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2ff501590b
Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
86 lines
2.9 KiB
C
86 lines
2.9 KiB
C
/*-------------------------------------------------------------------------
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*
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* dllist.h
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* simple doubly linked list primitives
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* the elements of the list are void* so the lists can contain anything
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* Dlelem can only be in one list at a time
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*
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*
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* Here's a small example of how to use Dllists:
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*
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* Dllist *lst;
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* Dlelem *elt;
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* void *in_stuff; -- stuff to stick in the list
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* void *out_stuff
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*
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* lst = DLNewList(); -- make a new dllist
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* DLAddHead(lst, DLNewElem(in_stuff)); -- add a new element to the list
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* with in_stuff as the value
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* ...
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* elt = DLGetHead(lst); -- retrieve the head element
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* out_stuff = (void*)DLE_VAL(elt); -- get the stuff out
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* DLRemove(elt); -- removes the element from its list
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* DLFreeElem(elt); -- free the element since we don't
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* use it anymore
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*
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*
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* It is also possible to use Dllist objects that are embedded in larger
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* structures instead of being separately malloc'd. To do this, use
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* DLInitElem() to initialize a Dllist field within a larger object.
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* Don't forget to DLRemove() each field from its list (if any) before
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* freeing the larger object!
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*
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*
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* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/include/lib/dllist.h,v 1.24 2004/12/31 22:03:31 pgsql Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef DLLIST_H
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#define DLLIST_H
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struct Dllist;
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struct Dlelem;
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typedef struct Dlelem
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{
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struct Dlelem *dle_next; /* next element */
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struct Dlelem *dle_prev; /* previous element */
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void *dle_val; /* value of the element */
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struct Dllist *dle_list; /* what list this element is in */
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} Dlelem;
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typedef struct Dllist
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{
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Dlelem *dll_head;
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Dlelem *dll_tail;
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} Dllist;
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extern Dllist *DLNewList(void); /* allocate and initialize a list header */
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extern void DLInitList(Dllist *list); /* init a header alloced by caller */
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extern void DLFreeList(Dllist *list); /* free up a list and all the
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* nodes in it */
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extern Dlelem *DLNewElem(void *val);
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extern void DLInitElem(Dlelem *e, void *val);
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extern void DLFreeElem(Dlelem *e);
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extern void DLRemove(Dlelem *e); /* removes node from list */
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extern void DLAddHead(Dllist *list, Dlelem *node);
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extern void DLAddTail(Dllist *list, Dlelem *node);
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extern Dlelem *DLRemHead(Dllist *list); /* remove and return the head */
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extern Dlelem *DLRemTail(Dllist *list);
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extern void DLMoveToFront(Dlelem *e); /* move node to front of its list */
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/* These are macros for speed */
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#define DLGetHead(list) ((list)->dll_head)
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#define DLGetTail(list) ((list)->dll_tail)
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#define DLGetSucc(elem) ((elem)->dle_next)
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#define DLGetPred(elem) ((elem)->dle_prev)
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#define DLGetListHdr(elem) ((elem)->dle_list)
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#define DLE_VAL(elem) ((elem)->dle_val)
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#endif /* DLLIST_H */
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