1 /* void_list.c - the opkg package management system
2
3 Carl D. Worth
4
5 Copyright (C) 2001 University of Southern California
6
7 This program is free software; you can redistribute it and/or
8 modify it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 2, or (at
10 your option) any later version.
11
12 This program is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
16 */
17
18 #include "void_list.h"
19 #include "libbb/libbb.h"
20
void_list_elt_init(void_list_elt_t * elt,void * data)21 void void_list_elt_init(void_list_elt_t * elt, void *data)
22 {
23 INIT_LIST_HEAD(&elt->node);
24 elt->data = data;
25 }
26
void_list_elt_new(void * data)27 static void_list_elt_t *void_list_elt_new(void *data)
28 {
29 void_list_elt_t *elt;
30 /* freed in void_list_elt_deinit */
31 elt = xcalloc(1, sizeof(void_list_elt_t));
32 void_list_elt_init(elt, data);
33 return elt;
34 }
35
void_list_elt_deinit(void_list_elt_t * elt)36 void void_list_elt_deinit(void_list_elt_t * elt)
37 {
38 list_del_init(&elt->node);
39 void_list_elt_init(elt, NULL);
40 free(elt);
41 }
42
void_list_init(void_list_t * list)43 void void_list_init(void_list_t * list)
44 {
45 INIT_LIST_HEAD(&list->head);
46 }
47
void_list_deinit(void_list_t * list)48 void void_list_deinit(void_list_t * list)
49 {
50 void_list_elt_t *elt;
51
52 while (!void_list_empty(list)) {
53 elt = void_list_pop(list);
54 void_list_elt_deinit(elt);
55 }
56 INIT_LIST_HEAD(&list->head);
57 }
58
void_list_append(void_list_t * list,void * data)59 void void_list_append(void_list_t * list, void *data)
60 {
61 void_list_elt_t *elt = void_list_elt_new(data);
62 list_add_tail(&elt->node, &list->head);
63 }
64
void_list_push(void_list_t * list,void * data)65 void void_list_push(void_list_t * list, void *data)
66 {
67 void_list_elt_t *elt = void_list_elt_new(data);
68 list_add(&elt->node, &list->head);
69 }
70
void_list_pop(void_list_t * list)71 void_list_elt_t *void_list_pop(void_list_t * list)
72 {
73 struct list_head *node;
74
75 if (void_list_empty(list))
76 return NULL;
77 node = list->head.next;
78 list_del_init(node);
79 return list_entry(node, void_list_elt_t, node);
80 }
81
void_list_remove(void_list_t * list,void_list_elt_t ** iter)82 void *void_list_remove(void_list_t * list, void_list_elt_t ** iter)
83 {
84 void_list_elt_t *pos, *n;
85 void_list_elt_t *old_elt;
86 void *old_data = NULL;
87
88 old_elt = *iter;
89 if (!old_elt)
90 return old_data;
91 old_data = old_elt->data;
92
93 list_for_each_entry_safe(pos, n, &list->head, node) {
94 if (pos == old_elt)
95 break;
96 }
97 if (pos != old_elt) {
98 opkg_msg(ERROR, "Internal error: element not found in list.\n");
99 return NULL;
100 }
101
102 *iter = list_entry(pos->node.prev, void_list_elt_t, node);
103 void_list_elt_deinit(pos);
104
105 return old_data;
106 }
107
108 /* remove element containing elt data, using cmp(elt->data, target_data) == 0. */
void_list_remove_elt(void_list_t * list,const void * target_data,void_list_cmp_t cmp)109 void *void_list_remove_elt(void_list_t * list, const void *target_data,
110 void_list_cmp_t cmp)
111 {
112 void_list_elt_t *pos, *n;
113 void *old_data = NULL;
114 list_for_each_entry_safe(pos, n, &list->head, node) {
115 if (pos->data && cmp(pos->data, target_data) == 0) {
116 old_data = pos->data;
117 void_list_elt_deinit(pos);
118 break;
119 }
120 }
121 return old_data;
122 }
123
void_list_first(void_list_t * list)124 void_list_elt_t *void_list_first(void_list_t * list)
125 {
126 struct list_head *elt;
127 if (!list)
128 return NULL;
129 elt = list->head.next;
130 if (elt == &list->head) {
131 return NULL;
132 }
133 return list_entry(elt, void_list_elt_t, node);
134 }
135
void_list_prev(void_list_t * list,void_list_elt_t * node)136 void_list_elt_t *void_list_prev(void_list_t * list, void_list_elt_t * node)
137 {
138 struct list_head *elt;
139 if (!list || !node)
140 return NULL;
141 elt = node->node.prev;
142 if (elt == &list->head) {
143 return NULL;
144 }
145 return list_entry(elt, void_list_elt_t, node);
146 }
147
void_list_next(void_list_t * list,void_list_elt_t * node)148 void_list_elt_t *void_list_next(void_list_t * list, void_list_elt_t * node)
149 {
150 struct list_head *elt;
151 if (!list || !node)
152 return NULL;
153 elt = node->node.next;
154 if (elt == &list->head) {
155 return NULL;
156 }
157 return list_entry(elt, void_list_elt_t, node);
158 }
159
void_list_last(void_list_t * list)160 void_list_elt_t *void_list_last(void_list_t * list)
161 {
162 struct list_head *elt;
163 if (!list)
164 return NULL;
165 elt = list->head.prev;
166 if (elt == &list->head) {
167 return NULL;
168 }
169 return list_entry(elt, void_list_elt_t, node);
170 }
171