commit 097085140e8258a1e3a3ff73c1725e5163c04b93
author Erik Språng <sprang@webrtc.org> Wed Mar 14 14:16:50 2018
committer Commit Bot <commit-bot@chromium.org> Wed Mar 14 17:03:25 2018
tree dfaf0124b14d3cf80c9760b35f795c2639a7b540
parent d00c8951cd8a912d09ddefd0a4b52bcd9f7ec087

Reland: Add ability to emulate degraded network in Call via field trial

This is especially useful in Chrome, allowing use to emulate network
conditions in incoming or outgoing media without the need for platform
specific tools or hacks. It also doesn't interfere with the rest of the
network traffic.

Also includes some refactorings.

TBR=stefan@webrtc.org, philipel@webrtc.org

Originally reviewed on: https://webrtc-review.googlesource.com/33013

Bug: webrtc:8910
Change-Id: I162dde5fa20a260b41e5187fcf30b49f5e6fb0e0
Reviewed-on: https://webrtc-review.googlesource.com/61782
Commit-Queue: Erik Språng <sprang@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22430}

call/callfactory.cc

diff --git a/call/callfactory.cc b/call/callfactory.cc
index 0f2eecb..4ab5b89 100644
--- a/call/callfactory.cc
+++ b/call/callfactory.cc
@@ -11,12 +11,74 @@
 #include "call/callfactory.h"
 
 #include <memory>
+#include <string>
+#include <utility>
 
+#include "api/optional.h"
 #include "call/call.h"
+#include "call/degraded_call.h"
+#include "call/fake_network_pipe.h"
+#include "system_wrappers/include/field_trial.h"
 
 namespace webrtc {
+namespace {
+bool ParseConfigParam(std::string exp_name, int* field) {
+  std::string group = field_trial::FindFullName(exp_name);
+  if (group == "")
+    return false;
+
+  return (sscanf(group.c_str(), "%d", field) == 1);
+}
+
+rtc::Optional<webrtc::FakeNetworkPipe::Config> ParseDegradationConfig(
+    bool send) {
+  std::string exp_prefix = "WebRTCFakeNetwork";
+  if (send) {
+    exp_prefix += "Send";
+  } else {
+    exp_prefix += "Receive";
+  }
+
+  webrtc::FakeNetworkPipe::Config config;
+  bool configured = false;
+  configured |=
+      ParseConfigParam(exp_prefix + "DelayMs", &config.queue_delay_ms);
+  configured |= ParseConfigParam(exp_prefix + "DelayStdDevMs",
+                                 &config.delay_standard_deviation_ms);
+  int queue_length = 0;
+  if (ParseConfigParam(exp_prefix + "QueueLength", &queue_length)) {
+    RTC_CHECK_GE(queue_length, 0);
+    config.queue_length_packets = queue_length;
+    configured = true;
+  }
+  configured |=
+      ParseConfigParam(exp_prefix + "CapacityKbps", &config.link_capacity_kbps);
+  configured |=
+      ParseConfigParam(exp_prefix + "LossPercent", &config.loss_percent);
+  int allow_reordering = 0;
+  if (ParseConfigParam(exp_prefix + "AllowReordering", &allow_reordering)) {
+    config.allow_reordering = true;
+    configured = true;
+  }
+  configured |= ParseConfigParam(exp_prefix + "AvgBurstLossLength",
+                                 &config.avg_burst_loss_length);
+  return configured ? rtc::Optional<webrtc::FakeNetworkPipe::Config>(config)
+                    : rtc::nullopt;
+}
+}  // namespace
 
 Call* CallFactory::CreateCall(const Call::Config& config) {
+  rtc::Optional<webrtc::FakeNetworkPipe::Config> send_degradation_config =
+      ParseDegradationConfig(true);
+  rtc::Optional<webrtc::FakeNetworkPipe::Config> receive_degradation_config =
+      ParseDegradationConfig(false);
+
+  if (send_degradation_config || receive_degradation_config) {
+    return new DegradedCall(std::unique_ptr<Call>(Call::Create(config)),
+                            send_degradation_config,
+                            receive_degradation_config);
+  }
+
   return Call::Create(config);
 }