Repo created

TMessagesProj/jni/voip/webrtc/base/time/time_exploded_ios.cc

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+// Copyright (c) 2019 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/time.h"
+
+#include <CoreFoundation/CFDate.h>
+#include <CoreFoundation/CFCalendar.h>
+#include <CoreFoundation/CFTimeZone.h>
+
+#include "base/mac/scoped_cftyperef.h"
+
+#if __LP64__
+#error Use posix implementation on 64-bit platforms.
+#endif  // __LP64__
+
+namespace base {
+
+// Note: These implementations of Time::FromExploded() and Time::Explode() are
+// only used on iOS now. Since Mac is now always 64-bit, we can use the POSIX
+// versions of these functions as time_t is not capped at year 2038 on 64-bit
+// builds. The POSIX functions are preferred since they don't suffer from some
+// performance problems that are present in these implementations.
+// See crbug.com/781601, crbug.com/985061 for more details.
+
+// static
+bool Time::FromExploded(bool is_local, const Exploded& exploded, Time* time) {
+  base::ScopedCFTypeRef<CFTimeZoneRef> time_zone(
+      is_local
+          ? CFTimeZoneCopySystem()
+          : CFTimeZoneCreateWithTimeIntervalFromGMT(kCFAllocatorDefault, 0));
+  base::ScopedCFTypeRef<CFCalendarRef> gregorian(CFCalendarCreateWithIdentifier(
+      kCFAllocatorDefault, kCFGregorianCalendar));
+  CFCalendarSetTimeZone(gregorian, time_zone);
+  CFAbsoluteTime absolute_time;
+  // 'S' is not defined in componentDesc in Apple documentation, but can be
+  // found at http://www.opensource.apple.com/source/CF/CF-855.17/CFCalendar.c
+  CFCalendarComposeAbsoluteTime(
+      gregorian, &absolute_time, "yMdHmsS", exploded.year, exploded.month,
+      exploded.day_of_month, exploded.hour, exploded.minute, exploded.second,
+      exploded.millisecond);
+  CFAbsoluteTime seconds = absolute_time + kCFAbsoluteTimeIntervalSince1970;
+
+  // CFAbsolutTime is typedef of double. Convert seconds to
+  // microseconds and then cast to int64. If
+  // it cannot be suited to int64, then fail to avoid overflows.
+  double microseconds =
+      (seconds * kMicrosecondsPerSecond) + kTimeTToMicrosecondsOffset;
+  if (microseconds > std::numeric_limits<int64_t>::max() ||
+      microseconds < std::numeric_limits<int64_t>::min()) {
+    *time = Time(0);
+    return false;
+  }
+
+  base::Time converted_time = Time(static_cast<int64_t>(microseconds));
+
+  // If |exploded.day_of_month| is set to 31
+  // on a 28-30 day month, it will return the first day of the next month.
+  // Thus round-trip the time and compare the initial |exploded| with
+  // |utc_to_exploded| time.
+  base::Time::Exploded to_exploded;
+  if (!is_local)
+    converted_time.UTCExplode(&to_exploded);
+  else
+    converted_time.LocalExplode(&to_exploded);
+
+  if (ExplodedMostlyEquals(to_exploded, exploded)) {
+    *time = converted_time;
+    return true;
+  }
+
+  *time = Time(0);
+  return false;
+}
+
+void Time::Explode(bool is_local, Exploded* exploded) const {
+  // Avoid rounding issues, by only putting the integral number of seconds
+  // (rounded towards -infinity) into a |CFAbsoluteTime| (which is a |double|).
+  int64_t microsecond = us_ % kMicrosecondsPerSecond;
+  if (microsecond < 0)
+    microsecond += kMicrosecondsPerSecond;
+  CFAbsoluteTime seconds = ((us_ - microsecond - kTimeTToMicrosecondsOffset) /
+                            kMicrosecondsPerSecond) -
+                           kCFAbsoluteTimeIntervalSince1970;
+
+  base::ScopedCFTypeRef<CFTimeZoneRef> time_zone(
+      is_local
+          ? CFTimeZoneCopySystem()
+          : CFTimeZoneCreateWithTimeIntervalFromGMT(kCFAllocatorDefault, 0));
+  base::ScopedCFTypeRef<CFCalendarRef> gregorian(CFCalendarCreateWithIdentifier(
+      kCFAllocatorDefault, kCFGregorianCalendar));
+  CFCalendarSetTimeZone(gregorian, time_zone);
+  int second, day_of_week;
+  // 'E' sets the day of week, but is not defined in componentDesc in Apple
+  // documentation. It can be found in open source code here:
+  // http://www.opensource.apple.com/source/CF/CF-855.17/CFCalendar.c
+  CFCalendarDecomposeAbsoluteTime(gregorian, seconds, "yMdHmsE",
+                                  &exploded->year, &exploded->month,
+                                  &exploded->day_of_month, &exploded->hour,
+                                  &exploded->minute, &second, &day_of_week);
+  // Make sure seconds are rounded down towards -infinity.
+  exploded->second = floor(second);
+  // |Exploded|'s convention for day of week is 0 = Sunday, i.e. different
+  // from CF's 1 = Sunday.
+  exploded->day_of_week = (day_of_week - 1) % 7;
+  // Calculate milliseconds ourselves, since we rounded the |seconds|, making
+  // sure to round towards -infinity.
+  exploded->millisecond =
+      (microsecond >= 0) ? microsecond / kMicrosecondsPerMillisecond
+                         : ((microsecond + 1) / kMicrosecondsPerMillisecond - 1);
+}
+
+}  // namespace base