Move congestion window field trial parsing to new class.

This cl is part of work to move several experiments into a joint experiment group. Most of them vill be ralted to video, hence the name. Bug: webrtc:10223 Change-Id: I8767c43abb6aa910ab51710eeb908e0f9df1e296 Reviewed-on: https://webrtc-review.googlesource.com/c/118361 Commit-Queue: Erik Språng <sprang@webrtc.org> Reviewed-by: Sebastian Jansson <srte@webrtc.org> Reviewed-by: Stefan Holmer <stefan@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26346}
2019-01-21 16:30:55 +01:00
parent b4c6d1e6d9
commit 7121564e97
12 changed files with 221 additions and 149 deletions
--- a/rtc_base/experiments/rate_control_settings.cc
+++ b/rtc_base/experiments/rate_control_settings.cc
@ -0,0 +1,114 @@
+/*
+ *  Copyright (c) 2019 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 "rtc_base/experiments/rate_control_settings.h"
+
+#include <inttypes.h>
+#include <stdio.h>
+
+#include <string>
+
+#include "api/transport/field_trial_based_config.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/numerics/safe_conversions.h"
+
+namespace webrtc {
+
+namespace {
+
+const char* kCongestionWindowFieldTrialName = "WebRTC-CwndExperiment";
+const int kDefaultAcceptedQueueMs = 250;
+
+const char* kCongestionWindowPushbackFieldTrialName =
+    "WebRTC-CongestionWindowPushback";
+const int kDefaultMinPushbackTargetBitrateBps = 30000;
+
+absl::optional<int> MaybeReadCwndExperimentParameter(
+    const WebRtcKeyValueConfig* const key_value_config) {
+  int64_t accepted_queue_ms;
+  std::string experiment_string =
+      key_value_config->Lookup(kCongestionWindowFieldTrialName);
+  int parsed_values =
+      sscanf(experiment_string.c_str(), "Enabled-%" PRId64, &accepted_queue_ms);
+  if (parsed_values == 1) {
+    RTC_CHECK_GE(accepted_queue_ms, 0)
+        << "Accepted must be greater than or equal to 0.";
+    return rtc::checked_cast<int>(accepted_queue_ms);
+  } else if (experiment_string.find("Enabled") == 0) {
+    return kDefaultAcceptedQueueMs;
+  }
+  return absl::nullopt;
+}
+
+absl::optional<int> MaybeReadCongestionWindowPushbackExperimentParameter(
+    const WebRtcKeyValueConfig* const key_value_config) {
+  uint32_t min_pushback_target_bitrate_bps;
+  std::string experiment_string =
+      key_value_config->Lookup(kCongestionWindowPushbackFieldTrialName);
+  int parsed_values = sscanf(experiment_string.c_str(), "Enabled-%" PRIu32,
+                             &min_pushback_target_bitrate_bps);
+  if (parsed_values == 1) {
+    RTC_CHECK_GE(min_pushback_target_bitrate_bps, 0)
+        << "Min pushback target bitrate must be greater than or equal to 0.";
+    return rtc::checked_cast<int>(min_pushback_target_bitrate_bps);
+  } else if (experiment_string.find("Enabled") == 0) {
+    return kDefaultMinPushbackTargetBitrateBps;
+  }
+  return absl::nullopt;
+}
+
+}  // namespace
+
+RateControlSettings::RateControlSettings(
+    const WebRtcKeyValueConfig* const key_value_config)
+    : congestion_window_("cwnd",
+                         MaybeReadCwndExperimentParameter(key_value_config)),
+      congestion_window_pushback_(
+          "cwnd_pushback",
+          MaybeReadCongestionWindowPushbackExperimentParameter(
+              key_value_config)) {
+  ParseFieldTrial({&congestion_window_, &congestion_window_pushback_},
+                  key_value_config->Lookup("WebRTC-VideoRateControl"));
+}
+
+RateControlSettings::~RateControlSettings() = default;
+RateControlSettings::RateControlSettings(RateControlSettings&&) = default;
+
+RateControlSettings RateControlSettings::ParseFromFieldTrials() {
+  FieldTrialBasedConfig field_trial_config;
+  return RateControlSettings(&field_trial_config);
+}
+
+RateControlSettings RateControlSettings::ParseFromKeyValueConfig(
+    const WebRtcKeyValueConfig* const key_value_config) {
+  FieldTrialBasedConfig field_trial_config;
+  return RateControlSettings(key_value_config ? key_value_config
+                                              : &field_trial_config);
+}
+
+bool RateControlSettings::UseCongestionWindow() const {
+  return congestion_window_;
+}
+
+int64_t RateControlSettings::GetCongestionWindowAdditionalTimeMs() const {
+  return congestion_window_.GetOptional().value_or(kDefaultAcceptedQueueMs);
+}
+
+bool RateControlSettings::UseCongestionWindowPushback() const {
+  return congestion_window_ && congestion_window_pushback_;
+}
+
+uint32_t RateControlSettings::CongestionWindowMinPushbackTargetBitrateBps()
+    const {
+  return congestion_window_pushback_.GetOptional().value_or(
+      kDefaultMinPushbackTargetBitrateBps);
+}
+
+}  // namespace webrtc