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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef BASE_PROFILER_TRACKED_TIME_H_ | |
6 #define BASE_PROFILER_TRACKED_TIME_H_ | |
7 | |
8 #include <stdint.h> | |
9 | |
10 #include "base/base_export.h" | |
11 #include "base/time/time.h" | |
12 | |
13 namespace tracked_objects { | |
14 | |
15 //------------------------------------------------------------------------------ | |
16 | |
17 // TimeTicks maintains a wasteful 64 bits of data (we need less than 32), and on | |
18 // windows, a 64 bit timer is expensive to even obtain. We use a simple | |
19 // millisecond counter for most of our time values, as well as millisecond units | |
20 // of duration between those values. This means we can only handle durations | |
21 // up to 49 days (range), or 24 days (non-negative time durations). | |
22 // We only define enough methods to service the needs of the tracking classes, | |
23 // and our interfaces are modeled after what TimeTicks and TimeDelta use (so we | |
24 // can swap them into place if we want to use the "real" classes). | |
25 | |
26 class BASE_EXPORT Duration { // Similar to base::TimeDelta. | |
27 public: | |
28 Duration(); | |
29 | |
30 Duration& operator+=(const Duration& other); | |
31 Duration operator+(const Duration& other) const; | |
32 | |
33 bool operator==(const Duration& other) const; | |
34 bool operator!=(const Duration& other) const; | |
35 bool operator>(const Duration& other) const; | |
36 | |
37 static Duration FromMilliseconds(int ms); | |
38 | |
39 int32_t InMilliseconds() const; | |
40 | |
41 private: | |
42 friend class TrackedTime; | |
43 explicit Duration(int32_t duration); | |
44 | |
45 // Internal time is stored directly in milliseconds. | |
46 int32_t ms_; | |
47 }; | |
48 | |
49 class BASE_EXPORT TrackedTime { // Similar to base::TimeTicks. | |
50 public: | |
51 TrackedTime(); | |
52 explicit TrackedTime(const base::TimeTicks& time); | |
53 | |
54 static TrackedTime Now(); | |
55 Duration operator-(const TrackedTime& other) const; | |
56 TrackedTime operator+(const Duration& other) const; | |
57 bool is_null() const; | |
58 | |
59 static TrackedTime FromMilliseconds(int32_t ms) { return TrackedTime(ms); } | |
60 | |
61 private: | |
62 friend class Duration; | |
63 explicit TrackedTime(int32_t ms); | |
64 | |
65 // Internal duration is stored directly in milliseconds. | |
66 uint32_t ms_; | |
67 }; | |
68 | |
69 } // namespace tracked_objects | |
70 | |
71 #endif // BASE_PROFILER_TRACKED_TIME_H_ | |
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