Convenient to optimize the SURF.

[simgrid.git] / src / xbt / swag.c

diff --git a/src/xbt/swag.c b/src/xbt/swag.c
index 233b4c9..c9730de 100644 (file)
--- a/src/xbt/swag.c
+++ b/src/xbt/swag.c
@@ -63,6 +63,44 @@ void xbt_swag_insert(void *obj, xbt_swag_t swag)
   swag->tail = obj;
 }
 
+void xbt_swag_insert_at_head(void *obj, xbt_swag_t swag)
+{
+
+  if (xbt_swag_belongs(obj, swag))
+    return;
+
+  (swag->count)++;
+  if (swag->head == NULL) {
+    swag->head = obj;
+    swag->tail = obj;
+    return;
+  }
+
+  NEXT(obj, swag->offset) = swag->head;
+  PREV(NEXT(obj, swag->offset), swag->offset) = obj;
+
+  swag->head = obj;
+}
+
+void xbt_swag_insert_at_tail(void *obj, xbt_swag_t swag)
+{
+
+  if (xbt_swag_belongs(obj, swag))
+    return;
+
+  (swag->count)++;
+  if (swag->head == NULL) {
+    swag->head = obj;
+    swag->tail = obj;
+    return;
+  }
+
+  PREV(obj, swag->offset) = swag->tail;
+  NEXT(PREV(obj, swag->offset), swag->offset) = obj;
+
+  swag->tail = obj;
+}
+
 void *xbt_swag_remove(void *obj, xbt_swag_t swag)
 {
   size_t offset = swag->offset;
@@ -112,6 +150,7 @@ void *xbt_swag_extract(xbt_swag_t swag)
     PREV(swag->head, offset) = NULL;
     NEXT(obj, offset) = NULL;
   }
+  (swag->count)--;
 
   return obj;
 }