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1 /* $OpenBSD: queue.h,v 1.16 2000/09/07 19:47:59 art Exp $ */ | |
2 /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ | |
3 | |
4 /* | |
5 * Copyright (c) 1991, 1993 | |
6 * The Regents of the University of California. All rights reserved. | |
7 * | |
8 * Redistribution and use in source and binary forms, with or without | |
9 * modification, are permitted provided that the following conditions | |
10 * are met: | |
11 * 1. Redistributions of source code must retain the above copyright | |
12 * notice, this list of conditions and the following disclaimer. | |
13 * 2. Redistributions in binary form must reproduce the above copyright | |
14 * notice, this list of conditions and the following disclaimer in the | |
15 * documentation and/or other materials provided with the distribution. | |
16 * 3. Neither the name of the University nor the names of its contributors | |
17 * may be used to endorse or promote products derived from this software | |
18 * without specific prior written permission. | |
19 * | |
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 * SUCH DAMAGE. | |
31 * | |
32 * @(#)queue.h 8.5 (Berkeley) 8/20/94 | |
33 */ | |
34 | |
35 #ifndef _SYS_QUEUE_H_ | |
36 #define _SYS_QUEUE_H_ | |
37 | |
38 /* | |
39 * This file defines five types of data structures: singly-linked lists, | |
40 * lists, simple queues, tail queues, and circular queues. | |
41 * | |
42 * | |
43 * A singly-linked list is headed by a single forward pointer. The elements | |
44 * are singly linked for minimum space and pointer manipulation overhead at | |
45 * the expense of O(n) removal for arbitrary elements. New elements can be | |
46 * added to the list after an existing element or at the head of the list. | |
47 * Elements being removed from the head of the list should use the explicit | |
48 * macro for this purpose for optimum efficiency. A singly-linked list may | |
49 * only be traversed in the forward direction. Singly-linked lists are ideal | |
50 * for applications with large datasets and few or no removals or for | |
51 * implementing a LIFO queue. | |
52 * | |
53 * A list is headed by a single forward pointer (or an array of forward | |
54 * pointers for a hash table header). The elements are doubly linked | |
55 * so that an arbitrary element can be removed without a need to | |
56 * traverse the list. New elements can be added to the list before | |
57 * or after an existing element or at the head of the list. A list | |
58 * may only be traversed in the forward direction. | |
59 * | |
60 * A simple queue is headed by a pair of pointers, one the head of the | |
61 * list and the other to the tail of the list. The elements are singly | |
62 * linked to save space, so elements can only be removed from the | |
63 * head of the list. New elements can be added to the list before or after | |
64 * an existing element, at the head of the list, or at the end of the | |
65 * list. A simple queue may only be traversed in the forward direction. | |
66 * | |
67 * A tail queue is headed by a pair of pointers, one to the head of the | |
68 * list and the other to the tail of the list. The elements are doubly | |
69 * linked so that an arbitrary element can be removed without a need to | |
70 * traverse the list. New elements can be added to the list before or | |
71 * after an existing element, at the head of the list, or at the end of | |
72 * the list. A tail queue may be traversed in either direction. | |
73 * | |
74 * A circle queue is headed by a pair of pointers, one to the head of the | |
75 * list and the other to the tail of the list. The elements are doubly | |
76 * linked so that an arbitrary element can be removed without a need to | |
77 * traverse the list. New elements can be added to the list before or after | |
78 * an existing element, at the head of the list, or at the end of the list. | |
79 * A circle queue may be traversed in either direction, but has a more | |
80 * complex end of list detection. | |
81 * | |
82 * For details on the use of these macros, see the queue(3) manual page. | |
83 */ | |
84 | |
85 /* | |
86 * Singly-linked List definitions. | |
87 */ | |
88 #define SLIST_HEAD(name, type) \ | |
89 struct name { \ | |
90 struct type *slh_first; /* first element */ \ | |
91 } | |
92 | |
93 #define SLIST_HEAD_INITIALIZER(head) \ | |
94 { NULL } | |
95 | |
96 #ifndef WIN32 | |
97 #define SLIST_ENTRY(type) \ | |
98 struct { \ | |
99 struct type *sle_next; /* next element */ \ | |
100 } | |
101 #endif | |
102 | |
103 /* | |
104 * Singly-linked List access methods. | |
105 */ | |
106 #define SLIST_FIRST(head) ((head)->slh_first) | |
107 #define SLIST_END(head) NULL | |
108 #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) | |
109 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) | |
110 | |
111 #define SLIST_FOREACH(var, head, field) \ | |
112 for((var) = SLIST_FIRST(head); \ | |
113 (var) != SLIST_END(head); \ | |
114 (var) = SLIST_NEXT(var, field)) | |
115 | |
116 /* | |
117 * Singly-linked List functions. | |
118 */ | |
119 #define SLIST_INIT(head) { \ | |
120 SLIST_FIRST(head) = SLIST_END(head); \ | |
121 } | |
122 | |
123 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ | |
124 (elm)->field.sle_next = (slistelm)->field.sle_next; \ | |
125 (slistelm)->field.sle_next = (elm); \ | |
126 } while (0) | |
127 | |
128 #define SLIST_INSERT_HEAD(head, elm, field) do { \ | |
129 (elm)->field.sle_next = (head)->slh_first; \ | |
130 (head)->slh_first = (elm); \ | |
131 } while (0) | |
132 | |
133 #define SLIST_REMOVE_HEAD(head, field) do { \ | |
134 (head)->slh_first = (head)->slh_first->field.sle_next; \ | |
135 } while (0) | |
136 | |
137 /* | |
138 * List definitions. | |
139 */ | |
140 #define LIST_HEAD(name, type) \ | |
141 struct name { \ | |
142 struct type *lh_first; /* first element */ \ | |
143 } | |
144 | |
145 #define LIST_HEAD_INITIALIZER(head) \ | |
146 { NULL } | |
147 | |
148 #define LIST_ENTRY(type) \ | |
149 struct { \ | |
150 struct type *le_next; /* next element */ \ | |
151 struct type **le_prev; /* address of previous next element */ \ | |
152 } | |
153 | |
154 /* | |
155 * List access methods | |
156 */ | |
157 #define LIST_FIRST(head) ((head)->lh_first) | |
158 #define LIST_END(head) NULL | |
159 #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) | |
160 #define LIST_NEXT(elm, field) ((elm)->field.le_next) | |
161 | |
162 #define LIST_FOREACH(var, head, field) \ | |
163 for((var) = LIST_FIRST(head); \ | |
164 (var)!= LIST_END(head); \ | |
165 (var) = LIST_NEXT(var, field)) | |
166 | |
167 /* | |
168 * List functions. | |
169 */ | |
170 #define LIST_INIT(head) do { \ | |
171 LIST_FIRST(head) = LIST_END(head); \ | |
172 } while (0) | |
173 | |
174 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ | |
175 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ | |
176 (listelm)->field.le_next->field.le_prev = \ | |
177 &(elm)->field.le_next; \ | |
178 (listelm)->field.le_next = (elm); \ | |
179 (elm)->field.le_prev = &(listelm)->field.le_next; \ | |
180 } while (0) | |
181 | |
182 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ | |
183 (elm)->field.le_prev = (listelm)->field.le_prev; \ | |
184 (elm)->field.le_next = (listelm); \ | |
185 *(listelm)->field.le_prev = (elm); \ | |
186 (listelm)->field.le_prev = &(elm)->field.le_next; \ | |
187 } while (0) | |
188 | |
189 #define LIST_INSERT_HEAD(head, elm, field) do { \ | |
190 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ | |
191 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ | |
192 (head)->lh_first = (elm); \ | |
193 (elm)->field.le_prev = &(head)->lh_first; \ | |
194 } while (0) | |
195 | |
196 #define LIST_REMOVE(elm, field) do { \ | |
197 if ((elm)->field.le_next != NULL) \ | |
198 (elm)->field.le_next->field.le_prev = \ | |
199 (elm)->field.le_prev; \ | |
200 *(elm)->field.le_prev = (elm)->field.le_next; \ | |
201 } while (0) | |
202 | |
203 #define LIST_REPLACE(elm, elm2, field) do { \ | |
204 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ | |
205 (elm2)->field.le_next->field.le_prev = \ | |
206 &(elm2)->field.le_next; \ | |
207 (elm2)->field.le_prev = (elm)->field.le_prev; \ | |
208 *(elm2)->field.le_prev = (elm2); \ | |
209 } while (0) | |
210 | |
211 /* | |
212 * Simple queue definitions. | |
213 */ | |
214 #define SIMPLEQ_HEAD(name, type) \ | |
215 struct name { \ | |
216 struct type *sqh_first; /* first element */ \ | |
217 struct type **sqh_last; /* addr of last next element */ \ | |
218 } | |
219 | |
220 #define SIMPLEQ_HEAD_INITIALIZER(head) \ | |
221 { NULL, &(head).sqh_first } | |
222 | |
223 #define SIMPLEQ_ENTRY(type) \ | |
224 struct { \ | |
225 struct type *sqe_next; /* next element */ \ | |
226 } | |
227 | |
228 /* | |
229 * Simple queue access methods. | |
230 */ | |
231 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) | |
232 #define SIMPLEQ_END(head) NULL | |
233 #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) | |
234 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) | |
235 | |
236 #define SIMPLEQ_FOREACH(var, head, field) \ | |
237 for((var) = SIMPLEQ_FIRST(head); \ | |
238 (var) != SIMPLEQ_END(head); \ | |
239 (var) = SIMPLEQ_NEXT(var, field)) | |
240 | |
241 /* | |
242 * Simple queue functions. | |
243 */ | |
244 #define SIMPLEQ_INIT(head) do { \ | |
245 (head)->sqh_first = NULL; \ | |
246 (head)->sqh_last = &(head)->sqh_first; \ | |
247 } while (0) | |
248 | |
249 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ | |
250 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ | |
251 (head)->sqh_last = &(elm)->field.sqe_next; \ | |
252 (head)->sqh_first = (elm); \ | |
253 } while (0) | |
254 | |
255 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ | |
256 (elm)->field.sqe_next = NULL; \ | |
257 *(head)->sqh_last = (elm); \ | |
258 (head)->sqh_last = &(elm)->field.sqe_next; \ | |
259 } while (0) | |
260 | |
261 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
262 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ | |
263 (head)->sqh_last = &(elm)->field.sqe_next; \ | |
264 (listelm)->field.sqe_next = (elm); \ | |
265 } while (0) | |
266 | |
267 #define SIMPLEQ_REMOVE_HEAD(head, elm, field) do { \ | |
268 if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) \ | |
269 (head)->sqh_last = &(head)->sqh_first; \ | |
270 } while (0) | |
271 | |
272 /* | |
273 * Tail queue definitions. | |
274 */ | |
275 #define TAILQ_HEAD(name, type) \ | |
276 struct name { \ | |
277 struct type *tqh_first; /* first element */ \ | |
278 struct type **tqh_last; /* addr of last next element */ \ | |
279 } | |
280 | |
281 #define TAILQ_HEAD_INITIALIZER(head) \ | |
282 { NULL, &(head).tqh_first } | |
283 | |
284 #define TAILQ_ENTRY(type) \ | |
285 struct { \ | |
286 struct type *tqe_next; /* next element */ \ | |
287 struct type **tqe_prev; /* address of previous next element */ \ | |
288 } | |
289 | |
290 /* | |
291 * tail queue access methods | |
292 */ | |
293 #define TAILQ_FIRST(head) ((head)->tqh_first) | |
294 #define TAILQ_END(head) NULL | |
295 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) | |
296 #define TAILQ_LAST(head, headname) \ | |
297 (*(((struct headname *)((head)->tqh_last))->tqh_last)) | |
298 /* XXX */ | |
299 #define TAILQ_PREV(elm, headname, field) \ | |
300 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) | |
301 #define TAILQ_EMPTY(head) \ | |
302 (TAILQ_FIRST(head) == TAILQ_END(head)) | |
303 | |
304 #define TAILQ_FOREACH(var, head, field) \ | |
305 for((var) = TAILQ_FIRST(head); \ | |
306 (var) != TAILQ_END(head); \ | |
307 (var) = TAILQ_NEXT(var, field)) | |
308 | |
309 #define TAILQ_FOREACH_REVERSE(var, head, field, headname) \ | |
310 for((var) = TAILQ_LAST(head, headname); \ | |
311 (var) != TAILQ_END(head); \ | |
312 (var) = TAILQ_PREV(var, headname, field)) | |
313 | |
314 /* | |
315 * Tail queue functions. | |
316 */ | |
317 #define TAILQ_INIT(head) do { \ | |
318 (head)->tqh_first = NULL; \ | |
319 (head)->tqh_last = &(head)->tqh_first; \ | |
320 } while (0) | |
321 | |
322 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ | |
323 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ | |
324 (head)->tqh_first->field.tqe_prev = \ | |
325 &(elm)->field.tqe_next; \ | |
326 else \ | |
327 (head)->tqh_last = &(elm)->field.tqe_next; \ | |
328 (head)->tqh_first = (elm); \ | |
329 (elm)->field.tqe_prev = &(head)->tqh_first; \ | |
330 } while (0) | |
331 | |
332 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ | |
333 (elm)->field.tqe_next = NULL; \ | |
334 (elm)->field.tqe_prev = (head)->tqh_last; \ | |
335 *(head)->tqh_last = (elm); \ | |
336 (head)->tqh_last = &(elm)->field.tqe_next; \ | |
337 } while (0) | |
338 | |
339 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
340 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ | |
341 (elm)->field.tqe_next->field.tqe_prev = \ | |
342 &(elm)->field.tqe_next; \ | |
343 else \ | |
344 (head)->tqh_last = &(elm)->field.tqe_next; \ | |
345 (listelm)->field.tqe_next = (elm); \ | |
346 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ | |
347 } while (0) | |
348 | |
349 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ | |
350 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ | |
351 (elm)->field.tqe_next = (listelm); \ | |
352 *(listelm)->field.tqe_prev = (elm); \ | |
353 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ | |
354 } while (0) | |
355 | |
356 #define TAILQ_REMOVE(head, elm, field) do { \ | |
357 if (((elm)->field.tqe_next) != NULL) \ | |
358 (elm)->field.tqe_next->field.tqe_prev = \ | |
359 (elm)->field.tqe_prev; \ | |
360 else \ | |
361 (head)->tqh_last = (elm)->field.tqe_prev; \ | |
362 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ | |
363 } while (0) | |
364 | |
365 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ | |
366 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ | |
367 (elm2)->field.tqe_next->field.tqe_prev = \ | |
368 &(elm2)->field.tqe_next; \ | |
369 else \ | |
370 (head)->tqh_last = &(elm2)->field.tqe_next; \ | |
371 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ | |
372 *(elm2)->field.tqe_prev = (elm2); \ | |
373 } while (0) | |
374 | |
375 /* | |
376 * Circular queue definitions. | |
377 */ | |
378 #define CIRCLEQ_HEAD(name, type) \ | |
379 struct name { \ | |
380 struct type *cqh_first; /* first element */ \ | |
381 struct type *cqh_last; /* last element */ \ | |
382 } | |
383 | |
384 #define CIRCLEQ_HEAD_INITIALIZER(head) \ | |
385 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } | |
386 | |
387 #define CIRCLEQ_ENTRY(type) \ | |
388 struct { \ | |
389 struct type *cqe_next; /* next element */ \ | |
390 struct type *cqe_prev; /* previous element */ \ | |
391 } | |
392 | |
393 /* | |
394 * Circular queue access methods | |
395 */ | |
396 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) | |
397 #define CIRCLEQ_LAST(head) ((head)->cqh_last) | |
398 #define CIRCLEQ_END(head) ((void *)(head)) | |
399 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) | |
400 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) | |
401 #define CIRCLEQ_EMPTY(head) \ | |
402 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) | |
403 | |
404 #define CIRCLEQ_FOREACH(var, head, field) \ | |
405 for((var) = CIRCLEQ_FIRST(head); \ | |
406 (var) != CIRCLEQ_END(head); \ | |
407 (var) = CIRCLEQ_NEXT(var, field)) | |
408 | |
409 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ | |
410 for((var) = CIRCLEQ_LAST(head); \ | |
411 (var) != CIRCLEQ_END(head); \ | |
412 (var) = CIRCLEQ_PREV(var, field)) | |
413 | |
414 /* | |
415 * Circular queue functions. | |
416 */ | |
417 #define CIRCLEQ_INIT(head) do { \ | |
418 (head)->cqh_first = CIRCLEQ_END(head); \ | |
419 (head)->cqh_last = CIRCLEQ_END(head); \ | |
420 } while (0) | |
421 | |
422 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
423 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ | |
424 (elm)->field.cqe_prev = (listelm); \ | |
425 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ | |
426 (head)->cqh_last = (elm); \ | |
427 else \ | |
428 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ | |
429 (listelm)->field.cqe_next = (elm); \ | |
430 } while (0) | |
431 | |
432 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ | |
433 (elm)->field.cqe_next = (listelm); \ | |
434 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ | |
435 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ | |
436 (head)->cqh_first = (elm); \ | |
437 else \ | |
438 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ | |
439 (listelm)->field.cqe_prev = (elm); \ | |
440 } while (0) | |
441 | |
442 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ | |
443 (elm)->field.cqe_next = (head)->cqh_first; \ | |
444 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ | |
445 if ((head)->cqh_last == CIRCLEQ_END(head)) \ | |
446 (head)->cqh_last = (elm); \ | |
447 else \ | |
448 (head)->cqh_first->field.cqe_prev = (elm); \ | |
449 (head)->cqh_first = (elm); \ | |
450 } while (0) | |
451 | |
452 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ | |
453 (elm)->field.cqe_next = CIRCLEQ_END(head); \ | |
454 (elm)->field.cqe_prev = (head)->cqh_last; \ | |
455 if ((head)->cqh_first == CIRCLEQ_END(head)) \ | |
456 (head)->cqh_first = (elm); \ | |
457 else \ | |
458 (head)->cqh_last->field.cqe_next = (elm); \ | |
459 (head)->cqh_last = (elm); \ | |
460 } while (0) | |
461 | |
462 #define CIRCLEQ_REMOVE(head, elm, field) do { \ | |
463 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ | |
464 (head)->cqh_last = (elm)->field.cqe_prev; \ | |
465 else \ | |
466 (elm)->field.cqe_next->field.cqe_prev = \ | |
467 (elm)->field.cqe_prev; \ | |
468 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ | |
469 (head)->cqh_first = (elm)->field.cqe_next; \ | |
470 else \ | |
471 (elm)->field.cqe_prev->field.cqe_next = \ | |
472 (elm)->field.cqe_next; \ | |
473 } while (0) | |
474 | |
475 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ | |
476 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ | |
477 CIRCLEQ_END(head)) \ | |
478 (head).cqh_last = (elm2); \ | |
479 else \ | |
480 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ | |
481 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ | |
482 CIRCLEQ_END(head)) \ | |
483 (head).cqh_first = (elm2); \ | |
484 else \ | |
485 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ | |
486 } while (0) | |
487 | |
488 #endif /* !_SYS_QUEUE_H_ */ | |
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