3 /* Copyright (c) 2004 Arnaud Legrand. All rights reserved. */
5 /* This program is free software; you can redistribute it and/or modify it
6 * under the terms of the license (GNU LGPL) which comes with this package. */
8 /* Warning, this module is done to be efficient and performs tons of
9 cast and dirty things. So avoid using it unless you really know
10 what you are doing. */
12 /* This type should be added to a type that is to be used in such a swag */
14 #include "xbt/sysdep.h"
15 #include "xbt/error.h"
18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(swag,xbt,"Swag : O(1) set library");
20 #define PREV(obj,offset) xbt_swag_getPrev(obj,offset)
21 #define NEXT(obj,offset) xbt_swag_getNext(obj,offset)
24 /** Creates a new swag.
25 * \param offset where the hookup is located in the structure
26 * \see xbt_swag_offset
28 * Usage : xbt_swag_new(&obj.setA-&obj);
30 xbt_swag_t xbt_swag_new(size_t offset)
32 xbt_swag_t swag = xbt_new0(s_xbt_swag_t, 1);
36 swag->offset = offset;
43 * \param swag poor victim
45 * kilkil a swag but not it's content. If you do not understand why
46 * xbt_swag_free should not free its content, don't use swags.
48 void xbt_swag_free(xbt_swag_t swag)
53 /** Creates a new swag.
54 * \param swag the swag to initialize
55 * \param offset where the hookup is located in the structure
56 * \see xbt_swag_offset
58 * Usage : xbt_swag_init(swag,&obj.setA-&obj);
60 void xbt_swag_init(xbt_swag_t swag, size_t offset)
64 swag->offset = offset;
70 * \param obj the objet to insert in the swag
73 * insert \a obj in \a swag
75 void xbt_swag_insert(void *obj, xbt_swag_t swag)
78 if (xbt_swag_belongs(obj, swag))
82 if (swag->head == NULL) {
83 xbt_assert0(!(swag->tail), "Inconsistent swag.");
89 PREV(obj, swag->offset) = swag->tail;
90 NEXT(PREV(obj, swag->offset), swag->offset) = obj;
96 * \param obj the objet to insert in the swag
99 * insert (at the head... you probably had a very good reason to do
100 * that, I hope you know what you're doing) \a obj in \a swag
102 void xbt_swag_insert_at_head(void *obj, xbt_swag_t swag)
105 if (xbt_swag_belongs(obj, swag))
109 if (swag->head == NULL) {
110 xbt_assert0(!(swag->tail), "Inconsistent swag.");
116 NEXT(obj, swag->offset) = swag->head;
117 PREV(NEXT(obj, swag->offset), swag->offset) = obj;
123 * \param obj the objet to insert in the swag
126 * insert (at the tail... you probably had a very good reason to do
127 * that, I hope you know what you're doing) \a obj in \a swag
129 void xbt_swag_insert_at_tail(void *obj, xbt_swag_t swag)
132 if (xbt_swag_belongs(obj, swag))
136 if (swag->head == NULL) {
137 xbt_assert0(!(swag->tail), "Inconsistent swag.");
143 PREV(obj, swag->offset) = swag->tail;
144 NEXT(PREV(obj, swag->offset), swag->offset) = obj;
150 * \param obj the objet to remove from the swag
152 * \return \a obj if it was in the \a swag and NULL otherwise
154 * removes \a obj from \a swag
156 void *xbt_swag_remove(void *obj, xbt_swag_t swag)
158 size_t offset = swag->offset;
160 if ((!obj) || (!swag))
162 if(!xbt_swag_belongs(obj, swag)) /* Trying to remove an object that
163 was not in this swag */
166 if (swag->head == swag->tail) { /* special case */
167 if (swag->head != obj) /* Trying to remove an object that was not in this swag */
171 NEXT(obj, offset) = PREV(obj, offset) = NULL;
172 } else if (obj == swag->head) { /* It's the head */
173 swag->head = NEXT(obj, offset);
174 PREV(swag->head, offset) = NULL;
175 NEXT(obj, offset) = NULL;
176 } else if (obj == swag->tail) { /* It's the tail */
177 swag->tail = PREV(obj, offset);
178 NEXT(swag->tail, offset) = NULL;
179 PREV(obj, offset) = NULL;
180 } else { /* It's in the middle */
181 NEXT(PREV(obj, offset), offset) = NEXT(obj, offset);
182 PREV(NEXT(obj, offset), offset) = PREV(obj, offset);
183 PREV(obj, offset) = NEXT(obj, offset) = NULL;
191 * \return an object from the \a swag
193 void *xbt_swag_extract(xbt_swag_t swag)
195 size_t offset = swag->offset;
198 if ((!swag) || (!(swag->head)))
203 if (swag->head == swag->tail) { /* special case */
204 swag->head = swag->tail = NULL;
205 PREV(obj, offset) = NEXT(obj, offset) = NULL;
207 swag->head = NEXT(obj, offset);
208 PREV(swag->head, offset) = NULL;
209 NEXT(obj, offset) = NULL;
217 * \return the number of objects in \a swag
219 int xbt_swag_size(xbt_swag_t swag)
221 return (swag->count);
225 * \param obj an object
227 * \return 1 if \a obj is in the \a swag and 0 otherwise
229 int xbt_swag_belongs(void *obj, xbt_swag_t swag)
231 return ((NEXT(obj, swag->offset)) || (PREV(obj, swag->offset))
232 || (swag->head == obj));