Landing Recent QUIC changes until 8/28/2015 18:03 UTC.

net/tools/quic/quic_time_wait_list_manager.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.
 //
 // Handles packets for connection_ids in time wait state by discarding the
 // packet and sending the clients a public reset packet with exponential
 // backoff.
 
 #ifndef NET_TOOLS_QUIC_QUIC_TIME_WAIT_LIST_MANAGER_H_
 #define NET_TOOLS_QUIC_QUIC_TIME_WAIT_LIST_MANAGER_H_
@@ skipping 83 matching lines @@
 
   // If necessary, trims the oldest connections from the time-wait list until
   // the size is under the configured maximum.
   void TrimTimeWaitListIfNeeded();
 
   // Given a ConnectionId that exists in the time wait list, returns the
   // QuicVersion associated with it.
   QuicVersion GetQuicVersionFromConnectionId(QuicConnectionId connection_id);
 
   // The number of connections on the time-wait list.
-  size_t num_connections() const { return connection_id_map_.size(); }
+  size_t num_connections() const { return num_connections_; }
 
  protected:
   virtual QuicEncryptedPacket* BuildPublicReset(
       const QuicPublicResetPacket& packet);
 
  private:
   friend class test::QuicTimeWaitListManagerPeer;
 
   // Internal structure to store pending public reset packets.
   class QueuedPacket;
@@ skipping 68 matching lines @@
 
   // Clock to efficiently measure approximate time.
   const QuicClock* clock_;
 
   // Interface that writes given buffer to the socket.
   QuicPacketWriter* writer_;
 
   // Interface that manages blocked writers.
   QuicServerSessionVisitor* visitor_;
 
+  // Number of connection IDs in |connection_id_map_|. According to b/23531792,
+  // cost of size() of linked_hash_map is linear instead of constant, and a
+  // separate counter is maintained so that cost of num_connections() is
+  // constant. TODO(b/23531792): Remove this counter.
+  size_t num_connections_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicTimeWaitListManager);
 };
 
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_TIME_WAIT_LIST_MANAGER_H_