Land Recent QUIC Changes.

net/quic/quic_packet_creator.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.
 //
 // Accumulates frames for the next packet until more frames no longer fit or
 // it's time to create a packet from them.  Also provides packet creation of
 // FEC packets based on previously created packets.
 
 #ifndef NET_QUIC_QUIC_PACKET_CREATOR_H_
 #define NET_QUIC_QUIC_PACKET_CREATOR_H_
@@ skipping 11 matching lines @@
 namespace test {
 class QuicPacketCreatorPeer;
 }
 
 class QuicAckNotifier;
 class QuicRandom;
 class QuicRandomBoolSource;
 
 class NET_EXPORT_PRIVATE QuicPacketCreator : public QuicFecBuilderInterface {
  public:
-  // Options for controlling how packets are created.
-  struct Options {
-    Options()
-        : max_packet_length(kDefaultMaxPacketSize),
-          max_packets_per_fec_group(0),
-          send_connection_id_length(PACKET_8BYTE_CONNECTION_ID),
-          send_sequence_number_length(PACKET_1BYTE_SEQUENCE_NUMBER) {}
-
-    size_t max_packet_length;
-    // 0 indicates fec is disabled.
-    size_t max_packets_per_fec_group;
-    // Length of connection_id to send over the wire.
-    QuicConnectionIdLength send_connection_id_length;
-    QuicSequenceNumberLength send_sequence_number_length;
-  };
-
   // QuicRandom* required for packet entropy.
   QuicPacketCreator(QuicConnectionId connection_id,
                     QuicFramer* framer,
                     QuicRandom* random_generator,
                     bool is_server);
 
   virtual ~QuicPacketCreator();
 
   // QuicFecBuilderInterface
   virtual void OnBuiltFecProtectedPayload(const QuicPacketHeader& header,
                                           base::StringPiece payload) OVERRIDE;
 
   // Turn on FEC protection for subsequently created packets. FEC should be
   // enabled first (max_packets_per_fec_group should be non-zero) for FEC
   // protection to start.
   void StartFecProtectingPackets();
 
   // Turn off FEC protection for subsequently created packets. If the creator
-  // has any open fec group, call will fail. It is the caller's responsibility
+  // has any open FEC group, call will fail. It is the caller's responsibility
   // to flush out FEC packets in generation, and to verify with ShouldSendFec()
   // that there is no open FEC group.
   void StopFecProtectingPackets();
 
   // Checks if it's time to send an FEC packet.  |force_close| forces this to
-  // return true if an fec group is open.
+  // return true if an FEC group is open.
   bool ShouldSendFec(bool force_close) const;
 
-  // Returns current max number of packets covered by an FEC group.
-  size_t max_packets_per_fec_group() const;
-
-  // Sets creator's max number of packets covered by an FEC group.
-  void set_max_packets_per_fec_group(size_t max_packets_per_fec_group);
-
   // Makes the framer not serialize the protocol version in sent packets.
   void StopSendingVersion();
 
   // Update the sequence number length to use in future packets as soon as it
   // can be safely changed.
   void UpdateSequenceNumberLength(
       QuicPacketSequenceNumber least_packet_awaited_by_peer,
       QuicByteCount congestion_window);
 
   // The overhead the framing will add for a packet with one frame.
@@ skipping 115 matching lines @@
   // Sequence number of the last created packet, or 0 if no packets have been
   // created.
   QuicPacketSequenceNumber sequence_number() const {
     return sequence_number_;
   }
 
   void set_sequence_number(QuicPacketSequenceNumber s) {
     sequence_number_ = s;
   }
 
-  Options* options() {
-    return &options_;
+  QuicConnectionIdLength connection_id_length() const {
+    return connection_id_length_;
+  }
+
+  QuicSequenceNumberLength next_sequence_number_length() const {
+    return next_sequence_number_length_;
+  }
+
+  void set_next_sequence_number_length(QuicSequenceNumberLength length) {
+    next_sequence_number_length_ = length;
+  }
+
+  size_t max_packet_length() const {
+    return max_packet_length_;
+  }
+
+  void set_max_packet_length(size_t length) {
+    // |max_packet_length_| should not be changed mid-packet or mid-FEC group.
+    DCHECK(fec_group_.get() == NULL && queued_frames_.empty());
+    max_packet_length_ = length;
+  }
+
+  // Returns current max number of packets covered by an FEC group.
+  size_t max_packets_per_fec_group() const {
+      return max_packets_per_fec_group_;
+  }
+
+  // Sets creator's max number of packets covered by an FEC group.
+  void set_max_packets_per_fec_group(
+      size_t max_packets_per_fec_group) {
+    // To turn off FEC protection, use StopFecProtectingPackets().
+    DCHECK_NE(0u, max_packets_per_fec_group);
+    max_packets_per_fec_group_ = max_packets_per_fec_group;
   }
 
  private:
   friend class test::QuicPacketCreatorPeer;
 
   static bool ShouldRetransmit(const QuicFrame& frame);
 
-  // Updates sequence number length on a packet or FEC group boundary.
-  // Also starts an FEC group if FEC protection is on and there is not already
-  // an FEC group open.
+  // Updates sequence number and max packet lengths on a packet or FEC group
+  // boundary.
+  void MaybeUpdateLengths();
+
+  // Updates lengths and also starts an FEC group if FEC protection is on and
+  // there is not already an FEC group open.
   InFecGroup MaybeUpdateLengthsAndStartFec();
 
   void FillPacketHeader(QuicFecGroupNumber fec_group,
                         bool fec_flag,
                         QuicPacketHeader* header);
 
   // Allows a frame to be added without creating retransmittable frames.
   // Particularly useful for retransmits using SerializeAllFrames().
   bool AddFrame(const QuicFrame& frame, bool save_retransmittable_frames);
 
   // Adds a padding frame to the current packet only if the current packet
   // contains a handshake message, and there is sufficient room to fit a
   // padding frame.
   void MaybeAddPadding();
 
-  Options options_;
   QuicConnectionId connection_id_;
   EncryptionLevel encryption_level_;
   QuicFramer* framer_;
   scoped_ptr<QuicRandomBoolSource> random_bool_source_;
   QuicPacketSequenceNumber sequence_number_;
   // If true, any created packets will be FEC protected.
   bool should_fec_protect_;
   QuicFecGroupNumber fec_group_number_;
   scoped_ptr<QuicFecGroup> fec_group_;
   // bool to keep track if this packet creator is being used the server.
   bool is_server_;
   // Controls whether protocol version should be included while serializing the
   // packet.
   bool send_version_in_packet_;
-  // The sequence number length for the current packet and the current FEC group
-  // if FEC is enabled.
-  // Mutable so PacketSize() can adjust it when the packet is empty.
+  // Maximum length including headers and encryption (UDP payload length.)
+  size_t max_packet_length_;
+  // 0 indicates FEC is disabled.
+  size_t max_packets_per_fec_group_;
+  // Length of connection_id to send over the wire.
+  QuicConnectionIdLength connection_id_length_;
+  // Staging variable to hold next packet sequence number length. When sequence
+  // number length is to be changed, this variable holds the new length until
+  // a packet or FEC group boundary, when the creator's sequence_number_length_
+  // can be changed to this new value.
+  QuicSequenceNumberLength next_sequence_number_length_;
+  // Sequence number length for the current packet and for the current FEC group
+  // when FEC is enabled. Mutable so PacketSize() can adjust it when the packet
+  // is empty.
   mutable QuicSequenceNumberLength sequence_number_length_;
   // packet_size_ is mutable because it's just a cache of the current size.
   // packet_size should never be read directly, use PacketSize() instead.
   mutable size_t packet_size_;
   QuicFrames queued_frames_;
   scoped_ptr<RetransmittableFrames> queued_retransmittable_frames_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicPacketCreator);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PACKET_CREATOR_H_