-/* 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
#include "xbt/error.h"
#include "xbt/swag.h"
+/** \defgroup XBT_swag A O(1) set datatype
+ * \brief a O(1) set based on linked lists
+ *
+ * Warning, this module is done to be efficient and performs tons of
+ * cast and dirty things. So avoid using it unless you really know
+ * what you are doing. It is basically a fifo but with restrictions so that
+ * it can be used as a set. Any operation (add, remove, belongs) is O(1) and
+ * no call to malloc/free is done.
+ */
+
+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);
+/** \name Functions
+ * \ingroup XBT_swag
*/
+/*@{*/
+/** Creates a new swag.
+ * \param offset where the hookup is located in the structure
+ * \see xbt_swag_offset
+ *
+ * Usage : xbt_swag_new(&obj.setA-&obj);
+ */
xbt_swag_t xbt_swag_new(size_t offset)
{
xbt_swag_t swag = xbt_new0(s_xbt_swag_t, 1);
return swag;
}
+/**
+ * \param swag poor victim
+ *
+ * kilkil a swag but not it's content. If you do not understand why
+ * xbt_swag_free should not free its content, don't use swags.
+ */
+void xbt_swag_free(xbt_swag_t swag)
+{
+ xbt_free(swag);
+}
+
+/** Creates a new swag.
+ * \param swag the swag to initialize
+ * \param offset where the hookup is located in the structure
+ * \see xbt_swag_offset
+ *
+ * Usage : xbt_swag_init(swag,&obj.setA-&obj);
+ */
void xbt_swag_init(xbt_swag_t swag, size_t offset)
{
swag->offset = offset;
}
+
+/**
+ * \param obj the objet to insert in the swag
+ * \param swag a swag
+ *
+ * insert \a obj in \a swag
+ */
void xbt_swag_insert(void *obj, xbt_swag_t swag)
{
(swag->count)++;
if (swag->head == NULL) {
+ xbt_assert0(!(swag->tail), "Inconsistent swag.");
+ swag->head = obj;
+ swag->tail = obj;
+ return;
+ }
+
+ PREV(obj, swag->offset) = swag->tail;
+ NEXT(PREV(obj, swag->offset), swag->offset) = obj;
+
+ swag->tail = obj;
+}
+
+/**
+ * \param obj the objet to insert in the swag
+ * \param swag a swag
+ *
+ * insert (at the head... you probably had a very good reason to do
+ * that, I hope you know what you're doing) \a obj in \a 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) {
+ xbt_assert0(!(swag->tail), "Inconsistent swag.");
+ swag->head = obj;
+ swag->tail = obj;
+ return;
+ }
+
+ NEXT(obj, swag->offset) = swag->head;
+ PREV(NEXT(obj, swag->offset), swag->offset) = obj;
+
+ swag->head = obj;
+}
+
+/**
+ * \param obj the objet to insert in the swag
+ * \param swag a swag
+ *
+ * insert (at the tail... you probably had a very good reason to do
+ * that, I hope you know what you're doing) \a obj in \a swag
+ */
+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) {
+ xbt_assert0(!(swag->tail), "Inconsistent swag.");
swag->head = obj;
swag->tail = obj;
return;
swag->tail = obj;
}
+/**
+ * \param obj the objet to remove from the swag
+ * \param swag a swag
+ * \return \a obj if it was in the \a swag and NULL otherwise
+ *
+ * removes \a obj from \a swag
+ */
void *xbt_swag_remove(void *obj, xbt_swag_t swag)
{
size_t offset = swag->offset;
return NULL;
swag->head = NULL;
swag->tail = NULL;
+ NEXT(obj, offset) = PREV(obj, offset) = NULL;
} else if (obj == swag->head) { /* It's the head */
swag->head = NEXT(obj, offset);
PREV(swag->head, offset) = NULL;
return obj;
}
+/**
+ * \param swag a swag
+ * \return an object from the \a swag
+ */
void *xbt_swag_extract(xbt_swag_t swag)
{
size_t offset = swag->offset;
if (swag->head == swag->tail) { /* special case */
swag->head = swag->tail = NULL;
+ PREV(obj, offset) = NEXT(obj, offset) = NULL;
} else {
swag->head = NEXT(obj, offset);
PREV(swag->head, offset) = NULL;
NEXT(obj, offset) = NULL;
}
+ (swag->count)--;
return obj;
}
-
+/**
+ * \param swag a swag
+ * \return the number of objects in \a swag
+ */
int xbt_swag_size(xbt_swag_t swag)
{
return (swag->count);
}
+/**
+ * \param obj an object
+ * \param swag a swag
+ * \return 1 if \a obj is in the \a swag and 0 otherwise
+ */
int xbt_swag_belongs(void *obj, xbt_swag_t swag)
{
return ((NEXT(obj, swag->offset)) || (PREV(obj, swag->offset))
|| (swag->head == obj));
}
+/*@}*/
