[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [42182] trunk/blender/source/blender/ blenlib: mempool utility function to get the element at an index BLI_mempool_findelem (), not used yet.

[Campbell Barton]

Revision: 42182
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=42182
Author:   campbellbarton
Date:     2011-11-27 01:20:08 +0000 (Sun, 27 Nov 2011)
Log Message:
-----------
mempool utility function to get the element at an index BLI_mempool_findelem(), not used yet.

Modified Paths:
--------------
    trunk/blender/source/blender/blenlib/BLI_mempool.h
    trunk/blender/source/blender/blenlib/intern/BLI_mempool.c

Modified: trunk/blender/source/blender/blenlib/BLI_mempool.h
===================================================================
--- trunk/blender/source/blender/blenlib/BLI_mempool.h	2011-11-26 21:42:04 UTC (rev 42181)
+++ trunk/blender/source/blender/blenlib/BLI_mempool.h	2011-11-27 01:20:08 UTC (rev 42182)
@@ -55,6 +55,7 @@
 void BLI_mempool_free(BLI_mempool *pool, void *addr);
 void BLI_mempool_destroy(BLI_mempool *pool);
 int BLI_mempool_count(BLI_mempool *pool);
+void *BLI_mempool_findelem(BLI_mempool *pool, const int index);
 
 /** iteration stuff.  note: this may easy to produce bugs with **/
 /*private structure*/

Modified: trunk/blender/source/blender/blenlib/intern/BLI_mempool.c
===================================================================
--- trunk/blender/source/blender/blenlib/intern/BLI_mempool.c	2011-11-26 21:42:04 UTC (rev 42181)
+++ trunk/blender/source/blender/blenlib/intern/BLI_mempool.c	2011-11-27 01:20:08 UTC (rev 42182)
@@ -68,8 +68,9 @@
 
 struct BLI_mempool {
 	struct ListBase chunks;
-	int esize, csize, pchunk;        /* size of elements and chunks in bytes
-	                                  * and number of elements per chunk*/
+	int esize;         /* element size in bytes */
+	int csize;         /* chunk size in bytes */
+	int pchunk;        /* number of elements per chunk */
 	short use_sysmalloc, allow_iter;
 	/* keeps aligned to 16 bits */
 
@@ -240,6 +241,23 @@
 	}
 }
 
+void *BLI_mempool_findelem(BLI_mempool *pool, const int index)
+{
+	if ((index >= 0) && (index < pool->totused)) {
+		BLI_mempool_chunk *mpchunk;
+		int i= 0;
+
+		for (mpchunk = pool->chunks.first; mpchunk; mpchunk = mpchunk->next) {
+			if (index < i + pool->pchunk) {
+				return ((char *)mpchunk->data) + (pool->esize * (index - i));
+			}
+			i += pool->pchunk;
+		}
+	}
+
+	return NULL;
+}
+
 void BLI_mempool_iternew(BLI_mempool *pool, BLI_mempool_iter *iter)
 {
 	if (!pool->allow_iter) {