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/**
* $Id$
*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* 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.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL LICENSE BLOCK *****
* Efficient memory allocation for lots of similar small chunks.
*/
#include "MEM_guardedalloc.h"
#include "BLI_memarena.h"
#include "BLI_linklist.h"
struct MemArena {
unsigned char *curbuf;
int bufsize, cursize;
const char *name;
int use_calloc;
int align;
LinkNode *bufs;
};
MemArena *BLI_memarena_new(int bufsize, const char *name) {
MemArena *ma= MEM_callocN(sizeof(*ma), "memarena");
ma->bufsize= bufsize;
ma->align = 8;
ma->name= name;
return ma;
}
void BLI_memarena_use_calloc(MemArena *ma) {
ma->use_calloc= 1;
}
void BLI_memarena_use_malloc(MemArena *ma) {
ma->use_calloc= 0;
}
void BLI_memarena_use_align(struct MemArena *ma, int align) {
/* align should be a power of two */
ma->align = align;
}
void BLI_memarena_free(MemArena *ma) {
BLI_linklist_free(ma->bufs, (void(*)(void*)) MEM_freeN);
MEM_freeN(ma);
}
/* amt must be power of two */
#define PADUP(num, amt) ((num+(amt-1))&~(amt-1))
void *BLI_memarena_alloc(MemArena *ma, int size) {
void *ptr;
/* ensure proper alignment by rounding
* size up to multiple of 8 */
size= PADUP(size, ma->align);
if (size>ma->cursize) {
unsigned char *tmp;
if(size > ma->bufsize - (ma->align - 1))
{
ma->cursize = PADUP(size+1, ma->align);
}
else ma->cursize = ma->bufsize;
if(ma->use_calloc)
ma->curbuf= MEM_callocN(ma->cursize, ma->name);
else
ma->curbuf= MEM_mallocN(ma->cursize, ma->name);
BLI_linklist_prepend(&ma->bufs, ma->curbuf);
/* align alloc'ed memory (needed if align > 8) */
tmp = (unsigned char*)PADUP( (intptr_t) ma->curbuf, ma->align);
ma->cursize -= (tmp - ma->curbuf);
ma->curbuf = tmp;
}
ptr= ma->curbuf;
ma->curbuf+= size;
ma->cursize-= size;
return ptr;
}
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