Allow the number of connections QUIC's send algorithms simulate to

net/quic/congestion_control/cubic.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.
 //
 // Cubic algorithm, helper class to TCP cubic.
 // For details see http://netsrv.csc.ncsu.edu/export/cubic_a_new_tcp_2008.pdf.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_CUBIC_H_
 #define NET_QUIC_CONGESTION_CONTROL_CUBIC_H_
 
 #include "base/basictypes.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_clock.h"
 #include "net/quic/quic_connection_stats.h"
 #include "net/quic/quic_time.h"
 
 namespace net {
 
 // TCP congestion window in QUIC is in packets, not bytes.
 typedef uint32 QuicTcpCongestionWindow;
 
 class NET_EXPORT_PRIVATE Cubic {
  public:
   Cubic(const QuicClock* clock, QuicConnectionStats* stats);
 
+  void SetNumConnections(int num_connections);
+
   // Call after a timeout to reset the cubic state.
   void Reset();
 
   // Compute a new congestion window to use after a loss event.
   // Returns the new congestion window in packets. The new congestion window is
   // a multiplicative decrease of our current window.
   QuicTcpCongestionWindow CongestionWindowAfterPacketLoss(
       QuicTcpCongestionWindow current);
 
   // Compute a new congestion window to use after a received ACK.
   // Returns the new congestion window in packets. The new congestion window
   // follows a cubic function that depends on the time passed since last
   // packet loss.
   QuicTcpCongestionWindow CongestionWindowAfterAck(
       QuicTcpCongestionWindow current,
       QuicTime::Delta delay_min);
 
  private:
   static const QuicTime::Delta MaxCubicTimeInterval() {
     return QuicTime::Delta::FromMilliseconds(30);
   }
 
+  // Compute the TCP Cubic alpha and beta based on the current number of
+  // connections.
+  float Alpha() const;
+  float Beta() const;
+
   // Update congestion control variables in QuicConnectionStats.
   void UpdateCongestionControlStats(QuicTcpCongestionWindow new_cubic_mode_cwnd,
                                     QuicTcpCongestionWindow new_reno_mode_cwnd);
   const QuicClock* clock_;
 
+  // Number of connections to simulate.
+  int num_connections_;
+
   // Time when this cycle started, after last loss event.
   QuicTime epoch_;
 
   // Time when we updated last_congestion_window.
   QuicTime last_update_time_;
 
   // Last congestion window (in packets) used.
   QuicTcpCongestionWindow last_congestion_window_;
 
   // Max congestion window (in packets) used just before last loss event.
@@ skipping 18 matching lines @@
 
   // QuicConnectionStats includes congestion control related stats.
   QuicConnectionStats* stats_;
 
   DISALLOW_COPY_AND_ASSIGN(Cubic);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_CUBIC_H_