/* * libtu/common.h * * Copyright (c) Tuomo Valkonen 1999-2002.  * * You may distribute and modify this library under the terms of either * the Clarified Artistic License or the GNU LGPL, version 2.1 or later. */#ifndef LIBTU_DLIST_H#define LIBTU_DLIST_H#define LINK_ITEM(LIST, ITEM, NEXT, PREV) \	(ITEM)->NEXT=NULL;                    \	if((LIST)==NULL){                     \		(LIST)=(ITEM);                    \		(ITEM)->PREV=(ITEM);              \	}else{                                \		(ITEM)->PREV=(LIST)->PREV;        \		(ITEM)->PREV->NEXT=(ITEM);        \		(LIST)->PREV=(ITEM);              \	}#define LINK_ITEM_FIRST(LIST, ITEM, NEXT, PREV) \	(ITEM)->NEXT=(LIST);                        \	if((LIST)==NULL){                           \		(ITEM)->PREV=(ITEM);                    \	}else{                                      \		(ITEM)->PREV=(LIST)->PREV;              \		(LIST)->PREV=(ITEM);                    \	}                                           \	(LIST)=(ITEM);#define LINK_ITEM_LIST LINK_ITEM#define LINK_ITEM_BEFORE(LIST, BEFORE, ITEM, NEXT, PREV) \	(ITEM)->NEXT=(BEFORE);                               \	(ITEM)->PREV=(BEFORE)->PREV;                         \	(BEFORE)->PREV=(ITEM);                               \	if((BEFORE)==(LIST))                                 \		(LIST)=(ITEM);                                   \	else                                                 \		(ITEM)->PREV->NEXT=(ITEM)#define LINK_ITEM_AFTER(LIST, AFTER, ITEM, NEXT, PREV) \	(ITEM)->NEXT=(AFTER)->NEXT;                        \	(ITEM)->PREV=(AFTER);                              \	(AFTER)->NEXT=(ITEM);                              \	if((ITEM)->NEXT==NULL)                             \		(LIST)->PREV=(ITEM);                           \	else                                               \		(ITEM)->NEXT->PREV=ITEM;#define UNLINK_ITEM(LIST, ITEM, NEXT, PREV) \	if((ITEM)==(LIST)){                     \		(LIST)=(ITEM)->NEXT;                \		if((LIST)!=NULL)                    \			(LIST)->PREV=(ITEM)->PREV;      \	}else if((ITEM)->NEXT==NULL){           \		(ITEM)->PREV->NEXT=NULL;            \		(LIST)->PREV=(ITEM)->PREV;          \	}else{                                  \		(ITEM)->PREV->NEXT=(ITEM)->NEXT;    \		(ITEM)->NEXT->PREV=(ITEM)->PREV;    \	}                                       \	(ITEM)->NEXT=NULL;                      \	(ITEM)->PREV=NULL;#endif /* LIBTU_DLIST_H */