1 /* 2 * Copyright 2005 The WebRTC Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_BASE_TIMEUTILS_H_ 12 #define WEBRTC_BASE_TIMEUTILS_H_ 13 14 #include <ctime> 15 #include <time.h> 16 17 #include "webrtc/base/basictypes.h" 18 19 namespace rtc { 20 21 static const int64_t kNumMillisecsPerSec = INT64_C(1000); 22 static const int64_t kNumMicrosecsPerSec = INT64_C(1000000); 23 static const int64_t kNumNanosecsPerSec = INT64_C(1000000000); 24 25 static const int64_t kNumMicrosecsPerMillisec = 26 kNumMicrosecsPerSec / kNumMillisecsPerSec; 27 static const int64_t kNumNanosecsPerMillisec = 28 kNumNanosecsPerSec / kNumMillisecsPerSec; 29 static const int64_t kNumNanosecsPerMicrosec = 30 kNumNanosecsPerSec / kNumMicrosecsPerSec; 31 32 // January 1970, in NTP milliseconds. 33 static const int64_t kJan1970AsNtpMillisecs = INT64_C(2208988800000); 34 35 typedef uint32_t TimeStamp; 36 37 // Returns the current time in milliseconds. 38 uint32_t Time(); 39 // Returns the current time in microseconds. 40 uint64_t TimeMicros(); 41 // Returns the current time in nanoseconds. 42 uint64_t TimeNanos(); 43 44 // Stores current time in *tm and microseconds in *microseconds. 45 void CurrentTmTime(struct tm *tm, int *microseconds); 46 47 // Returns a future timestamp, 'elapsed' milliseconds from now. 48 uint32_t TimeAfter(int32_t elapsed); 49 50 // Comparisons between time values, which can wrap around. 51 bool TimeIsBetween(uint32_t earlier, 52 uint32_t middle, 53 uint32_t later); // Inclusive 54 bool TimeIsLaterOrEqual(uint32_t earlier, uint32_t later); // Inclusive 55 bool TimeIsLater(uint32_t earlier, uint32_t later); // Exclusive 56 57 // Returns the later of two timestamps. 58 inline uint32_t TimeMax(uint32_t ts1, uint32_t ts2) { 59 return TimeIsLaterOrEqual(ts1, ts2) ? ts2 : ts1; 60 } 61 62 // Returns the earlier of two timestamps. 63 inline uint32_t TimeMin(uint32_t ts1, uint32_t ts2) { 64 return TimeIsLaterOrEqual(ts1, ts2) ? ts1 : ts2; 65 } 66 67 // Number of milliseconds that would elapse between 'earlier' and 'later' 68 // timestamps. The value is negative if 'later' occurs before 'earlier'. 69 int32_t TimeDiff(uint32_t later, uint32_t earlier); 70 71 // The number of milliseconds that have elapsed since 'earlier'. 72 inline int32_t TimeSince(uint32_t earlier) { 73 return TimeDiff(Time(), earlier); 74 } 75 76 // The number of milliseconds that will elapse between now and 'later'. 77 inline int32_t TimeUntil(uint32_t later) { 78 return TimeDiff(later, Time()); 79 } 80 81 // Converts a unix timestamp in nanoseconds to an NTP timestamp in ms. 82 inline int64_t UnixTimestampNanosecsToNtpMillisecs(int64_t unix_ts_ns) { 83 return unix_ts_ns / kNumNanosecsPerMillisec + kJan1970AsNtpMillisecs; 84 } 85 86 class TimestampWrapAroundHandler { 87 public: 88 TimestampWrapAroundHandler(); 89 90 int64_t Unwrap(uint32_t ts); 91 92 private: 93 uint32_t last_ts_; 94 int64_t num_wrap_; 95 }; 96 97 // Convert from std::tm, which is relative to 1900-01-01 00:00 to number of 98 // seconds from 1970-01-01 00:00 ("epoch"). Don't return time_t since that 99 // is still 32 bits on many systems. 100 int64_t TmToSeconds(const std::tm& tm); 101 102 } // namespace rtc 103 104 #endif // WEBRTC_BASE_TIMEUTILS_H_ 105
