Index: base/time_mac.cc |
=================================================================== |
--- base/time_mac.cc (revision 0) |
+++ base/time_mac.cc (revision 0) |
@@ -0,0 +1,121 @@ |
+// Copyright (c) 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. |
+ |
+#include "base/time.h" |
+ |
+#include <CoreFoundation/CFDate.h> |
+#include <CoreFoundation/CFTimeZone.h> |
+#include <mach/mach_time.h> |
+#include <sys/time.h> |
+#include <time.h> |
+ |
+#include "base/basictypes.h" |
+#include "base/logging.h" |
+#include "base/scoped_cftyperef.h" |
+ |
+namespace base { |
+ |
+// The Time routines in this file use Mach and CoreFoundation APIs, since the |
+// POSIX definition of time_t in Mac OS X wraps around after 2038--and |
+// there are already cookie expiration dates, etc., past that time out in |
+// the field. Using CFDate prevents that problem, and using mach_absolute_time |
+// for TimeTicks gives us nice high-resolution interval timing. |
+ |
+// Time ----------------------------------------------------------------------- |
+ |
+// The internal representation of Time uses a 64-bit microsecond count |
+// from 1970-01-01 00:00:00 UTC. Core Foundation uses a double second count |
+// since 2001-01-01 00:00:00 UTC. |
+ |
+// Some functions in time.c use time_t directly, so we provide a zero offset |
+// for them. The epoch is 1970-01-01 00:00:00 UTC. |
+// static |
+const int64 Time::kTimeTToMicrosecondsOffset = GG_INT64_C(0); |
+ |
+// static |
+Time Time::Now() { |
+ CFAbsoluteTime now = |
+ CFAbsoluteTimeGetCurrent() + kCFAbsoluteTimeIntervalSince1970; |
+ return Time(static_cast<int64>(now * kMicrosecondsPerSecond)); |
+} |
+ |
+// static |
+Time Time::FromExploded(bool is_local, const Exploded& exploded) { |
+ CFGregorianDate date; |
+ date.second = exploded.second + |
+ exploded.millisecond / static_cast<double>(kMillisecondsPerSecond); |
+ date.minute = exploded.minute; |
+ date.hour = exploded.hour; |
+ date.day = exploded.day_of_month; |
+ date.month = exploded.month; |
+ date.year = exploded.year; |
+ |
+ scoped_cftyperef<CFTimeZoneRef> time_zone; |
+ if (is_local) |
+ time_zone.reset(CFTimeZoneCopySystem()); |
+ CFAbsoluteTime seconds = CFGregorianDateGetAbsoluteTime(date, time_zone) + |
+ kCFAbsoluteTimeIntervalSince1970; |
+ return Time(static_cast<int64>(seconds * kMicrosecondsPerSecond)); |
+} |
+ |
+void Time::Explode(bool is_local, Exploded* exploded) const { |
+ CFAbsoluteTime seconds = |
+ (static_cast<double>(us_) / kMicrosecondsPerSecond) - |
+ kCFAbsoluteTimeIntervalSince1970; |
+ |
+ scoped_cftyperef<CFTimeZoneRef> time_zone; |
+ if (is_local) |
+ time_zone.reset(CFTimeZoneCopySystem()); |
+ CFGregorianDate date = CFAbsoluteTimeGetGregorianDate(seconds, time_zone); |
+ |
+ exploded->year = date.year; |
+ exploded->month = date.month; |
+ exploded->day_of_month = date.day; |
+ exploded->hour = date.hour; |
+ exploded->minute = date.minute; |
+ exploded->second = date.second; |
+ exploded->millisecond = |
+ static_cast<int>(date.second * kMillisecondsPerSecond) % |
+ kMillisecondsPerSecond; |
+} |
+ |
+// TimeTicks ------------------------------------------------------------------ |
+ |
+// static |
+TimeTicks TimeTicks::Now() { |
+ uint64_t absolute_micro; |
+ |
+ static mach_timebase_info_data_t timebase_info; |
+ if (timebase_info.denom == 0) { |
+ // Zero-initialization of statics guarantees that denom will be 0 before |
+ // calling mach_timebase_info. mach_timebase_info will never set denom to |
+ // 0 as that would be invalid, so the zero-check can be used to determine |
+ // whether mach_timebase_info has already been called. This is |
+ // recommended by Apple's QA1398. |
+ kern_return_t kr = mach_timebase_info(&timebase_info); |
+ DCHECK(kr == KERN_SUCCESS); |
+ } |
+ |
+ // mach_absolute_time is it when it comes to ticks on the Mac. Other calls |
+ // with less precision (such as TickCount) just call through to |
+ // mach_absolute_time. |
+ |
+ // timebase_info converts absolute time tick units into nanoseconds. Convert |
+ // to microseconds up front to stave off overflows. |
+ absolute_micro = mach_absolute_time() / Time::kNanosecondsPerMicrosecond * |
+ timebase_info.numer / timebase_info.denom; |
+ |
+ // Don't bother with the rollover handling that the Windows version does. |
+ // With numer and denom = 1 (the expected case), the 64-bit absolute time |
+ // reported in nanoseconds is enough to last nearly 585 years. |
+ |
+ return TimeTicks(absolute_micro); |
+} |
+ |
+// static |
+TimeTicks TimeTicks::HighResNow() { |
+ return Now(); |
+} |
+ |
+} // namespace base |
Property changes on: base/time_mac.cc |
___________________________________________________________________ |
Name: svn:eol-style |
+ LF |