/* Copyright (C) 2001 David Decotigny
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#ifndef _SOS_LIST_H_
#define _SOS_LIST_H_
/**
* @file list.h
*
* Circular doubly-linked lists implementation entirely based on C
* macros
*/
/* *_named are used when next and prev links are not exactly next
and prev. For instance when we have next_in_team, prev_in_team,
prev_global and next_global */
#define list_init_named(list,prev,next) \
((list) = NULL)
#define list_singleton_named(list,item,prev,next) ({ \
(item)->next = (item)->prev = (item); \
(list) = (item); \
})
#define list_is_empty_named(list,prev,next) \
((list) == NULL)
#define list_get_head_named(list,prev,next) \
(list)
#define list_get_tail_named(list,prev,next) \
((list)?((list)->prev):NULL)
/* Internal macro : insert before the head == insert at tail */
#define __list_insert_atleft_named(before_this,item,prev,next) ({ \
(before_this)->prev->next = (item); \
(item)->prev = (before_this)->prev; \
(before_this)->prev = (item); \
(item)->next = (before_this); \
})
/* @note Before_this and item are expected to be valid ! */
#define list_insert_before_named(list,before_this,item,prev,next) ({ \
__list_insert_atleft_named(before_this,item,prev,next); \
if ((list) == (before_this)) (list) = (item); \
})
/** @note After_this and item are expected to be valid ! */
#define list_insert_after_named(list,after_this,item,prev,next) ({ \
(after_this)->next->prev = (item); \
(item)->next = (after_this)->next; \
(after_this)->next = (item); \
(item)->prev = (after_this); \
})
#define list_add_head_named(list,item,prev,next) ({ \
if (list) \
list_insert_before_named(list,list,item,prev,next); \
else \
list_singleton_named(list,item,prev,next); \
(list) = (item); \
})
#define list_add_tail_named(list,item,prev,next) ({ \
if (list) \
__list_insert_atleft_named(list,item,prev,next); \
else \
list_singleton_named(list,item,prev,next); \
})
/** @note NO check whether item really is in list ! */
#define list_delete_named(list,item,prev,next) ({ \
if ( ((item)->next == (item)) && ((item)->prev == (item)) ) \
(item)->next = (item)->prev = (list) = NULL; \
else { \
(item)->prev->next = (item)->next; \
(item)->next->prev = (item)->prev; \
if ((item) == (list)) (list) = (item)->next; \
(item)->prev = (item)->next = NULL; \
} \
})
#define list_pop_head_named(list,prev,next) ({ \
typeof(list) __ret_elt = (list); \
list_delete_named(list,__ret_elt,prev,next); \
__ret_elt; })
/** Loop statement that iterates through all of its elements, from
head to tail */
#define list_foreach_forward_named(list,iterator,nb_elements,prev,next) \
for (nb_elements=0, (iterator) = (list) ; \
(iterator) && (!nb_elements || ((iterator) != (list))) ; \
nb_elements++, (iterator) = (iterator)->next )
/** Loop statement that iterates through all of its elements, from
tail back to head */
#define list_foreach_backward_named(list,iterator,nb_elements,prev,next) \
for (nb_elements=0, (iterator) = list_get_tail_named(list,prev,next) ; \
(iterator) && (!nb_elements || \
((iterator) != list_get_tail_named(list,prev,next))) ; \
nb_elements++, (iterator) = (iterator)->prev )
#define list_foreach_named list_foreach_forward_named
/** True when we exitted early from the foreach loop (ie break) */
#define list_foreach_early_break(list,iterator,nb_elements) \
((list) && ( \
((list) != (iterator)) || \
( ((list) == (iterator)) && (nb_elements == 0)) ))
/** Loop statement that also removes the item at each iteration */
#define list_collapse_named(list,iterator,prev,next) \
for ( ; ({ ((iterator) = (list)) ; \
if (list) list_delete_named(list,iterator,prev,next) ; \
(iterator); }) ; )
/*
* the same macros : assume that the prev and next fields are really
* named "prev" and "next"
*/
#define list_init(list) \
list_init_named(list,prev,next)
#define list_singleton(list,item) \
list_singleton_named(list,item,prev,next)
#define list_is_empty(list) \
list_is_empty_named(list,prev,next)
#define list_get_head(list) \
list_get_head_named(list,prev,next) \
#define list_get_tail(list) \
list_get_tail_named(list,prev,next) \
/* @note Before_this and item are expected to be valid ! */
#define list_insert_after(list,after_this,item) \
list_insert_after_named(list,after_this,item,prev,next)
/* @note After_this and item are expected to be valid ! */
#define list_insert_before(list,before_this,item) \
list_insert_before_named(list,before_this,item,prev,next)
#define list_add_head(list,item) \
list_add_head_named(list,item,prev,next)
#define list_add_tail(list,item) \
list_add_tail_named(list,item,prev,next)
/* @note NO check whether item really is in list ! */
#define list_delete(list,item) \
list_delete_named(list,item,prev,next)
#define list_pop_head(list) \
list_pop_head_named(list,prev,next)
#define list_foreach_forward(list,iterator,nb_elements) \
list_foreach_forward_named(list,iterator,nb_elements,prev,next)
#define list_foreach_backward(list,iterator,nb_elements) \
list_foreach_backward_named(list,iterator,nb_elements,prev,next)
#define list_foreach list_foreach_forward
#define list_collapse(list,iterator) \
list_collapse_named(list,iterator,prev,next)
#endif /* _SOS_LIST_H_ */
