net/quic/quic_ack_notifier.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_QUIC_QUIC_ACK_NOTIFIER_H_
   6 #define NET_QUIC_QUIC_ACK_NOTIFIER_H_
   7
   8 #include "net/quic/quic_protocol.h"
   9
  10 namespace net {
  11
  12 // Used to register with a QuicConnection for notification once a set of packets
  13 // have all been ACKed.
  14 // The connection informs this class of newly ACKed sequence numbers, and once
  15 // we have seen ACKs for all the sequence numbers we are interested in, we
  16 // trigger a call to a provided Closure.
  17 class NET_EXPORT_PRIVATE QuicAckNotifier {
  18  public:
  19   class NET_EXPORT_PRIVATE DelegateInterface {
  20    public:
  21     DelegateInterface();
  22     virtual ~DelegateInterface();
  23     virtual void OnAckNotification() = 0;
  24   };
  25
  26   explicit QuicAckNotifier(DelegateInterface* delegate);
  27   virtual ~QuicAckNotifier();
  28
  29   // Register a sequence number that this AckNotifier should be interested in.
  30   void AddSequenceNumber(const QuicPacketSequenceNumber& sequence_number);
  31
  32   // Register a set of sequence numbers that this AckNotifier should be
  33   // interested in.
  34   void AddSequenceNumbers(const SequenceNumberSet& sequence_numbers);
  35
  36   // Called by the QuicConnection on receipt of new ACK frame, with the sequence
  37   // number referenced by the ACK frame.
  38   // Deletes the matching sequence number from the stored set of sequence
  39   // numbers. If this set is now empty, call the stored delegate's
  40   // OnAckNotification method.
  41   //
  42   // Returns true if the provided sequence_number caused the delegate to be
  43   // called, false otherwise.
  44   bool OnAck(QuicPacketSequenceNumber sequence_number);
  45
  46   bool IsEmpty() { return sequence_numbers_.empty(); }
  47
  48   // If a packet is retransmitted by the connection it will be sent with a
  49   // different sequence number. Updates our internal set of sequence_numbers to
  50   // track the latest number.
  51   void UpdateSequenceNumber(QuicPacketSequenceNumber old_sequence_number,
  52                             QuicPacketSequenceNumber new_sequence_number);
  53
  54  private:
  55   // The delegate's OnAckNotification() method will be called once we have been
  56   // notified of ACKs for all the sequence numbers we are tracking.
  57   // This is not owned by OnAckNotifier and must outlive it.
  58   DelegateInterface* delegate_;
  59
  60   // Set of sequence numbers this notifier is waiting to hear about. The
  61   // delegate will not be called until this is an empty set.
  62   SequenceNumberSet sequence_numbers_;
  63 };
  64
  65 };  // namespace net
  66
  67 #endif  // NET_QUIC_QUIC_ACK_NOTIFIER_H_