From 7f379953cbe4a9a5b60472c218a6189d523856cd Mon Sep 17 00:00:00 2001
From: alegrand <alegrand@48e7efb5-ca39-0410-a469-dd3cf9ba447f>
Date: Fri, 31 Dec 2004 02:49:07 +0000
Subject: [PATCH 1/1] Convenient to optimize the SURF.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@703 48e7efb5-ca39-0410-a469-dd3cf9ba447f
---
 include/xbt/swag.h |  2 ++
 src/xbt/swag.c     | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/include/xbt/swag.h b/include/xbt/swag.h
index 7e6f1bd43b..21d40fd1f2 100644
--- a/include/xbt/swag.h
+++ b/include/xbt/swag.h
@@ -33,6 +33,8 @@ xbt_swag_t xbt_swag_new(size_t offset);
 void xbt_swag_free(xbt_swag_t swag);
 void xbt_swag_init(xbt_swag_t swag, size_t offset);
 void xbt_swag_insert(void *obj, xbt_swag_t swag);
+void xbt_swag_insert_at_head(void *obj, xbt_swag_t swag);
+void xbt_swag_insert_at_tail(void *obj, xbt_swag_t swag);
 void *xbt_swag_remove(void *obj, xbt_swag_t swag);
 void *xbt_swag_extract(xbt_swag_t swag);
 int xbt_swag_size(xbt_swag_t swag);
diff --git a/src/xbt/swag.c b/src/xbt/swag.c
index 3c2793a3aa..c9730dee16 100644
--- 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;
-- 
2.20.1