--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/internet/model/pending-data.h	Fri Feb 25 10:32:35 2011 -0800
@@ -0,0 +1,118 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+//
+// Copyright (c) 2006 Georgia Tech Research Corporation
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 2 as
+// published by the Free Software Foundation;
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+// Author: Rajib Bhattacharjea<raj.b@gatech.edu>
+//
+
+// Georgia Tech Network Simulator - Data Descriptors
+// George F. Riley.  Georgia Tech, Spring 2002
+
+#ifndef __datapdu_h__
+#define __datapdu_h__
+
+#include "ns3/packet.h"
+#include "pending-data.h"
+#include "ns3/sequence-number.h"
+
+#include "ns3/ptr.h"
+namespace ns3
+{
+class Packet;
+
+/**
+ * \ingroup tcp
+ *
+ * \brief class for managing I/O between applications and TCP
+ */
+class PendingData {
+public:
+  PendingData ();
+  PendingData (uint32_t s, uint8_t* d = NULL, uint32_t msg = 0, uint32_t resp = 0);
+  PendingData (const std::string&); // Construct from string
+  PendingData (uint8_t*, uint32_t&, Packet*); // Construct from serialized buffer
+  PendingData (const PendingData&);   // Copy constructor
+  virtual ~PendingData ();     // Destructor
+  uint32_t Size () const { return size;}
+  // Serialization
+  uint8_t*  Serialize (uint8_t*, uint32_t&); // Serialize to a buffer
+  uint8_t*  Construct (uint8_t*, uint32_t&); // Construct from buffer
+  virtual void Clear ();// Remove all associated data
+  virtual void Add (uint32_t s, const uint8_t* d = 0);// Add some data to end
+  virtual void Add (Ptr<Packet> p);
+  /**
+   * This method returns the number of bytes in the PendingData buffer
+   * beyond the sequence number specified by seqOffset.
+   *
+   * The variables seqFront and seqOffset correspond to a sequence number
+   * space in use by the user.  What is significant in this method is the
+   * difference between them; i.e. the quantity (seqOffset - seqFront). 
+   * This difference is subtracted from Size(), yielding the number of
+   * bytes beyond seqOffset, from the user perspective, in the PendingData
+   * buffer.
+   *
+   * If the first number specified is not a sequence number that corresponds
+   * to the first data byte in the PendingData buffer, the computation
+   * returned will be in error.
+   * 
+   * \return number of bytes 
+   * \param seqFront sequence number of assumed first byte in the PendingData
+   * \param seqOffset sequence number of offset 
+   */
+  virtual uint32_t SizeFromSeq (const SequenceNumber32& seqFront, const SequenceNumber32& seqOffset);
+  // Inquire available data from offset
+  /**
+   * \return number of bytes in the data buffer beyond the offset specified
+   * \param offset offset (from zero) 
+   */
+  virtual uint32_t SizeFromOffset (uint32_t offset);
+  // Available size from sequence difference 
+  /**
+   * Subtracts seqFront from seqOffset after enforcing seqFront is less
+   * than seqOffset
+   *
+   * \param seqFront sequence number to be subtracted from seqOffset
+   * \param seqOffset higher sequence number
+   * \return seqOffset-seqFront
+   */
+  virtual uint32_t OffsetFromSeq (const SequenceNumber32& seqFront, const SequenceNumber32& seqOffset);
+  virtual Ptr<Packet> CopyFromOffset (uint32_t, uint32_t);  // Size, offset, ret packet
+  // Copy data, size, offset specified by sequence difference
+  virtual Ptr<Packet> CopyFromSeq (uint32_t, const SequenceNumber32&, const SequenceNumber32&);
+  /**
+   * Permits object to clear any pending data between seqFront and 
+   * seqOffset - 1).  Callers should check the return value to determine
+   * whether any data was removed from the front.
+   *
+   * \param seqFront sequence number to start to try to remove from 
+   * \param seqOffset first sequence number in buffer that should be retained
+   * \return number of bytes from the front that were removed from the buffer
+   */
+  virtual uint32_t RemoveToSeq (const SequenceNumber32& seqFront, const SequenceNumber32& seqOffset);
+  PendingData*   Copy () const;          // Create a copy of this header
+  PendingData*   CopyS (uint32_t);         // Copy with new size
+  PendingData*   CopySD (uint32_t, uint8_t*); // Copy with new size, new data
+public:
+  uint32_t size;        // Number of data bytes
+  std::vector<Ptr<Packet> > data;         // Corresponding data (may be null)
+  // The next two fields allow simulated applications to exchange some info
+  uint32_t msgSize;     // Total size of message
+  uint32_t responseSize;// Size of response requested
+};
+
+}//namepsace ns3
+#endif
+