data.h

/*

 Copyright (c) 2011, Charles Smith
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification,
 are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
 this
      list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
 this
      list of conditions and the following disclaimer in the documentation
 and/or
      other materials provided with the distribution.
    * Neither the name of Vallona Networks nor the names of its contributors
      may be used to endorse or promote products derived from this software
 without
      specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.
 IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
 DIRECT,
 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 ADVISED
 OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef _DATA_H
#define _DATA_H

#include <cstring>
#include <iostream>
#include <string>
using namespace std;

#include "frame.h"
#include "saratoga.h"
#include "sarflags.h"
#include "screen.h"
#include "timestamp.h"

namespace saratoga {
/*
 **********************************************************************
 * DATA
 **********************************************************************
 */

class data : public frame
{
private:
  Fflag _flags;         // Data's Flags
  session_t _session;   // THe session ID
  offset_t _offset;     // How far into the transfer we are
  timestamp _timestamp; // If we have a timestamp what is it
  char* _dbuf;          // THe buffer holding the data
  size_t _dbuflen;      // How long the buffer is

protected:
  bool _badframe; // Are we a good or bad data frame
  char* _payload; // Complete payload of frame
  size_t _paylen; // Length of payload
public:
  const static size_t maxframesize = MAXDATA; // Maximum size of a data frame

  // This is how we assemble a local data
  // To get ready for transmission
  // The optional timestamp is created within
  // this constructor. There is a data::timestamp()
  // to amend it if needed.
  data(const enum f_descriptor&, const enum f_transfer&,
       const enum f_reqstatus&, const enum f_eod&,
       const enum f_reqtstamp&, // If we want a timestamp
       const session_t&,        // Session NUmber
       const offset_t&,         // offset
       const char*,             // payload
       const size_t&);          // length of payload

  // We have received a remote frame that is DATA
  data(char*,         // Pointer to buffer received
       const size_t); // Total length of buffer

  ~data() { this->clear(); };

  void clear()
  {
    if (_paylen > 0)
      delete[] _payload;
    _paylen = 0;
    _timestamp = T_TSTAMP_32;
    _session = 0;
    _offset = 0;
    _dbuf = nullptr;
    _dbuflen = 0;
    _flags = 0;
    _badframe = true;
  };

  // Copy constructor
  data(const data& old)
  {
    if (old._paylen > 0) {
      _payload = new char[old._paylen];
      memcpy(_payload, old._payload, old._paylen);
    } else
      _payload = nullptr;
    _paylen = old._paylen;
    _flags = old._flags;
    _session = old._session;
    _offset = old._offset;

    Fdescriptor descriptor = _flags.get();
    _dbuf = _payload + sizeof(flag_t) + sizeof(session_t) + descriptor.length();
    Freqtstamp reqtstamp = _flags.get();
    if (reqtstamp.get() == F_TIMESTAMP_YES) {
      _timestamp = old._timestamp;
      _dbuf += _timestamp.length();
    } else
      _timestamp = T_TSTAMP_32;
    _dbuflen = old._dbuflen;
  }

  // Assignment of existing data
  data& operator=(const data& old)
  {
    if (old._paylen > 0) {
      _payload = new char[old._paylen];
      memcpy(_payload, old._payload, old._paylen);
    } else
      _payload = nullptr;
    _paylen = old._paylen;
    _flags = old._flags;
    _session = old._session;
    _offset = old._offset;

    _dbuf = _payload + sizeof(flag_t) + sizeof(session_t);
    Fdescriptor descriptor = _flags.get();
    _dbuf += descriptor.length();
    Freqtstamp reqtstamp = _flags.get();
    if (reqtstamp.get() == F_TIMESTAMP_YES) {
      _timestamp = old._timestamp;
      _dbuf += _timestamp.length();
    } else
      _timestamp = T_TSTAMP_32;
    _dbuflen = old._dbuflen;
    return (*this);
  }

  bool badframe() { return _badframe; };
  size_t paylen() { return _paylen; };
  char* payload() { return _payload; };

  // Get various flags applicable to data
  enum f_descriptor descriptor();
  enum f_transfer transfer();
  enum f_reqstatus reqstatus();
  enum f_eod eod();
  enum f_reqtstamp reqtstamp();

  // Set various flags applicable to data
  enum f_descriptor descriptor(f_descriptor);
  enum f_transfer transfer(f_transfer);
  enum f_reqstatus reqstatus(f_reqstatus);
  enum f_eod eod(f_eod);
  enum f_reqtstamp reqtstamp(f_reqtstamp);

  // What is the session number for this transaction
  session_t session() { return _session; };

  // How far into the transfer are we and we can set it
  offset_t offset() { return _offset; };
  offset_t offset(offset_t o)
  {
    _offset = o;
    return _offset;
  };

  // The data frames flags
  flag_t flags() { return _flags.get(); };

  // Yes I am a data frame
  f_frametype type() { return F_FRAMETYPE_DATA; };

  // What is the length of the data buffer in this frame
  char* dbuf() { return _dbuf; };
  size_t dbuflen() { return _dbuflen; };

  ssize_t rx() { return (-1); };

  ssize_t tx(sarnet::udp* sock) { return (sock->tx(_payload, _paylen)); };

  string print();
};

} // Namespace saratoga

#endif // _DATA_H