WADS of WADS/WadsOfWads.1994.zip/OTHER/REJECT/SOURCE.ZIP/MEMHANDL.CPP

C/C++ Source or Header | 1994-05-31 | 8KB | 237 lines

//**********************************************************************************
//    REJECT.EXE - Reject data table builder for DOOM
//    Copyright (C) 1994 L.M.WITEK
//
//    This program is free software; you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation; either version 1, 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.

//**********************************************************************************
#include <string.h>
#include "memhandl.hpp"


//*********************************************************************************
//*********************************************************************************
//**
//**      Implementation of the MemoryBlock class
//**
//*********************************************************************************
//*********************************************************************************

/*********************************************************************************
**
**  CONSTRUCTOR: MemoryBlock::MemoryBlock (size_t size)
**
**               Allocate buffer & set ref count to 0.
**
*********************************************************************************/

MemoryBlock::MemoryBlock (size_t size)
            : szbuffer (size), count (0), buffer (new unsigned char[size])
{
}


/*********************************************************************************
**
**  CONSTRUCTOR: MemoryBlock::~MemoryBlock ()
**
**               Delete the block of memory.
**
*********************************************************************************/

MemoryBlock::~MemoryBlock ()
{
     delete [] buffer;
}



//*********************************************************************************
//*********************************************************************************
//**
//**      Implementation of the MemHandle class
//**
//*********************************************************************************
//*********************************************************************************


/*********************************************************************************
**
**  CONSTRUCTOR: MemHandle::MemHandle (MemHandle &mh)
**
**              Constructs a memory handle to an existing block of memory
**              specified by the 'mh' parameter.
**
*********************************************************************************/

MemHandle::MemHandle (const MemHandle &mh)
{
     mem = mh.mem;
     (mem->count)++;
}


/*********************************************************************************
**
**  CONSTRUCTOR: MemHandle::MemHandle (size_t size)
**
**              Constructs a memory handle to a new block of memory of 'size'
**              bytes. The block of memory is not initialised to any specific
**              value.
**
*********************************************************************************/

MemHandle::MemHandle (size_t size)
          :mem (new MemoryBlock (size))
{
     (mem->count)++;
}

/*********************************************************************************
**
**  CONSTRUCTOR: MemHandle::MemHandle (size_t size, unsigned char filler)
**
**              Constructs a memory handle to a new block of memory of 'size'
**              bytes and initialises the block to the value specified by
**              the 'filler' parameter.
**
*********************************************************************************/

MemHandle::MemHandle (size_t size, unsigned char filler)
          :mem (new MemoryBlock (size))
{
     (mem->count)++;
     memset (mem->buffer, filler, size);
}

/*********************************************************************************
**
**  DESTRUCTOR: MemHandle::~MemHandle
**
**              Destroys the memory handle. If the block of memory associated
**              with this handle has no other handles referencing it then it
**              id deleted also.
**
*********************************************************************************/

MemHandle::~MemHandle ()
{
     (mem->count)--;
     if (mem->count == 0) delete mem;
}

/*********************************************************************************
**
**  FUNCTION: MemHandle::Clone () const
**
**            Make a copy of the memory block held by the MemHandle object.
**
**  RETURNS:  a MemHandle to the cloned memory block
**
*********************************************************************************/

MemHandle MemHandle::Clone () const
{
     MemHandle mh (Size());                               // make a memory block the same size as me
     memcpy (mh.mem->buffer, mem->buffer, Size());        // copy my data to this new memory block

     return (mh);                                         // return the handle to this new memory block
}


/*********************************************************************************
**
**  FUNCTION: MemHandle& MemHandle::operator= (const MemHandle& mh)
**
**            Assign a new memory block to this handle
**
*********************************************************************************/

MemHandle& MemHandle::operator= (const MemHandle& mh)
{
     if (mh.mem != mem)                          // make sure we dont copy ourself
     {
          (mem->count)--;                        // detatch from old memory block
          if (mem->count == 0) delete mem;

          mem = mh.mem;                          // attach to new memory block
          (mem->count)++;
     }
     return *this;
}


/*********************************************************************************
**
**  FUNCTION: void MemHandle::Shrink (size_t newsz)
**
**            Shrink the size of a memory block. Does not change the memory
**            the memory allocation just marks the block a being smaller.
**            Useful for creating a buffer to hold some data where the data
**            size is unknown. Memory block can be shrunk after data is
**            placed in buffer.
**
*********************************************************************************/

void MemHandle::Shrink (size_t newsz)
{
     if (newsz < mem->szbuffer)
          mem->szbuffer = newsz;
}


//*********************************************************************************
//*********************************************************************************
//**
//**      Test rig for the MemHandle class
//**
//*********************************************************************************
//*********************************************************************************
//#define _TEST_MEMHANDLE_

#ifdef _TEST_MEMHANDLE_

#include <stdio.h>

void main ()
{
     MemHandle mh1 (1024);
     MemHandle mh2 (512);
     MemHandle mh3 (mh2);

     strcpy (mh1, "First Block");
     strcpy (mh2, "Second Block");

//     memcpy (mh1, mh2, 3);

     {
          MemHandle mhx (mh3);
     }


     puts (mh1);
     puts (mh2);

     mh1 = mh2;
     mh1 = mh2;

     puts (mh1);

     puts (mh1);

}

#endif