root/base/time/time.cc

DEFINITIONS

1. Max
2. InDays
3. InHours
4. InMinutes
5. InSecondsF
6. InSeconds
7. InMillisecondsF
8. InMilliseconds
9. InMillisecondsRoundedUp
10. InMicroseconds
11. Max
12. FromTimeT
13. ToTimeT
14. FromDoubleT
15. ToDoubleT
16. FromTimeSpec
17. FromJsTime
18. ToJsTime
19. ToJavaTime
20. UnixEpoch
21. LocalMidnight
22. FromStringInternal
23. unix_epoch
24. UnixEpoch
25. is_in_range
26. HasValidValues

// Copyright (c) 2012 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 <limits>
#include <ostream>

#include "base/float_util.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/third_party/nspr/prtime.h"

namespace base {

// TimeDelta ------------------------------------------------------------------

// static
TimeDelta TimeDelta::Max() {
  return TimeDelta(std::numeric_limits<int64>::max());
}

int TimeDelta::InDays() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int>::max();
  }
  return static_cast<int>(delta_ / Time::kMicrosecondsPerDay);
}

int TimeDelta::InHours() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int>::max();
  }
  return static_cast<int>(delta_ / Time::kMicrosecondsPerHour);
}

int TimeDelta::InMinutes() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int>::max();
  }
  return static_cast<int>(delta_ / Time::kMicrosecondsPerMinute);
}

double TimeDelta::InSecondsF() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<double>::infinity();
  }
  return static_cast<double>(delta_) / Time::kMicrosecondsPerSecond;
}

int64 TimeDelta::InSeconds() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int64>::max();
  }
  return delta_ / Time::kMicrosecondsPerSecond;
}

double TimeDelta::InMillisecondsF() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<double>::infinity();
  }
  return static_cast<double>(delta_) / Time::kMicrosecondsPerMillisecond;
}

int64 TimeDelta::InMilliseconds() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int64>::max();
  }
  return delta_ / Time::kMicrosecondsPerMillisecond;
}

int64 TimeDelta::InMillisecondsRoundedUp() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int64>::max();
  }
  return (delta_ + Time::kMicrosecondsPerMillisecond - 1) /
      Time::kMicrosecondsPerMillisecond;
}

int64 TimeDelta::InMicroseconds() const {
  if (is_max()) {
    // Preserve max to prevent overflow.
    return std::numeric_limits<int64>::max();
  }
  return delta_;
}

// Time -----------------------------------------------------------------------

// static
Time Time::Max() {
  return Time(std::numeric_limits<int64>::max());
}

// static
Time Time::FromTimeT(time_t tt) {
  if (tt == 0)
    return Time();  // Preserve 0 so we can tell it doesn't exist.
  if (tt == std::numeric_limits<time_t>::max())
    return Max();
  return Time((tt * kMicrosecondsPerSecond) + kTimeTToMicrosecondsOffset);
}

time_t Time::ToTimeT() const {
  if (is_null())
    return 0;  // Preserve 0 so we can tell it doesn't exist.
  if (is_max()) {
    // Preserve max without offset to prevent overflow.
    return std::numeric_limits<time_t>::max();
  }
  if (std::numeric_limits<int64>::max() - kTimeTToMicrosecondsOffset <= us_) {
    DLOG(WARNING) << "Overflow when converting base::Time with internal " <<
                     "value " << us_ << " to time_t.";
    return std::numeric_limits<time_t>::max();
  }
  return (us_ - kTimeTToMicrosecondsOffset) / kMicrosecondsPerSecond;
}

// static
Time Time::FromDoubleT(double dt) {
  if (dt == 0 || IsNaN(dt))
    return Time();  // Preserve 0 so we can tell it doesn't exist.
  if (dt == std::numeric_limits<double>::infinity())
    return Max();
  return Time(static_cast<int64>((dt *
                                  static_cast<double>(kMicrosecondsPerSecond)) +
                                 kTimeTToMicrosecondsOffset));
}

double Time::ToDoubleT() const {
  if (is_null())
    return 0;  // Preserve 0 so we can tell it doesn't exist.
  if (is_max()) {
    // Preserve max without offset to prevent overflow.
    return std::numeric_limits<double>::infinity();
  }
  return (static_cast<double>(us_ - kTimeTToMicrosecondsOffset) /
          static_cast<double>(kMicrosecondsPerSecond));
}

#if defined(OS_POSIX)
// static
Time Time::FromTimeSpec(const timespec& ts) {
  return FromDoubleT(ts.tv_sec +
                     static_cast<double>(ts.tv_nsec) /
                         base::Time::kNanosecondsPerSecond);
}
#endif

// static
Time Time::FromJsTime(double ms_since_epoch) {
  // The epoch is a valid time, so this constructor doesn't interpret
  // 0 as the null time.
  if (ms_since_epoch == std::numeric_limits<double>::infinity())
    return Max();
  return Time(static_cast<int64>(ms_since_epoch * kMicrosecondsPerMillisecond) +
              kTimeTToMicrosecondsOffset);
}

double Time::ToJsTime() const {
  if (is_null()) {
    // Preserve 0 so the invalid result doesn't depend on the platform.
    return 0;
  }
  if (is_max()) {
    // Preserve max without offset to prevent overflow.
    return std::numeric_limits<double>::infinity();
  }
  return (static_cast<double>(us_ - kTimeTToMicrosecondsOffset) /
          kMicrosecondsPerMillisecond);
}

int64 Time::ToJavaTime() const {
  if (is_null()) {
    // Preserve 0 so the invalid result doesn't depend on the platform.
    return 0;
  }
  if (is_max()) {
    // Preserve max without offset to prevent overflow.
    return std::numeric_limits<int64>::max();
  }
  return ((us_ - kTimeTToMicrosecondsOffset) /
          kMicrosecondsPerMillisecond);
}

// static
Time Time::UnixEpoch() {
  Time time;
  time.us_ = kTimeTToMicrosecondsOffset;
  return time;
}

Time Time::LocalMidnight() const {
  Exploded exploded;
  LocalExplode(&exploded);
  exploded.hour = 0;
  exploded.minute = 0;
  exploded.second = 0;
  exploded.millisecond = 0;
  return FromLocalExploded(exploded);
}

// static
bool Time::FromStringInternal(const char* time_string,
                              bool is_local,
                              Time* parsed_time) {
  DCHECK((time_string != NULL) && (parsed_time != NULL));

  if (time_string[0] == '\0')
    return false;

  PRTime result_time = 0;
  PRStatus result = PR_ParseTimeString(time_string,
                                       is_local ? PR_FALSE : PR_TRUE,
                                       &result_time);
  if (PR_SUCCESS != result)
    return false;

  result_time += kTimeTToMicrosecondsOffset;
  *parsed_time = Time(result_time);
  return true;
}

// Local helper class to hold the conversion from Time to TickTime at the
// time of the Unix epoch.
class UnixEpochSingleton {
 public:
  UnixEpochSingleton()
      : unix_epoch_(TimeTicks::Now() - (Time::Now() - Time::UnixEpoch())) {}

  TimeTicks unix_epoch() const { return unix_epoch_; }

 private:
  const TimeTicks unix_epoch_;

  DISALLOW_COPY_AND_ASSIGN(UnixEpochSingleton);
};

static LazyInstance<UnixEpochSingleton>::Leaky
    leaky_unix_epoch_singleton_instance = LAZY_INSTANCE_INITIALIZER;

// Static
TimeTicks TimeTicks::UnixEpoch() {
  return leaky_unix_epoch_singleton_instance.Get().unix_epoch();
}

// Time::Exploded -------------------------------------------------------------

inline bool is_in_range(int value, int lo, int hi) {
  return lo <= value && value <= hi;
}

bool Time::Exploded::HasValidValues() const {
  return is_in_range(month, 1, 12) &&
         is_in_range(day_of_week, 0, 6) &&
         is_in_range(day_of_month, 1, 31) &&
         is_in_range(hour, 0, 23) &&
         is_in_range(minute, 0, 59) &&
         is_in_range(second, 0, 60) &&
         is_in_range(millisecond, 0, 999);
}

}  // namespace base