1 /*
2 * Copyright (c) 2018 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
11 #include "rtc_base/experiments/alr_experiment.h"
12
13 #include <inttypes.h>
14 #include <stdio.h>
15
16 #include <string>
17
18 #include "absl/strings/string_view.h"
19 #include "api/transport/field_trial_based_config.h"
20 #include "rtc_base/logging.h"
21
22 namespace webrtc {
23
24 const char AlrExperimentSettings::kScreenshareProbingBweExperimentName[] =
25 "WebRTC-ProbingScreenshareBwe";
26 const char AlrExperimentSettings::kStrictPacingAndProbingExperimentName[] =
27 "WebRTC-StrictPacingAndProbing";
28 const char kDefaultProbingScreenshareBweSettings[] = "1.0,2875,80,40,-60,3";
29
MaxOneFieldTrialEnabled()30 bool AlrExperimentSettings::MaxOneFieldTrialEnabled() {
31 return AlrExperimentSettings::MaxOneFieldTrialEnabled(
32 FieldTrialBasedConfig());
33 }
34
MaxOneFieldTrialEnabled(const FieldTrialsView & key_value_config)35 bool AlrExperimentSettings::MaxOneFieldTrialEnabled(
36 const FieldTrialsView& key_value_config) {
37 return key_value_config.Lookup(kStrictPacingAndProbingExperimentName)
38 .empty() ||
39 key_value_config.Lookup(kScreenshareProbingBweExperimentName).empty();
40 }
41
42 absl::optional<AlrExperimentSettings>
CreateFromFieldTrial(absl::string_view experiment_name)43 AlrExperimentSettings::CreateFromFieldTrial(absl::string_view experiment_name) {
44 return AlrExperimentSettings::CreateFromFieldTrial(FieldTrialBasedConfig(),
45 experiment_name);
46 }
47
48 absl::optional<AlrExperimentSettings>
CreateFromFieldTrial(const FieldTrialsView & key_value_config,absl::string_view experiment_name)49 AlrExperimentSettings::CreateFromFieldTrial(
50 const FieldTrialsView& key_value_config,
51 absl::string_view experiment_name) {
52 absl::optional<AlrExperimentSettings> ret;
53 std::string group_name = key_value_config.Lookup(experiment_name);
54
55 const std::string kIgnoredSuffix = "_Dogfood";
56 std::string::size_type suffix_pos = group_name.rfind(kIgnoredSuffix);
57 if (suffix_pos != std::string::npos &&
58 suffix_pos == group_name.length() - kIgnoredSuffix.length()) {
59 group_name.resize(group_name.length() - kIgnoredSuffix.length());
60 }
61
62 if (group_name.empty()) {
63 if (experiment_name == kScreenshareProbingBweExperimentName) {
64 // This experiment is now default-on with fixed settings.
65 // TODO(sprang): Remove this kill-switch and clean up experiment code.
66 group_name = kDefaultProbingScreenshareBweSettings;
67 } else {
68 return ret;
69 }
70 }
71
72 AlrExperimentSettings settings;
73 if (sscanf(group_name.c_str(), "%f,%" PRId64 ",%d,%d,%d,%d",
74 &settings.pacing_factor, &settings.max_paced_queue_time,
75 &settings.alr_bandwidth_usage_percent,
76 &settings.alr_start_budget_level_percent,
77 &settings.alr_stop_budget_level_percent,
78 &settings.group_id) == 6) {
79 ret.emplace(settings);
80 RTC_LOG(LS_INFO) << "Using ALR experiment settings: "
81 "pacing factor: "
82 << settings.pacing_factor << ", max pacer queue length: "
83 << settings.max_paced_queue_time
84 << ", ALR bandwidth usage percent: "
85 << settings.alr_bandwidth_usage_percent
86 << ", ALR start budget level percent: "
87 << settings.alr_start_budget_level_percent
88 << ", ALR end budget level percent: "
89 << settings.alr_stop_budget_level_percent
90 << ", ALR experiment group ID: " << settings.group_id;
91 } else {
92 RTC_LOG(LS_INFO) << "Failed to parse ALR experiment: " << experiment_name;
93 }
94
95 return ret;
96 }
97
98 } // namespace webrtc
99