diff options
Diffstat (limited to 'busybox/libbb/inode_hash.c')
-rw-r--r-- | busybox/libbb/inode_hash.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/busybox/libbb/inode_hash.c b/busybox/libbb/inode_hash.c new file mode 100644 index 000000000..fbcd81327 --- /dev/null +++ b/busybox/libbb/inode_hash.c | |||
@@ -0,0 +1,111 @@ | |||
1 | /* vi: set sw=4 ts=4: */ | ||
2 | /* | ||
3 | * Utility routines. | ||
4 | * | ||
5 | * Copyright (C) many different people. | ||
6 | * If you wrote this, please acknowledge your work. | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify | ||
9 | * it under the terms of the GNU General Public License as published by | ||
10 | * the Free Software Foundation; either version 2 of the License, or | ||
11 | * (at your option) any later version. | ||
12 | * | ||
13 | * This program is distributed in the hope that it will be useful, but | ||
14 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
16 | * General Public License for more details. | ||
17 | * | ||
18 | * You should have received a copy of the GNU General Public License | ||
19 | * along with this program; if not, write to the Free Software | ||
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | ||
21 | * USA | ||
22 | */ | ||
23 | |||
24 | #include <stdio.h> | ||
25 | #include <stdlib.h> | ||
26 | #include <string.h> | ||
27 | #include "libbb.h" | ||
28 | |||
29 | #define HASH_SIZE 311 /* Should be prime */ | ||
30 | #define hash_inode(i) ((i) % HASH_SIZE) | ||
31 | |||
32 | typedef struct ino_dev_hash_bucket_struct { | ||
33 | struct ino_dev_hash_bucket_struct *next; | ||
34 | ino_t ino; | ||
35 | dev_t dev; | ||
36 | char name[1]; | ||
37 | } ino_dev_hashtable_bucket_t; | ||
38 | |||
39 | static ino_dev_hashtable_bucket_t *ino_dev_hashtable[HASH_SIZE]; | ||
40 | |||
41 | /* | ||
42 | * Return 1 if statbuf->st_ino && statbuf->st_dev are recorded in | ||
43 | * `ino_dev_hashtable', else return 0 | ||
44 | * | ||
45 | * If NAME is a non-NULL pointer to a character pointer, and there is | ||
46 | * a match, then set *NAME to the value of the name slot in that | ||
47 | * bucket. | ||
48 | */ | ||
49 | int is_in_ino_dev_hashtable(const struct stat *statbuf, char **name) | ||
50 | { | ||
51 | ino_dev_hashtable_bucket_t *bucket; | ||
52 | |||
53 | bucket = ino_dev_hashtable[hash_inode(statbuf->st_ino)]; | ||
54 | while (bucket != NULL) { | ||
55 | if ((bucket->ino == statbuf->st_ino) && | ||
56 | (bucket->dev == statbuf->st_dev)) | ||
57 | { | ||
58 | if (name) *name = bucket->name; | ||
59 | return 1; | ||
60 | } | ||
61 | bucket = bucket->next; | ||
62 | } | ||
63 | return 0; | ||
64 | } | ||
65 | |||
66 | /* Add statbuf to statbuf hash table */ | ||
67 | void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name) | ||
68 | { | ||
69 | int i; | ||
70 | size_t s; | ||
71 | ino_dev_hashtable_bucket_t *bucket; | ||
72 | |||
73 | i = hash_inode(statbuf->st_ino); | ||
74 | s = name ? strlen(name) : 0; | ||
75 | bucket = xmalloc(sizeof(ino_dev_hashtable_bucket_t) + s); | ||
76 | bucket->ino = statbuf->st_ino; | ||
77 | bucket->dev = statbuf->st_dev; | ||
78 | if (name) | ||
79 | strcpy(bucket->name, name); | ||
80 | else | ||
81 | bucket->name[0] = '\0'; | ||
82 | bucket->next = ino_dev_hashtable[i]; | ||
83 | ino_dev_hashtable[i] = bucket; | ||
84 | } | ||
85 | |||
86 | #ifdef CONFIG_FEATURE_CLEAN_UP | ||
87 | /* Clear statbuf hash table */ | ||
88 | void reset_ino_dev_hashtable(void) | ||
89 | { | ||
90 | int i; | ||
91 | ino_dev_hashtable_bucket_t *bucket; | ||
92 | |||
93 | for (i = 0; i < HASH_SIZE; i++) { | ||
94 | while (ino_dev_hashtable[i] != NULL) { | ||
95 | bucket = ino_dev_hashtable[i]->next; | ||
96 | free(ino_dev_hashtable[i]); | ||
97 | ino_dev_hashtable[i] = bucket; | ||
98 | } | ||
99 | } | ||
100 | } | ||
101 | #endif | ||
102 | |||
103 | |||
104 | /* END CODE */ | ||
105 | /* | ||
106 | Local Variables: | ||
107 | c-file-style: "linux" | ||
108 | c-basic-offset: 4 | ||
109 | tab-width: 4 | ||
110 | End: | ||
111 | */ | ||