-  }
-  Time operator-(const TimeDelta& delta) const {
-    return Time(us_ - delta.InMicroseconds());
-  }
-
-  // Comparison operators
-  bool operator==(const Time& other) const {
-    return us_ == other.us_;
-  }
-  bool operator!=(const Time& other) const {
-    return us_ != other.us_;
-  }
-  bool operator<(const Time& other) const {
-    return us_ < other.us_;
-  }
-  bool operator<=(const Time& other) const {
-    return us_ <= other.us_;
-  }
-  bool operator>(const Time& other) const {
-    return us_ > other.us_;
-  }
-  bool operator>=(const Time& other) const {
-    return us_ >= other.us_;
-  }
-
- private:
-  explicit Time(int64_t us) : us_(us) {}
-
-  // Time in microseconds in UTC.
-  int64_t us_;
-};
-
-inline Time operator+(const TimeDelta& delta, const Time& time) {
-  return time + delta;
-}
-
-
-// -----------------------------------------------------------------------------
-// TimeTicks
-//
-// This class represents an abstract time that is most of the time incrementing
-// for use in measuring time durations. It is internally represented in
-// microseconds.  It can not be converted to a human-readable time, but is
-// guaranteed not to decrease (if the user changes the computer clock,
-// Time::Now() may actually decrease or jump).  But note that TimeTicks may
-// "stand still", for example if the computer suspended.
-
-class TimeTicks V8_FINAL BASE_EMBEDDED {
- public:
-  TimeTicks() : ticks_(0) {}
-
-  // Platform-dependent tick count representing "right now."
-  // The resolution of this clock is ~1-15ms.  Resolution varies depending
-  // on hardware/operating system configuration.
-  // This method never returns a null TimeTicks.
-  static TimeTicks Now();
-
-  // Returns a platform-dependent high-resolution tick count. Implementation
-  // is hardware dependent and may or may not return sub-millisecond
-  // resolution.  THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND
-  // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED.
-  // This method never returns a null TimeTicks.
-  static TimeTicks HighResNow();
-
-  // Returns true if this object has not been initialized.
-  bool IsNull() const { return ticks_ == 0; }
-
-  TimeTicks& operator=(const TimeTicks other) {
-    ticks_ = other.ticks_;
-    return *this;
-  }
-
-  // Compute the difference between two times.
-  TimeDelta operator-(const TimeTicks other) const {
-    return TimeDelta::FromMicroseconds(ticks_ - other.ticks_);
-  }
-
-  // Modify by some time delta.
-  TimeTicks& operator+=(const TimeDelta& delta) {
-    ticks_ += delta.InMicroseconds();
-    return *this;
-  }
-  TimeTicks& operator-=(const TimeDelta& delta) {
-    ticks_ -= delta.InMicroseconds();
-    return *this;
-  }
-
-  // Return a new TimeTicks modified by some delta.
-  TimeTicks operator+(const TimeDelta& delta) const {
-    return TimeTicks(ticks_ + delta.InMicroseconds());
-  }
-  TimeTicks operator-(const TimeDelta& delta) const {
-    return TimeTicks(ticks_ - delta.InMicroseconds());
-  }
-
-  // Comparison operators
-  bool operator==(const TimeTicks& other) const {
-    return ticks_ == other.ticks_;
-  }
-  bool operator!=(const TimeTicks& other) const {
-    return ticks_ != other.ticks_;
-  }
-  bool operator<(const TimeTicks& other) const {
-    return ticks_ < other.ticks_;
-  }
-  bool operator<=(const TimeTicks& other) const {
-    return ticks_ <= other.ticks_;
-  }
-  bool operator>(const TimeTicks& other) const {
-    return ticks_ > other.ticks_;
-  }
-  bool operator>=(const TimeTicks& other) const {
-    return ticks_ >= other.ticks_;
-  }
-
- private:
-  // Please use Now() to create a new object. This is for internal use
-  // and testing. Ticks is in microseconds.
-  explicit TimeTicks(int64_t ticks) : ticks_(ticks) {}
-
-  // Tick count in microseconds.
-  int64_t ticks_;
-};
-
-inline TimeTicks operator+(const TimeDelta& delta, const TimeTicks& ticks) {
-  return ticks + delta;
-}
-
-} }  // namespace v8::internal
-
-#endif  // V8_TIME_TIME_H_