pcompress/utils/phash/recycle.h

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/*
* This file is a part of Pcompress, a chunked parallel multi-
* algorithm lossless compression and decompression program.
*
* Copyright (C) 2012-2013 Moinak Ghosh. All rights reserved.
* Use is subject to license terms.
*
* 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/>.
*
* moinakg@belenix.org, http://moinakg.wordpress.com/
*
*/
/*
--------------------------------------------------------------------
By Bob Jenkins, September 1996. recycle.h
You may use this code in any way you wish, and it is free. No warranty.
This manages memory for commonly-allocated structures.
It allocates RESTART to REMAX items at a time.
Timings have shown that, if malloc is used for every new structure,
malloc will consume about 90% of the time in a program. This
module cuts down the number of mallocs by an order of magnitude.
This also decreases memory fragmentation, and freeing all structures
only requires freeing the root.
--------------------------------------------------------------------
*/
#ifndef STANDARD
#include "standard.h"
#endif
#ifndef RECYCLE
#define RECYCLE
#define RESTART 0
#define REMAX 32000
struct recycle
{
struct recycle *next;
};
typedef struct recycle recycle;
struct reroot
{
struct recycle *list; /* list of malloced blocks */
struct recycle *trash; /* list of deleted items */
size_t size; /* size of an item */
size_t logsize; /* log_2 of number of items in a block */
word numleft; /* number of bytes left in this block */
};
typedef struct reroot reroot;
/* make a new recycling root */
reroot *remkroot(/*_ size_t mysize _*/);
/* free a recycling root and all the items it has made */
void refree(/*_ struct reroot *r _*/);
/* get a new (cleared) item from the root */
#define renew(r) ((r)->numleft ? \
(((char *)((r)->list+1))+((r)->numleft-=(r)->size)) : renewx(r))
char *renewx(/*_ struct reroot *r _*/);
/* delete an item; let the root recycle it */
/* void redel(/o_ struct reroot *r, struct recycle *item _o/); */
#define redel(root,item) { \
((recycle *)item)->next=(root)->trash; \
(root)->trash=(recycle *)(item); \
}
/* malloc, but complain to stderr and exit program if no joy */
/* use plain free() to free memory allocated by remalloc() */
char *remalloc(/*_ size_t len, char *purpose _*/);
#endif /* RECYCLE */