/* ldap_queue.h -- queue macros */
/* $OpenLDAP: pkg/ldap/include/ldap_queue.h,v 1.11.2.4 2007/01/13 11:19:07 ando Exp $ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2001-2007 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
* <http://www.OpenLDAP.org/license.html>.
*/
/* 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.
*
* 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) { \
(entry)->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, type, field) \
for ((var) = LDAP_TAILQ_LAST((head), type, field); \
(var); \
(var) = LDAP_TAILQ_PREV((var), head, type, field))
#define LDAP_TAILQ_FIRST(head) ((head)->tqh_first)
#define LDAP_TAILQ_LAST(head, type, field) \
(LDAP_TAILQ_EMPTY(head) ? \
NULL : \
((struct type *) \
((char *)((head)->tqh_last) - offsetof(struct type, field))))
#define LDAP_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
#define LDAP_TAILQ_PREV(elm, head, type, field) \
((struct type *)((elm)->field.tqe_prev) == LDAP_TAILQ_FIRST(head) ? \
NULL : \
((struct type *) \
((char *)((elm)->field.tqe_prev) - offsetof(struct type, field))))
#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_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)
#endif /* !_LDAP_QUEUE_H_ */
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