Move timing files into base/time, install forwarding headers.

base/time.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2013 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 the Windows epoch (1601-01-01 00:00:00 UTC)
-// (See http://crbug.com/14734).  System-dependent clock interface routines are
-// defined in time_PLATFORM.cc.
-//
-// TimeDelta represents a duration of time, internally represented in
-// microseconds.
-//
-// TimeTicks 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.
-//
-// 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/atomicops.h"
-#include "base/base_export.h"
-#include "base/basictypes.h"
-
-#if defined(OS_MACOSX)
-#include <CoreFoundation/CoreFoundation.h>
-// Avoid Mac system header macro leak.
-#undef TYPE_BOOL
-#endif
-
-#if defined(OS_POSIX)
-// For struct timeval.
-#include <sys/time.h>
-#endif
-
-#if defined(OS_WIN)
-// For FILETIME in FromFileTime, until it moves to a new converter class.
-// See TODO(iyengar) below.
-#include <windows.h>
-#endif
-
-#include <limits>
-
-namespace base {
-
-class Time;
-class TimeTicks;
-
-// TimeDelta ------------------------------------------------------------------
-
-class BASE_EXPORT 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);
-#if defined(OS_WIN)
-  static TimeDelta FromQPCValue(LONGLONG qpc_value);
-#endif
-
-  // Converts an integer value representing TimeDelta to a class. This is used
-  // when deserializing a |TimeDelta| 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 TimeDelta FromInternalValue(int64 delta) {
-    return TimeDelta(delta);
-  }
-
-  // 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.
-  // For serializing, use FromInternalValue to reconstitute.
-  int64 ToInternalValue() const {
-    return delta_;
-  }
-
-#if defined(OS_POSIX)
-  struct timespec ToTimeSpec() const;
-#endif
-
-  // 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 InSeconds() const;
-  double InMillisecondsF() const;
-  int64 InMilliseconds() const;
-  int64 InMillisecondsRoundedUp() 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 BASE_EXPORT 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;
-
-#if !defined(OS_WIN)
-  // On Mac & Linux, this value is the delta from the Windows epoch of 1601 to
-  // the Posix delta of 1970. This is used for migrating between the old
-  // 1970-based epochs to the new 1601-based ones. It should be removed from
-  // this global header and put in the platform-specific ones when we remove the
-  // migration code.
-  static const int64 kWindowsEpochDeltaMicroseconds;
-#endif
-
-  // 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 BASE_EXPORT 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)
-
-    // A cursory test for whether the data members are within their
-    // respective ranges. A 'true' return value does not guarantee the
-    // Exploded value can be successfully converted to a Time value.
-    bool HasValidValues() const;
-  };
-
-  // 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 is_null() const {
-    return us_ == 0;
-  }
-
-  // Returns true if the time object is the maximum time.
-  bool is_max() const {
-    return us_ == std::numeric_limits<int64>::max();
-  }
-
-  // Returns the time for epoch in Unix-like system (Jan 1, 1970).
-  static Time UnixEpoch();
-
-  // 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 maximum time, which should be greater than any reasonable time
-  // with which we might compare it.
-  static Time Max();
-
-  // 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.
-  // Because WebKit initializes double time value to 0 to indicate "not
-  // initialized", we map it to empty Time object that also means "not
-  // initialized".
-  static Time FromDoubleT(double dt);
-  double ToDoubleT() const;
-
-#if defined(OS_POSIX)
-  // Converts the timespec structure to time. MacOS X 10.8.3 (and tentatively,
-  // earlier versions) will have the |ts|'s tv_nsec component zeroed out,
-  // having a 1 second resolution, which agrees with
-  // https://developer.apple.com/legacy/library/#technotes/tn/tn1150.html#HFSPlusDates.
-  static Time FromTimeSpec(const timespec& ts);
-#endif
-
-  // Converts to/from the Javascript convention for times, a number of
-  // milliseconds since the epoch:
-  // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getTime.
-  static Time FromJsTime(double ms_since_epoch);
-  double ToJsTime() const;
-
-#if defined(OS_POSIX)
-  static Time FromTimeVal(struct timeval t);
-  struct timeval ToTimeVal() const;
-#endif
-
-#if defined(OS_MACOSX)
-  static Time FromCFAbsoluteTime(CFAbsoluteTime t);
-  CFAbsoluteTime ToCFAbsoluteTime() const;
-#endif
-
-#if defined(OS_WIN)
-  static Time FromFileTime(FILETIME ft);
-  FILETIME ToFileTime() const;
-
-  // The minimum time of a low resolution timer.  This is basically a windows
-  // constant of ~15.6ms.  While it does vary on some older OS versions, we'll
-  // treat it as static across all windows versions.
-  static const int kMinLowResolutionThresholdMs = 16;
-
-  // Enable or disable Windows high resolution timer. If the high resolution
-  // timer is not enabled, calls to ActivateHighResolutionTimer will fail.
-  // When disabling the high resolution timer, this function will not cause
-  // the high resolution timer to be deactivated, but will prevent future
-  // activations.
-  // Must be called from the main thread.
-  // For more details see comments in time_win.cc.
-  static void EnableHighResolutionTimer(bool enable);
-
-  // Activates or deactivates the high resolution timer based on the |activate|
-  // flag.  If the HighResolutionTimer is not Enabled (see
-  // EnableHighResolutionTimer), this function will return false.  Otherwise
-  // returns true.  Each successful activate call must be paired with a
-  // subsequent deactivate call.
-  // All callers to activate the high resolution timer must eventually call
-  // this function to deactivate the high resolution timer.
-  static bool ActivateHighResolutionTimer(bool activate);
-
-  // Returns true if the high resolution timer is both enabled and activated.
-  // This is provided for testing only, and is not tracked in a thread-safe
-  // way.
-  static bool IsHighResolutionTimerInUse();
-#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, FromString assumes local time and FromUTCString
-  // assumes UTC. A timezone that cannot be parsed (e.g. "UTC" which is not
-  // specified in RFC822) is treated as if the timezone is not specified.
-  // TODO(iyengar) Move the FromString/FromTimeT/ToTimeT/FromFileTime to
-  // a new time converter class.
-  static bool FromString(const char* time_string, Time* parsed_time) {
-    return FromStringInternal(time_string, true, parsed_time);
-  }
-  static bool FromUTCString(const char* time_string, Time* parsed_time) {
-    return FromStringInternal(time_string, false, 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 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;
-
-  explicit Time(int64 us) : us_(us) {
-  }
-
-  // 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);
-
-  // 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, local time |is_local = true| or
-  // UTC |is_local = false| is assumed. A timezone that cannot be parsed
-  // (e.g. "UTC" which is not specified in RFC822) is treated as if the
-  // timezone is not specified.
-  static bool FromStringInternal(const char* time_string,
-                                 bool is_local,
-                                 Time* parsed_time);
-
-  // The representation of Jan 1, 1970 UTC in microseconds since the
-  // platform-dependent epoch.
-  static const int64 kTimeTToMicrosecondsOffset;
-
-#if defined(OS_WIN)
-  // Indicates whether fast timers are usable right now.  For instance,
-  // when using battery power, we might elect to prevent high speed timers
-  // which would draw more power.
-  static bool high_resolution_timer_enabled_;
-  // Count of activations on the high resolution timer.  Only use in tests
-  // which are single threaded.
-  static int high_resolution_timer_activated_;
-#endif
-
-  // Time in microseconds in UTC.
-  int64 us_;
-};
-
-// 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);
-}
-
-inline Time TimeDelta::operator+(Time t) const {
-  return Time(t.us_ + delta_);
-}
-
-// TimeTicks ------------------------------------------------------------------
-
-class BASE_EXPORT 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 the current system trace time or, if none is defined, the current
-  // high-res time (i.e. HighResNow()). On systems where a global trace clock
-  // is defined, timestamping TraceEvents's with this value guarantees
-  // synchronization between events collected inside chrome and events
-  // collected outside (e.g. kernel, X server).
-  static TimeTicks NowFromSystemTraceTime();
-
-#if defined(OS_WIN)
-  // Get the absolute value of QPC time drift. For testing.
-  static int64 GetQPCDriftMicroseconds();
-
-  static TimeTicks FromQPCValue(LONGLONG qpc_value);
-
-  // Returns true if the high resolution clock is working on this system.
-  // This is only for testing.
-  static bool IsHighResClockWorking();
-#endif
-
-  // Returns true if this object has not been initialized.
-  bool is_null() const {
-    return ticks_ == 0;
-  }
-
-  // Converts an integer value representing TimeTicks to a class. This is used
-  // when deserializing a |TimeTicks| 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 TimeTicks FromInternalValue(int64 ticks) {
-    return TimeTicks(ticks);
-  }
-
-  // Returns the internal numeric value of the TimeTicks object.
-  // For serializing, use FromInternalValue to reconstitute.
-  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;
-
-  // 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_
+// This file has moved, please use the new location.
+// TODO(avi): Remove this file when all users have been updated.
+#include "base/time/time.h"