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      1 /*
      2  * libjingle
      3  * Copyright 2004--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_TIME_H__
     29 #define TALK_BASE_TIME_H__
     30 
     31 #ifndef WIN32
     32 #include_next <time.h>
     33 #endif
     34 
     35 #include "talk/base/basictypes.h"
     36 
     37 namespace talk_base {
     38 
     39 typedef uint32 TimeStamp;
     40 
     41 // Returns the current time in milliseconds.
     42 uint32 Time();
     43 
     44 // Approximate time when the program started.
     45 uint32 StartTime();
     46 
     47 // Returns a future timestamp, 'elapsed' milliseconds from now.
     48 uint32 TimeAfter(int32 elapsed);
     49 
     50 // Comparisons between time values, which can wrap around.
     51 bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later);  // Inclusive
     52 bool TimeIsLaterOrEqual(uint32 earlier, uint32 later);  // Inclusive
     53 bool TimeIsLater(uint32 earlier, uint32 later);  // Exclusive
     54 
     55 // Returns the later of two timestamps.
     56 inline uint32 TimeMax(uint32 ts1, uint32 ts2) {
     57   return TimeIsLaterOrEqual(ts1, ts2) ? ts2 : ts1;
     58 }
     59 
     60 // Returns the earlier of two timestamps.
     61 inline uint32 TimeMin(uint32 ts1, uint32 ts2) {
     62   return TimeIsLaterOrEqual(ts1, ts2) ? ts1 : ts2;
     63 }
     64 
     65 // Number of milliseconds that would elapse between 'earlier' and 'later'
     66 // timestamps.  The value is negative if 'later' occurs before 'earlier'.
     67 int32 TimeDiff(uint32 later, uint32 earlier);
     68 
     69 // The number of milliseconds that have elapsed since 'earlier'.
     70 inline int32 TimeSince(uint32 earlier) {
     71   return TimeDiff(Time(), earlier);
     72 }
     73 
     74 // The number of milliseconds that will elapse between now and 'later'.
     75 inline int32 TimeUntil(uint32 later) {
     76   return TimeDiff(later, Time());
     77 }
     78 
     79 } // namespace talk_base
     80 
     81 #endif // TALK_BASE_TIME_H__
     82