summaryrefslogtreecommitdiff
path: root/main/simple_list.h
blob: 5ef39e14cc693e13a0f32a50515b8605baace289 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/**
 * \file simple_list.h
 * Simple macros for type-safe, intrusive lists.
 *
 *  Intended to work with a list sentinal which is created as an empty
 *  list.  Insert & delete are O(1).
 *  
 * \author
 *  (C) 1997, Keith Whitwell
 */

/*
 * Mesa 3-D graphics library
 * Version:  3.5
 *
 * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


#ifndef _SIMPLE_LIST_H
#define _SIMPLE_LIST_H

struct simple_node {
   struct simple_node *next;
   struct simple_node *prev;
};

/**
 * Remove an element from list.
 *
 * \param elem element to remove.
 */
#define remove_from_list(elem)			\
do {						\
   (elem)->next->prev = (elem)->prev;		\
   (elem)->prev->next = (elem)->next;		\
} while (0)

/**
 * Insert an element to the list head.
 *
 * \param list list.
 * \param elem element to insert.
 */
#define insert_at_head(list, elem)		\
do {						\
   (elem)->prev = list;				\
   (elem)->next = (list)->next;			\
   (list)->next->prev = elem;			\
   (list)->next = elem;				\
} while(0)

/**
 * Insert an element to the list tail.
 *
 * \param list list.
 * \param elem element to insert.
 */
#define insert_at_tail(list, elem)		\
do {						\
   (elem)->next = list;				\
   (elem)->prev = (list)->prev;			\
   (list)->prev->next = elem;			\
   (list)->prev = elem;				\
} while(0)

/**
 * Move an element to the list head.
 *
 * \param list list.
 * \param elem element to move.
 */
#define move_to_head(list, elem)		\
do {						\
   remove_from_list(elem);			\
   insert_at_head(list, elem);			\
} while (0)

/**
 * Move an element to the list tail.
 *
 * \param list list.
 * \param elem element to move.
 */
#define move_to_tail(list, elem)		\
do {						\
   remove_from_list(elem);			\
   insert_at_tail(list, elem);			\
} while (0)

/**
 * Consatinate a cyclic list to a list
 *
 * Appends the sequence of nodes starting with \c tail to the list \c head.
 * A "cyclic list" is a list that does not have a sentinal node.  This means
 * that the data pointed to by \c tail is an actual node, not a dataless
 * sentinal.  Note that if \c tail constist of a single node, this macro
 * behaves identically to \c insert_at_tail
 *
 * \param head Head of the list to be appended to.  This may or may not
 *             be a cyclic list.
 * \param tail Head of the cyclic list to be appended to \c head.
 * \param temp Temporary \c simple_list used by the macro
 *
 * \sa insert_at_tail
 */
#define concat_list_and_cycle(head, tail, temp)	\
do {						\
   (head)->prev->next = (tail);			\
   (tail)->prev->next = (head);			\
   (temp) = (head)->prev;			\
   (head)->prev = (tail)->prev;			\
   (tail)->prev = (temp);			\
} while (0)

#define concat_list(head, next_list)		\
do {						\
   (next_list)->next->prev = (head)->prev;	\
   (next_list)->prev->next = (head);		\
   (head)->prev->next = (next_list)->next;	\
   (head)->prev = (next_list)->prev;		\
} while (0)

/**
 * Make a empty list empty.
 *
 * \param sentinal list (sentinal element).
 */
#define make_empty_list(sentinal)		\
do {						\
   (sentinal)->next = sentinal;			\
   (sentinal)->prev = sentinal;			\
} while (0)

/**
 * Get list first element.
 *
 * \param list list.
 *
 * \return pointer to first element.
 */
#define first_elem(list)       ((list)->next)

/**
 * Get list last element.
 *
 * \param list list.
 *
 * \return pointer to last element.
 */
#define last_elem(list)        ((list)->prev)

/**
 * Get next element.
 *
 * \param elem element.
 *
 * \return pointer to next element.
 */
#define next_elem(elem)        ((elem)->next)

/**
 * Get previous element.
 *
 * \param elem element.
 *
 * \return pointer to previous element.
 */
#define prev_elem(elem)        ((elem)->prev)

/**
 * Test whether element is at end of the list.
 * 
 * \param list list.
 * \param elem element.
 * 
 * \return non-zero if element is at end of list, or zero otherwise.
 */
#define at_end(list, elem)     ((elem) == (list))

/**
 * Test if a list is empty.
 * 
 * \param list list.
 * 
 * \return non-zero if list empty, or zero otherwise.
 */
#define is_empty_list(list)    ((list)->next == (list))

/**
 * Walk through the elements of a list.
 *
 * \param ptr pointer to the current element.
 * \param list list.
 *
 * \note It should be followed by a { } block or a single statement, as in a \c
 * for loop.
 */
#define foreach(ptr, list)     \
        for( ptr=(list)->next ;  ptr!=list ;  ptr=(ptr)->next )

/**
 * Walk through the elements of a list.
 *
 * Same as #foreach but lets you unlink the current value during a list
 * traversal.  Useful for freeing a list, element by element.
 * 
 * \param ptr pointer to the current element.
 * \param t temporary pointer.
 * \param list list.
 *
 * \note It should be followed by a { } block or a single statement, as in a \c
 * for loop.
 */
#define foreach_s(ptr, t, list)   \
        for(ptr=(list)->next,t=(ptr)->next; list != ptr; ptr=t, t=(t)->next)

#endif