Implement Turn/Turn first logic for connection selection.

webrtc/p2p/base/p2ptransportchannel.h

Index: webrtc/p2p/base/p2ptransportchannel.h
diff --git a/webrtc/p2p/base/p2ptransportchannel.h b/webrtc/p2p/base/p2ptransportchannel.h
index 3927b17659b0d226a029d5717b23868274641003..1273764e1eefbd3771d1fa6871e7eecda8b86e70 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -21,6 +21,7 @@
 #define WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_
 
 #include <map>
+#include <set>
 #include <string>
 #include <vector>
 #include "webrtc/p2p/base/candidate.h"
@@ -35,6 +36,7 @@
 namespace cricket {
 
 extern const uint32_t WEAK_PING_DELAY;
+extern const uint32_t MAX_CURRENT_STRONG_DELAY;
 
 struct IceParameters {
   std::string ufrag;
@@ -91,6 +93,7 @@ class P2PTransportChannel : public TransportChannelImpl,
   // Sets the receiving timeout and gather_continually.
   // This also sets the check_receiving_delay proportionally.
   void SetIceConfig(const IceConfig& config) override;
+  IceConfig GetIceConfig() const;
 
   // From TransportChannel:
   int SendPacket(const char* data,
@@ -184,6 +187,45 @@ class P2PTransportChannel : public TransportChannelImpl,
   }
 
  private:
+  // This class maintains the std::vector interface to allow enumeration and
+  // wraps the logic of determining the next pingable connection. Connections[0]
+  // is always the candidate of the best connection after sorted.
+  class Connections : public std::vector<Connection*> {

[pthatcher1, 2016/01/27 19:59:58]

This seems a little crazy.

[guoweis_webrtc, 2016/02/29 18:03:00]

Removed the class.

+   public:
+    typedef std::vector<Connection*> Base;
+    Connections(P2PTransportChannel* channel);
+    void enable_most_likely_first(bool enable);
+    bool most_likely_first() const { return ping_most_likely_first_; }
+    iterator erase(iterator pos);
+    void push_back(Connection*& connection);
+    Connection* FindNextPingableConnection(uint32_t now);
+    void MarkConnectionPinged(Connection* connection);
+
+   private:
+    // Disallow any modifier functions.
+    using Base::erase;
+    using Base::insert;
+    using Base::emplace;
+    using Base::emplace_back;
+    using Base::pop_back;
+    using Base::push_back;
+    using Base::clear;
+    using Base::resize;
+    using Base::swap;
+
+    // Between |conn1| and |conn2|, this function returns the one which should
+    // be pinged first.
+    Connection* Compare(Connection* conn1, Connection* conn2);
+
+    bool IsTurnTurn(Connection* conn);
+
+    P2PTransportChannel* channel_ = nullptr;
+    bool ping_most_likely_first_ = false;
+
+    std::set<Connection*> pinged_connections_;
+    std::set<Connection*> unpinged_connections_;
+  };
+
   rtc::Thread* thread() { return worker_thread_; }
   bool IsGettingPorts() { return allocator_session()->IsGettingPorts(); }
 
@@ -271,7 +313,7 @@ class P2PTransportChannel : public TransportChannelImpl,
   int error_;
   std::vector<PortAllocatorSession*> allocator_sessions_;
   std::vector<PortInterface *> ports_;
-  std::vector<Connection *> connections_;
+  Connections connections_;
   Connection* best_connection_;
   // Connection selected by the controlling agent. This should be used only
   // at controlled side when protocol type is RFC5245.