| // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Time represents an absolute point in time, internally represented as |
| // microseconds (s/1,000,000) since a platform-dependent epoch. Each |
| // platform's epoch, along with other system-dependent clock interface |
| // routines, is defined in time_PLATFORM.cc. |
| // |
| // TimeDelta represents a duration of time, internally represented in |
| // microseconds. |
| // |
| // TimeTicks represents an abstract time that is always 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). |
| // |
| // These classes are represented as only a 64-bit value, so they can be |
| // efficiently passed by value. |
| |
| #ifndef BASE_TIME_H_ |
| #define BASE_TIME_H_ |
| |
| #include <time.h> |
| |
| #include "base/basictypes.h" |
| |
| #if defined(OS_WIN) |
| // For FILETIME in FromFileTime, until it moves to a new converter class. |
| // See TODO(iyengar) below. |
| #include <windows.h> |
| #endif |
| |
| namespace base { |
| |
| class Time; |
| class TimeTicks; |
| |
| // This unit test does a lot of manual time manipulation. |
| class PageLoadTrackerUnitTest; |
| |
| // TimeDelta ------------------------------------------------------------------ |
| |
| class TimeDelta { |
| public: |
| TimeDelta() : delta_(0) { |
| } |
| |
| // Converts units of time to TimeDeltas. |
| static TimeDelta FromDays(int64 days); |
| static TimeDelta FromHours(int64 hours); |
| static TimeDelta FromMinutes(int64 minutes); |
| static TimeDelta FromSeconds(int64 secs); |
| static TimeDelta FromMilliseconds(int64 ms); |
| static TimeDelta FromMicroseconds(int64 us); |
| |
| // Returns the internal numeric value of the TimeDelta object. Please don't |
| // use this and do arithmetic on it, as it is more error prone than using the |
| // provided operators. |
| int64 ToInternalValue() const { |
| return delta_; |
| } |
| |
| // Returns the time delta in some unit. The F versions return a floating |
| // point value, the "regular" versions return a rounded-down value. |
| int InDays() const; |
| int InHours() const; |
| int InMinutes() const; |
| double InSecondsF() const; |
| int64 InSeconds() const; |
| double InMillisecondsF() const; |
| int64 InMilliseconds() const; |
| int64 InMicroseconds() const; |
| |
| TimeDelta& operator=(TimeDelta other) { |
| delta_ = other.delta_; |
| return *this; |
| } |
| |
| // Computations with other deltas. |
| TimeDelta operator+(TimeDelta other) const { |
| return TimeDelta(delta_ + other.delta_); |
| } |
| TimeDelta operator-(TimeDelta other) const { |
| return TimeDelta(delta_ - other.delta_); |
| } |
| |
| TimeDelta& operator+=(TimeDelta other) { |
| delta_ += other.delta_; |
| return *this; |
| } |
| TimeDelta& operator-=(TimeDelta other) { |
| delta_ -= other.delta_; |
| return *this; |
| } |
| TimeDelta operator-() const { |
| return TimeDelta(-delta_); |
| } |
| |
| // Computations with ints, note that we only allow multiplicative operations |
| // with ints, and additive operations with other deltas. |
| TimeDelta operator*(int64 a) const { |
| return TimeDelta(delta_ * a); |
| } |
| TimeDelta operator/(int64 a) const { |
| return TimeDelta(delta_ / a); |
| } |
| TimeDelta& operator*=(int64 a) { |
| delta_ *= a; |
| return *this; |
| } |
| TimeDelta& operator/=(int64 a) { |
| delta_ /= a; |
| return *this; |
| } |
| int64 operator/(TimeDelta a) const { |
| return delta_ / a.delta_; |
| } |
| |
| // Defined below because it depends on the definition of the other classes. |
| Time operator+(Time t) const; |
| TimeTicks operator+(TimeTicks t) const; |
| |
| // Comparison operators. |
| bool operator==(TimeDelta other) const { |
| return delta_ == other.delta_; |
| } |
| bool operator!=(TimeDelta other) const { |
| return delta_ != other.delta_; |
| } |
| bool operator<(TimeDelta other) const { |
| return delta_ < other.delta_; |
| } |
| bool operator<=(TimeDelta other) const { |
| return delta_ <= other.delta_; |
| } |
| bool operator>(TimeDelta other) const { |
| return delta_ > other.delta_; |
| } |
| bool operator>=(TimeDelta other) const { |
| return delta_ >= other.delta_; |
| } |
| |
| private: |
| friend class Time; |
| friend class TimeTicks; |
| friend TimeDelta operator*(int64 a, TimeDelta td); |
| |
| // 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 delta_us) : delta_(delta_us) { |
| } |
| |
| // Delta in microseconds. |
| int64 delta_; |
| }; |
| |
| inline TimeDelta operator*(int64 a, TimeDelta td) { |
| return TimeDelta(a * td.delta_); |
| } |
| |
| // Time ----------------------------------------------------------------------- |
| |
| // Represents a wall clock time. |
| class Time { |
| public: |
| static const int64 kMillisecondsPerSecond = 1000; |
| static const int64 kMicrosecondsPerMillisecond = 1000; |
| static const int64 kMicrosecondsPerSecond = kMicrosecondsPerMillisecond * |
| kMillisecondsPerSecond; |
| static const int64 kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60; |
| static const int64 kMicrosecondsPerHour = kMicrosecondsPerMinute * 60; |
| static const int64 kMicrosecondsPerDay = kMicrosecondsPerHour * 24; |
| static const int64 kMicrosecondsPerWeek = kMicrosecondsPerDay * 7; |
| static const int64 kNanosecondsPerMicrosecond = 1000; |
| static const int64 kNanosecondsPerSecond = kNanosecondsPerMicrosecond * |
| kMicrosecondsPerSecond; |
| |
| // Represents an exploded time that can be formatted nicely. This is kind of |
| // like the Win32 SYSTEMTIME structure or the Unix "struct tm" with a few |
| // additions and changes to prevent errors. |
| struct Exploded { |
| int year; // Four digit year "2007" |
| int month; // 1-based month (values 1 = January, etc.) |
| int day_of_week; // 0-based day of week (0 = Sunday, etc.) |
| int day_of_month; // 1-based day of month (1-31) |
| int hour; // Hour within the current day (0-23) |
| int minute; // Minute within the current hour (0-59) |
| int second; // Second within the current minute (0-59 plus leap |
| // seconds which may take it up to 60). |
| int millisecond; // Milliseconds within the current second (0-999) |
| }; |
| |
| // Contains the NULL time. Use Time::Now() to get the current time. |
| explicit Time() : us_(0) { |
| } |
| |
| // Returns true if the time object has not been initialized. |
| bool is_null() const { |
| return us_ == 0; |
| } |
| |
| // 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(); |
| |
| // Converts to/from time_t in UTC and a Time class. |
| // TODO(brettw) this should be removed once everybody starts using the |Time| |
| // class. |
| static Time FromTimeT(time_t tt); |
| time_t ToTimeT() const; |
| |
| // Converts time to/from a double which is the number of seconds since epoch |
| // (Jan 1, 1970). Webkit uses this format to represent time. |
| static Time FromDoubleT(double dt); |
| double ToDoubleT() const; |
| |
| |
| #if defined(OS_WIN) |
| static Time FromFileTime(FILETIME ft); |
| FILETIME ToFileTime() const; |
| |
| // Monitor system power state and disable high resolution timer when we're |
| // on battery. See time_win.cc for more details. |
| static void StartSystemMonitorObserver(); |
| |
| // Enable high resolution timer unconditionally. Only for test code. |
| static void EnableHiResClockForTests(); |
| #endif |
| |
| // Converts an exploded structure representing either the local time or UTC |
| // into a Time class. |
| static Time FromUTCExploded(const Exploded& exploded) { |
| return FromExploded(false, exploded); |
| } |
| static Time FromLocalExploded(const Exploded& exploded) { |
| return FromExploded(true, exploded); |
| } |
| |
| // Converts an integer value representing Time to a class. This is used |
| // when deserializing a |Time| structure, using a value known to be |
| // compatible. It is not provided as a constructor because the integer type |
| // may be unclear from the perspective of a caller. |
| static Time FromInternalValue(int64 us) { |
| return Time(us); |
| } |
| |
| // Converts a string representation of time to a Time object. |
| // An example of a time string which is converted is as below:- |
| // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified |
| // in the input string, we assume local time. |
| // TODO(iyengar) Move the FromString/FromTimeT/ToTimeT/FromFileTime to |
| // a new time converter class. |
| static bool FromString(const wchar_t* time_string, Time* parsed_time); |
| |
| // For serializing, use FromInternalValue to reconstitute. Please don't use |
| // this and do arithmetic on it, as it is more error prone than using the |
| // provided operators. |
| int64 ToInternalValue() const { |
| return us_; |
| } |
| |
| // Fills the given exploded structure with either the local time or UTC from |
| // this time structure (containing UTC). |
| void UTCExplode(Exploded* exploded) const { |
| return Explode(false, exploded); |
| } |
| void LocalExplode(Exploded* exploded) const { |
| return Explode(true, exploded); |
| } |
| |
| // Rounds this time down to the nearest day in local time. It will represent |
| // midnight on that day. |
| Time LocalMidnight() const; |
| |
| Time& operator=(Time other) { |
| us_ = other.us_; |
| return *this; |
| } |
| |
| // Compute the difference between two times. |
| TimeDelta operator-(Time other) const { |
| return TimeDelta(us_ - other.us_); |
| } |
| |
| // Modify by some time delta. |
| Time& operator+=(TimeDelta delta) { |
| us_ += delta.delta_; |
| return *this; |
| } |
| Time& operator-=(TimeDelta delta) { |
| us_ -= delta.delta_; |
| return *this; |
| } |
| |
| // Return a new time modified by some delta. |
| Time operator+(TimeDelta delta) const { |
| return us_ + delta.delta_; |
| } |
| Time operator-(TimeDelta delta) const { |
| return us_ - delta.delta_; |
| } |
| |
| // Comparison operators |
| bool operator==(Time other) const { |
| return us_ == other.us_; |
| } |
| bool operator!=(Time other) const { |
| return us_ != other.us_; |
| } |
| bool operator<(Time other) const { |
| return us_ < other.us_; |
| } |
| bool operator<=(Time other) const { |
| return us_ <= other.us_; |
| } |
| bool operator>(Time other) const { |
| return us_ > other.us_; |
| } |
| bool operator>=(Time other) const { |
| return us_ >= other.us_; |
| } |
| |
| private: |
| friend class TimeDelta; |
| |
| // Explodes the given time to either local time |is_local = true| or UTC |
| // |is_local = false|. |
| void Explode(bool is_local, Exploded* exploded) const; |
| |
| // Unexplodes a given time assuming the source is either local time |
| // |is_local = true| or UTC |is_local = false|. |
| static Time FromExploded(bool is_local, const Exploded& exploded); |
| |
| Time(int64 us) : us_(us) { |
| } |
| |
| // The representation of Jan 1, 1970 UTC in microseconds since the |
| // platform-dependent epoch. |
| static const int64 kTimeTToMicrosecondsOffset; |
| |
| // Time in microseconds in UTC. |
| int64 us_; |
| }; |
| |
| inline Time TimeDelta::operator+(Time t) const { |
| return Time(t.us_ + delta_); |
| } |
| |
| // Inline the TimeDelta factory methods, for fast TimeDelta construction. |
| |
| // static |
| inline TimeDelta TimeDelta::FromDays(int64 days) { |
| return TimeDelta(days * Time::kMicrosecondsPerDay); |
| } |
| |
| // static |
| inline TimeDelta TimeDelta::FromHours(int64 hours) { |
| return TimeDelta(hours * Time::kMicrosecondsPerHour); |
| } |
| |
| // static |
| inline TimeDelta TimeDelta::FromMinutes(int64 minutes) { |
| return TimeDelta(minutes * Time::kMicrosecondsPerMinute); |
| } |
| |
| // static |
| inline TimeDelta TimeDelta::FromSeconds(int64 secs) { |
| return TimeDelta(secs * Time::kMicrosecondsPerSecond); |
| } |
| |
| // static |
| inline TimeDelta TimeDelta::FromMilliseconds(int64 ms) { |
| return TimeDelta(ms * Time::kMicrosecondsPerMillisecond); |
| } |
| |
| // static |
| inline TimeDelta TimeDelta::FromMicroseconds(int64 us) { |
| return TimeDelta(us); |
| } |
| |
| // TimeTicks ------------------------------------------------------------------ |
| |
| class TimeTicks { |
| 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. |
| 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. |
| static TimeTicks HighResNow(); |
| |
| // Returns true if this object has not been initialized. |
| bool is_null() const { |
| return ticks_ == 0; |
| } |
| |
| // Returns the internal numeric value of the TimeTicks object. |
| int64 ToInternalValue() const { |
| return ticks_; |
| } |
| |
| TimeTicks& operator=(TimeTicks other) { |
| ticks_ = other.ticks_; |
| return *this; |
| } |
| |
| // Compute the difference between two times. |
| TimeDelta operator-(TimeTicks other) const { |
| return TimeDelta(ticks_ - other.ticks_); |
| } |
| |
| // Modify by some time delta. |
| TimeTicks& operator+=(TimeDelta delta) { |
| ticks_ += delta.delta_; |
| return *this; |
| } |
| TimeTicks& operator-=(TimeDelta delta) { |
| ticks_ -= delta.delta_; |
| return *this; |
| } |
| |
| // Return a new TimeTicks modified by some delta. |
| TimeTicks operator+(TimeDelta delta) const { |
| return TimeTicks(ticks_ + delta.delta_); |
| } |
| TimeTicks operator-(TimeDelta delta) const { |
| return TimeTicks(ticks_ - delta.delta_); |
| } |
| |
| // Comparison operators |
| bool operator==(TimeTicks other) const { |
| return ticks_ == other.ticks_; |
| } |
| bool operator!=(TimeTicks other) const { |
| return ticks_ != other.ticks_; |
| } |
| bool operator<(TimeTicks other) const { |
| return ticks_ < other.ticks_; |
| } |
| bool operator<=(TimeTicks other) const { |
| return ticks_ <= other.ticks_; |
| } |
| bool operator>(TimeTicks other) const { |
| return ticks_ > other.ticks_; |
| } |
| bool operator>=(TimeTicks other) const { |
| return ticks_ >= other.ticks_; |
| } |
| |
| protected: |
| friend class TimeDelta; |
| friend class PageLoadTrackerUnitTest; |
| |
| // Please use Now() to create a new object. This is for internal use |
| // and testing. Ticks is in microseconds. |
| explicit TimeTicks(int64 ticks) : ticks_(ticks) { |
| } |
| |
| // Tick count in microseconds. |
| int64 ticks_; |
| |
| #if defined(OS_WIN) |
| typedef DWORD (*TickFunctionType)(void); |
| static TickFunctionType SetMockTickFunction(TickFunctionType ticker); |
| #endif |
| }; |
| |
| inline TimeTicks TimeDelta::operator+(TimeTicks t) const { |
| return TimeTicks(t.ticks_ + delta_); |
| } |
| |
| } // namespace base |
| |
| #endif // BASE_TIME_H_ |