1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "CameraLatencyHistogram"
18 #include <inttypes.h>
19 #include <utils/Log.h>
20 #include <utils/String8.h>
21
22 #include "LatencyHistogram.h"
23
24 namespace android {
25
CameraLatencyHistogram(int32_t binSizeMs,int32_t binCount)26 CameraLatencyHistogram::CameraLatencyHistogram(int32_t binSizeMs, int32_t binCount) :
27 mBinSizeMs(binSizeMs),
28 mBinCount(binCount),
29 mBins(binCount),
30 mTotalCount(0) {
31 }
32
add(nsecs_t start,nsecs_t end)33 void CameraLatencyHistogram::add(nsecs_t start, nsecs_t end) {
34 nsecs_t duration = end - start;
35 int32_t durationMs = static_cast<int32_t>(duration / 1000000LL);
36 int32_t binIndex = durationMs / mBinSizeMs;
37
38 if (binIndex < 0) {
39 binIndex = 0;
40 } else if (binIndex >= mBinCount) {
41 binIndex = mBinCount-1;
42 }
43
44 mBins[binIndex]++;
45 mTotalCount++;
46 }
47
reset()48 void CameraLatencyHistogram::reset() {
49 mBins.clear();
50 mTotalCount = 0;
51 }
52
dump(int fd,const char * name) const53 void CameraLatencyHistogram::dump(int fd, const char* name) const {
54 if (mTotalCount == 0) {
55 return;
56 }
57
58 String8 lines;
59 lines.appendFormat("%s (%" PRId64 ") samples\n", name, mTotalCount);
60
61 String8 lineBins, lineBinCounts;
62 formatHistogramText(lineBins, lineBinCounts);
63
64 lineBins.append("\n");
65 lineBinCounts.append("\n");
66 lines.append(lineBins);
67 lines.append(lineBinCounts);
68
69 write(fd, lines.string(), lines.size());
70 }
71
log(const char * fmt,...)72 void CameraLatencyHistogram::log(const char* fmt, ...) {
73 if (mTotalCount == 0) {
74 return;
75 }
76
77 va_list args;
78 va_start(args, fmt);
79 String8 histogramName = String8::formatV(fmt, args);
80 ALOGI("%s (%" PRId64 ") samples:", histogramName.string(), mTotalCount);
81 va_end(args);
82
83 String8 lineBins, lineBinCounts;
84 formatHistogramText(lineBins, lineBinCounts);
85
86 ALOGI("%s", lineBins.c_str());
87 ALOGI("%s", lineBinCounts.c_str());
88 }
89
formatHistogramText(String8 & lineBins,String8 & lineBinCounts) const90 void CameraLatencyHistogram::formatHistogramText(
91 String8& lineBins, String8& lineBinCounts) const {
92 lineBins = " ";
93 lineBinCounts = " ";
94
95 for (int32_t i = 0; i < mBinCount; i++) {
96 if (i == mBinCount - 1) {
97 lineBins.append(" inf (max ms)");
98 } else {
99 lineBins.appendFormat("%7d", mBinSizeMs*(i+1));
100 }
101 lineBinCounts.appendFormat(" %02.2f", 100.0*mBins[i]/mTotalCount);
102 }
103 lineBinCounts.append(" (%)");
104 }
105
106 }; //namespace android
107