Add OnConnectionClosed event. (#19)

* Add CanWrite method.

* Working on connection closed event.

* Call QuicTransportServerSession::OnConnectionClosed.

QuicTransportOwtServerSession calls its base class to respond connection
termination.

Author: jianjunz

quic_transport/api/owt/quic/quic_transport_session_interface.h

@@ -20,6 +20,7 @@ class OWT_EXPORT QuicTransportSessionInterface {
     virtual ~Visitor() = default;
     virtual void OnIncomingStream(QuicTransportStreamInterface*) = 0;
     virtual void OnCanCreateNewOutgoingStream(bool unidirectional) = 0;
+    virtual void OnConnectionClosed() = 0;
   };
   virtual ~QuicTransportSessionInterface() = default;
   virtual const char* ConnectionId() const = 0;

quic_transport/api/owt/quic/quic_transport_stream_interface.h

@@ -43,6 +43,8 @@ class OWT_EXPORT QuicTransportStreamInterface {
   virtual void Close() = 0;
   // Bytes of data buffered.
   virtual uint64_t BufferedDataBytes() const = 0;
+  // Ready to write new data.
+  virtual bool CanWrite() const = 0;
 };
 }  // namespace quic
 }  // namespace owt

quic_transport/impl/quic_transport_owt_server_session.cc

@@ -189,5 +189,14 @@ const ConnectionStats& QuicTransportOwtServerSession::GetStats() {
   return stats_;
 }
 
+void QuicTransportOwtServerSession::OnConnectionClosed(
+    const ::quic::QuicConnectionCloseFrame& frame,
+    ::quic::ConnectionCloseSource source) {
+  ::quic::QuicTransportServerSession::OnConnectionClosed(frame, source);
+  if (visitor_) {
+    visitor_->OnConnectionClosed();
+  }
+}
+
 }  // namespace quic
 }  // namespace owt

quic_transport/impl/quic_transport_owt_server_session.h

@@ -58,6 +58,9 @@ class QuicTransportOwtServerSession
   QuicTransportStreamInterface* CreateBidirectionalStream() override;
   const ConnectionStats& GetStats() override;
 
+  void OnConnectionClosed(const ::quic::QuicConnectionCloseFrame& frame,
+                          ::quic::ConnectionCloseSource source) override;
+
  protected:
   void OnIncomingDataStream(::quic::QuicTransportStream* stream) override;
   void OnCanCreateNewOutgoingStream(bool unidirectional) override;

quic_transport/impl/quic_transport_stream_impl.cc

@@ -175,5 +175,9 @@ uint64_t QuicTransportStreamImpl::BufferedDataBytes() const {
   return stream_->BufferedDataBytes();
 }
 
+bool QuicTransportStreamImpl::CanWrite() const {
+  return stream_->CanWrite();
+}
+
 }  // namespace quic
 }  // namespace owt

quic_transport/impl/quic_transport_stream_impl.h

@@ -43,6 +43,7 @@ class QuicTransportStreamImpl : public QuicTransportStreamInterface,
   size_t ReadableBytes() const override;
   void Close() override;
   uint64_t BufferedDataBytes() const override;
+  bool CanWrite() const override;
 
   // Overrides ::quic::QuicTransportStream::Visitor.
   void OnCanRead() override;