/* ldap_queue.h -- queue macros */ /* $OpenLDAP$ */ /* This work is part of OpenLDAP Software . * * Copyright 2001-2024 The OpenLDAP Foundation. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted only as authorized by the OpenLDAP * Public License. * * A copy of this license is available in file LICENSE in the * top-level directory of the distribution or, alternatively, at * . */ /* Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)queue.h 8.5 (Berkeley) 8/20/94 * $FreeBSD: src/sys/sys/queue.h,v 1.32.2.5 2001/09/30 21:12:54 luigi Exp $ * * See also: ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change */ /* ACKNOWLEDGEMENTS: * This work is derived from FreeBSD queue.h work. Adapted for use in * OpenLDAP Software by Kurt D. Zeilenga. */ #ifndef _LDAP_QUEUE_H_ #define _LDAP_QUEUE_H_ /* * This file defines five types of data structures: singly-linked lists, * singly-linked tail queues, lists, tail queues, and circular queues. * * A singly-linked list is headed by a single forward pointer. The elements * are singly linked for minimum space and pointer manipulation overhead at * the expense of O(n) removal for arbitrary elements. New elements can be * added to the list after an existing element or at the head of the list. * Elements being removed from the head of the list should use the explicit * macro for this purpose for optimum efficiency. A singly-linked list may * only be traversed in the forward direction. Singly-linked lists are ideal * for applications with large datasets and few or no removals or for * implementing a LIFO queue. * * A singly-linked tail queue is headed by a pair of pointers, one to the * head of the list and the other to the tail of the list. The elements are * singly linked for minimum space and pointer manipulation overhead at the * expense of O(n) removal for arbitrary elements. New elements can be added * to the list after an existing element, at the head of the list, or at the * end of the list. Elements being removed from the head of the tail queue * should use the explicit macro for this purpose for optimum efficiency. * A singly-linked tail queue may only be traversed in the forward direction. * Singly-linked tail queues are ideal for applications with large datasets * and few or no removals or for implementing a FIFO queue. * * A list is headed by a single forward pointer (or an array of forward * pointers for a hash table header). The elements are doubly linked * so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before * or after an existing element or at the head of the list. A list * may only be traversed in the forward direction. * * A tail queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or * after an existing element, at the head of the list, or at the end of * the list. A tail queue may be traversed in either direction. * * A circle queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or after * an existing element, at the head of the list, or at the end of the list. * A circle queue may be traversed in either direction, but has a more * complex end of list detection. Also, it is possible to rotate the queue, * rejoining the ends and splitting it so that a given element becomes the * new head or tail. * * For details on the use of these macros, see the queue(3) manual page. * All macros are prefixed with LDAP_. * * SLIST_ LIST_ STAILQ_ TAILQ_ CIRCLEQ_ * _HEAD + + + + + * _ENTRY + + + + + * _INIT + + + + + * _ENTRY_INIT + + + + + * _EMPTY + + + + + * _FIRST + + + + + * _NEXT + + + + + * _PREV - - - + + * _LAST - - + + + * _FOREACH + + + + + * _FOREACH_REVERSE - - - + + * _INSERT_HEAD + + + + + * _INSERT_BEFORE - + - + + * _INSERT_AFTER + + + + + * _INSERT_TAIL - - + + + * _REMOVE_HEAD + - + - - * _REMOVE + + + + + * */ /* * Singly-linked List definitions. */ #define LDAP_SLIST_HEAD(name, type) \ struct name { \ struct type *slh_first; /* first element */ \ } #define LDAP_SLIST_HEAD_INITIALIZER(head) \ { NULL } #define LDAP_SLIST_ENTRY(type) \ struct { \ struct type *sle_next; /* next element */ \ } #define LDAP_SLIST_ENTRY_INITIALIZER(entry) \ { NULL } /* * Singly-linked List functions. */ #define LDAP_SLIST_EMPTY(head) ((head)->slh_first == NULL) #define LDAP_SLIST_FIRST(head) ((head)->slh_first) #define LDAP_SLIST_FOREACH(var, head, field) \ for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) #define LDAP_SLIST_INIT(head) { \ (head)->slh_first = NULL; \ } #define LDAP_SLIST_ENTRY_INIT(var, field) { \ (var)->field.sle_next = NULL; \ } #define LDAP_SLIST_INSERT_AFTER(slistelm, elm, field) do { \ (elm)->field.sle_next = (slistelm)->field.sle_next; \ (slistelm)->field.sle_next = (elm); \ } while (0) #define LDAP_SLIST_INSERT_HEAD(head, elm, field) do { \ (elm)->field.sle_next = (head)->slh_first; \ (head)->slh_first = (elm); \ } while (0) #define LDAP_SLIST_NEXT(elm, field) ((elm)->field.sle_next) #define LDAP_SLIST_REMOVE_HEAD(head, field) do { \ (head)->slh_first = (head)->slh_first->field.sle_next; \ } while (0) #define LDAP_SLIST_REMOVE(head, elm, type, field) do { \ if ((head)->slh_first == (elm)) { \ LDAP_SLIST_REMOVE_HEAD((head), field); \ } \ else { \ struct type *curelm = (head)->slh_first; \ while( curelm->field.sle_next != (elm) ) \ curelm = curelm->field.sle_next; \ curelm->field.sle_next = \ curelm->field.sle_next->field.sle_next; \ } \ } while (0) /* * Singly-linked Tail queue definitions. */ #define LDAP_STAILQ_HEAD(name, type) \ struct name { \ struct type *stqh_first;/* first element */ \ struct type **stqh_last;/* addr of last next element */ \ } #define LDAP_STAILQ_HEAD_INITIALIZER(head) \ { NULL, &(head).stqh_first } #define LDAP_STAILQ_ENTRY(type) \ struct { \ struct type *stqe_next; /* next element */ \ } #define LDAP_STAILQ_ENTRY_INITIALIZER(entry) \ { NULL } /* * Singly-linked Tail queue functions. */ #define LDAP_STAILQ_EMPTY(head) ((head)->stqh_first == NULL) #define LDAP_STAILQ_INIT(head) do { \ (head)->stqh_first = NULL; \ (head)->stqh_last = &(head)->stqh_first; \ } while (0) #define LDAP_STAILQ_ENTRY_INIT(var, field) { \ (var)->field.stqe_next = NULL; \ } #define LDAP_STAILQ_FIRST(head) ((head)->stqh_first) #define LDAP_STAILQ_LAST(head, type, field) \ (LDAP_STAILQ_EMPTY(head) ? \ NULL : \ ((struct type *) \ ((char *)((head)->stqh_last) - offsetof(struct type, field)))) #define LDAP_STAILQ_FOREACH(var, head, field) \ for((var) = (head)->stqh_first; (var); (var) = (var)->field.stqe_next) #define LDAP_STAILQ_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \ (head)->stqh_last = &(elm)->field.stqe_next; \ (head)->stqh_first = (elm); \ } while (0) #define LDAP_STAILQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.stqe_next = NULL; \ *(head)->stqh_last = (elm); \ (head)->stqh_last = &(elm)->field.stqe_next; \ } while (0) #define LDAP_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\ (head)->stqh_last = &(elm)->field.stqe_next; \ (tqelm)->field.stqe_next = (elm); \ } while (0) #define LDAP_STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) #define LDAP_STAILQ_REMOVE_HEAD(head, field) do { \ if (((head)->stqh_first = \ (head)->stqh_first->field.stqe_next) == NULL) \ (head)->stqh_last = &(head)->stqh_first; \ } while (0) #define LDAP_STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \ if (((head)->stqh_first = (elm)->field.stqe_next) == NULL) \ (head)->stqh_last = &(head)->stqh_first; \ } while (0) #define LDAP_STAILQ_REMOVE(head, elm, type, field) do { \ if ((head)->stqh_first == (elm)) { \ LDAP_STAILQ_REMOVE_HEAD(head, field); \ } \ else { \ struct type *curelm = (head)->stqh_first; \ while( curelm->field.stqe_next != (elm) ) \ curelm = curelm->field.stqe_next; \ if((curelm->field.stqe_next = \ curelm->field.stqe_next->field.stqe_next) == NULL) \ (head)->stqh_last = &(curelm)->field.stqe_next; \ } \ } while (0) /* * List definitions. */ #define LDAP_LIST_HEAD(name, type) \ struct name { \ struct type *lh_first; /* first element */ \ } #define LDAP_LIST_HEAD_INITIALIZER(head) \ { NULL } #define LDAP_LIST_ENTRY(type) \ struct { \ struct type *le_next; /* next element */ \ struct type **le_prev; /* address of previous next element */ \ } #define LDAP_LIST_ENTRY_INITIALIZER(entry) \ { NULL, NULL } /* * List functions. */ #define LDAP_LIST_EMPTY(head) ((head)->lh_first == NULL) #define LDAP_LIST_FIRST(head) ((head)->lh_first) #define LDAP_LIST_FOREACH(var, head, field) \ for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next) #define LDAP_LIST_INIT(head) do { \ (head)->lh_first = NULL; \ } while (0) #define LDAP_LIST_ENTRY_INIT(var, field) do { \ (var)->field.le_next = NULL; \ (var)->field.le_prev = NULL; \ } while (0) #define LDAP_LIST_INSERT_AFTER(listelm, elm, field) do { \ if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ (listelm)->field.le_next->field.le_prev = \ &(elm)->field.le_next; \ (listelm)->field.le_next = (elm); \ (elm)->field.le_prev = &(listelm)->field.le_next; \ } while (0) #define LDAP_LIST_INSERT_BEFORE(listelm, elm, field) do { \ (elm)->field.le_prev = (listelm)->field.le_prev; \ (elm)->field.le_next = (listelm); \ *(listelm)->field.le_prev = (elm); \ (listelm)->field.le_prev = &(elm)->field.le_next; \ } while (0) #define LDAP_LIST_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.le_next = (head)->lh_first) != NULL) \ (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ (head)->lh_first = (elm); \ (elm)->field.le_prev = &(head)->lh_first; \ } while (0) #define LDAP_LIST_NEXT(elm, field) ((elm)->field.le_next) #define LDAP_LIST_REMOVE(elm, field) do { \ if ((elm)->field.le_next != NULL) \ (elm)->field.le_next->field.le_prev = \ (elm)->field.le_prev; \ *(elm)->field.le_prev = (elm)->field.le_next; \ } while (0) /* * Tail queue definitions. */ #define LDAP_TAILQ_HEAD(name, type) \ struct name { \ struct type *tqh_first; /* first element */ \ struct type **tqh_last; /* addr of last next element */ \ } #define LDAP_TAILQ_HEAD_INITIALIZER(head) \ { NULL, &(head).tqh_first } #define LDAP_TAILQ_ENTRY(type) \ struct { \ struct type *tqe_next; /* next element */ \ struct type **tqe_prev; /* address of previous next element */ \ } #define LDAP_TAILQ_ENTRY_INITIALIZER(entry) \ { NULL, NULL } /* * Tail queue functions. */ #define LDAP_TAILQ_EMPTY(head) ((head)->tqh_first == NULL) #define LDAP_TAILQ_FOREACH(var, head, field) \ for (var = LDAP_TAILQ_FIRST(head); var; var = LDAP_TAILQ_NEXT(var, field)) #define LDAP_TAILQ_FOREACH_REVERSE(var, head, headname, field) \ for ((var) = LDAP_TAILQ_LAST((head), headname); \ (var); \ (var) = LDAP_TAILQ_PREV((var), headname, field)) #define LDAP_TAILQ_FIRST(head) ((head)->tqh_first) #define LDAP_TAILQ_LAST(head, headname) \ (*(((struct headname *)((head)->tqh_last))->tqh_last)) #define LDAP_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) #define LDAP_TAILQ_PREV(elm, headname, field) \ (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) #define LDAP_TAILQ_INIT(head) do { \ (head)->tqh_first = NULL; \ (head)->tqh_last = &(head)->tqh_first; \ } while (0) #define LDAP_TAILQ_ENTRY_INIT(var, field) do { \ (var)->field.tqe_next = NULL; \ (var)->field.tqe_prev = NULL; \ } while (0) #define LDAP_TAILQ_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ (head)->tqh_first->field.tqe_prev = \ &(elm)->field.tqe_next; \ else \ (head)->tqh_last = &(elm)->field.tqe_next; \ (head)->tqh_first = (elm); \ (elm)->field.tqe_prev = &(head)->tqh_first; \ } while (0) #define LDAP_TAILQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.tqe_next = NULL; \ (elm)->field.tqe_prev = (head)->tqh_last; \ *(head)->tqh_last = (elm); \ (head)->tqh_last = &(elm)->field.tqe_next; \ } while (0) #define LDAP_TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ (elm)->field.tqe_next->field.tqe_prev = \ &(elm)->field.tqe_next; \ else \ (head)->tqh_last = &(elm)->field.tqe_next; \ (listelm)->field.tqe_next = (elm); \ (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ } while (0) #define LDAP_TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ (elm)->field.tqe_next = (listelm); \ *(listelm)->field.tqe_prev = (elm); \ (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ } while (0) #define LDAP_TAILQ_REMOVE(head, elm, field) do { \ if (((elm)->field.tqe_next) != NULL) \ (elm)->field.tqe_next->field.tqe_prev = \ (elm)->field.tqe_prev; \ else \ (head)->tqh_last = (elm)->field.tqe_prev; \ *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ } while (0) /* * Circular queue definitions. */ #define LDAP_CIRCLEQ_HEAD(name, type) \ struct name { \ struct type *cqh_first; /* first element */ \ struct type *cqh_last; /* last element */ \ } #define LDAP_CIRCLEQ_HEAD_INITIALIZER(head) \ { (void *)&(head), (void *)&(head) } #define LDAP_CIRCLEQ_ENTRY(type) \ struct { \ struct type *cqe_next; /* next element */ \ struct type *cqe_prev; /* previous element */ \ } /* * Circular queue functions. */ #define LDAP_CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) #define LDAP_CIRCLEQ_FIRST(head) ((head)->cqh_first) #define LDAP_CIRCLEQ_FOREACH(var, head, field) \ for((var) = (head)->cqh_first; \ (var) != (void *)(head); \ (var) = (var)->field.cqe_next) #define LDAP_CIRCLEQ_FOREACH_REVERSE(var, head, field) \ for((var) = (head)->cqh_last; \ (var) != (void *)(head); \ (var) = (var)->field.cqe_prev) #define LDAP_CIRCLEQ_INIT(head) do { \ (head)->cqh_first = (void *)(head); \ (head)->cqh_last = (void *)(head); \ } while (0) #define LDAP_CIRCLEQ_ENTRY_INIT(var, field) do { \ (var)->field.cqe_next = NULL; \ (var)->field.cqe_prev = NULL; \ } while (0) #define LDAP_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ (elm)->field.cqe_next = (listelm)->field.cqe_next; \ (elm)->field.cqe_prev = (listelm); \ if ((listelm)->field.cqe_next == (void *)(head)) \ (head)->cqh_last = (elm); \ else \ (listelm)->field.cqe_next->field.cqe_prev = (elm); \ (listelm)->field.cqe_next = (elm); \ } while (0) #define LDAP_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ (elm)->field.cqe_next = (listelm); \ (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ if ((listelm)->field.cqe_prev == (void *)(head)) \ (head)->cqh_first = (elm); \ else \ (listelm)->field.cqe_prev->field.cqe_next = (elm); \ (listelm)->field.cqe_prev = (elm); \ } while (0) #define LDAP_CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ (elm)->field.cqe_next = (head)->cqh_first; \ (elm)->field.cqe_prev = (void *)(head); \ if ((head)->cqh_last == (void *)(head)) \ (head)->cqh_last = (elm); \ else \ (head)->cqh_first->field.cqe_prev = (elm); \ (head)->cqh_first = (elm); \ } while (0) #define LDAP_CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.cqe_next = (void *)(head); \ (elm)->field.cqe_prev = (head)->cqh_last; \ if ((head)->cqh_first == (void *)(head)) \ (head)->cqh_first = (elm); \ else \ (head)->cqh_last->field.cqe_next = (elm); \ (head)->cqh_last = (elm); \ } while (0) #define LDAP_CIRCLEQ_LAST(head) ((head)->cqh_last) #define LDAP_CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next) #define LDAP_CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev) #define LDAP_CIRCLEQ_REMOVE(head, elm, field) do { \ if ((elm)->field.cqe_next == (void *)(head)) \ (head)->cqh_last = (elm)->field.cqe_prev; \ else \ (elm)->field.cqe_next->field.cqe_prev = \ (elm)->field.cqe_prev; \ if ((elm)->field.cqe_prev == (void *)(head)) \ (head)->cqh_first = (elm)->field.cqe_next; \ else \ (elm)->field.cqe_prev->field.cqe_next = \ (elm)->field.cqe_next; \ } while (0) #define LDAP_CIRCLEQ_LOOP_NEXT(head, elm, field) \ (((elm)->field.cqe_next == (void *)(head)) \ ? ((head)->cqh_first) \ : ((elm)->field.cqe_next)) #define LDAP_CIRCLEQ_LOOP_PREV(head, elm, field) \ (((elm)->field.cqe_prev == (void *)(head)) \ ? ((head)->cqh_last) \ : ((elm)->field.cqe_prev)) #define LDAP_CIRCLEQ_MAKE_HEAD(head, elm, field) do { \ if ((elm)->field.cqe_prev != (void *)(head)) { \ (head)->cqh_first->field.cqe_prev = (head)->cqh_last; \ (head)->cqh_last->field.cqe_next = (head)->cqh_first; \ (head)->cqh_first = elm; \ (head)->cqh_last = (elm)->field.cqe_prev; \ (elm)->field.cqe_prev->field.cqe_next = (void *)(head); \ (elm)->field.cqe_prev = (void *)(head); \ } \ } while (0) #define LDAP_CIRCLEQ_MAKE_TAIL(head, elm, field) do { \ if ((elm)->field.cqe_next != (void *)(head)) { \ (head)->cqh_first->field.cqe_prev = (head)->cqh_last; \ (head)->cqh_last->field.cqe_next = (head)->cqh_first; \ (head)->cqh_first = (elm)->field.cqe_next; \ (head)->cqh_last = elm; \ (elm)->field.cqe_next->field.cqe_prev = (void *)(head); \ (elm)->field.cqe_next = (void *)(head); \ } \ } while (0) #endif /* !_LDAP_QUEUE_H_ */