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 <time.h>
15
16 #include "webrtc/base/basictypes.h"
17
18 namespace rtc {
19
20 static const int64 kNumMillisecsPerSec = INT64_C(1000);
21 static const int64 kNumMicrosecsPerSec = INT64_C(1000000);
22 static const int64 kNumNanosecsPerSec = INT64_C(1000000000);
23
24 static const int64 kNumMicrosecsPerMillisec = kNumMicrosecsPerSec /
25 kNumMillisecsPerSec;
26 static const int64 kNumNanosecsPerMillisec = kNumNanosecsPerSec /
27 kNumMillisecsPerSec;
28 static const int64 kNumNanosecsPerMicrosec = kNumNanosecsPerSec /
29 kNumMicrosecsPerSec;
30
31 // January 1970, in NTP milliseconds.
32 static const int64 kJan1970AsNtpMillisecs = INT64_C(2208988800000);
33
34 typedef uint32 TimeStamp;
35
36 // Returns the current time in milliseconds.
37 uint32 Time();
38 // Returns the current time in microseconds.
39 uint64 TimeMicros();
40 // Returns the current time in nanoseconds.
41 uint64 TimeNanos();
42
43 // Stores current time in *tm and microseconds in *microseconds.
44 void CurrentTmTime(struct tm *tm, int *microseconds);
45
46 // Returns a future timestamp, 'elapsed' milliseconds from now.
47 uint32 TimeAfter(int32 elapsed);
48
49 // Comparisons between time values, which can wrap around.
50 bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later); // Inclusive
51 bool TimeIsLaterOrEqual(uint32 earlier, uint32 later); // Inclusive
52 bool TimeIsLater(uint32 earlier, uint32 later); // Exclusive
53
54 // Returns the later of two timestamps.
TimeMax(uint32 ts1,uint32 ts2)55 inline uint32 TimeMax(uint32 ts1, uint32 ts2) {
56 return TimeIsLaterOrEqual(ts1, ts2) ? ts2 : ts1;
57 }
58
59 // Returns the earlier of two timestamps.
TimeMin(uint32 ts1,uint32 ts2)60 inline uint32 TimeMin(uint32 ts1, uint32 ts2) {
61 return TimeIsLaterOrEqual(ts1, ts2) ? ts1 : ts2;
62 }
63
64 // Number of milliseconds that would elapse between 'earlier' and 'later'
65 // timestamps. The value is negative if 'later' occurs before 'earlier'.
66 int32 TimeDiff(uint32 later, uint32 earlier);
67
68 // The number of milliseconds that have elapsed since 'earlier'.
TimeSince(uint32 earlier)69 inline int32 TimeSince(uint32 earlier) {
70 return TimeDiff(Time(), earlier);
71 }
72
73 // The number of milliseconds that will elapse between now and 'later'.
TimeUntil(uint32 later)74 inline int32 TimeUntil(uint32 later) {
75 return TimeDiff(later, Time());
76 }
77
78 // Converts a unix timestamp in nanoseconds to an NTP timestamp in ms.
UnixTimestampNanosecsToNtpMillisecs(int64 unix_ts_ns)79 inline int64 UnixTimestampNanosecsToNtpMillisecs(int64 unix_ts_ns) {
80 return unix_ts_ns / kNumNanosecsPerMillisec + kJan1970AsNtpMillisecs;
81 }
82
83 class TimestampWrapAroundHandler {
84 public:
85 TimestampWrapAroundHandler();
86
87 int64 Unwrap(uint32 ts);
88
89 private:
90 uint32 last_ts_;
91 int64 num_wrap_;
92 };
93
94 } // namespace rtc
95
96 #endif // WEBRTC_BASE_TIMEUTILS_H_
97