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Issue 624713003: Keep only base/extractor.[cc|h]. (Closed) Base URL: https://chromium.googlesource.com/external/omaha.git@master
Patch Set: Created 6 years, 2 months ago
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1 // Copyright 2006-2009 Google Inc.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 // ========================================================================
15 #include "omaha/base/highres_timer-win32.h"
16
17 namespace omaha {
18
19 bool HighresTimer::perf_freq_collected_ = false;
20 ULONGLONG HighresTimer::perf_freq_ = 0;
21
22 ULONGLONG HighresTimer::GetElapsedMs() const {
23 ULONGLONG end_time = GetCurrentTicks();
24
25 // Scale to ms and round to nearerst ms - rounding is important
26 // because otherwise the truncation error may accumulate e.g. in sums.
27 //
28 // Given infinite resolution, this expression could be written as:
29 // trunc((end - start (units:freq*sec))/freq (units:sec) *
30 // 1000 (unit:ms) + 1/2 (unit:ms))
31 ULONGLONG freq = GetTimerFrequency();
32 return ((end_time - start_ticks_) * 1000L + freq / 2) / freq;
33 }
34
35 ULONGLONG HighresTimer::GetElapsedSec() const {
36 ULONGLONG end_time = GetCurrentTicks();
37
38 // Scale to ms and round to nearerst ms - rounding is important
39 // because otherwise the truncation error may accumulate e.g. in sums.
40 //
41 // Given infinite resolution, this expression could be written as:
42 // trunc((end - start (units:freq*sec))/freq (unit:sec) + 1/2 (unit:sec))
43 ULONGLONG freq = GetTimerFrequency();
44 return ((end_time - start_ticks_) + freq / 2) / freq;
45 }
46
47 void HighresTimer::CollectPerfFreq() {
48 LARGE_INTEGER freq;
49
50 // Note that this is racy.
51 // It's OK, however, because even concurrent executions of this
52 // are idempotent.
53 if (::QueryPerformanceFrequency(&freq)) {
54 perf_freq_ = freq.QuadPart;
55 perf_freq_collected_ = true;
56 }
57 }
58
59 } // namespace omaha
60
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