1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/webui/flags/flags_ui_metrics.h"
#include <set>
#include <string>
#include "base/logging.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/metrics_hashes.h"
#include "base/notreached.h"
#include "base/strings/string_util.h"
namespace flags_ui {
namespace {
// Records a set of feature switches (prefixed with "--").
void ReportAboutFlagsHistogramSwitches(const std::string& uma_histogram_name,
const std::set<std::string>& switches) {
for (const std::string& flag : switches) {
int uma_id = testing::kBadSwitchFormatHistogramId;
if (base::StartsWith(flag, "--", base::CompareCase::SENSITIVE)) {
// Skip '--' before switch name.
std::string switch_name(flag.substr(2));
// Kill value, if any.
const size_t value_pos = switch_name.find('=');
if (value_pos != std::string::npos) {
switch_name.resize(value_pos);
}
uma_id = GetSwitchUMAId(switch_name);
} else {
NOTREACHED() << "ReportAboutFlagsHistogram(): flag '" << flag
<< "' has incorrect format.";
}
DVLOG(1) << "ReportAboutFlagsHistogram(): histogram='" << uma_histogram_name
<< "' '" << flag << "', uma_id=" << uma_id;
base::UmaHistogramSparse(uma_histogram_name, uma_id);
}
}
// Records a set of FEATURE_VALUE_TYPE features (suffixed with ":enabled" or
// "disabled", depending on their state).
void ReportAboutFlagsHistogramFeatures(const std::string& uma_histogram_name,
const std::set<std::string>& features) {
for (const std::string& feature : features) {
int uma_id = GetSwitchUMAId(feature);
DVLOG(1) << "ReportAboutFlagsHistogram(): histogram='" << uma_histogram_name
<< "' '" << feature << "', uma_id=" << uma_id;
base::UmaHistogramSparse(uma_histogram_name, uma_id);
}
}
} // namespace
base::HistogramBase::Sample32 GetSwitchUMAId(const std::string& switch_name) {
return static_cast<base::HistogramBase::Sample32>(
base::HashMetricName(switch_name));
}
void ReportAboutFlagsHistogram(const std::string& uma_histogram_name,
const std::set<std::string>& switches,
const std::set<std::string>& features) {
ReportAboutFlagsHistogramSwitches(uma_histogram_name, switches);
ReportAboutFlagsHistogramFeatures(uma_histogram_name, features);
}
namespace testing {
const base::HistogramBase::Sample32 kBadSwitchFormatHistogramId = 0;
} // namespace testing
} // namespace flags_ui
|
