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 #ifdef POSIX
29 #include <sys/time.h>
30 #endif
31
32 #ifdef WIN32
33 #define WIN32_LEAN_AND_MEAN
34 #include <windows.h>
35 #endif
36
37 #include "talk/base/common.h"
38 #include "talk/base/time.h"
39
40 #define EFFICIENT_IMPLEMENTATION 1
41
42 namespace talk_base {
43
44 const uint32 LAST = 0xFFFFFFFF;
45 const uint32 HALF = 0x80000000;
46
47 #ifdef POSIX
Time()48 uint32 Time() {
49 struct timeval tv;
50 gettimeofday(&tv, 0);
51 return tv.tv_sec * 1000 + tv.tv_usec / 1000;
52 }
53 #endif
54
55 #ifdef WIN32
Time()56 uint32 Time() {
57 return GetTickCount();
58 }
59 #endif
60
StartTime()61 uint32 StartTime() {
62 // Close to program execution time
63 static const uint32 g_start = Time();
64 return g_start;
65 }
66
67 // Make sure someone calls it so that it gets initialized
68 static uint32 ignore = StartTime();
69
TimeAfter(int32 elapsed)70 uint32 TimeAfter(int32 elapsed) {
71 ASSERT(elapsed >= 0);
72 ASSERT(static_cast<uint32>(elapsed) < HALF);
73 return Time() + elapsed;
74 }
75
TimeIsBetween(uint32 earlier,uint32 middle,uint32 later)76 bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later) {
77 if (earlier <= later) {
78 return ((earlier <= middle) && (middle <= later));
79 } else {
80 return !((later < middle) && (middle < earlier));
81 }
82 }
83
TimeIsLaterOrEqual(uint32 earlier,uint32 later)84 bool TimeIsLaterOrEqual(uint32 earlier, uint32 later) {
85 #if EFFICIENT_IMPLEMENTATION
86 int32 diff = later - earlier;
87 return (diff >= 0 && static_cast<uint32>(diff) < HALF);
88 #else
89 const bool later_or_equal = TimeIsBetween(earlier, later, earlier + HALF);
90 return later_or_equal;
91 #endif
92 }
93
TimeIsLater(uint32 earlier,uint32 later)94 bool TimeIsLater(uint32 earlier, uint32 later) {
95 #if EFFICIENT_IMPLEMENTATION
96 int32 diff = later - earlier;
97 return (diff > 0 && static_cast<uint32>(diff) < HALF);
98 #else
99 const bool earlier_or_equal = TimeIsBetween(later, earlier, later + HALF);
100 return !earlier_or_equal;
101 #endif
102 }
103
TimeDiff(uint32 later,uint32 earlier)104 int32 TimeDiff(uint32 later, uint32 earlier) {
105 #if EFFICIENT_IMPLEMENTATION
106 return later - earlier;
107 #else
108 const bool later_or_equal = TimeIsBetween(earlier, later, earlier + HALF);
109 if (later_or_equal) {
110 if (earlier <= later) {
111 return static_cast<long>(later - earlier);
112 } else {
113 return static_cast<long>(later + (LAST - earlier) + 1);
114 }
115 } else {
116 if (later <= earlier) {
117 return -static_cast<long>(earlier - later);
118 } else {
119 return -static_cast<long>(earlier + (LAST - later) + 1);
120 }
121 }
122 #endif
123 }
124
125 } // namespace talk_base
126