blob: c26225162e1cb63b4f40991d76261ebcffcef886 [file] [log] [blame]
/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "modules/pacing/alr_detector.h"
#include <string>
#include "rtc_base/checks.h"
#include "rtc_base/format_macros.h"
#include "rtc_base/logging.h"
#include "rtc_base/timeutils.h"
#include "system_wrappers/include/field_trial.h"
namespace webrtc {
const char AlrDetector::kScreenshareProbingBweExperimentName[] =
"WebRTC-ProbingScreenshareBwe";
const char AlrDetector::kStrictPacingAndProbingExperimentName[] =
"WebRTC-StrictPacingAndProbing";
AlrDetector::AlrDetector()
: bandwidth_usage_percent_(kDefaultAlrBandwidthUsagePercent),
alr_start_budget_level_percent_(kDefaultAlrStartBudgetLevelPercent),
alr_stop_budget_level_percent_(kDefaultAlrStopBudgetLevelPercent),
alr_budget_(0, true) {
RTC_CHECK(
field_trial::FindFullName(kStrictPacingAndProbingExperimentName)
.empty() ||
field_trial::FindFullName(kScreenshareProbingBweExperimentName).empty());
rtc::Optional<AlrExperimentSettings> experiment_settings =
ParseAlrSettingsFromFieldTrial(kScreenshareProbingBweExperimentName);
if (!experiment_settings) {
experiment_settings =
ParseAlrSettingsFromFieldTrial(kStrictPacingAndProbingExperimentName);
}
if (experiment_settings) {
alr_stop_budget_level_percent_ =
experiment_settings->alr_stop_budget_level_percent;
alr_start_budget_level_percent_ =
experiment_settings->alr_start_budget_level_percent;
bandwidth_usage_percent_ = experiment_settings->alr_bandwidth_usage_percent;
}
}
AlrDetector::~AlrDetector() {}
void AlrDetector::OnBytesSent(size_t bytes_sent, int64_t delta_time_ms) {
alr_budget_.UseBudget(bytes_sent);
alr_budget_.IncreaseBudget(delta_time_ms);
if (alr_budget_.budget_level_percent() > alr_start_budget_level_percent_ &&
!alr_started_time_ms_) {
alr_started_time_ms_.emplace(rtc::TimeMillis());
} else if (alr_budget_.budget_level_percent() <
alr_stop_budget_level_percent_ &&
alr_started_time_ms_) {
alr_started_time_ms_.reset();
}
}
void AlrDetector::SetEstimatedBitrate(int bitrate_bps) {
RTC_DCHECK(bitrate_bps);
const auto target_rate_kbps = int64_t{bitrate_bps} *
bandwidth_usage_percent_ / (1000 * 100);
alr_budget_.set_target_rate_kbps(rtc::dchecked_cast<int>(target_rate_kbps));
}
rtc::Optional<int64_t> AlrDetector::GetApplicationLimitedRegionStartTime()
const {
return alr_started_time_ms_;
}
rtc::Optional<AlrDetector::AlrExperimentSettings>
AlrDetector::ParseAlrSettingsFromFieldTrial(const char* experiment_name) {
rtc::Optional<AlrExperimentSettings> ret;
std::string group_name = field_trial::FindFullName(experiment_name);
const std::string kIgnoredSuffix = "_Dogfood";
std::string::size_type suffix_pos = group_name.rfind(kIgnoredSuffix);
if (suffix_pos != std::string::npos &&
suffix_pos == group_name.length() - kIgnoredSuffix.length()) {
group_name.resize(group_name.length() - kIgnoredSuffix.length());
}
if (group_name.empty())
return ret;
AlrExperimentSettings settings;
if (sscanf(group_name.c_str(), "%f,%" PRId64 ",%d,%d,%d,%d",
&settings.pacing_factor, &settings.max_paced_queue_time,
&settings.alr_bandwidth_usage_percent,
&settings.alr_start_budget_level_percent,
&settings.alr_stop_budget_level_percent,
&settings.group_id) == 6) {
ret.emplace(settings);
RTC_LOG(LS_INFO) << "Using ALR experiment settings: "
"pacing factor: "
<< settings.pacing_factor << ", max pacer queue length: "
<< settings.max_paced_queue_time
<< ", ALR start bandwidth usage percent: "
<< settings.alr_bandwidth_usage_percent
<< ", ALR end budget level percent: "
<< settings.alr_start_budget_level_percent
<< ", ALR end budget level percent: "
<< settings.alr_stop_budget_level_percent
<< ", ALR experiment group ID: " << settings.group_id;
} else {
RTC_LOG(LS_INFO) << "Failed to parse ALR experiment: " << experiment_name;
}
return ret;
}
} // namespace webrtc