michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: // Time represents an absolute point in time, internally represented as
michael@0: // microseconds (s/1,000,000) since a platform-dependent epoch.  Each
michael@0: // platform's epoch, along with other system-dependent clock interface
michael@0: // routines, is defined in time_PLATFORM.cc.
michael@0: //
michael@0: // TimeDelta represents a duration of time, internally represented in
michael@0: // microseconds.
michael@0: //
michael@0: // TimeTicks represents an abstract time that is always incrementing for use
michael@0: // in measuring time durations. It is internally represented in microseconds.
michael@0: // It can not be converted to a human-readable time, but is guaranteed not to
michael@0: // decrease (if the user changes the computer clock, Time::Now() may actually
michael@0: // decrease or jump).
michael@0: //
michael@0: // These classes are represented as only a 64-bit value, so they can be
michael@0: // efficiently passed by value.
michael@0: 
michael@0: #ifndef BASE_TIME_H_
michael@0: #define BASE_TIME_H_
michael@0: 
michael@0: #include <time.h>
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: // For FILETIME in FromFileTime, until it moves to a new converter class.
michael@0: // See TODO(iyengar) below.
michael@0: #include <windows.h>
michael@0: #endif
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: class Time;
michael@0: class TimeTicks;
michael@0: 
michael@0: // This unit test does a lot of manual time manipulation.
michael@0: class PageLoadTrackerUnitTest;
michael@0: 
michael@0: // TimeDelta ------------------------------------------------------------------
michael@0: 
michael@0: class TimeDelta {
michael@0:  public:
michael@0:   TimeDelta() : delta_(0) {
michael@0:   }
michael@0: 
michael@0:   // Converts units of time to TimeDeltas.
michael@0:   static TimeDelta FromDays(int64_t days);
michael@0:   static TimeDelta FromHours(int64_t hours);
michael@0:   static TimeDelta FromMinutes(int64_t minutes);
michael@0:   static TimeDelta FromSeconds(int64_t secs);
michael@0:   static TimeDelta FromMilliseconds(int64_t ms);
michael@0:   static TimeDelta FromMicroseconds(int64_t us);
michael@0: 
michael@0:   // Returns the internal numeric value of the TimeDelta object. Please don't
michael@0:   // use this and do arithmetic on it, as it is more error prone than using the
michael@0:   // provided operators.
michael@0:   int64_t ToInternalValue() const {
michael@0:     return delta_;
michael@0:   }
michael@0: 
michael@0:   // Returns the time delta in some unit. The F versions return a floating
michael@0:   // point value, the "regular" versions return a rounded-down value.
michael@0:   int InDays() const;
michael@0:   int InHours() const;
michael@0:   int InMinutes() const;
michael@0:   double InSecondsF() const;
michael@0:   int64_t InSeconds() const;
michael@0:   double InMillisecondsF() const;
michael@0:   int64_t InMilliseconds() const;
michael@0:   int64_t InMicroseconds() const;
michael@0: 
michael@0:   TimeDelta& operator=(TimeDelta other) {
michael@0:     delta_ = other.delta_;
michael@0:     return *this;
michael@0:   }
michael@0: 
michael@0:   // Computations with other deltas.
michael@0:   TimeDelta operator+(TimeDelta other) const {
michael@0:     return TimeDelta(delta_ + other.delta_);
michael@0:   }
michael@0:   TimeDelta operator-(TimeDelta other) const {
michael@0:     return TimeDelta(delta_ - other.delta_);
michael@0:   }
michael@0: 
michael@0:   TimeDelta& operator+=(TimeDelta other) {
michael@0:     delta_ += other.delta_;
michael@0:     return *this;
michael@0:   }
michael@0:   TimeDelta& operator-=(TimeDelta other) {
michael@0:     delta_ -= other.delta_;
michael@0:     return *this;
michael@0:   }
michael@0:   TimeDelta operator-() const {
michael@0:     return TimeDelta(-delta_);
michael@0:   }
michael@0: 
michael@0:   // Computations with ints, note that we only allow multiplicative operations
michael@0:   // with ints, and additive operations with other deltas.
michael@0:   TimeDelta operator*(int64_t a) const {
michael@0:     return TimeDelta(delta_ * a);
michael@0:   }
michael@0:   TimeDelta operator/(int64_t a) const {
michael@0:     return TimeDelta(delta_ / a);
michael@0:   }
michael@0:   TimeDelta& operator*=(int64_t a) {
michael@0:     delta_ *= a;
michael@0:     return *this;
michael@0:   }
michael@0:   TimeDelta& operator/=(int64_t a) {
michael@0:     delta_ /= a;
michael@0:     return *this;
michael@0:   }
michael@0:   int64_t operator/(TimeDelta a) const {
michael@0:     return delta_ / a.delta_;
michael@0:   }
michael@0: 
michael@0:   // Defined below because it depends on the definition of the other classes.
michael@0:   Time operator+(Time t) const;
michael@0:   TimeTicks operator+(TimeTicks t) const;
michael@0: 
michael@0:   // Comparison operators.
michael@0:   bool operator==(TimeDelta other) const {
michael@0:     return delta_ == other.delta_;
michael@0:   }
michael@0:   bool operator!=(TimeDelta other) const {
michael@0:     return delta_ != other.delta_;
michael@0:   }
michael@0:   bool operator<(TimeDelta other) const {
michael@0:     return delta_ < other.delta_;
michael@0:   }
michael@0:   bool operator<=(TimeDelta other) const {
michael@0:     return delta_ <= other.delta_;
michael@0:   }
michael@0:   bool operator>(TimeDelta other) const {
michael@0:     return delta_ > other.delta_;
michael@0:   }
michael@0:   bool operator>=(TimeDelta other) const {
michael@0:     return delta_ >= other.delta_;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   friend class Time;
michael@0:   friend class TimeTicks;
michael@0:   friend TimeDelta operator*(int64_t a, TimeDelta td);
michael@0: 
michael@0:   // Constructs a delta given the duration in microseconds. This is private
michael@0:   // to avoid confusion by callers with an integer constructor. Use
michael@0:   // FromSeconds, FromMilliseconds, etc. instead.
michael@0:   explicit TimeDelta(int64_t delta_us) : delta_(delta_us) {
michael@0:   }
michael@0: 
michael@0:   // Delta in microseconds.
michael@0:   int64_t delta_;
michael@0: };
michael@0: 
michael@0: inline TimeDelta operator*(int64_t a, TimeDelta td) {
michael@0:   return TimeDelta(a * td.delta_);
michael@0: }
michael@0: 
michael@0: // Time -----------------------------------------------------------------------
michael@0: 
michael@0: // Represents a wall clock time.
michael@0: class Time {
michael@0:  public:
michael@0:   static const int64_t kMillisecondsPerSecond = 1000;
michael@0:   static const int64_t kMicrosecondsPerMillisecond = 1000;
michael@0:   static const int64_t kMicrosecondsPerSecond = kMicrosecondsPerMillisecond *
michael@0:                                               kMillisecondsPerSecond;
michael@0:   static const int64_t kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60;
michael@0:   static const int64_t kMicrosecondsPerHour = kMicrosecondsPerMinute * 60;
michael@0:   static const int64_t kMicrosecondsPerDay = kMicrosecondsPerHour * 24;
michael@0:   static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7;
michael@0:   static const int64_t kNanosecondsPerMicrosecond = 1000;
michael@0:   static const int64_t kNanosecondsPerSecond = kNanosecondsPerMicrosecond *
michael@0:                                              kMicrosecondsPerSecond;
michael@0: 
michael@0:   // Represents an exploded time that can be formatted nicely. This is kind of
michael@0:   // like the Win32 SYSTEMTIME structure or the Unix "struct tm" with a few
michael@0:   // additions and changes to prevent errors.
michael@0:   struct Exploded {
michael@0:     int year;                 // Four digit year "2007"
michael@0:     signed char month;        // 1-based month (values 1 = January, etc.)
michael@0:     signed char day_of_week;  // 0-based day of week (0 = Sunday, etc.)
michael@0:     signed char day_of_month; // 1-based day of month (1-31)
michael@0:     signed char hour;         // Hour within the current day (0-23)
michael@0:     signed char minute;       // Minute within the current hour (0-59)
michael@0:     signed char second;       // Second within the current minute (0-59 plus
michael@0:                               // leap seconds which may take it up to 60).
michael@0:     int millisecond;          // Milliseconds within the current second (0-999)
michael@0:   };
michael@0: 
michael@0:   // Contains the NULL time. Use Time::Now() to get the current time.
michael@0:   explicit Time() : us_(0) {
michael@0:   }
michael@0: 
michael@0:   // Returns true if the time object has not been initialized.
michael@0:   bool is_null() const {
michael@0:     return us_ == 0;
michael@0:   }
michael@0: 
michael@0:   // Returns the current time. Watch out, the system might adjust its clock
michael@0:   // in which case time will actually go backwards. We don't guarantee that
michael@0:   // times are increasing, or that two calls to Now() won't be the same.
michael@0:   static Time Now();
michael@0: 
michael@0:   // Returns the current time. Same as Now() except that this function always
michael@0:   // uses system time so that there are no discrepancies between the returned
michael@0:   // time and system time even on virtual environments including our test bot.
michael@0:   // For timing sensitive unittests, this function should be used.
michael@0:   static Time NowFromSystemTime();
michael@0: 
michael@0:   // Converts to/from time_t in UTC and a Time class.
michael@0:   // TODO(brettw) this should be removed once everybody starts using the |Time|
michael@0:   // class.
michael@0:   static Time FromTimeT(time_t tt);
michael@0:   time_t ToTimeT() const;
michael@0: 
michael@0:   // Converts time to/from a double which is the number of seconds since epoch
michael@0:   // (Jan 1, 1970).  Webkit uses this format to represent time.
michael@0:   static Time FromDoubleT(double dt);
michael@0:   double ToDoubleT() const;
michael@0: 
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0:   static Time FromFileTime(FILETIME ft);
michael@0:   FILETIME ToFileTime() const;
michael@0: #endif
michael@0: 
michael@0:   // Converts an exploded structure representing either the local time or UTC
michael@0:   // into a Time class.
michael@0:   static Time FromUTCExploded(const Exploded& exploded) {
michael@0:     return FromExploded(false, exploded);
michael@0:   }
michael@0:   static Time FromLocalExploded(const Exploded& exploded) {
michael@0:     return FromExploded(true, exploded);
michael@0:   }
michael@0: 
michael@0:   // Converts an integer value representing Time to a class. This is used
michael@0:   // when deserializing a |Time| structure, using a value known to be
michael@0:   // compatible. It is not provided as a constructor because the integer type
michael@0:   // may be unclear from the perspective of a caller.
michael@0:   static Time FromInternalValue(int64_t us) {
michael@0:     return Time(us);
michael@0:   }
michael@0: 
michael@0:   // Converts a string representation of time to a Time object.
michael@0:   // An example of a time string which is converted is as below:-
michael@0:   // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified
michael@0:   // in the input string, we assume local time.
michael@0:   // TODO(iyengar) Move the FromString/FromTimeT/ToTimeT/FromFileTime to
michael@0:   // a new time converter class.
michael@0:   static bool FromString(const wchar_t* time_string, Time* parsed_time);
michael@0: 
michael@0:   // For serializing, use FromInternalValue to reconstitute. Please don't use
michael@0:   // this and do arithmetic on it, as it is more error prone than using the
michael@0:   // provided operators.
michael@0:   int64_t ToInternalValue() const {
michael@0:     return us_;
michael@0:   }
michael@0: 
michael@0:   // Fills the given exploded structure with either the local time or UTC from
michael@0:   // this time structure (containing UTC).
michael@0:   void UTCExplode(Exploded* exploded) const {
michael@0:     return Explode(false, exploded);
michael@0:   }
michael@0:   void LocalExplode(Exploded* exploded) const {
michael@0:     return Explode(true, exploded);
michael@0:   }
michael@0: 
michael@0:   // Rounds this time down to the nearest day in local time. It will represent
michael@0:   // midnight on that day.
michael@0:   Time LocalMidnight() const;
michael@0: 
michael@0:   Time& operator=(Time other) {
michael@0:     us_ = other.us_;
michael@0:     return *this;
michael@0:   }
michael@0: 
michael@0:   // Compute the difference between two times.
michael@0:   TimeDelta operator-(Time other) const {
michael@0:     return TimeDelta(us_ - other.us_);
michael@0:   }
michael@0: 
michael@0:   // Modify by some time delta.
michael@0:   Time& operator+=(TimeDelta delta) {
michael@0:     us_ += delta.delta_;
michael@0:     return *this;
michael@0:   }
michael@0:   Time& operator-=(TimeDelta delta) {
michael@0:     us_ -= delta.delta_;
michael@0:     return *this;
michael@0:   }
michael@0: 
michael@0:   // Return a new time modified by some delta.
michael@0:   Time operator+(TimeDelta delta) const {
michael@0:     return us_ + delta.delta_;
michael@0:   }
michael@0:   Time operator-(TimeDelta delta) const {
michael@0:     return us_ - delta.delta_;
michael@0:   }
michael@0: 
michael@0:   // Comparison operators
michael@0:   bool operator==(Time other) const {
michael@0:     return us_ == other.us_;
michael@0:   }
michael@0:   bool operator!=(Time other) const {
michael@0:     return us_ != other.us_;
michael@0:   }
michael@0:   bool operator<(Time other) const {
michael@0:     return us_ < other.us_;
michael@0:   }
michael@0:   bool operator<=(Time other) const {
michael@0:     return us_ <= other.us_;
michael@0:   }
michael@0:   bool operator>(Time other) const {
michael@0:     return us_ > other.us_;
michael@0:   }
michael@0:   bool operator>=(Time other) const {
michael@0:     return us_ >= other.us_;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   friend class TimeDelta;
michael@0: 
michael@0:   // Explodes the given time to either local time |is_local = true| or UTC
michael@0:   // |is_local = false|.
michael@0:   void Explode(bool is_local, Exploded* exploded) const;
michael@0: 
michael@0:   // Unexplodes a given time assuming the source is either local time
michael@0:   // |is_local = true| or UTC |is_local = false|.
michael@0:   static Time FromExploded(bool is_local, const Exploded& exploded);
michael@0: 
michael@0:   Time(int64_t us) : us_(us) {
michael@0:   }
michael@0: 
michael@0:   // The representation of Jan 1, 1970 UTC in microseconds since the
michael@0:   // platform-dependent epoch.
michael@0:   static const int64_t kTimeTToMicrosecondsOffset;
michael@0: 
michael@0:   // Time in microseconds in UTC.
michael@0:   int64_t us_;
michael@0: };
michael@0: 
michael@0: inline Time TimeDelta::operator+(Time t) const {
michael@0:   return Time(t.us_ + delta_);
michael@0: }
michael@0: 
michael@0: // Inline the TimeDelta factory methods, for fast TimeDelta construction.
michael@0: 
michael@0: // static
michael@0: inline TimeDelta TimeDelta::FromDays(int64_t days) {
michael@0:   return TimeDelta(days * Time::kMicrosecondsPerDay);
michael@0: }
michael@0: 
michael@0: // static
michael@0: inline TimeDelta TimeDelta::FromHours(int64_t hours) {
michael@0:   return TimeDelta(hours * Time::kMicrosecondsPerHour);
michael@0: }
michael@0: 
michael@0: // static
michael@0: inline TimeDelta TimeDelta::FromMinutes(int64_t minutes) {
michael@0:   return TimeDelta(minutes * Time::kMicrosecondsPerMinute);
michael@0: }
michael@0: 
michael@0: // static
michael@0: inline TimeDelta TimeDelta::FromSeconds(int64_t secs) {
michael@0:   return TimeDelta(secs * Time::kMicrosecondsPerSecond);
michael@0: }
michael@0: 
michael@0: // static
michael@0: inline TimeDelta TimeDelta::FromMilliseconds(int64_t ms) {
michael@0:   return TimeDelta(ms * Time::kMicrosecondsPerMillisecond);
michael@0: }
michael@0: 
michael@0: // static
michael@0: inline TimeDelta TimeDelta::FromMicroseconds(int64_t us) {
michael@0:   return TimeDelta(us);
michael@0: }
michael@0: 
michael@0: // TimeTicks ------------------------------------------------------------------
michael@0: 
michael@0: class TimeTicks {
michael@0:  public:
michael@0:   TimeTicks() : ticks_(0) {
michael@0:   }
michael@0: 
michael@0:   // Platform-dependent tick count representing "right now."
michael@0:   // The resolution of this clock is ~1-15ms.  Resolution varies depending
michael@0:   // on hardware/operating system configuration.
michael@0:   static TimeTicks Now();
michael@0: 
michael@0:   // Returns a platform-dependent high-resolution tick count. Implementation
michael@0:   // is hardware dependent and may or may not return sub-millisecond
michael@0:   // resolution.  THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND
michael@0:   // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED.
michael@0:   static TimeTicks HighResNow();
michael@0: 
michael@0:   // Returns true if this object has not been initialized.
michael@0:   bool is_null() const {
michael@0:     return ticks_ == 0;
michael@0:   }
michael@0: 
michael@0:   // Returns the internal numeric value of the TimeTicks object.
michael@0:   int64_t ToInternalValue() const {
michael@0:     return ticks_;
michael@0:   }
michael@0: 
michael@0:   TimeTicks& operator=(TimeTicks other) {
michael@0:     ticks_ = other.ticks_;
michael@0:     return *this;
michael@0:   }
michael@0: 
michael@0:   // Compute the difference between two times.
michael@0:   TimeDelta operator-(TimeTicks other) const {
michael@0:     return TimeDelta(ticks_ - other.ticks_);
michael@0:   }
michael@0: 
michael@0:   // Modify by some time delta.
michael@0:   TimeTicks& operator+=(TimeDelta delta) {
michael@0:     ticks_ += delta.delta_;
michael@0:     return *this;
michael@0:   }
michael@0:   TimeTicks& operator-=(TimeDelta delta) {
michael@0:     ticks_ -= delta.delta_;
michael@0:     return *this;
michael@0:   }
michael@0: 
michael@0:   // Return a new TimeTicks modified by some delta.
michael@0:   TimeTicks operator+(TimeDelta delta) const {
michael@0:     return TimeTicks(ticks_ + delta.delta_);
michael@0:   }
michael@0:   TimeTicks operator-(TimeDelta delta) const {
michael@0:     return TimeTicks(ticks_ - delta.delta_);
michael@0:   }
michael@0: 
michael@0:   // Comparison operators
michael@0:   bool operator==(TimeTicks other) const {
michael@0:     return ticks_ == other.ticks_;
michael@0:   }
michael@0:   bool operator!=(TimeTicks other) const {
michael@0:     return ticks_ != other.ticks_;
michael@0:   }
michael@0:   bool operator<(TimeTicks other) const {
michael@0:     return ticks_ < other.ticks_;
michael@0:   }
michael@0:   bool operator<=(TimeTicks other) const {
michael@0:     return ticks_ <= other.ticks_;
michael@0:   }
michael@0:   bool operator>(TimeTicks other) const {
michael@0:     return ticks_ > other.ticks_;
michael@0:   }
michael@0:   bool operator>=(TimeTicks other) const {
michael@0:     return ticks_ >= other.ticks_;
michael@0:   }
michael@0: 
michael@0:  protected:
michael@0:   friend class TimeDelta;
michael@0:   friend class PageLoadTrackerUnitTest;
michael@0: 
michael@0:   // Please use Now() to create a new object. This is for internal use
michael@0:   // and testing. Ticks is in microseconds.
michael@0:   explicit TimeTicks(int64_t ticks) : ticks_(ticks) {
michael@0:   }
michael@0: 
michael@0:   // Tick count in microseconds.
michael@0:   int64_t ticks_;
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0:   typedef DWORD (*TickFunctionType)(void);
michael@0:   static TickFunctionType SetMockTickFunction(TickFunctionType ticker);
michael@0: #endif
michael@0: };
michael@0: 
michael@0: inline TimeTicks TimeDelta::operator+(TimeTicks t) const {
michael@0:   return TimeTicks(t.ticks_ + delta_);
michael@0: }
michael@0: 
michael@0: }  // namespace base
michael@0: 
michael@0: #endif  // BASE_TIME_H_