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Diffstat (limited to 'main/simple_list.h')
| -rw-r--r-- | main/simple_list.h | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/main/simple_list.h b/main/simple_list.h new file mode 100644 index 0000000..5ef39e1 --- /dev/null +++ b/main/simple_list.h @@ -0,0 +1,235 @@ +/** + * \file simple_list.h + * Simple macros for type-safe, intrusive lists. + * + * Intended to work with a list sentinal which is created as an empty + * list. Insert & delete are O(1). + * + * \author + * (C) 1997, Keith Whitwell + */ + +/* + * Mesa 3-D graphics library + * Version: 3.5 + * + * Copyright (C) 1999-2001 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN + * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + +#ifndef _SIMPLE_LIST_H +#define _SIMPLE_LIST_H + +struct simple_node { + struct simple_node *next; + struct simple_node *prev; +}; + +/** + * Remove an element from list. + * + * \param elem element to remove. + */ +#define remove_from_list(elem) \ +do { \ + (elem)->next->prev = (elem)->prev; \ + (elem)->prev->next = (elem)->next; \ +} while (0) + +/** + * Insert an element to the list head. + * + * \param list list. + * \param elem element to insert. + */ +#define insert_at_head(list, elem) \ +do { \ + (elem)->prev = list; \ + (elem)->next = (list)->next; \ + (list)->next->prev = elem; \ + (list)->next = elem; \ +} while(0) + +/** + * Insert an element to the list tail. + * + * \param list list. + * \param elem element to insert. + */ +#define insert_at_tail(list, elem) \ +do { \ + (elem)->next = list; \ + (elem)->prev = (list)->prev; \ + (list)->prev->next = elem; \ + (list)->prev = elem; \ +} while(0) + +/** + * Move an element to the list head. + * + * \param list list. + * \param elem element to move. + */ +#define move_to_head(list, elem) \ +do { \ + remove_from_list(elem); \ + insert_at_head(list, elem); \ +} while (0) + +/** + * Move an element to the list tail. + * + * \param list list. + * \param elem element to move. + */ +#define move_to_tail(list, elem) \ +do { \ + remove_from_list(elem); \ + insert_at_tail(list, elem); \ +} while (0) + +/** + * Consatinate a cyclic list to a list + * + * Appends the sequence of nodes starting with \c tail to the list \c head. + * A "cyclic list" is a list that does not have a sentinal node. This means + * that the data pointed to by \c tail is an actual node, not a dataless + * sentinal. Note that if \c tail constist of a single node, this macro + * behaves identically to \c insert_at_tail + * + * \param head Head of the list to be appended to. This may or may not + * be a cyclic list. + * \param tail Head of the cyclic list to be appended to \c head. + * \param temp Temporary \c simple_list used by the macro + * + * \sa insert_at_tail + */ +#define concat_list_and_cycle(head, tail, temp) \ +do { \ + (head)->prev->next = (tail); \ + (tail)->prev->next = (head); \ + (temp) = (head)->prev; \ + (head)->prev = (tail)->prev; \ + (tail)->prev = (temp); \ +} while (0) + +#define concat_list(head, next_list) \ +do { \ + (next_list)->next->prev = (head)->prev; \ + (next_list)->prev->next = (head); \ + (head)->prev->next = (next_list)->next; \ + (head)->prev = (next_list)->prev; \ +} while (0) + +/** + * Make a empty list empty. + * + * \param sentinal list (sentinal element). + */ +#define make_empty_list(sentinal) \ +do { \ + (sentinal)->next = sentinal; \ + (sentinal)->prev = sentinal; \ +} while (0) + +/** + * Get list first element. + * + * \param list list. + * + * \return pointer to first element. + */ +#define first_elem(list) ((list)->next) + +/** + * Get list last element. + * + * \param list list. + * + * \return pointer to last element. + */ +#define last_elem(list) ((list)->prev) + +/** + * Get next element. + * + * \param elem element. + * + * \return pointer to next element. + */ +#define next_elem(elem) ((elem)->next) + +/** + * Get previous element. + * + * \param elem element. + * + * \return pointer to previous element. + */ +#define prev_elem(elem) ((elem)->prev) + +/** + * Test whether element is at end of the list. + * + * \param list list. + * \param elem element. + * + * \return non-zero if element is at end of list, or zero otherwise. + */ +#define at_end(list, elem) ((elem) == (list)) + +/** + * Test if a list is empty. + * + * \param list list. + * + * \return non-zero if list empty, or zero otherwise. + */ +#define is_empty_list(list) ((list)->next == (list)) + +/** + * Walk through the elements of a list. + * + * \param ptr pointer to the current element. + * \param list list. + * + * \note It should be followed by a { } block or a single statement, as in a \c + * for loop. + */ +#define foreach(ptr, list) \ + for( ptr=(list)->next ; ptr!=list ; ptr=(ptr)->next ) + +/** + * Walk through the elements of a list. + * + * Same as #foreach but lets you unlink the current value during a list + * traversal. Useful for freeing a list, element by element. + * + * \param ptr pointer to the current element. + * \param t temporary pointer. + * \param list list. + * + * \note It should be followed by a { } block or a single statement, as in a \c + * for loop. + */ +#define foreach_s(ptr, t, list) \ + for(ptr=(list)->next,t=(ptr)->next; list != ptr; ptr=t, t=(t)->next) + +#endif |