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unison/src/internet-stack/pending-data.h
2010-03-27 19:09:18 -04:00

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/* -*- 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 "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 SequenceNumber& seqFront, const SequenceNumber& 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 SequenceNumber& seqFront, const SequenceNumber& 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 SequenceNumber&, const SequenceNumber&);
/**
* 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 SequenceNumber& seqFront, const SequenceNumber& 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