Convenient to optimize the SURF.

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

diff --git a/src/xbt/swag.c b/src/xbt/swag.c
index dc09977..c9730de 100644 (file)
--- a/src/xbt/swag.c
+++ b/src/xbt/swag.c
@@ -1,7 +1,9 @@
-/* Authors: Arnaud Legrand                                                  */
+/*     $Id$     */
+
+/* Copyright (c) 2004 Arnaud Legrand. All rights reserved.                  */
 
 /* This program is free software; you can redistribute it and/or modify it
-   under the terms of the license (GNU LGPL) which comes with this package. */
+ * under the terms of the license (GNU LGPL) which comes with this package. */
 
 /* Warning, this module is done to be efficient and performs tons of
    cast and dirty things. So avoid using it unless you really know
@@ -13,11 +15,13 @@
 #include "xbt/error.h"
 #include "xbt/swag.h"
 
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(swag,xbt,"Swag : O(1) set library");
+
 #define PREV(obj,offset) xbt_swag_getPrev(obj,offset)
 #define NEXT(obj,offset) xbt_swag_getNext(obj,offset)
 
 /*
-  Usage : xbt_swag_new(&obj.setA-&obj.setA);
+  Usage : xbt_swag_new(&obj.setA-&obj);
  */
 
 xbt_swag_t xbt_swag_new(size_t offset)
@@ -29,6 +33,12 @@ xbt_swag_t xbt_swag_new(size_t offset)
   return swag;
 }
 
+
+void xbt_swag_free(xbt_swag_t swag)
+{
+  xbt_free(swag);
+}
+
 void xbt_swag_init(xbt_swag_t swag, size_t offset)
 {
   swag->offset = offset;
@@ -53,11 +63,49 @@ void xbt_swag_insert(void *obj, xbt_swag_t swag)
   swag->tail = obj;
 }
 
-void *xbt_swag_extract(void *obj, xbt_swag_t swag)
+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;
 
-  if (!obj)
+  if ((!obj) || (!swag))
     return NULL;
   if(!xbt_swag_belongs(obj, swag)) /* Trying to remove an object that
                                      was not in this swag */
@@ -85,6 +133,28 @@ void *xbt_swag_extract(void *obj, xbt_swag_t swag)
   return obj;
 }
 
+void *xbt_swag_extract(xbt_swag_t swag)
+{
+  size_t offset = swag->offset;
+  void *obj = NULL;
+
+  if ((!swag) || (!(swag->head)))
+    return NULL;
+
+  obj = swag->head;
+
+  if (swag->head == swag->tail) {      /* special case */
+    swag->head = swag->tail = NULL;
+  } else {
+    swag->head = NEXT(obj, offset);
+    PREV(swag->head, offset) = NULL;
+    NEXT(obj, offset) = NULL;
+  }
+  (swag->count)--;
+
+  return obj;
+}
+
 int xbt_swag_size(xbt_swag_t swag)
 {
   return (swag->count);