/src/nss/lib/base/list.c

Source (jump to first uncovered line)
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * list.c
 *
 * This contains the implementation of NSS's thread-safe linked list.
 */

#ifndef BASE_H
#include "base.h"
#endif /* BASE_H */

struct nssListElementStr {
    PRCList link;
    void *data;
};

typedef struct nssListElementStr nssListElement;

struct nssListStr {
    NSSArena *arena;
    PZLock *lock;
    nssListElement *head;
    PRUint32 count;
    nssListCompareFunc compareFunc;
    nssListSortFunc sortFunc;
    PRBool i_alloced_arena;
};

struct nssListIteratorStr {
    PZLock *lock;
    nssList *list;
    nssListElement *current;
};

#define NSSLIST_LOCK_IF(list) \
    if ((list)->lock)         \
    PZ_Lock((list)->lock)

#define NSSLIST_UNLOCK_IF(list) \
    if ((list)->lock)           \
    PZ_Unlock((list)->lock)

static PRBool
pointer_compare(void *a, void *b)
{
    return (PRBool)(a == b);
}

static nssListElement *
nsslist_get_matching_element(nssList *list, void *data)
{
    nssListElement *node;
    node = list->head;
    if (!node) {
        return NULL;
    }
    while (node) {
        /* using a callback slows things down when it's just compare ... */
        if (list->compareFunc(node->data, data)) {
            break;
        }
        if (&node->link == PR_LIST_TAIL(&list->head->link)) {
            node = NULL;
            break;
        }
        node = (nssListElement *)PR_NEXT_LINK(&node->link);
    }
    return node;
}

NSS_IMPLEMENT nssList *
nssList_Create(NSSArena *arenaOpt, PRBool threadSafe)
{
    NSSArena *arena;
    nssList *list;
    PRBool i_alloced;
    if (arenaOpt) {
        arena = arenaOpt;
        i_alloced = PR_FALSE;
    } else {
        arena = nssArena_Create();
        i_alloced = PR_TRUE;
    }
    if (!arena) {
        return (nssList *)NULL;
    }
    list = nss_ZNEW(arena, nssList);
    if (!list) {
        if (!arenaOpt) {
            NSSArena_Destroy(arena);
        }
        return (nssList *)NULL;
    }
    if (threadSafe) {
        list->lock = PZ_NewLock(nssILockOther);
        if (!list->lock) {
            if (arenaOpt) {
                nss_ZFreeIf(list);
            } else {
                NSSArena_Destroy(arena);
            }
            return (nssList *)NULL;
        }
    }
    list->arena = arena;
    list->i_alloced_arena = i_alloced;
    list->compareFunc = pointer_compare;
    return list;
}

NSS_IMPLEMENT PRStatus
nssList_Destroy(nssList *list)
{
    if (!list) {
        return PR_SUCCESS;
    }
    if (!list->i_alloced_arena) {
        nssList_Clear(list, NULL);
    }
    if (list->lock) {
        (void)PZ_DestroyLock(list->lock);
    }
    if (list->i_alloced_arena) {
        NSSArena_Destroy(list->arena);
        list = NULL;
    }
    nss_ZFreeIf(list);
    return PR_SUCCESS;
}

NSS_IMPLEMENT void
nssList_SetCompareFunction(nssList *list, nssListCompareFunc compareFunc)
{
    list->compareFunc = compareFunc;
}

NSS_IMPLEMENT void
nssList_SetSortFunction(nssList *list, nssListSortFunc sortFunc)
{
    /* XXX if list already has elements, sort them */
    list->sortFunc = sortFunc;
}

NSS_IMPLEMENT nssListCompareFunc
nssList_GetCompareFunction(nssList *list)
{
    return list->compareFunc;
}

NSS_IMPLEMENT void
nssList_Clear(nssList *list, nssListElementDestructorFunc destructor)
{
    PRCList *link;
    nssListElement *node, *tmp;
    if (!list) {
        return;
    }
    NSSLIST_LOCK_IF(list);
    node = list->head;
    list->head = NULL;
    while (node && list->count > 0) {
        if (destructor)
            (*destructor)(node->data);
        link = &node->link;
        tmp = (nssListElement *)PR_NEXT_LINK(link);
        PR_REMOVE_LINK(link);
        nss_ZFreeIf(node);
        node = tmp;
        --list->count;
    }
    NSSLIST_UNLOCK_IF(list);
}

static PRStatus
nsslist_add_element(nssList *list, void *data)
{
    nssListElement *node = nss_ZNEW(list->arena, nssListElement);
    if (!node) {
        return PR_FAILURE;
    }
    PR_INIT_CLIST(&node->link);
    node->data = data;
    if (list->head) {
        if (list->sortFunc) {
            PRCList *link;
            nssListElement *currNode;
            currNode = list->head;
            /* insert in ordered list */
            while (currNode) {
                link = &currNode->link;
                if (list->sortFunc(data, currNode->data) <= 0) {
                    /* new element goes before current node */
                    PR_INSERT_BEFORE(&node->link, link);
                    /* reset head if this is first */
                    if (currNode == list->head)
                        list->head = node;
                    break;
                }
                if (link == PR_LIST_TAIL(&list->head->link)) {
                    /* reached end of list, append */
                    PR_INSERT_AFTER(&node->link, link);
                    break;
                }
                currNode = (nssListElement *)PR_NEXT_LINK(&currNode->link);
            }
        } else {
            /* not sorting */
            PR_APPEND_LINK(&node->link, &list->head->link);
        }
    } else {
        list->head = node;
    }
    ++list->count;
    return PR_SUCCESS;
}

NSS_IMPLEMENT PRStatus
nssList_Add(nssList *list, void *data)
{
    NSSLIST_LOCK_IF(list);
    (void)nsslist_add_element(list, data);
    NSSLIST_UNLOCK_IF(list);
    return PR_SUCCESS;
}

NSS_IMPLEMENT PRStatus
nssList_AddUnique(nssList *list, void *data)
{
    PRStatus nssrv;
    nssListElement *node;
    NSSLIST_LOCK_IF(list);
    node = nsslist_get_matching_element(list, data);
    if (node) {
        /* already in, finish */
        NSSLIST_UNLOCK_IF(list);
        return PR_SUCCESS;
    }
    nssrv = nsslist_add_element(list, data);
    NSSLIST_UNLOCK_IF(list);
    return nssrv;
}

NSS_IMPLEMENT PRStatus
nssList_Remove(nssList *list, void *data)
{
    nssListElement *node;
    NSSLIST_LOCK_IF(list);
    node = nsslist_get_matching_element(list, data);
    if (node) {
        if (node == list->head) {
            list->head = (nssListElement *)PR_NEXT_LINK(&node->link);
        }
        PR_REMOVE_LINK(&node->link);
        nss_ZFreeIf(node);
        if (--list->count == 0) {
            list->head = NULL;
        }
    }
    NSSLIST_UNLOCK_IF(list);
    return PR_SUCCESS;
}

NSS_IMPLEMENT void *
nssList_Get(nssList *list, void *data)
{
    nssListElement *node;
    NSSLIST_LOCK_IF(list);
    node = nsslist_get_matching_element(list, data);
    NSSLIST_UNLOCK_IF(list);
    return (node) ? node->data : NULL;
}

NSS_IMPLEMENT PRUint32
nssList_Count(nssList *list)
{
    return list->count;
}

NSS_IMPLEMENT PRStatus
nssList_GetArray(nssList *list, void **rvArray, PRUint32 maxElements)
{
    nssListElement *node;
    PRUint32 i = 0;
    PR_ASSERT(maxElements > 0);
    node = list->head;
    if (!node) {
        return PR_SUCCESS;
    }
    NSSLIST_LOCK_IF(list);
    while (node) {
        rvArray[i++] = node->data;
        if (i == maxElements)
            break;
        node = (nssListElement *)PR_NEXT_LINK(&node->link);
        if (node == list->head) {
            break;
        }
    }
    NSSLIST_UNLOCK_IF(list);
    return PR_SUCCESS;
}

NSS_IMPLEMENT nssList *
nssList_Clone(nssList *list)
{
    nssList *rvList;
    nssListElement *node;
    rvList = nssList_Create(NULL, (list->lock != NULL));
    if (!rvList) {
        return NULL;
    }
    NSSLIST_LOCK_IF(list);
    if (list->count > 0) {
        node = list->head;
        while (PR_TRUE) {
            nssList_Add(rvList, node->data);
            node = (nssListElement *)PR_NEXT_LINK(&node->link);
            if (node == list->head) {
                break;
            }
        }
    }
    NSSLIST_UNLOCK_IF(list);
    return rvList;
}

NSS_IMPLEMENT nssListIterator *
nssList_CreateIterator(nssList *list)
{
    nssListIterator *rvIterator;
    rvIterator = nss_ZNEW(NULL, nssListIterator);
    if (!rvIterator) {
        return NULL;
    }
    rvIterator->list = nssList_Clone(list);
    if (!rvIterator->list) {
        nss_ZFreeIf(rvIterator);
        return NULL;
    }
    rvIterator->current = rvIterator->list->head;
    if (list->lock) {
        rvIterator->lock = PZ_NewLock(nssILockOther);
        if (!rvIterator->lock) {
            nssList_Destroy(rvIterator->list);
            nss_ZFreeIf(rvIterator);
            rvIterator = NULL;
        }
    }
    return rvIterator;
}

NSS_IMPLEMENT void
nssListIterator_Destroy(nssListIterator *iter)
{
    if (iter->lock) {
        (void)PZ_DestroyLock(iter->lock);
    }
    if (iter->list) {
        nssList_Destroy(iter->list);
    }
    nss_ZFreeIf(iter);
}

NSS_IMPLEMENT void *
nssListIterator_Start(nssListIterator *iter)
{
    NSSLIST_LOCK_IF(iter);
    if (iter->list->count == 0) {
        return NULL;
    }
    iter->current = iter->list->head;
    return iter->current->data;
}

NSS_IMPLEMENT void *
nssListIterator_Next(nssListIterator *iter)
{
    nssListElement *node;
    PRCList *link;
    if (iter->list->count == 1 || iter->current == NULL) {
        /* Reached the end of the list.  Don't change the state, force to
         * user to call nssList_Finish to clean up.
         */
        return NULL;
    }
    node = (nssListElement *)PR_NEXT_LINK(&iter->current->link);
    link = &node->link;
    if (link == PR_LIST_TAIL(&iter->list->head->link)) {
        /* Signal the end of the list. */
        iter->current = NULL;
        return node->data;
    }
    iter->current = node;
    return node->data;
}

NSS_IMPLEMENT PRStatus
nssListIterator_Finish(nssListIterator *iter)
{
    iter->current = iter->list->head;
    return (iter->lock) ? PZ_Unlock(iter->lock) : PR_SUCCESS;
}

Coverage Report

Created: 2025-07-01 06:25

Line	Count	Source (jump to first uncovered line)
1		/* This Source Code Form is subject to the terms of the Mozilla Public
2		* License, v. 2.0. If a copy of the MPL was not distributed with this
3		* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5		/*
6		* list.c
7		*
8		* This contains the implementation of NSS's thread-safe linked list.
9		*/
10
11		#ifndef BASE_H
12		#include "base.h"
13		#endif /* BASE_H */
14
15		struct nssListElementStr {
16		PRCList link;
17		void *data;
18		};
19
20		typedef struct nssListElementStr nssListElement;
21
22		struct nssListStr {
23		NSSArena *arena;
24		PZLock *lock;
25		nssListElement *head;
26		PRUint32 count;
27		nssListCompareFunc compareFunc;
28		nssListSortFunc sortFunc;
29		PRBool i_alloced_arena;
30		};
31
32		struct nssListIteratorStr {
33		PZLock *lock;
34		nssList *list;
35		nssListElement *current;
36		};
37
38		#define NSSLIST_LOCK_IF(list) \
39	0	if ((list)->lock) \
40	0	PZ_Lock((list)->lock)
41
42		#define NSSLIST_UNLOCK_IF(list) \
43	0	if ((list)->lock) \
44	0	PZ_Unlock((list)->lock)
45
46		static PRBool
47		pointer_compare(void a, void b)
48	0	{
49	0	return (PRBool)(a == b);
50	0	}
51
52		static nssListElement *
53		nsslist_get_matching_element(nssList list, void data)
54	0	{
55	0	nssListElement *node;
56	0	node = list->head;
57	0	if (!node) {
58	0	return NULL;
59	0	}
60	0	while (node) {
61		/* using a callback slows things down when it's just compare ... */
62	0	if (list->compareFunc(node->data, data)) {
63	0	break;
64	0	}
65	0	if (&node->link == PR_LIST_TAIL(&list->head->link)) {
66	0	node = NULL;
67	0	break;
68	0	}
69	0	node = (nssListElement *)PR_NEXT_LINK(&node->link);
70	0	}
71	0	return node;
72	0	}
73
74		NSS_IMPLEMENT nssList *
75		nssList_Create(NSSArena *arenaOpt, PRBool threadSafe)
76	0	{
77	0	NSSArena *arena;
78	0	nssList *list;
79	0	PRBool i_alloced;
80	0	if (arenaOpt) {
81	0	arena = arenaOpt;
82	0	i_alloced = PR_FALSE;
83	0	} else {
84	0	arena = nssArena_Create();
85	0	i_alloced = PR_TRUE;
86	0	}
87	0	if (!arena) {
88	0	return (nssList *)NULL;
89	0	}
90	0	list = nss_ZNEW(arena, nssList);
91	0	if (!list) {
92	0	if (!arenaOpt) {
93	0	NSSArena_Destroy(arena);
94	0	}
95	0	return (nssList *)NULL;
96	0	}
97	0	if (threadSafe) {
98	0	list->lock = PZ_NewLock(nssILockOther);
99	0	if (!list->lock) {
100	0	if (arenaOpt) {
101	0	nss_ZFreeIf(list);
102	0	} else {
103	0	NSSArena_Destroy(arena);
104	0	}
105	0	return (nssList *)NULL;
106	0	}
107	0	}
108	0	list->arena = arena;
109	0	list->i_alloced_arena = i_alloced;
110	0	list->compareFunc = pointer_compare;
111	0	return list;
112	0	}
113
114		NSS_IMPLEMENT PRStatus
115		nssList_Destroy(nssList *list)
116	0	{
117	0	if (!list) {
118	0	return PR_SUCCESS;
119	0	}
120	0	if (!list->i_alloced_arena) {
121	0	nssList_Clear(list, NULL);
122	0	}
123	0	if (list->lock) {
124	0	(void)PZ_DestroyLock(list->lock);
125	0	}
126	0	if (list->i_alloced_arena) {
127	0	NSSArena_Destroy(list->arena);
128	0	list = NULL;
129	0	}
130	0	nss_ZFreeIf(list);
131	0	return PR_SUCCESS;
132	0	}
133
134		NSS_IMPLEMENT void
135		nssList_SetCompareFunction(nssList *list, nssListCompareFunc compareFunc)
136	0	{
137	0	list->compareFunc = compareFunc;
138	0	}
139
140		NSS_IMPLEMENT void
141		nssList_SetSortFunction(nssList *list, nssListSortFunc sortFunc)
142	0	{
143		/* XXX if list already has elements, sort them */
144	0	list->sortFunc = sortFunc;
145	0	}
146
147		NSS_IMPLEMENT nssListCompareFunc
148		nssList_GetCompareFunction(nssList *list)
149	0	{
150	0	return list->compareFunc;
151	0	}
152
153		NSS_IMPLEMENT void
154		nssList_Clear(nssList *list, nssListElementDestructorFunc destructor)
155	0	{
156	0	PRCList *link;
157	0	nssListElement node, tmp;
158	0	if (!list) {
159	0	return;
160	0	}
161	0	NSSLIST_LOCK_IF(list);
162	0	node = list->head;
163	0	list->head = NULL;
164	0	while (node && list->count > 0) {
165	0	if (destructor)
166	0	(*destructor)(node->data);
167	0	link = &node->link;
168	0	tmp = (nssListElement *)PR_NEXT_LINK(link);
169	0	PR_REMOVE_LINK(link);
170	0	nss_ZFreeIf(node);
171	0	node = tmp;
172	0	--list->count;
173	0	}
174	0	NSSLIST_UNLOCK_IF(list);
175	0	}
176
177		static PRStatus
178		nsslist_add_element(nssList list, void data)
179	0	{
180	0	nssListElement *node = nss_ZNEW(list->arena, nssListElement);
181	0	if (!node) {
182	0	return PR_FAILURE;
183	0	}
184	0	PR_INIT_CLIST(&node->link);
185	0	node->data = data;
186	0	if (list->head) {
187	0	if (list->sortFunc) {
188	0	PRCList *link;
189	0	nssListElement *currNode;
190	0	currNode = list->head;
191		/* insert in ordered list */
192	0	while (currNode) {
193	0	link = &currNode->link;
194	0	if (list->sortFunc(data, currNode->data) <= 0) {
195		/* new element goes before current node */
196	0	PR_INSERT_BEFORE(&node->link, link);
197		/* reset head if this is first */
198	0	if (currNode == list->head)
199	0	list->head = node;
200	0	break;
201	0	}
202	0	if (link == PR_LIST_TAIL(&list->head->link)) {
203		/* reached end of list, append */
204	0	PR_INSERT_AFTER(&node->link, link);
205	0	break;
206	0	}
207	0	currNode = (nssListElement *)PR_NEXT_LINK(&currNode->link);
208	0	}
209	0	} else {
210		/* not sorting */
211	0	PR_APPEND_LINK(&node->link, &list->head->link);
212	0	}
213	0	} else {
214	0	list->head = node;
215	0	}
216	0	++list->count;
217	0	return PR_SUCCESS;
218	0	}
219
220		NSS_IMPLEMENT PRStatus
221		nssList_Add(nssList list, void data)
222	0	{
223	0	NSSLIST_LOCK_IF(list);
224	0	(void)nsslist_add_element(list, data);
225	0	NSSLIST_UNLOCK_IF(list);
226	0	return PR_SUCCESS;
227	0	}
228
229		NSS_IMPLEMENT PRStatus
230		nssList_AddUnique(nssList list, void data)
231	0	{
232	0	PRStatus nssrv;
233	0	nssListElement *node;
234	0	NSSLIST_LOCK_IF(list);
235	0	node = nsslist_get_matching_element(list, data);
236	0	if (node) {
237		/* already in, finish */
238	0	NSSLIST_UNLOCK_IF(list);
239	0	return PR_SUCCESS;
240	0	}
241	0	nssrv = nsslist_add_element(list, data);
242	0	NSSLIST_UNLOCK_IF(list);
243	0	return nssrv;
244	0	}
245
246		NSS_IMPLEMENT PRStatus
247		nssList_Remove(nssList list, void data)
248	0	{
249	0	nssListElement *node;
250	0	NSSLIST_LOCK_IF(list);
251	0	node = nsslist_get_matching_element(list, data);
252	0	if (node) {
253	0	if (node == list->head) {
254	0	list->head = (nssListElement *)PR_NEXT_LINK(&node->link);
255	0	}
256	0	PR_REMOVE_LINK(&node->link);
257	0	nss_ZFreeIf(node);
258	0	if (--list->count == 0) {
259	0	list->head = NULL;
260	0	}
261	0	}
262	0	NSSLIST_UNLOCK_IF(list);
263	0	return PR_SUCCESS;
264	0	}
265
266		NSS_IMPLEMENT void *
267		nssList_Get(nssList list, void data)
268	0	{
269	0	nssListElement *node;
270	0	NSSLIST_LOCK_IF(list);
271	0	node = nsslist_get_matching_element(list, data);
272	0	NSSLIST_UNLOCK_IF(list);
273	0	return (node) ? node->data : NULL;
274	0	}
275
276		NSS_IMPLEMENT PRUint32
277		nssList_Count(nssList *list)
278	0	{
279	0	return list->count;
280	0	}
281
282		NSS_IMPLEMENT PRStatus
283		nssList_GetArray(nssList list, void *rvArray, PRUint32 maxElements)
284	0	{
285	0	nssListElement *node;
286	0	PRUint32 i = 0;
287	0	PR_ASSERT(maxElements > 0);
288	0	node = list->head;
289	0	if (!node) {
290	0	return PR_SUCCESS;
291	0	}
292	0	NSSLIST_LOCK_IF(list);
293	0	while (node) {
294	0	rvArray[i++] = node->data;
295	0	if (i == maxElements)
296	0	break;
297	0	node = (nssListElement *)PR_NEXT_LINK(&node->link);
298	0	if (node == list->head) {
299	0	break;
300	0	}
301	0	}
302	0	NSSLIST_UNLOCK_IF(list);
303	0	return PR_SUCCESS;
304	0	}
305
306		NSS_IMPLEMENT nssList *
307		nssList_Clone(nssList *list)
308	0	{
309	0	nssList *rvList;
310	0	nssListElement *node;
311	0	rvList = nssList_Create(NULL, (list->lock != NULL));
312	0	if (!rvList) {
313	0	return NULL;
314	0	}
315	0	NSSLIST_LOCK_IF(list);
316	0	if (list->count > 0) {
317	0	node = list->head;
318	0	while (PR_TRUE) {
319	0	nssList_Add(rvList, node->data);
320	0	node = (nssListElement *)PR_NEXT_LINK(&node->link);
321	0	if (node == list->head) {
322	0	break;
323	0	}
324	0	}
325	0	}
326	0	NSSLIST_UNLOCK_IF(list);
327	0	return rvList;
328	0	}
329
330		NSS_IMPLEMENT nssListIterator *
331		nssList_CreateIterator(nssList *list)
332	0	{
333	0	nssListIterator *rvIterator;
334	0	rvIterator = nss_ZNEW(NULL, nssListIterator);
335	0	if (!rvIterator) {
336	0	return NULL;
337	0	}
338	0	rvIterator->list = nssList_Clone(list);
339	0	if (!rvIterator->list) {
340	0	nss_ZFreeIf(rvIterator);
341	0	return NULL;
342	0	}
343	0	rvIterator->current = rvIterator->list->head;
344	0	if (list->lock) {
345	0	rvIterator->lock = PZ_NewLock(nssILockOther);
346	0	if (!rvIterator->lock) {
347	0	nssList_Destroy(rvIterator->list);
348	0	nss_ZFreeIf(rvIterator);
349	0	rvIterator = NULL;
350	0	}
351	0	}
352	0	return rvIterator;
353	0	}
354
355		NSS_IMPLEMENT void
356		nssListIterator_Destroy(nssListIterator *iter)
357	0	{
358	0	if (iter->lock) {
359	0	(void)PZ_DestroyLock(iter->lock);
360	0	}
361	0	if (iter->list) {
362	0	nssList_Destroy(iter->list);
363	0	}
364	0	nss_ZFreeIf(iter);
365	0	}
366
367		NSS_IMPLEMENT void *
368		nssListIterator_Start(nssListIterator *iter)
369	0	{
370	0	NSSLIST_LOCK_IF(iter);
371	0	if (iter->list->count == 0) {
372	0	return NULL;
373	0	}
374	0	iter->current = iter->list->head;
375	0	return iter->current->data;
376	0	}
377
378		NSS_IMPLEMENT void *
379		nssListIterator_Next(nssListIterator *iter)
380	0	{
381	0	nssListElement *node;
382	0	PRCList *link;
383	0	if (iter->list->count == 1 \|\| iter->current == NULL) {
384		/* Reached the end of the list. Don't change the state, force to
385		* user to call nssList_Finish to clean up.
386		*/
387	0	return NULL;
388	0	}
389	0	node = (nssListElement *)PR_NEXT_LINK(&iter->current->link);
390	0	link = &node->link;
391	0	if (link == PR_LIST_TAIL(&iter->list->head->link)) {
392		/* Signal the end of the list. */
393	0	iter->current = NULL;
394	0	return node->data;
395	0	}
396	0	iter->current = node;
397	0	return node->data;
398	0	}
399
400		NSS_IMPLEMENT PRStatus
401		nssListIterator_Finish(nssListIterator *iter)
402	0	{
403	0	iter->current = iter->list->head;
404	0	return (iter->lock) ? PZ_Unlock(iter->lock) : PR_SUCCESS;
405	0	}