1 /*
2 * Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10 #include "api/test/metrics/stdout_metrics_exporter.h"
11
12 #include <stdio.h>
13
14 #include <cmath>
15 #include <string>
16
17 #include "absl/types/optional.h"
18 #include "api/array_view.h"
19 #include "api/test/metrics/metric.h"
20 #include "rtc_base/strings/string_builder.h"
21
22 namespace webrtc {
23 namespace test {
24 namespace {
25
26 // Returns positive integral part of the number.
IntegralPart(double value)27 int64_t IntegralPart(double value) {
28 return std::lround(std::floor(std::abs(value)));
29 }
30
AppendWithPrecision(double value,int digits_after_comma,rtc::StringBuilder & out)31 void AppendWithPrecision(double value,
32 int digits_after_comma,
33 rtc::StringBuilder& out) {
34 int64_t multiplier = std::lround(std::pow(10, digits_after_comma));
35 int64_t integral_part = IntegralPart(value);
36 double decimal_part = std::abs(value) - integral_part;
37
38 // If decimal part has leading zeros then when it will be multiplied on
39 // `multiplier`, leading zeros will be lost. To preserve them we add "1"
40 // so then leading digit will be greater than 0 and won't be removed.
41 //
42 // During conversion to the string leading digit has to be stripped.
43 //
44 // Also due to rounding it may happen that leading digit may be incremented,
45 // like with `digits_after_comma` 3 number 1.9995 will be rounded to 2. In
46 // such case this increment has to be propagated to the `integral_part`.
47 int64_t decimal_holder = std::lround((1 + decimal_part) * multiplier);
48 if (decimal_holder >= 2 * multiplier) {
49 // Rounding incremented added leading digit, so we need to transfer 1 to
50 // integral part.
51 integral_part++;
52 decimal_holder -= multiplier;
53 }
54 // Remove trailing zeros.
55 while (decimal_holder % 10 == 0) {
56 decimal_holder /= 10;
57 }
58
59 // Print serialized number to output.
60 if (value < 0) {
61 out << "-";
62 }
63 out << integral_part;
64 if (decimal_holder != 1) {
65 out << "." << std::to_string(decimal_holder).substr(1, digits_after_comma);
66 }
67 }
68
69 } // namespace
70
StdoutMetricsExporter()71 StdoutMetricsExporter::StdoutMetricsExporter() : output_(stdout) {}
72
Export(rtc::ArrayView<const Metric> metrics)73 bool StdoutMetricsExporter::Export(rtc::ArrayView<const Metric> metrics) {
74 for (const Metric& metric : metrics) {
75 PrintMetric(metric);
76 }
77 return true;
78 }
79
PrintMetric(const Metric & metric)80 void StdoutMetricsExporter::PrintMetric(const Metric& metric) {
81 rtc::StringBuilder value_stream;
82 value_stream << metric.test_case << " / " << metric.name << "= {mean=";
83 if (metric.stats.mean.has_value()) {
84 AppendWithPrecision(*metric.stats.mean, 8, value_stream);
85 } else {
86 value_stream << "-";
87 }
88 value_stream << ", stddev=";
89 if (metric.stats.stddev.has_value()) {
90 AppendWithPrecision(*metric.stats.stddev, 8, value_stream);
91 } else {
92 value_stream << "-";
93 }
94 value_stream << "} " << ToString(metric.unit) << " ("
95 << ToString(metric.improvement_direction) << ")";
96
97 fprintf(output_, "RESULT: %s\n", value_stream.str().c_str());
98 }
99
100 } // namespace test
101 } // namespace webrtc
102