1/*	$NetBSD: lstInt.h,v 1.20 2009/01/24 14:43:29 dsl Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1989, 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Adam de Boor.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	from: @(#)lstInt.h	8.1 (Berkeley) 6/6/93
35 */
36
37/*-
38 * lstInt.h --
39 *	Internals for the list library
40 */
41#ifndef _LSTINT_H_
42#define _LSTINT_H_
43
44#include	  "../lst.h"
45#include	  "../make_malloc.h"
46
47typedef struct ListNode {
48	struct ListNode	*prevPtr;   /* previous element in list */
49	struct ListNode	*nextPtr;   /* next in list */
50	unsigned int	useCount:8, /* Count of functions using the node.
51				     * node may not be deleted until count
52				     * goes to 0 */
53 	    	    	flags:8;    /* Node status flags */
54	void		*datum;	    /* datum associated with this element */
55} *ListNode;
56/*
57 * Flags required for synchronization
58 */
59#define LN_DELETED  	0x0001      /* List node should be removed when done */
60
61typedef enum {
62    Head, Middle, Tail, Unknown
63} Where;
64
65typedef struct	List {
66	ListNode  	firstPtr; /* first node in list */
67	ListNode  	lastPtr;  /* last node in list */
68	Boolean	  	isCirc;	  /* true if the list should be considered
69				   * circular */
70/*
71 * fields for sequential access
72 */
73	Where	  	atEnd;	  /* Where in the list the last access was */
74	Boolean	  	isOpen;	  /* true if list has been Lst_Open'ed */
75	ListNode  	curPtr;	  /* current node, if open. NULL if
76				   * *just* opened */
77	ListNode  	prevPtr;  /* Previous node, if open. Used by
78				   * Lst_Remove */
79} *List;
80
81/*
82 * PAlloc (var, ptype) --
83 *	Allocate a pointer-typedef structure 'ptype' into the variable 'var'
84 */
85#define	PAlloc(var,ptype)	var = (ptype) bmake_malloc(sizeof *(var))
86
87/*
88 * LstValid (l) --
89 *	Return TRUE if the list l is valid
90 */
91#define LstValid(l)	((Lst)(l) != NULL)
92
93/*
94 * LstNodeValid (ln, l) --
95 *	Return TRUE if the LstNode ln is valid with respect to l
96 */
97#define LstNodeValid(ln, l)	((ln) != NULL)
98
99/*
100 * LstIsEmpty (l) --
101 *	TRUE if the list l is empty.
102 */
103#define LstIsEmpty(l)	(((List)(l))->firstPtr == NULL)
104
105#endif /* _LSTINT_H_ */
106