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Diffstat (limited to 'ipc/chromium/src/base/time.h')
| -rw-r--r-- | ipc/chromium/src/base/time.h | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/time.h b/ipc/chromium/src/base/time.h new file mode 100644 index 000000000..55bc7b451 --- /dev/null +++ b/ipc/chromium/src/base/time.h @@ -0,0 +1,486 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// 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_t days); + static TimeDelta FromHours(int64_t hours); + static TimeDelta FromMinutes(int64_t minutes); + static TimeDelta FromSeconds(int64_t secs); + static TimeDelta FromMilliseconds(int64_t ms); + static TimeDelta FromMicroseconds(int64_t 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_t 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_t InSeconds() const; + double InMillisecondsF() const; + int64_t InMilliseconds() const; + int64_t 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_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/(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_t 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_t delta_us) : delta_(delta_us) { + } + + // Delta in microseconds. + int64_t delta_; +}; + +inline TimeDelta operator*(int64_t a, TimeDelta td) { + return TimeDelta(a * td.delta_); +} + +// Time ----------------------------------------------------------------------- + +// Represents a wall clock time. +class Time { + 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; + + // 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" + signed char month; // 1-based month (values 1 = January, etc.) + signed char day_of_week; // 0-based day of week (0 = Sunday, etc.) + signed char day_of_month; // 1-based day of month (1-31) + signed char hour; // Hour within the current day (0-23) + signed char minute; // Minute within the current hour (0-59) + signed char 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; +#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_t 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_t 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 Time(us_ + delta.delta_); + } + Time operator-(TimeDelta delta) const { + return Time(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); + + explicit Time(int64_t us) : us_(us) { + } + + // The representation of Jan 1, 1970 UTC in microseconds since the + // platform-dependent epoch. + static const int64_t kTimeTToMicrosecondsOffset; + + // Time in microseconds in UTC. + int64_t 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_t days) { + return TimeDelta(days * Time::kMicrosecondsPerDay); +} + +// static +inline TimeDelta TimeDelta::FromHours(int64_t hours) { + return TimeDelta(hours * Time::kMicrosecondsPerHour); +} + +// static +inline TimeDelta TimeDelta::FromMinutes(int64_t minutes) { + return TimeDelta(minutes * Time::kMicrosecondsPerMinute); +} + +// static +inline TimeDelta TimeDelta::FromSeconds(int64_t secs) { + return TimeDelta(secs * Time::kMicrosecondsPerSecond); +} + +// static +inline TimeDelta TimeDelta::FromMilliseconds(int64_t ms) { + return TimeDelta(ms * Time::kMicrosecondsPerMillisecond); +} + +// static +inline TimeDelta TimeDelta::FromMicroseconds(int64_t 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_t 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_t ticks) : ticks_(ticks) { + } + + // Tick count in microseconds. + int64_t 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_ |