The Tor Browser: ipc/chromium/src/base/time

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 // Copyright (c) 2008 The Chromium Authors. All rights reserved.

     2 // Use of this source code is governed by a BSD-style license that can be

     3 // found in the LICENSE file.

     5 #include "base/time.h"

     7 #include <CoreFoundation/CFDate.h>

     8 #include <CoreFoundation/CFTimeZone.h>

     9 #include <mach/mach_time.h>

    10 #include <sys/time.h>

    11 #include <time.h>

    13 #include "base/basictypes.h"

    14 #include "base/logging.h"

    15 #include "base/scoped_cftyperef.h"

    17 namespace base {

    19 // The Time routines in this file use Mach and CoreFoundation APIs, since the

    20 // POSIX definition of time_t in Mac OS X wraps around after 2038--and

    21 // there are already cookie expiration dates, etc., past that time out in

    22 // the field.  Using CFDate prevents that problem, and using mach_absolute_time

    23 // for TimeTicks gives us nice high-resolution interval timing.

    25 // Time -----------------------------------------------------------------------

    27 // The internal representation of Time uses a 64-bit microsecond count

    28 // from 1970-01-01 00:00:00 UTC.  Core Foundation uses a double second count

    29 // since 2001-01-01 00:00:00 UTC.

    31 // Some functions in time.cc use time_t directly, so we provide a zero offset

    32 // for them.  The epoch is 1970-01-01 00:00:00 UTC.

    33 // static

    34 const int64_t Time::kTimeTToMicrosecondsOffset = GG_INT64_C(0);

    36 // static

    37 Time Time::Now() {

    38   CFAbsoluteTime now =

    39       CFAbsoluteTimeGetCurrent() + kCFAbsoluteTimeIntervalSince1970;

    40   return Time(static_cast<int64_t>(now * kMicrosecondsPerSecond));

    41 }

    43 // static

    44 Time Time::NowFromSystemTime() {

    45   // Just use Now() because Now() returns the system time.

    46   return Now();

    47 }

    49 // static

    50 Time Time::FromExploded(bool is_local, const Exploded& exploded) {

    51   CFGregorianDate date;

    52   date.second = exploded.second +

    53       exploded.millisecond / static_cast<double>(kMillisecondsPerSecond);

    54   date.minute = exploded.minute;

    55   date.hour = exploded.hour;

    56   date.day = exploded.day_of_month;

    57   date.month = exploded.month;

    58   date.year = exploded.year;

    60   scoped_cftyperef<CFTimeZoneRef>

    61       time_zone(is_local ? CFTimeZoneCopySystem() : NULL);

    62   CFAbsoluteTime seconds = CFGregorianDateGetAbsoluteTime(date, time_zone) +

    63       kCFAbsoluteTimeIntervalSince1970;

    64   return Time(static_cast<int64_t>(seconds * kMicrosecondsPerSecond));

    65 }

    67 void Time::Explode(bool is_local, Exploded* exploded) const {

    68   CFAbsoluteTime seconds =

    69       (static_cast<double>(us_) / kMicrosecondsPerSecond) -

    70       kCFAbsoluteTimeIntervalSince1970;

    72   scoped_cftyperef<CFTimeZoneRef>

    73       time_zone(is_local ? CFTimeZoneCopySystem() : NULL);

    74   CFGregorianDate date = CFAbsoluteTimeGetGregorianDate(seconds, time_zone);

    76   exploded->year = date.year;

    77   exploded->month = date.month;

    78   exploded->day_of_month = date.day;

    79   exploded->hour = date.hour;

    80   exploded->minute = date.minute;

    81   exploded->second = date.second;

    82   exploded->millisecond  =

    83       static_cast<int>(date.second * kMillisecondsPerSecond) %

    84       kMillisecondsPerSecond;

    85 }

    87 // TimeTicks ------------------------------------------------------------------

    89 // static

    90 TimeTicks TimeTicks::Now() {

    91   uint64_t absolute_micro;

    93   static mach_timebase_info_data_t timebase_info;

    94   if (timebase_info.denom == 0) {

    95     // Zero-initialization of statics guarantees that denom will be 0 before

    96     // calling mach_timebase_info.  mach_timebase_info will never set denom to

    97     // 0 as that would be invalid, so the zero-check can be used to determine

    98     // whether mach_timebase_info has already been called.  This is

    99     // recommended by Apple's QA1398.

   100     kern_return_t kr = mach_timebase_info(&timebase_info);

   101     DCHECK(kr == KERN_SUCCESS);

   102   }

   104   // mach_absolute_time is it when it comes to ticks on the Mac.  Other calls

   105   // with less precision (such as TickCount) just call through to

   106   // mach_absolute_time.

   108   // timebase_info converts absolute time tick units into nanoseconds.  Convert

   109   // to microseconds up front to stave off overflows.

   110   absolute_micro = mach_absolute_time() / Time::kNanosecondsPerMicrosecond *

   111                    timebase_info.numer / timebase_info.denom;

   113   // Don't bother with the rollover handling that the Windows version does.

   114   // With numer and denom = 1 (the expected case), the 64-bit absolute time

   115   // reported in nanoseconds is enough to last nearly 585 years.

   117   return TimeTicks(absolute_micro);

   118 }

   120 // static

   121 TimeTicks TimeTicks::HighResNow() {

   122   return Now();

   123 }

   125 }  // namespace base

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