1 /*
2 * libjingle
3 * Copyright 2005 Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #ifndef TALK_BASE_TIMEUTILS_H_
29 #define TALK_BASE_TIMEUTILS_H_
30
31 #include <time.h>
32
33 #include "talk/base/basictypes.h"
34
35 namespace talk_base {
36
37 static const int64 kNumMillisecsPerSec = INT64_C(1000);
38 static const int64 kNumMicrosecsPerSec = INT64_C(1000000);
39 static const int64 kNumNanosecsPerSec = INT64_C(1000000000);
40
41 static const int64 kNumMicrosecsPerMillisec = kNumMicrosecsPerSec /
42 kNumMillisecsPerSec;
43 static const int64 kNumNanosecsPerMillisec = kNumNanosecsPerSec /
44 kNumMillisecsPerSec;
45 static const int64 kNumNanosecsPerMicrosec = kNumNanosecsPerSec /
46 kNumMicrosecsPerSec;
47
48 // January 1970, in NTP milliseconds.
49 static const int64 kJan1970AsNtpMillisecs = INT64_C(2208988800000);
50
51 typedef uint32 TimeStamp;
52
53 // Returns the current time in milliseconds.
54 uint32 Time();
55 // Returns the current time in microseconds.
56 uint64 TimeMicros();
57 // Returns the current time in nanoseconds.
58 uint64 TimeNanos();
59
60 // Stores current time in *tm and microseconds in *microseconds.
61 void CurrentTmTime(struct tm *tm, int *microseconds);
62
63 // Returns a future timestamp, 'elapsed' milliseconds from now.
64 uint32 TimeAfter(int32 elapsed);
65
66 // Comparisons between time values, which can wrap around.
67 bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later); // Inclusive
68 bool TimeIsLaterOrEqual(uint32 earlier, uint32 later); // Inclusive
69 bool TimeIsLater(uint32 earlier, uint32 later); // Exclusive
70
71 // Returns the later of two timestamps.
TimeMax(uint32 ts1,uint32 ts2)72 inline uint32 TimeMax(uint32 ts1, uint32 ts2) {
73 return TimeIsLaterOrEqual(ts1, ts2) ? ts2 : ts1;
74 }
75
76 // Returns the earlier of two timestamps.
TimeMin(uint32 ts1,uint32 ts2)77 inline uint32 TimeMin(uint32 ts1, uint32 ts2) {
78 return TimeIsLaterOrEqual(ts1, ts2) ? ts1 : ts2;
79 }
80
81 // Number of milliseconds that would elapse between 'earlier' and 'later'
82 // timestamps. The value is negative if 'later' occurs before 'earlier'.
83 int32 TimeDiff(uint32 later, uint32 earlier);
84
85 // The number of milliseconds that have elapsed since 'earlier'.
TimeSince(uint32 earlier)86 inline int32 TimeSince(uint32 earlier) {
87 return TimeDiff(Time(), earlier);
88 }
89
90 // The number of milliseconds that will elapse between now and 'later'.
TimeUntil(uint32 later)91 inline int32 TimeUntil(uint32 later) {
92 return TimeDiff(later, Time());
93 }
94
95 // Converts a unix timestamp in nanoseconds to an NTP timestamp in ms.
UnixTimestampNanosecsToNtpMillisecs(int64 unix_ts_ns)96 inline int64 UnixTimestampNanosecsToNtpMillisecs(int64 unix_ts_ns) {
97 return unix_ts_ns / kNumNanosecsPerMillisec + kJan1970AsNtpMillisecs;
98 }
99
100 class TimestampWrapAroundHandler {
101 public:
102 TimestampWrapAroundHandler();
103
104 int64 Unwrap(uint32 ts);
105
106 private:
107 uint32 last_ts_;
108 int64 num_wrap_;
109 };
110
111 } // namespace talk_base
112
113 #endif // TALK_BASE_TIMEUTILS_H_
114