src/common/list.h

   1 /*
   2  * Copyright (C) 2002 Free Software Foundation, Inc.
   3  * This file is part of the GNU C Library.
   4  * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; only
   9  * version 2.1 of the License.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef _BT_LIST_H
  22 #define _BT_LIST_H      1
  23
  24 /* The definitions of this file are adopted from those which can be
  25    found in the Linux kernel headers to enable people familiar with
  26    the latter find their way in these sources as well.  */
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif
  31
  32 /* Basic type for the double-link list.  */
  33 struct bt_list_head
  34 {
  35   struct bt_list_head *next;
  36   struct bt_list_head *prev;
  37 };
  38
  39
  40 /* Define a variable with the head and tail of the list.  */
  41 #define BT_LIST_HEAD(name) \
  42   struct bt_list_head name = { &(name), &(name) }
  43
  44 /* Initialize a new list head.  */
  45 #define BT_INIT_LIST_HEAD(ptr) \
  46   (ptr)->next = (ptr)->prev = (ptr)
  47
  48 #define BT_LIST_HEAD_INIT(name) { .prev = &(name), .next = &(name) }
  49
  50 /* Add new element at the head of the list.  */
  51 static inline void
  52 bt_list_add (struct bt_list_head *newp, struct bt_list_head *head)
  53 {
  54   head->next->prev = newp;
  55   newp->next = head->next;
  56   newp->prev = head;
  57   head->next = newp;
  58 }
  59
  60
  61 /* Add new element at the tail of the list.  */
  62 static inline void
  63 bt_list_add_tail (struct bt_list_head *newp, struct bt_list_head *head)
  64 {
  65   head->prev->next = newp;
  66   newp->next = head;
  67   newp->prev = head->prev;
  68   head->prev = newp;
  69 }
  70
  71
  72 /* Remove element from list.  */
  73 static inline void
  74 __bt_list_del (struct bt_list_head *prev, struct bt_list_head *next)
  75 {
  76   next->prev = prev;
  77   prev->next = next;
  78 }
  79
  80 /* Remove element from list.  */
  81 static inline void
  82 bt_list_del (struct bt_list_head *elem)
  83 {
  84   __bt_list_del (elem->prev, elem->next);
  85 }
  86
  87 /* delete from list, add to another list as head */
  88 static inline void
  89 bt_list_move (struct bt_list_head *elem, struct bt_list_head *head)
  90 {
  91   __bt_list_del (elem->prev, elem->next);
  92   bt_list_add (elem, head);
  93 }
  94
  95 /* replace an old entry.
  96  */
  97 static inline void
  98 bt_list_replace(struct bt_list_head *old, struct bt_list_head *_new)
  99 {
 100         _new->next = old->next;
 101         _new->prev = old->prev;
 102         _new->prev->next = _new;
 103         _new->next->prev = _new;
 104 }
 105
 106 /* Join two lists.  */
 107 static inline void
 108 bt_list_splice (struct bt_list_head *add, struct bt_list_head *head)
 109 {
 110   /* Do nothing if the list which gets added is empty.  */
 111   if (add != add->next)
 112     {
 113       add->next->prev = head;
 114       add->prev->next = head->next;
 115       head->next->prev = add->prev;
 116       head->next = add->next;
 117     }
 118 }
 119
 120
 121 /* Get typed element from list at a given position.  */
 122 #define bt_list_entry(ptr, type, member) \
 123   ((type *) ((char *) (ptr) - (uintptr_t) (&((type *) 0)->member)))
 124
 125
 126
 127 /* Iterate forward over the elements of the list.  */
 128 #define bt_list_for_each(pos, head) \
 129   for (pos = (head)->next; pos != (head); pos = pos->next)
 130
 131
 132 /* Iterate forward over the elements of the list.  */
 133 #define bt_list_for_each_prev(pos, head) \
 134   for (pos = (head)->prev; pos != (head); pos = pos->prev)
 135
 136
 137 /* Iterate backwards over the elements list.  The list elements can be
 138    removed from the list while doing this.  */
 139 #define bt_list_for_each_prev_safe(pos, p, head) \
 140   for (pos = (head)->prev, p = pos->prev; \
 141        pos != (head); \
 142        pos = p, p = pos->prev)
 143
 144 #define bt_list_for_each_entry(pos, head, member)                               \
 145         for (pos = bt_list_entry((head)->next, typeof(*pos), member);   \
 146              &pos->member != (head);                                    \
 147              pos = bt_list_entry(pos->member.next, typeof(*pos), member))
 148
 149 #define bt_list_for_each_entry_reverse(pos, head, member)                       \
 150         for (pos = bt_list_entry((head)->prev, typeof(*pos), member);   \
 151              &pos->member != (head);                                    \
 152              pos = bt_list_entry(pos->member.prev, typeof(*pos), member))
 153
 154 #define bt_list_for_each_entry_safe(pos, p, head, member)                       \
 155         for (pos = bt_list_entry((head)->next, typeof(*pos), member),   \
 156                      p = bt_list_entry(pos->member.next,typeof(*pos), member); \
 157              &pos->member != (head);                                    \
 158              pos = p, p = bt_list_entry(pos->member.next, typeof(*pos), member))
 159
 160 static inline int bt_list_empty(struct bt_list_head *head)
 161 {
 162         return head == head->next;
 163 }
 164
 165 static inline void bt_list_replace_init(struct bt_list_head *old,
 166                                      struct bt_list_head *_new)
 167 {
 168         struct bt_list_head *head = old->next;
 169         bt_list_del(old);
 170         bt_list_add_tail(_new, head);
 171         BT_INIT_LIST_HEAD(old);
 172 }
 173
 174 #ifdef __cplusplus
 175 }
 176 #endif
 177
 178 #endif  /* _BT_LIST_H */