Add a new SpdyStream::Delegate method to handle trailers

net/spdy/spdy_stream.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_SPDY_SPDY_STREAM_H_
 #define NET_SPDY_SPDY_STREAM_H_
 
 #include <deque>
 #include <string>
 #include <vector>
@@ skipping 36 matching lines @@
 };
 
 // Passed to some SpdyStream functions to indicate whether there's
 // more data to send.
 enum SpdySendStatus {
   MORE_DATA_TO_SEND,
   NO_MORE_DATA_TO_SEND
 };
 
 // Returned by SpdyStream::OnResponseHeadersUpdated() to indicate
-// whether the current response headers are complete or not.
+// whether the current response headers are complete or not, or whether
+// trailers have been received. TRAILERS_RECEIVED denotes the state where
+// headers are received after DATA frames, and this state also implies that
+// response headers are complete.

[Ryan Hamilton, 2015/08/10 22:37:38]

It looks like (from comments in the .cc file) that the TRAILERS_RECEIVED state
is only for REQUEST_RESPONSE sockets. Can you mention that here too?

[xunjieli, 2015/08/11 15:07:14]

Done.

 enum SpdyResponseHeadersStatus {
   RESPONSE_HEADERS_ARE_INCOMPLETE,
-  RESPONSE_HEADERS_ARE_COMPLETE
+  RESPONSE_HEADERS_ARE_COMPLETE,
+  TRAILERS_RECEIVED,
 };
 
 // The SpdyStream is used by the SpdySession to represent each stream known
 // on the SpdySession.  This class provides interfaces for SpdySession to use.
 // Streams can be created either by the client or by the server.  When they
 // are initiated by the client, both the SpdySession and client object (such as
 // a SpdyNetworkTransaction) will maintain a reference to the stream.  When
 // initiated by the server, only the SpdySession will maintain any reference,
 // until such a time as a client object requests a stream for the path.
 class NET_EXPORT_PRIVATE SpdyStream {
@@ skipping 41 matching lines @@
     //     exactly once before data is received, and it is expected
     //     that RESPONSE_HEADERS_ARE_COMPLETE is returned. If
     //     RESPONSE_HEADERS_ARE_INCOMPLETE is returned, this is
     //     treated as a protocol error.
     //
     //   - For push streams, it is expected that this function will be
     //     called until RESPONSE_HEADERS_ARE_COMPLETE is returned
     //     before any data is received; any deviation from this is
     //     treated as a protocol error.
     //
-    // TODO(akalin): Treat headers received after data has been
-    // received as a protocol error for non-bidirectional streams.
     // TODO(jgraettinger): This should be at the semantic (HTTP) rather
     // than stream layer. Streams shouldn't have a notion of header
     // completeness. Move to SpdyHttpStream/SpdyWebsocketStream.
     virtual SpdyResponseHeadersStatus OnResponseHeadersUpdated(
         const SpdyHeaderBlock& response_headers) = 0;
 
     // Called when data is received after all required response
     // headers have been received. |buffer| may be NULL, which signals
     // EOF.  Must return OK if the data was received successfully, or
     // a network error code otherwise.
     //
     // May cause the stream to be closed.
     virtual void OnDataReceived(scoped_ptr<SpdyBuffer> buffer) = 0;
 
     // Called when data is sent. Must not cause the stream to be
     // closed.
     virtual void OnDataSent() = 0;
 
+    // Called when trailers are received. Note that trailers HEADER frame will
+    // have END_STREAM flag set according to section 8.1 of the HTTP/2 RFC,
+    // so this will be followed by OnClose.
+    virtual void OnTrailers(const SpdyHeaderBlock& trailers) = 0;
+
     // Called when SpdyStream is closed. No other delegate functions
     // will be called after this is called, and the delegate must not
     // access the stream after this is called. Must not cause the
     // stream to be be (re-)closed.
     //
     // TODO(akalin): Allow this function to re-close the stream and
     // handle it gracefully.
     virtual void OnClose(int status) = 0;
 
    protected:
@@ skipping 422 matching lines @@
   bool write_handler_guard_;
 
   base::WeakPtrFactory<SpdyStream> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SpdyStream);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_STREAM_H_