85 lines
2.4 KiB
C
85 lines
2.4 KiB
C
/*-
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* lstInt.h --
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* Internals for the list library
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*
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* Copyright (c) 1988 by University of California Regents
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*
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* Permission to use, copy, modify, and distribute this
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* software and its documentation for any purpose and without
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* fee is hereby granted, provided that the above copyright
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* notice appears in all copies. Neither the University of California nor
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* Adam de Boor makes any representations about the suitability of this
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* software for any purpose. It is provided "as is" without
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* express or implied warranty.
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*
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* $Id: lstInt.h,v 1.4 1995/04/30 19:06:30 jwag Exp $ SPRITE (Berkeley)
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*/
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#ifndef _LSTINT_H_
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#define _LSTINT_H_
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#include "lst.h"
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typedef struct ListNode {
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struct ListNode *prevPtr; /* previous element in list */
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struct ListNode *nextPtr; /* next in list */
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short useCount:8, /* Count of functions using the node.
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* node may not be deleted until count
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* goes to 0 */
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flags:8; /* Node status flags */
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ClientData datum; /* datum associated with this element */
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} *ListNode;
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/*
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* Flags required for synchronization
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*/
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#define LN_DELETED 0x0001 /* List node should be removed when done */
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#define NilListNode ((ListNode)-1)
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typedef enum {
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Head, Middle, Tail, Unknown
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} Where;
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typedef struct {
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ListNode firstPtr; /* first node in list */
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ListNode lastPtr; /* last node in list */
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Boolean isCirc; /* true if the list should be considered
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* circular */
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/*
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* fields for sequential access
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*/
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Where atEnd; /* Where in the list the last access was */
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Boolean isOpen; /* true if list has been Lst_Open'ed */
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ListNode curPtr; /* current node, if open. NilListNode if
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* *just* opened */
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ListNode prevPtr; /* Previous node, if open. Used by
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* Lst_Remove */
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} *List;
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#define NilList ((List)-1)
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/*
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* PAlloc (var, ptype) --
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* Allocate a pointer-typedef structure 'ptype' into the variable 'var'
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*/
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#define PAlloc(var,ptype) var = (ptype) Malloc (sizeof (*var))
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/*
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* LstValid (l) --
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* Return TRUE if the list l is valid
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*/
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#define LstValid(l) (((Lst)l == NILLST) ? FALSE : TRUE)
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/*
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* LstNodeValid (ln, l) --
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* Return TRUE if the LstNode ln is valid with respect to l
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*/
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#define LstNodeValid(ln, l) ((((LstNode)ln) == NILLNODE) ? FALSE : TRUE)
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/*
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* LstIsEmpty (l) --
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* TRUE if the list l is empty.
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*/
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#define LstIsEmpty(l) (((List)l)->firstPtr == NilListNode)
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#endif _LSTINT_H_
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