Contents of /tags/mkinitrd-6_1_3/busybox/libbb/llist.c
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Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
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Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File MIME type: text/plain
File size: 2003 byte(s)
tagged 'mkinitrd-6_1_3'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * linked list helper functions. |
4 | * |
5 | * Copyright (C) 2003 Glenn McGrath |
6 | * Copyright (C) 2005 Vladimir Oleynik |
7 | * Copyright (C) 2005 Bernhard Reutner-Fischer |
8 | * Copyright (C) 2006 Rob Landley <rob@landley.net> |
9 | * |
10 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
11 | */ |
12 | |
13 | #include "libbb.h" |
14 | |
15 | /* Add data to the start of the linked list. */ |
16 | void FAST_FUNC llist_add_to(llist_t **old_head, void *data) |
17 | { |
18 | llist_t *new_head = xmalloc(sizeof(llist_t)); |
19 | |
20 | new_head->data = data; |
21 | new_head->link = *old_head; |
22 | *old_head = new_head; |
23 | } |
24 | |
25 | /* Add data to the end of the linked list. */ |
26 | void FAST_FUNC llist_add_to_end(llist_t **list_head, void *data) |
27 | { |
28 | llist_t *new_item = xmalloc(sizeof(llist_t)); |
29 | |
30 | new_item->data = data; |
31 | new_item->link = NULL; |
32 | |
33 | if (!*list_head) |
34 | *list_head = new_item; |
35 | else { |
36 | llist_t *tail = *list_head; |
37 | |
38 | while (tail->link) |
39 | tail = tail->link; |
40 | tail->link = new_item; |
41 | } |
42 | } |
43 | |
44 | /* Remove first element from the list and return it */ |
45 | void* FAST_FUNC llist_pop(llist_t **head) |
46 | { |
47 | void *data, *next; |
48 | |
49 | if (!*head) |
50 | return NULL; |
51 | |
52 | data = (*head)->data; |
53 | next = (*head)->link; |
54 | free(*head); |
55 | *head = next; |
56 | |
57 | return data; |
58 | } |
59 | |
60 | /* Unlink arbitrary given element from the list */ |
61 | void FAST_FUNC llist_unlink(llist_t **head, llist_t *elm) |
62 | { |
63 | llist_t *crt; |
64 | |
65 | if (!(elm && *head)) |
66 | return; |
67 | |
68 | if (elm == *head) { |
69 | *head = (*head)->link; |
70 | return; |
71 | } |
72 | |
73 | for (crt = *head; crt; crt = crt->link) { |
74 | if (crt->link == elm) { |
75 | crt->link = elm->link; |
76 | return; |
77 | } |
78 | } |
79 | } |
80 | |
81 | /* Recursively free all elements in the linked list. If freeit != NULL |
82 | * call it on each datum in the list */ |
83 | void FAST_FUNC llist_free(llist_t *elm, void (*freeit) (void *data)) |
84 | { |
85 | while (elm) { |
86 | void *data = llist_pop(&elm); |
87 | |
88 | if (freeit) |
89 | freeit(data); |
90 | } |
91 | } |
92 | |
93 | /* Reverse list order. */ |
94 | llist_t* FAST_FUNC llist_rev(llist_t *list) |
95 | { |
96 | llist_t *rev = NULL; |
97 | |
98 | while (list) { |
99 | llist_t *next = list->link; |
100 | |
101 | list->link = rev; |
102 | rev = list; |
103 | list = next; |
104 | } |
105 | return rev; |
106 | } |