Updated structures and functions for setting the max bitrate limit to take rtc::Optional<int>

webrtc/call/call.cc

Index: webrtc/call/call.cc
diff --git a/webrtc/call/call.cc b/webrtc/call/call.cc
index 3fd7a931d0cecc88cff0b30a47557db5a21ed586..7ae0b1c22053f3d41325cf6fd42ebd3dc7d21de7 100644
--- a/webrtc/call/call.cc
+++ b/webrtc/call/call.cc
@@ -47,6 +47,9 @@
 namespace webrtc {
 
 const int Call::Config::kDefaultStartBitrateBps = 300000;
+// Indicates to the bandwidth estimator that there is no upper cap on the
+// estimated bitrate.
+static const int kBitrateUnlimited = -1;
 
 namespace internal {
 
@@ -207,8 +210,9 @@ Call::Call(const Call::Config& config)
   RTC_DCHECK_GE(config.bitrate_config.min_bitrate_bps, 0);
   RTC_DCHECK_GE(config.bitrate_config.start_bitrate_bps,
                 config.bitrate_config.min_bitrate_bps);
-  if (config.bitrate_config.max_bitrate_bps != -1) {
-    RTC_DCHECK_GE(config.bitrate_config.max_bitrate_bps,
+  if (config.bitrate_config.max_bitrate_bps) {
+    RTC_DCHECK_GT(*config.bitrate_config.max_bitrate_bps, 0);

[Taylor Brandstetter, 2016/03/29 02:26:58]

Is a max of 0 not allowed?

[skvlad, 2016/03/30 19:40:44]

No. The bitrate limit must be positive or unset. This avoids dealing with the
ambiguities of what the meaning of a 0 limit is.

+    RTC_DCHECK_GE(*config.bitrate_config.max_bitrate_bps,
                   config.bitrate_config.start_bitrate_bps);
   }
   if (config.audio_state.get()) {
@@ -219,10 +223,14 @@ Call::Call(const Call::Config& config)
   Trace::CreateTrace();
   call_stats_->RegisterStatsObserver(congestion_controller_.get());
 
+  // The congestion controller uses -1 to represent unlimited bitrate.
+  // TODO(skvlad): Remove this conversion when congestion controller code
+  // is updated to use rtc::Optional.
+  int bwe_max_bitrate =
+      config_.bitrate_config.max_bitrate_bps.value_or(kBitrateUnlimited);
   congestion_controller_->SetBweBitrates(
       config_.bitrate_config.min_bitrate_bps,
-      config_.bitrate_config.start_bitrate_bps,
-      config_.bitrate_config.max_bitrate_bps);
+      config_.bitrate_config.start_bitrate_bps, bwe_max_bitrate);
   congestion_controller_->GetBitrateController()->SetEventLog(event_log_);
 
   module_process_thread_->Start();
@@ -531,8 +539,8 @@ void Call::SetBitrateConfig(
   TRACE_EVENT0("webrtc", "Call::SetBitrateConfig");
   RTC_DCHECK(configuration_thread_checker_.CalledOnValidThread());
   RTC_DCHECK_GE(bitrate_config.min_bitrate_bps, 0);
-  if (bitrate_config.max_bitrate_bps != -1)
-    RTC_DCHECK_GT(bitrate_config.max_bitrate_bps, 0);
+  if (bitrate_config.max_bitrate_bps)

[Taylor Brandstetter, 2016/03/29 02:26:58]

nit: as long as you're modifying this line, might as well add { } s

[skvlad, 2016/03/30 19:40:44]

Done.

+    RTC_DCHECK_GT(*bitrate_config.max_bitrate_bps, 0);
   if (config_.bitrate_config.min_bitrate_bps ==
           bitrate_config.min_bitrate_bps &&
       (bitrate_config.start_bitrate_bps <= 0 ||
@@ -544,9 +552,14 @@ void Call::SetBitrateConfig(
     return;
   }
   config_.bitrate_config = bitrate_config;
+  // The congestion controller uses -1 to represent unlimited bitrate.
+  // TODO(skvlad): Remove this conversion when congestion controller code
+  // is updated to use rtc::Optional.
+  int bwe_max_bitrate =
+      bitrate_config.max_bitrate_bps.value_or(kBitrateUnlimited);
   congestion_controller_->SetBweBitrates(bitrate_config.min_bitrate_bps,
                                          bitrate_config.start_bitrate_bps,
-                                         bitrate_config.max_bitrate_bps);
+                                         bwe_max_bitrate);
 }
 
 void Call::SignalNetworkState(NetworkState state) {