deprecate FLAGS_quic_disable_pre_34

net/quic/core/quic_sent_entropy_manager.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.
-//
-// Manages the packet entropy calculation for both sent and received packets
-// for a connection.
-
-#ifndef NET_QUIC_QUIC_SENT_ENTROPY_MANAGER_H_
-#define NET_QUIC_QUIC_SENT_ENTROPY_MANAGER_H_
-
-#include <deque>
-
-#include "base/macros.h"
-#include "net/base/linked_hash_map.h"
-#include "net/base/net_export.h"
-#include "net/quic/core/quic_framer.h"
-#include "net/quic/core/quic_protocol.h"
-
-namespace net {
-
-namespace test {
-class QuicConnectionPeer;
-}  // namespace test
-
-// Records all sent packets by a connection to track the cumulative entropy of
-// sent packets.  It is used by the connection to validate an ack
-// frame sent by the peer as a preventive measure against the optimistic ack
-// attack.
-class NET_EXPORT_PRIVATE QuicSentEntropyManager {
- public:
-  QuicSentEntropyManager();
-  virtual ~QuicSentEntropyManager();
-
-  // Record |entropy_hash| for sent packet corresponding to |packet_number|.
-  void RecordPacketEntropyHash(QuicPacketNumber packet_number,
-                               QuicPacketEntropyHash entropy_hash);
-
-  // Retrieves the cumulative entropy up to |packet_number|.
-  // Must always be called with a monotonically increasing |packet_number|.
-  QuicPacketEntropyHash GetCumulativeEntropy(QuicPacketNumber packet_number);
-
-  // Returns true if |entropy_hash| matches the expected sent entropy hash
-  // up to |largest_observed| removing packet numbers from |missing_packets|.
-  // Must always be called with a monotonically increasing |largest_observed|.
-  bool IsValidEntropy(QuicPacketNumber largest_observed,
-                      const PacketNumberQueue& missing_packets,
-                      QuicPacketEntropyHash entropy_hash);
-
-  // Removes unnecessary entries before |packet_number|.
-  void ClearEntropyBefore(QuicPacketNumber packet_number);
-
- private:
-  friend class test::QuicConnectionPeer;
-
-  typedef std::deque<QuicPacketEntropyHash> SentEntropyMap;
-
-  struct CumulativeEntropy {
-    CumulativeEntropy() : packet_number(0), entropy(0) {}
-
-    QuicPacketNumber packet_number;
-    QuicPacketEntropyHash entropy;
-  };
-
-  // Convenience methods to get the largest and smallest packets with entropies.
-  QuicPacketNumber GetLargestPacketWithEntropy() const;
-  QuicPacketNumber GetSmallestPacketWithEntropy() const;
-  // Convenience method to get the entropy hash for |packet_number|.
-  QuicPacketEntropyHash GetPacketEntropy(QuicPacketNumber packet_number) const;
-
-  // Update the cumulative entropy to |packet_number|.
-  void UpdateCumulativeEntropy(QuicPacketNumber packet_number,
-                               CumulativeEntropy* cumulative) const;
-
-  // Maps packet numbers to the sent entropy hash for the packet number.
-  SentEntropyMap packets_entropy_;
-  QuicPacketNumber map_offset_;
-
-  // Cache the cumulative entropy for IsValidEntropy.
-  CumulativeEntropy last_valid_entropy_;
-
-  // Cache the cumulative entropy for the packet number used by EntropyHash.
-  CumulativeEntropy last_cumulative_entropy_;
-
-  DISALLOW_COPY_AND_ASSIGN(QuicSentEntropyManager);
-};
-
-}  // namespace net
-
-#endif  // NET_QUIC_QUIC_SENT_ENTROPY_MANAGER_H_