split.h

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//
// srecord - manipulate eprom load files
// Copyright (C) 1998, 1999, 2001, 2002, 2005-2010 Peter Miller
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see
// <http://www.gnu.org/licenses/>.
//
 
#ifndef SRECORD_INPUT_FILTER_SPLIT_H
#define SRECORD_INPUT_FILTER_SPLIT_H
 
#include <srecord/input/filter.h>
#include <srecord/record.h>
 
namespace srecord
{
 
/**
  * The srecord::input_filter_split class is used to represent a filter
  * which splits ints input source into piceces.  The data of each
  * swathe then has the address adjusted to fill in the gaps.
  *
  * For example, this filter can be used to create each of the images
  * for 8-bit EPROMS for systems which use a 16-bit bus.
  *
  * Note that you need to invoke this filter N times when you have N
  * swathes, once for each swathe.
  *
  * <pre>
  *           --> |    modulus    | <--
  * Input data:   |               |
  * ~-+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+-~
  *   |   | X | X | 0 | 1 | X | X | 4 | 5 | X | X | 8 | 9 | X | X |   |
  * ~-+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+-~
  *               |       |      /       /       /       /
  *               |       |     /       /      /       /
  *               |       |    /       /     /       /
  *               |       |   /       /    /       /    This diagram shows
  *               |       |  /       /   /       /      offset zero.  You
  *               |       | /       /  /       /        would need a second
  * Output data:  |       |/       //       /           pass with an offset
  * ~-+---+---+---+---+---+---+---+---+---+---+---+-~   of two for the other
  *   |   |   |   | 0 | 1 | 4 | 5 | 8 | 9 |   |   |     half of the data.
  * ~-+---+---+---+---+---+---+---+---+---+---+---+-~
  *               |       |
  *           --> | width | <--                                           </pre>
  */
class input_filter_split:
    public input_filter
{
public:
    /**
      * The destructor.
      */
    virtual ~input_filter_split();
 
private:
    /**
      * The constructor.
      *
      * @param deeper
      *     The deeper input source to be filtered.
      * @param modulus
      *     The number of bytes wide each swathe is.
      * @param offset
      *     The offset within the swathe.
      * @param width
      *     The width of each stripe within the swathe.
      */
    input_filter_split(const input::pointer &deeper, int modulus,
        int offset, int width);
 
public:
    /**
      * The create class method is used to create new dynamically
      * allocated instances of this class.
      *
      * @param deeper
      *     The incoming data source to be filtered
      * @param modulus
      *     The number of bytes wide each swathe is.
      * @param offset
      *     The offset within the swathe.
      * @param width
      *     The width of each stripe within the swathe.
      */
    static pointer create(const input::pointer &deeper, int modulus,
        int offset, int width);
 
protected:
    // See base class for documentation.
    bool read(record &record);
 
private:
    /**
      * The modulus instance variable is used to remember the number of
      * bytes wide each swathe is.
      */
    record::address_t modulus;
 
    /**
      * The offset instance variable is used to remember the offset
      * within the swathe.
      */
    record::address_t offset;
 
    /**
      * The width instance variable is used to remember the width of
      * each stripe within the swathe.
      */
    record::address_t width;
 
    /**
      * The buffer instance variable is used to remember the last lot
      * of data read from the deeper inputs source, and currently being
      * processed.
      */
    record buffer;
 
    /**
      * The buffer_pos instance variable is used to remember where we
      * are up to in the "buffer" instance varaible.
      */
    size_t buffer_pos;
 
    /**
      * The default constructor.  Do not use.
      */
    input_filter_split();
 
    /**
      * The copy constructor.  Do not use.
      */
    input_filter_split(const input_filter_split &);
 
    /**
      * The assignment operator.  Do not use.
      */
    input_filter_split &operator=(const input_filter_split &);
};
 
};
 
#endif // SRECORD_INPUT_FILTER_SPLIT_H