webrtc/talk/base/timeutils.h

99 lines
3.7 KiB
C++

/*
* libjingle
* Copyright 2005 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef TALK_BASE_TIMEUTILS_H_
#define TALK_BASE_TIMEUTILS_H_
#include <time.h>
#include "talk/base/basictypes.h"
namespace talk_base {
static const int64 kNumMillisecsPerSec = INT64_C(1000);
static const int64 kNumMicrosecsPerSec = INT64_C(1000000);
static const int64 kNumNanosecsPerSec = INT64_C(1000000000);
static const int64 kNumMicrosecsPerMillisec = kNumMicrosecsPerSec /
kNumMillisecsPerSec;
static const int64 kNumNanosecsPerMillisec = kNumNanosecsPerSec /
kNumMillisecsPerSec;
// January 1970, in NTP milliseconds.
static const int64 kJan1970AsNtpMillisecs = INT64_C(2208988800000);
typedef uint32 TimeStamp;
// Returns the current time in milliseconds.
uint32 Time();
// Returns the current time in nanoseconds.
uint64 TimeNanos();
// Stores current time in *tm and microseconds in *microseconds.
void CurrentTmTime(struct tm *tm, int *microseconds);
// Returns a future timestamp, 'elapsed' milliseconds from now.
uint32 TimeAfter(int32 elapsed);
// Comparisons between time values, which can wrap around.
bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later); // Inclusive
bool TimeIsLaterOrEqual(uint32 earlier, uint32 later); // Inclusive
bool TimeIsLater(uint32 earlier, uint32 later); // Exclusive
// Returns the later of two timestamps.
inline uint32 TimeMax(uint32 ts1, uint32 ts2) {
return TimeIsLaterOrEqual(ts1, ts2) ? ts2 : ts1;
}
// Returns the earlier of two timestamps.
inline uint32 TimeMin(uint32 ts1, uint32 ts2) {
return TimeIsLaterOrEqual(ts1, ts2) ? ts1 : ts2;
}
// Number of milliseconds that would elapse between 'earlier' and 'later'
// timestamps. The value is negative if 'later' occurs before 'earlier'.
int32 TimeDiff(uint32 later, uint32 earlier);
// The number of milliseconds that have elapsed since 'earlier'.
inline int32 TimeSince(uint32 earlier) {
return TimeDiff(Time(), earlier);
}
// The number of milliseconds that will elapse between now and 'later'.
inline int32 TimeUntil(uint32 later) {
return TimeDiff(later, Time());
}
// Converts a unix timestamp in nanoseconds to an NTP timestamp in ms.
inline int64 UnixTimestampNanosecsToNtpMillisecs(int64 unix_ts_ns) {
return unix_ts_ns / kNumNanosecsPerMillisec + kJan1970AsNtpMillisecs;
}
} // namespace talk_base
#endif // TALK_BASE_TIMEUTILS_H_