base/time/time.cc

   1 // Copyright (c) 2012 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.
   4
   5 #include "base/time/time.h"
   6
   7 #include <ios>
   8 #include <limits>
   9 #include <ostream>
  10 #include <sstream>
  11
  12 #include "base/float_util.h"
  13 #include "base/lazy_instance.h"
  14 #include "base/logging.h"
  15 #include "base/strings/stringprintf.h"
  16 #include "base/third_party/nspr/prtime.h"
  17
  18 namespace base {
  19
  20 // TimeDelta ------------------------------------------------------------------
  21
  22 // static
  23 TimeDelta TimeDelta::Max() {
  24   return TimeDelta(std::numeric_limits<int64>::max());
  25 }
  26
  27 int TimeDelta::InDays() const {
  28   if (is_max()) {
  29     // Preserve max to prevent overflow.
  30     return std::numeric_limits<int>::max();
  31   }
  32   return static_cast<int>(delta_ / Time::kMicrosecondsPerDay);
  33 }
  34
  35 int TimeDelta::InHours() const {
  36   if (is_max()) {
  37     // Preserve max to prevent overflow.
  38     return std::numeric_limits<int>::max();
  39   }
  40   return static_cast<int>(delta_ / Time::kMicrosecondsPerHour);
  41 }
  42
  43 int TimeDelta::InMinutes() const {
  44   if (is_max()) {
  45     // Preserve max to prevent overflow.
  46     return std::numeric_limits<int>::max();
  47   }
  48   return static_cast<int>(delta_ / Time::kMicrosecondsPerMinute);
  49 }
  50
  51 double TimeDelta::InSecondsF() const {
  52   if (is_max()) {
  53     // Preserve max to prevent overflow.
  54     return std::numeric_limits<double>::infinity();
  55   }
  56   return static_cast<double>(delta_) / Time::kMicrosecondsPerSecond;
  57 }
  58
  59 int64 TimeDelta::InSeconds() const {
  60   if (is_max()) {
  61     // Preserve max to prevent overflow.
  62     return std::numeric_limits<int64>::max();
  63   }
  64   return delta_ / Time::kMicrosecondsPerSecond;
  65 }
  66
  67 double TimeDelta::InMillisecondsF() const {
  68   if (is_max()) {
  69     // Preserve max to prevent overflow.
  70     return std::numeric_limits<double>::infinity();
  71   }
  72   return static_cast<double>(delta_) / Time::kMicrosecondsPerMillisecond;
  73 }
  74
  75 int64 TimeDelta::InMilliseconds() const {
  76   if (is_max()) {
  77     // Preserve max to prevent overflow.
  78     return std::numeric_limits<int64>::max();
  79   }
  80   return delta_ / Time::kMicrosecondsPerMillisecond;
  81 }
  82
  83 int64 TimeDelta::InMillisecondsRoundedUp() const {
  84   if (is_max()) {
  85     // Preserve max to prevent overflow.
  86     return std::numeric_limits<int64>::max();
  87   }
  88   return (delta_ + Time::kMicrosecondsPerMillisecond - 1) /
  89       Time::kMicrosecondsPerMillisecond;
  90 }
  91
  92 int64 TimeDelta::InMicroseconds() const {
  93   if (is_max()) {
  94     // Preserve max to prevent overflow.
  95     return std::numeric_limits<int64>::max();
  96   }
  97   return delta_;
  98 }
  99
 100 std::ostream& operator<<(std::ostream& os, TimeDelta time_delta) {
 101   return os << time_delta.InSecondsF() << "s";
 102 }
 103
 104 // Time -----------------------------------------------------------------------
 105
 106 // static
 107 Time Time::Max() {
 108   return Time(std::numeric_limits<int64>::max());
 109 }
 110
 111 // static
 112 Time Time::FromTimeT(time_t tt) {
 113   if (tt == 0)
 114     return Time();  // Preserve 0 so we can tell it doesn't exist.
 115   if (tt == std::numeric_limits<time_t>::max())
 116     return Max();
 117   return Time((tt * kMicrosecondsPerSecond) + kTimeTToMicrosecondsOffset);
 118 }
 119
 120 time_t Time::ToTimeT() const {
 121   if (is_null())
 122     return 0;  // Preserve 0 so we can tell it doesn't exist.
 123   if (is_max()) {
 124     // Preserve max without offset to prevent overflow.
 125     return std::numeric_limits<time_t>::max();
 126   }
 127   if (std::numeric_limits<int64>::max() - kTimeTToMicrosecondsOffset <= us_) {
 128     DLOG(WARNING) << "Overflow when converting base::Time with internal " <<
 129                      "value " << us_ << " to time_t.";
 130     return std::numeric_limits<time_t>::max();
 131   }
 132   return (us_ - kTimeTToMicrosecondsOffset) / kMicrosecondsPerSecond;
 133 }
 134
 135 // static
 136 Time Time::FromDoubleT(double dt) {
 137   if (dt == 0 || IsNaN(dt))
 138     return Time();  // Preserve 0 so we can tell it doesn't exist.
 139   if (dt == std::numeric_limits<double>::infinity())
 140     return Max();
 141   return Time(static_cast<int64>((dt *
 142                                   static_cast<double>(kMicrosecondsPerSecond)) +
 143                                  kTimeTToMicrosecondsOffset));
 144 }
 145
 146 double Time::ToDoubleT() const {
 147   if (is_null())
 148     return 0;  // Preserve 0 so we can tell it doesn't exist.
 149   if (is_max()) {
 150     // Preserve max without offset to prevent overflow.
 151     return std::numeric_limits<double>::infinity();
 152   }
 153   return (static_cast<double>(us_ - kTimeTToMicrosecondsOffset) /
 154           static_cast<double>(kMicrosecondsPerSecond));
 155 }
 156
 157 #if defined(OS_POSIX)
 158 // static
 159 Time Time::FromTimeSpec(const timespec& ts) {
 160   return FromDoubleT(ts.tv_sec +
 161                      static_cast<double>(ts.tv_nsec) /
 162                          base::Time::kNanosecondsPerSecond);
 163 }
 164 #endif
 165
 166 // static
 167 Time Time::FromJsTime(double ms_since_epoch) {
 168   // The epoch is a valid time, so this constructor doesn't interpret
 169   // 0 as the null time.
 170   if (ms_since_epoch == std::numeric_limits<double>::infinity())
 171     return Max();
 172   return Time(static_cast<int64>(ms_since_epoch * kMicrosecondsPerMillisecond) +
 173               kTimeTToMicrosecondsOffset);
 174 }
 175
 176 double Time::ToJsTime() const {
 177   if (is_null()) {
 178     // Preserve 0 so the invalid result doesn't depend on the platform.
 179     return 0;
 180   }
 181   if (is_max()) {
 182     // Preserve max without offset to prevent overflow.
 183     return std::numeric_limits<double>::infinity();
 184   }
 185   return (static_cast<double>(us_ - kTimeTToMicrosecondsOffset) /
 186           kMicrosecondsPerMillisecond);
 187 }
 188
 189 int64 Time::ToJavaTime() const {
 190   if (is_null()) {
 191     // Preserve 0 so the invalid result doesn't depend on the platform.
 192     return 0;
 193   }
 194   if (is_max()) {
 195     // Preserve max without offset to prevent overflow.
 196     return std::numeric_limits<int64>::max();
 197   }
 198   return ((us_ - kTimeTToMicrosecondsOffset) /
 199           kMicrosecondsPerMillisecond);
 200 }
 201
 202 // static
 203 Time Time::UnixEpoch() {
 204   Time time;
 205   time.us_ = kTimeTToMicrosecondsOffset;
 206   return time;
 207 }
 208
 209 Time Time::LocalMidnight() const {
 210   Exploded exploded;
 211   LocalExplode(&exploded);
 212   exploded.hour = 0;
 213   exploded.minute = 0;
 214   exploded.second = 0;
 215   exploded.millisecond = 0;
 216   return FromLocalExploded(exploded);
 217 }
 218
 219 // static
 220 bool Time::FromStringInternal(const char* time_string,
 221                               bool is_local,
 222                               Time* parsed_time) {
 223   DCHECK((time_string != NULL) && (parsed_time != NULL));
 224
 225   if (time_string[0] == '\0')
 226     return false;
 227
 228   PRTime result_time = 0;
 229   PRStatus result = PR_ParseTimeString(time_string,
 230                                        is_local ? PR_FALSE : PR_TRUE,
 231                                        &result_time);
 232   if (PR_SUCCESS != result)
 233     return false;
 234
 235   result_time += kTimeTToMicrosecondsOffset;
 236   *parsed_time = Time(result_time);
 237   return true;
 238 }
 239
 240 std::ostream& operator<<(std::ostream& os, Time time) {
 241   Time::Exploded exploded;
 242   time.UTCExplode(&exploded);
 243   // Use StringPrintf because iostreams formatting is painful.
 244   return os << StringPrintf("%04d-%02d-%02d %02d:%02d:%02d.%03d UTC",
 245                             exploded.year,
 246                             exploded.month,
 247                             exploded.day_of_month,
 248                             exploded.hour,
 249                             exploded.minute,
 250                             exploded.second,
 251                             exploded.millisecond);
 252 }
 253
 254 // Local helper class to hold the conversion from Time to TickTime at the
 255 // time of the Unix epoch.
 256 class UnixEpochSingleton {
 257  public:
 258   UnixEpochSingleton()
 259       : unix_epoch_(TimeTicks::Now() - (Time::Now() - Time::UnixEpoch())) {}
 260
 261   TimeTicks unix_epoch() const { return unix_epoch_; }
 262
 263  private:
 264   const TimeTicks unix_epoch_;
 265
 266   DISALLOW_COPY_AND_ASSIGN(UnixEpochSingleton);
 267 };
 268
 269 static LazyInstance<UnixEpochSingleton>::Leaky
 270     leaky_unix_epoch_singleton_instance = LAZY_INSTANCE_INITIALIZER;
 271
 272 // Static
 273 TimeTicks TimeTicks::UnixEpoch() {
 274   return leaky_unix_epoch_singleton_instance.Get().unix_epoch();
 275 }
 276
 277 std::ostream& operator<<(std::ostream& os, TimeTicks time_ticks) {
 278   // This function formats a TimeTicks object as "bogo-microseconds".
 279   // The origin and granularity of the count are platform-specific, and may very
 280   // from run to run. Although bogo-microseconds usually roughly correspond to
 281   // real microseconds, the only real guarantee is that the number never goes
 282   // down during a single run.
 283   const TimeDelta as_time_delta = time_ticks - TimeTicks();
 284   return os << as_time_delta.InMicroseconds() << " bogo-microseconds";
 285 }
 286
 287 // Time::Exploded -------------------------------------------------------------
 288
 289 inline bool is_in_range(int value, int lo, int hi) {
 290   return lo <= value && value <= hi;
 291 }
 292
 293 bool Time::Exploded::HasValidValues() const {
 294   return is_in_range(month, 1, 12) &&
 295          is_in_range(day_of_week, 0, 6) &&
 296          is_in_range(day_of_month, 1, 31) &&
 297          is_in_range(hour, 0, 23) &&
 298          is_in_range(minute, 0, 59) &&
 299          is_in_range(second, 0, 60) &&
 300          is_in_range(millisecond, 0, 999);
 301 }
 302
 303 }  // namespace base