alr_detector.h (2637B)
1 /* 2 * Copyright (c) 2016 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 #ifndef MODULES_CONGESTION_CONTROLLER_GOOG_CC_ALR_DETECTOR_H_ 12 #define MODULES_CONGESTION_CONTROLLER_GOOG_CC_ALR_DETECTOR_H_ 13 14 #include <optional> 15 16 #include "api/environment/environment.h" 17 #include "api/field_trials_view.h" 18 #include "api/units/data_rate.h" 19 #include "api/units/data_size.h" 20 #include "api/units/timestamp.h" 21 #include "modules/pacing/interval_budget.h" 22 23 namespace webrtc { 24 25 // Application limited region detector is a class that utilizes signals of 26 // elapsed time and bytes sent to estimate whether network traffic is 27 // currently limited by the application's ability to generate traffic. 28 // 29 // AlrDetector provides a signal that can be utilized to adjust 30 // estimate bandwidth. 31 // Note: This class is not thread-safe. 32 class AlrDetector { 33 public: 34 explicit AlrDetector(const Environment& env); 35 36 AlrDetector(const AlrDetector&) = delete; 37 AlrDetector& operator=(const AlrDetector&) = delete; 38 39 ~AlrDetector(); 40 41 void OnBytesSent(DataSize bytes_sent, Timestamp send_time); 42 43 // Set current estimated bandwidth. 44 void SetEstimatedBitrate(DataRate bitrate); 45 46 // Returns time when the current application-limited region started or empty 47 // result if the sender is currently not application-limited. 48 std::optional<Timestamp> GetApplicationLimitedRegionStartTime() const; 49 50 private: 51 friend class GoogCcStatePrinter; 52 struct AlrDetectorConfig { 53 explicit AlrDetectorConfig(const FieldTrialsView& key_value_config); 54 55 // Sent traffic ratio as a function of network capacity used to determine 56 // application-limited region. ALR region start when bandwidth usage drops 57 // below kAlrStartUsageRatio and ends when it raises above 58 // kAlrEndUsageRatio. NOTE: This is intentionally conservative at the moment 59 // until BW adjustments of application limited region is fine tuned. 60 double bandwidth_usage_ratio = 0.65; 61 double start_budget_level_ratio = 0.80; 62 double stop_budget_level_ratio = 0.50; 63 }; 64 65 const Environment env_; 66 const AlrDetectorConfig conf_; 67 68 std::optional<Timestamp> last_send_time_; 69 70 IntervalBudget alr_budget_; 71 std::optional<Timestamp> alr_started_time_; 72 }; 73 } // namespace webrtc 74 75 #endif // MODULES_CONGESTION_CONTROLLER_GOOG_CC_ALR_DETECTOR_H_