X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=include%2Fldap_queue.h;h=34588478372d87840a773a5f1eb323f5bee10a15;hb=HEAD;hp=13ce86a7d2910db54b134a44919db07c8fec64d9;hpb=1add666e5a6ace4281df809ad5d37c4534333616;p=openldap

diff --git a/include/ldap_queue.h b/include/ldap_queue.h
index 13ce86a7d2..3458847837 100644
--- a/include/ldap_queue.h
+++ b/include/ldap_queue.h
@@ -2,7 +2,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2001-2015 The OpenLDAP Foundation.
+ * Copyright 2001-2018 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -102,7 +102,9 @@
  * 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.
+ * 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_.
@@ -225,7 +227,7 @@ struct {								\
 } while (0)
 
 #define LDAP_STAILQ_ENTRY_INIT(var, field) {				\
-	(entry)->field.stqe_next = NULL;				\
+	(var)->field.stqe_next = NULL;					\
 }
 
 #define LDAP_STAILQ_FIRST(head)	((head)->stqh_first)
@@ -384,26 +386,20 @@ struct {								\
 #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);		\
+#define LDAP_TAILQ_FOREACH_REVERSE(var, head, headname, field)		\
+	for ((var) = LDAP_TAILQ_LAST((head), headname);			\
 	     (var);							\
-	     (var) = LDAP_TAILQ_PREV((var), head, type, field))
+	     (var) = LDAP_TAILQ_PREV((var), headname, 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_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, 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_PREV(elm, headname, field) \
+	(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 
 #define	LDAP_TAILQ_INIT(head) do {					\
 	(head)->tqh_first = NULL;					\
@@ -467,6 +463,9 @@ struct name {								\
 	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 */		\
@@ -559,4 +558,36 @@ struct {								\
 		    (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_ */