Initial revision

source/blender/blenlib/intern/BLI_memarena.c

@@ -0,0 +1,80 @@
+/**
+ * $Id$
+ *
+ * ***** BEGIN GPL/BL DUAL 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. The Blender
+ * Foundation also sells licenses for use in proprietary software under
+ * the Blender License.  See http://www.blender.org/BL/ for information
+ * about this.
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, 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/BL DUAL LICENSE BLOCK *****
+ * Efficient memory allocation for lots of similar small chunks.
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_blenlib.h"
+#include "BLI_memarena.h"
+#include "BLI_linklist.h"
+
+struct MemArena {
+	unsigned char *curbuf;
+	int bufsize, cursize;
+	
+	LinkNode *bufs;
+};
+
+MemArena *BLI_memarena_new(int bufsize) {
+	MemArena *ma= MEM_callocN(sizeof(*ma), "memarena");
+	ma->bufsize= bufsize;
+	
+	return ma;
+}
+void BLI_memarena_free(MemArena *ma) {
+	BLI_linklist_free(ma->bufs, 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, 8);
+	
+	if (size>=ma->cursize) {
+		ma->cursize= (size>ma->bufsize)?size:ma->bufsize;
+		ma->curbuf= MEM_mallocN(ma->cursize, "ma->curbuf");
+		
+		BLI_linklist_prepend(&ma->bufs, ma->curbuf);
+	}
+	
+	ptr= ma->curbuf;
+	ma->curbuf+= size;
+	ma->cursize-= size;
+	
+	return ptr;
+}