scummvm/engines/sci/sci_memory.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 2
 * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */


/** This header file defines a portable library for allocating memory safely
 ** throughout FreeSCI.
 ** Implementations of basic functions found here are in this file and
 ** $(SRCDIR)/src/scicore/sci_memory.c
 *
 **************
 *
 * Sets behaviour if memory allocation call fails.
 * UNCHECKED_MALLOCS:  use C library routine without checks
 * (nothing defined):  check mallocs and exit immediately on fail (recommended)
 *
 ** -- Alex Angas
 **
 **/


#ifndef SCI_SCI_MEMORY_H
#define SCI_SCI_MEMORY_H

#include "common/scummsys.h"

namespace Sci {

/********** memory allocation routines **********/

extern void *sci_malloc(size_t size);
/* Allocates the specified amount of memory.
** Parameters: (size_t) size: Number of bytes to allocate
** Returns   : (void *) A pointer to the allocated memory chunk
** To free this string, use the free() command.
** If the call fails, behaviour is dependent on the definition of SCI_ALLOC.
*/

extern void *sci_calloc(size_t num, size_t size);
/* Allocates num * size bytes of zeroed-out memory.
** Parameters: (size_t) num: Number of elements to allocate
**             (size_t) size: Amount of memory per element to allocate
** Returns   : (void *) A pointer to the allocated memory chunk
** To free this string, use the free() command.
** See _SCI_MALLOC() for more information if call fails.
*/

extern void *sci_realloc(void *ptr, size_t size);
/* Increases the size of an allocated memory chunk.
** Parameters: (void *) ptr: The original pointer
**             (size_t) size: New size of the memory chunk
** Returns   : (void *) A possibly new pointer, containing 'size'
**             bytes of memory and everything contained in the original 'ptr'
**             (possibly minus some trailing data if the new memory area is
**             smaller than the old one).
** To free this string, use the free() command.
** See _SCI_MALLOC() for more information if call fails.
*/


extern char *sci_strdup(const char *src);
/* Duplicates a string.
** Parameters: (const char *) src: The original pointer
** Returns   : (char *) a pointer to the storage location for the copied
**             string.
** To free this string, use the free() command.
** See _SCI_MALLOC() for more information if call fails.
*/


extern char *sci_strndup(const char *src, size_t length);
/* Copies a string into a newly allocated memory part, up to a certain length.
** Parameters: (char *) src: The source string
**             (int) length: The maximum length of the string (not counting
**                           a trailing \0).
** Returns   : (char *) The resulting copy, allocated with sci_malloc().
** To free this string, use the free() command.
** See _SCI_MALLOC() for more information if call fails.
*/

/****************************************/
/* Refcounting garbage collected memory */
/****************************************/

/* Refcounting memory calls are a little slower than the others,
** and using it improperly may cause memory leaks. It conserves
** memory, though.  */

extern void *sci_refcount_alloc(size_t length);
/* Allocates "garbage" memory
** Parameters: (size_t) length: Number of bytes to allocate
** Returns   : (void *) The allocated memory
** Memory allocated in this fashion will be marked as holding one reference.
** It cannot be freed with 'free()', only by using sci_refcount_decref().
*/

extern void *sci_refcount_incref(void *data);
/* Adds another reference to refcounted memory
** Parameters: (void *) data: The data to add a reference to
** Returns   : (void *) data
*/

extern void sci_refcount_decref(void *data);
/* Decrements the reference count for refcounted memory
** Parameters: (void *) data: The data to add a reference to
** Returns   : (void *) data
** If the refcount reaches zero, the memory will be deallocated
*/

extern void *sci_refcount_memdup(void *data, size_t len);
/* Duplicates non-refcounted memory into a refcounted block
** Parameters: (void *) data: The memory to copy from
**             (size_t) len: The number of bytes to copy/allocate
** Returns   : (void *) Newly allocated refcounted memory
** The number of references accounted for will be one.
*/

} // End of namespace Sci

#endif	// SCI_SCI_MEMORY_H