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The Tor Browser
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Time.h (4467B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This code is made available to you under your choice of the following sets
      4 * of licensing terms:
      5 */
      6 /* This Source Code Form is subject to the terms of the Mozilla Public
      7 * License, v. 2.0. If a copy of the MPL was not distributed with this
      8 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
      9 */
     10 /* Copyright 2014 Mozilla Contributors
     11 *
     12 * Licensed under the Apache License, Version 2.0 (the "License");
     13 * you may not use this file except in compliance with the License.
     14 * You may obtain a copy of the License at
     15 *
     16 *     http://www.apache.org/licenses/LICENSE-2.0
     17 *
     18 * Unless required by applicable law or agreed to in writing, software
     19 * distributed under the License is distributed on an "AS IS" BASIS,
     20 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     21 * See the License for the specific language governing permissions and
     22 * limitations under the License.
     23 */
     24 
     25 #ifndef mozilla_pkix_Time_h
     26 #define mozilla_pkix_Time_h
     27 
     28 #include <stdint.h>
     29 #include <ctime>
     30 #include <limits>
     31 
     32 #include "mozpkix/Result.h"
     33 
     34 namespace mozilla {
     35 namespace pkix {
     36 
     37 // Time with a range from the first second of year 0 (AD) through at least the
     38 // last second of year 9999, which is the range of legal times in X.509 and
     39 // OCSP. This type has second-level precision. The time zone is always UTC.
     40 //
     41 // Pass by value, not by reference.
     42 class Time final {
     43 public:
     44  // Construct an uninitialized instance.
     45  //
     46  // This will fail to compile because there is no default constructor:
     47  //    Time x;
     48  //
     49  // This will succeed, leaving the time uninitialized:
     50  //    Time x(Time::uninitialized);
     51  enum Uninitialized { uninitialized };
     52  explicit Time(Uninitialized) {}
     53 
     54  bool operator==(const Time& other) const {
     55    return elapsedSecondsAD == other.elapsedSecondsAD;
     56  }
     57  bool operator>(const Time& other) const {
     58    return elapsedSecondsAD > other.elapsedSecondsAD;
     59  }
     60  bool operator>=(const Time& other) const {
     61    return elapsedSecondsAD >= other.elapsedSecondsAD;
     62  }
     63  bool operator<(const Time& other) const {
     64    return elapsedSecondsAD < other.elapsedSecondsAD;
     65  }
     66  bool operator<=(const Time& other) const {
     67    return elapsedSecondsAD <= other.elapsedSecondsAD;
     68  }
     69 
     70  Result AddSeconds(uint64_t seconds) {
     71    if (std::numeric_limits<uint64_t>::max() - elapsedSecondsAD < seconds) {
     72      return Result::FATAL_ERROR_INVALID_ARGS;  // integer overflow
     73    }
     74    elapsedSecondsAD += seconds;
     75    return Success;
     76  }
     77 
     78  Result SubtractSeconds(uint64_t seconds) {
     79    if (seconds > elapsedSecondsAD) {
     80      return Result::FATAL_ERROR_INVALID_ARGS;  // integer overflow
     81    }
     82    elapsedSecondsAD -= seconds;
     83    return Success;
     84  }
     85 
     86  static const uint64_t ONE_DAY_IN_SECONDS =
     87      UINT64_C(24) * UINT64_C(60) * UINT64_C(60);
     88 
     89 private:
     90  // This constructor is hidden to prevent accidents like this:
     91  //
     92  //    Time foo(time_t t)
     93  //    {
     94  //      // WRONG! 1970-01-01-00:00:00 == time_t(0), but not Time(0)!
     95  //      return Time(t);
     96  //    }
     97  explicit Time(uint64_t aElapsedSecondsAD)
     98      : elapsedSecondsAD(aElapsedSecondsAD) {}
     99  friend Time TimeFromElapsedSecondsAD(uint64_t);
    100  friend class Duration;
    101 
    102  uint64_t elapsedSecondsAD;
    103 };
    104 
    105 inline Time TimeFromElapsedSecondsAD(uint64_t aElapsedSecondsAD) {
    106  return Time(aElapsedSecondsAD);
    107 }
    108 
    109 Time Now();
    110 
    111 // Note the epoch is the unix epoch (ie 00:00:00 UTC, 1 January 1970)
    112 Time TimeFromEpochInSeconds(uint64_t secondsSinceEpoch);
    113 
    114 // Note the epoch is the unix epoch (ie 00:00:00 UTC, 1 January 1970)
    115 Result SecondsSinceEpochFromTime(Time time, uint64_t* outSeconds);
    116 
    117 class Duration final {
    118 public:
    119  Duration(Time timeA, Time timeB)
    120      : durationInSeconds(
    121            timeA < timeB ? timeB.elapsedSecondsAD - timeA.elapsedSecondsAD
    122                          : timeA.elapsedSecondsAD - timeB.elapsedSecondsAD) {}
    123 
    124  explicit Duration(uint64_t aDurationInSeconds)
    125      : durationInSeconds(aDurationInSeconds) {}
    126 
    127  bool operator>(const Duration& other) const {
    128    return durationInSeconds > other.durationInSeconds;
    129  }
    130  bool operator<(const Duration& other) const {
    131    return durationInSeconds < other.durationInSeconds;
    132  }
    133 
    134 private:
    135  friend Result SecondsSinceEpochFromTime(Time time, uint64_t* outSeconds);
    136 
    137  uint64_t durationInSeconds;
    138 };
    139 }  // namespace pkix
    140 }  // namespace mozilla
    141 
    142 #endif  // mozilla_pkix_Time_h