3 * Copyright 2005 Google Inc.
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28 #ifndef TALK_BASE_TIMEUTILS_H_
29 #define TALK_BASE_TIMEUTILS_H_
33 #include "talk/base/basictypes.h"
37 static const int64 kNumMillisecsPerSec = INT64_C(1000);
38 static const int64 kNumMicrosecsPerSec = INT64_C(1000000);
39 static const int64 kNumNanosecsPerSec = INT64_C(1000000000);
41 static const int64 kNumMicrosecsPerMillisec = kNumMicrosecsPerSec /
43 static const int64 kNumNanosecsPerMillisec = kNumNanosecsPerSec /
46 // January 1970, in NTP milliseconds.
47 static const int64 kJan1970AsNtpMillisecs = INT64_C(2208988800000);
49 typedef uint32 TimeStamp;
51 // Returns the current time in milliseconds.
53 // Returns the current time in nanoseconds.
56 // Stores current time in *tm and microseconds in *microseconds.
57 void CurrentTmTime(struct tm *tm, int *microseconds);
59 // Returns a future timestamp, 'elapsed' milliseconds from now.
60 uint32 TimeAfter(int32 elapsed);
62 // Comparisons between time values, which can wrap around.
63 bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later); // Inclusive
64 bool TimeIsLaterOrEqual(uint32 earlier, uint32 later); // Inclusive
65 bool TimeIsLater(uint32 earlier, uint32 later); // Exclusive
67 // Returns the later of two timestamps.
68 inline uint32 TimeMax(uint32 ts1, uint32 ts2) {
69 return TimeIsLaterOrEqual(ts1, ts2) ? ts2 : ts1;
72 // Returns the earlier of two timestamps.
73 inline uint32 TimeMin(uint32 ts1, uint32 ts2) {
74 return TimeIsLaterOrEqual(ts1, ts2) ? ts1 : ts2;
77 // Number of milliseconds that would elapse between 'earlier' and 'later'
78 // timestamps. The value is negative if 'later' occurs before 'earlier'.
79 int32 TimeDiff(uint32 later, uint32 earlier);
81 // The number of milliseconds that have elapsed since 'earlier'.
82 inline int32 TimeSince(uint32 earlier) {
83 return TimeDiff(Time(), earlier);
86 // The number of milliseconds that will elapse between now and 'later'.
87 inline int32 TimeUntil(uint32 later) {
88 return TimeDiff(later, Time());
91 // Converts a unix timestamp in nanoseconds to an NTP timestamp in ms.
92 inline int64 UnixTimestampNanosecsToNtpMillisecs(int64 unix_ts_ns) {
93 return unix_ts_ns / kNumNanosecsPerMillisec + kJan1970AsNtpMillisecs;
96 } // namespace talk_base
98 #endif // TALK_BASE_TIMEUTILS_H_