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240 lines
6.2 KiB
C
240 lines
6.2 KiB
C
/*
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* BIRD Library -- Typed Linked Lists
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*
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* (c) 2022 Maria Matejka <mq@jmq.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*
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*
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* This implementation of linked lists forces its members to be
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* typed. On the other hand, it needs to be implemented as ugly macros to
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* keep the needed genericity.
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*
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* Usage:
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* 1. Include this file
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* 2. Define the node structure
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* 3. For every list type you need to define:
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* A. #define TLIST_PREFIX and other macros
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* B. Include this file once again
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*
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* Macros to define:
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* TLIST_PREFIX: prefix to prepend to everything generated
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* TLIST_TYPE: the actual node type
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* TLIST_ITEM: where the tlist structure is
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* TLIST_WANT_WALK: if defined, generates a helper functions for list walking macros
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* TLIST_WANT_ADD_HEAD: if defined, TLIST_PREFIX_add_head() is generated to
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* add an item to the beginning of the list
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* TLIST_WANT_ADD_TAIL: if defined, TLIST_PREFIX_add_tail() is generated to
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* add an item to the end of the list
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*
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* TLIST_PREFIX_rem_node() is generated always.
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*
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* All these macros are #undef-ed by including this file.
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*
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* Example:
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*
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* #include "lib/tlists.h"
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*
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* struct foo {
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* ...
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* TLIST_NODE(bar, struct foo) baz;
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* ...
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* };
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*
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* #define TLIST_PREFIX bar
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* #define TLIST_TYPE struct foo
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* #define TLIST_ITEM baz
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*
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* #define TLIST_WANT_WALK
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* #define TLIST_WANT_ADD_HEAD
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*
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* #include "lib/tlists.h"
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*
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* ...
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* (end of example)
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*
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*/
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#ifdef _BIRD_LIB_TLISTS_H_
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# ifdef TLIST_PREFIX
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/* Check for mandatory arguments */
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#ifndef TLIST_TYPE
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#error "TLIST_TYPE must be defined"
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#endif
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#ifndef TLIST_ITEM
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#error "TLIST_ITEM must be defined"
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#endif
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#ifndef TLIST_PREFIX
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#error "TLIST_PREFIX must be defined"
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#endif
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#define TLIST_NAME(x) MACRO_CONCAT_AFTER(TLIST_PREFIX,_##x)
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#ifndef TLIST_LIST_STRUCT
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#define TLIST_LIST_STRUCT struct TLIST_NAME(list)
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#endif
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#ifndef TLIST_DEFINED_BEFORE
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TLIST_STRUCT_DEF(TLIST_PREFIX, TLIST_TYPE);
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#endif
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static inline TLIST_LIST_STRUCT * TLIST_NAME(enlisted)(TLIST_TYPE *node)
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{
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return node->TLIST_ITEM.list;
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}
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#ifdef TLIST_WANT_WALK
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static inline struct TLIST_NAME(node) * TLIST_NAME(node_get)(TLIST_TYPE *node)
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{ return &(node->TLIST_ITEM); }
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#endif
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#if defined(TLIST_WANT_ADD_HEAD) || defined(TLIST_WANT_ADD_AFTER)
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static inline void TLIST_NAME(add_head)(TLIST_LIST_STRUCT *list, TLIST_TYPE *node)
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{
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ASSERT_DIE(!TLIST_NAME(enlisted)(node));
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node->TLIST_ITEM.list = list;
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if (node->TLIST_ITEM.next = list->first)
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list->first->TLIST_ITEM.prev = node;
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else
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list->last = node;
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list->first = node;
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}
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#endif
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#ifdef TLIST_WANT_ADD_TAIL
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static inline void TLIST_NAME(add_tail)(TLIST_LIST_STRUCT *list, TLIST_TYPE *node)
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{
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ASSERT_DIE(!TLIST_NAME(enlisted)(node));
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node->TLIST_ITEM.list = list;
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if (node->TLIST_ITEM.prev = list->last)
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list->last->TLIST_ITEM.next = node;
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else
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list->first = node;
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list->last = node;
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}
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#endif
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#ifdef TLIST_WANT_UPDATE_NODE
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static inline void TLIST_NAME(update_node)(TLIST_LIST_STRUCT *list, TLIST_TYPE *node)
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{
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ASSERT_DIE(TLIST_NAME(enlisted)(node) == list);
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if (node->TLIST_ITEM.prev)
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node->TLIST_ITEM.prev->TLIST_ITEM.next = node;
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else
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list->first = node;
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if (node->TLIST_ITEM.next)
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node->TLIST_ITEM.next->TLIST_ITEM.prev = node;
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else
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list->last = node;
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}
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#endif
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#ifdef TLIST_WANT_ADD_AFTER
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static inline void TLIST_NAME(add_after)(TLIST_LIST_STRUCT *list, TLIST_TYPE *node, TLIST_TYPE *after)
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{
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ASSERT_DIE(!TLIST_NAME(enlisted)(node));
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/* Adding to beginning */
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if (!(node->TLIST_ITEM.prev = after))
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return TLIST_NAME(add_head)(list, node);
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/* OK, Adding after a real node */
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node->TLIST_ITEM.list = list;
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/* There is another node after the anchor */
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if (node->TLIST_ITEM.next = after->TLIST_ITEM.next)
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/* Link back */
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node->TLIST_ITEM.next->TLIST_ITEM.prev = node;
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else
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/* Or we are adding the last node */
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list->last = node;
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/* Link forward from "after" */
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after->TLIST_ITEM.next = node;
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}
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#endif
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static inline void TLIST_NAME(rem_node)(TLIST_LIST_STRUCT *list, TLIST_TYPE *node)
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{
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ASSERT_DIE(TLIST_NAME(enlisted)(node) == list);
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if (node->TLIST_ITEM.prev)
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node->TLIST_ITEM.prev->TLIST_ITEM.next = node->TLIST_ITEM.next;
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else
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{
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ASSERT_DIE(list->first == node);
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list->first = node->TLIST_ITEM.next;
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}
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if (node->TLIST_ITEM.next)
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node->TLIST_ITEM.next->TLIST_ITEM.prev = node->TLIST_ITEM.prev;
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else
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{
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ASSERT_DIE(list->last == node);
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list->last = node->TLIST_ITEM.prev;
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}
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node->TLIST_ITEM.next = node->TLIST_ITEM.prev = NULL;
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node->TLIST_ITEM.list = NULL;
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}
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#undef TLIST_PREFIX
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#undef TLIST_NAME
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#undef TLIST_LIST_STRUCT
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#undef TLIST_TYPE
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#undef TLIST_ITEM
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#undef TLIST_WANT_ADD_HEAD
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#undef TLIST_WANT_ADD_TAIL
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#undef TLIST_WANT_UPDATE_NODE
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#undef TLIST_DEFINED_BEFORE
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# endif
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#else
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#define _BIRD_LIB_TLISTS_H_
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#include "lib/macro.h"
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#if defined(TLIST_NAME) || defined(TLIST_PREFIX)
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#error "You should first include lib/tlists.h without requesting a TLIST"
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#endif
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#define TLIST_LIST(_name) struct _name##_list
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#define TLIST_STRUCT_DEF(_name, _type) TLIST_LIST(_name) { _type *first, *last; }
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#define TLIST_NODE_IN(_name, _type) { _type *next; _type *prev; TLIST_LIST(_name) *list; }
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#define TLIST_NODE(_name, _type) struct _name##_node TLIST_NODE_IN(_name, _type)
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#define TLIST_DEFAULT_NODE struct MACRO_CONCAT_AFTER(TLIST_PREFIX,_node) \
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TLIST_NODE_IN(TLIST_PREFIX,TLIST_TYPE) TLIST_ITEM
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/* Use ->first and ->last to access HEAD and TAIL */
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#define THEAD(_name, _list) (_list)->first
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#define TTAIL(_name, _list) (_list)->last
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/* Walkaround macros: simple and resilient to node removal */
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#define WALK_TLIST(_name, _node, _list) \
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for (typeof((_list)->first) _node = (_list)->first; \
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_node; _node = _name##_node_get((_node))->next)
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#define WALK_TLIST_DELSAFE(_name, _node, _list) \
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for (typeof((_list)->first) _node = (_list)->first, \
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_helper = _node ? _name##_node_get((_list)->first)->next : NULL; \
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_node; \
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(_node = _helper) ? (_helper = _name##_node_get(_helper)->next) : 0)
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/* Empty check */
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#define EMPTY_TLIST(_name, _list) (!(_list)->first)
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/* List length */
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#define TLIST_LENGTH(_name, _list) ({ uint _len = 0; WALK_TLIST(_name, _, _list) _len++; _len; })
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#endif
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