xref: /aosp_15_r20/external/webrtc/rtc_base/experiments/alr_experiment.cc (revision d9f758449e529ab9291ac668be2861e7a55c2422)
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