relnote: QUIC header streams support to receive PUSH_PROMISE. Protected by --quic_supports_push_pr…

net/quic/quic_headers_stream.h

 // Copyright 2013 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_QUIC_QUIC_HEADERS_STREAM_H_
 #define NET_QUIC_QUIC_HEADERS_STREAM_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/reliable_quic_stream.h"
 #include "net/spdy/spdy_framer.h"
 
 namespace net {
 
 class QuicSpdySession;
 
-// Headers in QUIC are sent as HTTP/2 HEADERS frames over a reserved reliable
-// stream with the id 3.  Each endpoint (client and server) will allocate an
-// instance of QuicHeadersStream to send and receive headers.
+// Headers in QUIC are sent as HTTP/2 HEADERS or PUSH_PROMISE frames
+// over a reserved reliable stream with the id 3.  Each endpoint
+// (client and server) will allocate an instance of QuicHeadersStream
+// to send and receive headers.
 class NET_EXPORT_PRIVATE QuicHeadersStream : public ReliableQuicStream {
  public:
   explicit QuicHeadersStream(QuicSpdySession* session);
   ~QuicHeadersStream() override;
 
   // Writes |headers| for |stream_id| in an HTTP/2 HEADERS frame to the peer.
   // If |fin| is true, the fin flag will be set on the HEADERS frame.  Returns
   // the size, in bytes, of the resulting HEADERS frame.
   size_t WriteHeaders(QuicStreamId stream_id,
                       const SpdyHeaderBlock& headers,
                       bool fin,
                       SpdyPriority priority,
                       QuicAckListenerInterface* ack_listener);
 
   // Write |headers| for |promised_stream_id| on |original_stream_id| in a
   // PUSH_PROMISE frame to peer.
   // Return the size, in bytes, of the resulting PUSH_PROMISE frame.
   size_t WritePushPromise(QuicStreamId original_stream_id,
                           QuicStreamId promised_stream_id,
                           const SpdyHeaderBlock& headers,
                           QuicAckListenerInterface* ack_listener);
 
   // ReliableQuicStream implementation
   void OnDataAvailable() override;
   SpdyPriority Priority() const override;
 
+  bool supports_push_promise() { return supports_push_promise_; }
+
  private:
   class SpdyFramerVisitor;
 
   // The following methods are called by the SimpleVisitor.
 
   // Called when a HEADERS frame has been received.
   void OnHeaders(SpdyStreamId stream_id,
                  bool has_priority,
                  SpdyPriority priority,
                  bool fin);
 
+  // Called when a PUSH_PROMISE frame has been received.
+  void OnPushPromise(SpdyStreamId stream_id,
+                     SpdyStreamId promised_stream_id,
+                     bool end);
+
   // Called when a chunk of header data is available. This is called
   // after OnHeaders.
   // |stream_id| The stream receiving the header data.
   // |header_data| A buffer containing the header data chunk received.
   // |len| The length of the header data buffer. A length of zero indicates
   //       that the header data block has been completely sent.
   void OnControlFrameHeaderData(SpdyStreamId stream_id,
                                 const char* header_data,
                                 size_t len);
 
   // Called when the size of the compressed frame payload is available.
   void OnCompressedFrameSize(size_t frame_len);
 
   // Returns true if the session is still connected.
   bool IsConnected();
 
   QuicSpdySession* spdy_session_;
 
   // Data about the stream whose headers are being processed.
   QuicStreamId stream_id_;
+  QuicStreamId promised_stream_id_;
   bool fin_;
   size_t frame_len_;
 
-  // Helper variable that caches the corresponding feature flag.
+  // Helper variables that cache the corresponding feature flag.
   bool measure_headers_hol_blocking_time_;
+  bool supports_push_promise_;
 
   // Timestamps used to measure HOL blocking, these are recorded by
   // the sequencer approximate to the time of arrival off the wire.
   // |cur_max_timestamp_| tracks the most recent arrival time of
   // frames for current (at the headers stream level) processed
   // stream's headers, and |prev_max_timestamp_| tracks the most
   // recent arrival time of lower numbered streams.
   QuicTime cur_max_timestamp_;
   QuicTime prev_max_timestamp_;
 
   SpdyFramer spdy_framer_;
   scoped_ptr<SpdyFramerVisitor> spdy_framer_visitor_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicHeadersStream);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_HEADERS_STREAM_H_