/[svn]/ircd-hybrid-7.2/include/tools.h
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Contents of /ircd-hybrid-7.2/include/tools.h

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Revision 34 - (show annotations)
Sun Oct 2 21:05:51 2005 UTC (14 years ago) by lusky
File MIME type: text/x-csrc
File size: 6457 byte(s)
create 7.2 branch, we can move/rename it as needed.


1 /*
2 * ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3 * tools.h: Header for the various tool functions.
4 *
5 * Copyright (C) 2002 by the past and present ircd coders, and others.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 * USA
21 *
22 * $Id$
23 */
24
25 #ifndef __TOOLS_H__
26 #define __TOOLS_H__
27 #include "stdinc.h"
28
29 /*
30 * double-linked-list and single-linked-list stuff
31 */
32 typedef struct _dlink_node dlink_node;
33 typedef struct _dlink_list dlink_list;
34
35 struct _dlink_node
36 {
37 void *data;
38 dlink_node *prev;
39 dlink_node *next;
40 };
41
42 struct _dlink_list
43 {
44 dlink_node *head;
45 dlink_node *tail;
46 unsigned long length;
47 };
48
49 extern void dlinkAdd(void *data, dlink_node * m, dlink_list * list);
50 extern void dlinkAddBefore(dlink_node *b, void *data, dlink_node *m, dlink_list *list);
51 extern void dlinkAddTail(void *data, dlink_node *m, dlink_list *list);
52 extern void dlinkDelete(dlink_node *m, dlink_list *list);
53 extern void dlinkMoveList(dlink_list *from, dlink_list *to);
54 extern dlink_node *dlinkFind(dlink_list *m, void *data);
55 extern dlink_node *dlinkFindDelete(dlink_list *m, void *data);
56
57 #ifndef NDEBUG
58 void mem_frob(void *data, int len);
59 #else
60 #define mem_frob(x, y)
61 #endif
62
63 /* These macros are basically swiped from the linux kernel
64 * they are simple yet effective
65 */
66
67 /*
68 * Walks forward of a list.
69 * pos is your node
70 * head is your list head
71 */
72 #define DLINK_FOREACH(pos, head) for (pos = (head); pos != NULL; pos = pos->next)
73
74 /*
75 * Walks forward of a list safely while removing nodes
76 * pos is your node
77 * n is another list head for temporary storage
78 * head is your list head
79 */
80 #define DLINK_FOREACH_SAFE(pos, n, head) for (pos = (head), n = pos ? pos->next : NULL; pos != NULL; pos = n, n = pos ? pos->next : NULL)
81 #define DLINK_FOREACH_PREV(pos, head) for (pos = (head); pos != NULL; pos = pos->prev)
82
83 /* Returns the list length */
84 #define dlink_list_length(list) (list)->length
85
86 /*
87 * The functions below are included for the sake of inlining
88 * hopefully this will speed up things just a bit
89 *
90 */
91 /* forte (and maybe others) dont like these being declared twice,
92 * so we dont declare the inlines unless GNUC.
93 */
94 #ifdef __GNUC__
95
96 /*
97 * dlink_ routines are stolen from squid, except for dlinkAddBefore,
98 * which is mine.
99 * -- adrian
100 */
101 extern inline void
102 dlinkAdd(void *data, dlink_node * m, dlink_list * list)
103 {
104 m->data = data;
105 m->prev = NULL;
106 m->next = list->head;
107 /* Assumption: If list->tail != NULL, list->head != NULL */
108 if (list->head != NULL)
109 list->head->prev = m;
110 else if (list->tail == NULL)
111 list->tail = m;
112 list->head = m;
113 list->length++;
114 }
115
116 extern inline void
117 dlinkAddBefore(dlink_node *b, void *data, dlink_node *m, dlink_list *list)
118 {
119 /* Shortcut - if its the first one, call dlinkAdd only */
120 if (b == list->head)
121 dlinkAdd(data, m, list);
122 else {
123 m->data = data;
124 b->prev->next = m;
125 m->prev = b->prev;
126 b->prev = m;
127 m->next = b;
128 list->length++;
129 }
130 }
131
132 extern inline void
133 dlinkAddTail(void *data, dlink_node *m, dlink_list *list)
134 {
135 m->data = data;
136 m->next = NULL;
137 m->prev = list->tail;
138 /* Assumption: If list->tail != NULL, list->head != NULL */
139 if (list->tail != NULL)
140 list->tail->next = m;
141 else if (list->head == NULL)
142 list->head = m;
143 list->tail = m;
144 list->length++;
145 }
146
147 /* Execution profiles show that this function is called the most
148 * often of all non-spontaneous functions. So it had better be
149 * efficient. */
150 extern inline void
151 dlinkDelete(dlink_node *m, dlink_list *list)
152 {
153 /* Assumption: If m->next == NULL, then list->tail == m
154 * and: If m->prev == NULL, then list->head == m
155 */
156 if (m->next)
157 m->next->prev = m->prev;
158 else {
159 assert(list->tail == m);
160 list->tail = m->prev;
161 }
162 if (m->prev)
163 m->prev->next = m->next;
164 else {
165 assert(list->head == m);
166 list->head = m->next;
167 }
168 /* Set this to NULL does matter */
169 m->next = m->prev = NULL;
170 list->length--;
171 }
172
173 /*
174 * dlinkFind
175 * inputs - list to search
176 * - data
177 * output - pointer to link or NULL if not found
178 * side effects - Look for ptr in the linked listed pointed to by link.
179 */
180 extern inline dlink_node *
181 dlinkFind(dlink_list *list, void *data)
182 {
183 dlink_node *ptr;
184
185 DLINK_FOREACH(ptr, list->head)
186 {
187 if (ptr->data == data)
188 return(ptr);
189 }
190
191 return(NULL);
192 }
193
194 extern inline void
195 dlinkMoveList(dlink_list *from, dlink_list *to)
196 {
197 /* There are three cases */
198 /* case one, nothing in from list */
199
200 if (from->head == NULL)
201 return;
202
203 /* case two, nothing in to list */
204 /* actually if to->head is NULL and to->tail isn't, thats a bug */
205
206 if (to->head == NULL)
207 {
208 to->head = from->head;
209 to->tail = from->tail;
210 from->head = from->tail = NULL;
211 to->length = from->length;
212 from->length = 0;
213 return;
214 }
215
216 /* third case play with the links */
217
218 from->tail->next = to->head;
219 from->head->prev = to->head->prev;
220 to->head->prev = from->tail;
221 to->head = from->head;
222 from->head = from->tail = NULL;
223 to->length += from->length;
224 from->length = 0;
225
226 /* I think I got that right */
227 }
228
229 extern inline dlink_node *
230 dlinkFindDelete(dlink_list *list, void *data)
231 {
232 dlink_node *m;
233
234 DLINK_FOREACH(m, list->head)
235 {
236 if (m->data == data)
237 {
238 if (m->next)
239 m->next->prev = m->prev;
240 else
241 {
242 assert(list->tail == m);
243 list->tail = m->prev;
244 }
245 if (m->prev)
246 m->prev->next = m->next;
247 else
248 {
249 assert(list->head == m);
250 list->head = m->next;
251 }
252 /* Set this to NULL does matter */
253 m->next = m->prev = NULL;
254 list->length--;
255
256 return(m);
257 }
258 }
259
260 return(NULL);
261 }
262
263 #endif /* __GNUC__ */
264
265 #endif /* __TOOLS_H__ */

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