src/list.h

   1 /* list.h -- doubly linked list header file for vlock,
   2  *           the VT locking program for linux
   3  *
   4  * This program is copyright (C) 2007 Frank Benkstein, and is free
   5  * software which is freely distributable under the terms of the
   6  * GNU General Public License version 2, included as the file COPYING in this
   7  * distribution.  It is NOT public domain software, and any
   8  * redistribution not permitted by the GNU General Public License is
   9  * expressly forbidden without prior written permission from
  10  * the author.
  11  *
  12  */
  13
  14 struct list_item
  15 {
  16   void *data;
  17   struct list_item *next;
  18   struct list_item *previous;
  19 };
  20
  21 struct list
  22 {
  23   struct list_item *first;
  24   struct list_item *last;
  25 };
  26
  27 struct list *list_new(void);
  28 void list_free(struct list *l);
  29
  30 size_t list_length(struct list *l);
  31 void list_append(struct list *l, void *data);
  32
  33 #define list_for_each(list, item) \
  34   for (struct list_item *item = (list)->first; item != NULL; item = item->next)
  35
  36
  37 #if 0
  38 /* Inspired by the doubly linked list code from glib:
  39  *
  40  * GLIB - Library of useful routines for C programming
  41  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
  42  *
  43  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  44  * file for a list of people on the GLib Team.  See the ChangeLog
  45  * files for a list of changes.  These files are distributed with
  46  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  47  */
  48
  49 /* An item of the list.
  50  *
  51  * Any item also represents the full list.
  52  *
  53  * An empty list is represented by the NULL pointer.
  54  */
  55 struct List {
  56   void *data;
  57   struct List *next;
  58   struct List *previous;
  59 };
  60
  61 /* Get the first item of the list.  Returns the first item of the list or NULL
  62  * if the list is empty. */
  63 struct List *list_first(struct List *list);
  64
  65 /* Get the last item of the list.  Returns the last item of the list or NULL if
  66  * the list is empty. */
  67 struct List *list_last(struct List *list);
  68
  69 /* Get the next item.  Returns the item after the given item or NULL if the
  70  * list is empty. */
  71 struct List *list_next(struct List *list);
  72
  73 /* Get the previous item.  Returns the item before the given item or NULL if
  74  * the list is empty. */
  75 struct List *list_previous(struct List *list);
  76
  77 /* Allocate a new list item with the given data pointer and append it to the
  78  * end of the list.  Returns the new start of the list.  Calls abort() on
  79  * memory errors. */
  80 struct List *list_append(struct List *list, void *data);
  81
  82 /* Removes the first item with the given data pointer and deletes it from the
  83  * list.  Returns the new start of the list.  Does not free the data. */
  84 struct List *list_remove(struct List *list, void *data);
  85
  86 /* Delete one item from the list.  Returns the new start of the list. */
  87 struct List *list_delete_link(struct List *list, struct List *item);
  88
  89 /* Returns the first item with the given data pointer or NULL if none is found.
  90  */
  91 struct List *list_find(struct List *list, void *data);
  92
  93 /* Make a copy of the list.  Returns a shallow copy of the entire list.  Calls
  94  * abort() on memory error. */
  95 struct List *list_copy(struct List *list);
  96
  97 /* Free the entire list.  Does free the items'. */
  98 void list_free(struct List *list);
  99
 100 #define list_for_each(list, item) \
 101   for (struct List *item = list_first(list); item != NULL; item = list_next(item))
 102
 103 #define list_reverse_for_each(list, item) \
 104     for (struct List *item = list_last(plugins); item != NULL; item = list_previous(item))
 105 #endif