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 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9 */
10
11#include "libbb.h"
12
13typedef struct ino_dev_hash_bucket_struct {
14	struct ino_dev_hash_bucket_struct *next;
15	ino_t ino;
16	dev_t dev;
17	char name[1];
18} ino_dev_hashtable_bucket_t;
19
20#define HASH_SIZE	311		/* Should be prime */
21#define hash_inode(i)	((i) % HASH_SIZE)
22
23/* array of [HASH_SIZE] elements */
24static ino_dev_hashtable_bucket_t **ino_dev_hashtable;
25
26/*
27 * Return name if statbuf->st_ino && statbuf->st_dev are recorded in
28 * ino_dev_hashtable, else return NULL
29 */
30char *is_in_ino_dev_hashtable(const struct stat *statbuf)
31{
32	ino_dev_hashtable_bucket_t *bucket;
33
34	if (!ino_dev_hashtable)
35		return NULL;
36
37	bucket = ino_dev_hashtable[hash_inode(statbuf->st_ino)];
38	while (bucket != NULL) {
39		if ((bucket->ino == statbuf->st_ino)
40		 && (bucket->dev == statbuf->st_dev)
41		) {
42			return bucket->name;
43		}
44		bucket = bucket->next;
45	}
46	return NULL;
47}
48
49/* Add statbuf to statbuf hash table */
50void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name)
51{
52	int i;
53	ino_dev_hashtable_bucket_t *bucket;
54
55	i = hash_inode(statbuf->st_ino);
56	if (!name)
57		name = "";
58	bucket = xmalloc(sizeof(ino_dev_hashtable_bucket_t) + strlen(name));
59	bucket->ino = statbuf->st_ino;
60	bucket->dev = statbuf->st_dev;
61	strcpy(bucket->name, name);
62
63	if (!ino_dev_hashtable)
64		ino_dev_hashtable = xzalloc(HASH_SIZE * sizeof(*ino_dev_hashtable));
65
66	bucket->next = ino_dev_hashtable[i];
67	ino_dev_hashtable[i] = bucket;
68}
69
70#if ENABLE_FEATURE_CLEAN_UP
71/* Clear statbuf hash table */
72void reset_ino_dev_hashtable(void)
73{
74	int i;
75	ino_dev_hashtable_bucket_t *bucket;
76
77	for (i = 0; ino_dev_hashtable && i < HASH_SIZE; i++) {
78		while (ino_dev_hashtable[i] != NULL) {
79			bucket = ino_dev_hashtable[i]->next;
80			free(ino_dev_hashtable[i]);
81			ino_dev_hashtable[i] = bucket;
82		}
83	}
84	free(ino_dev_hashtable);
85	ino_dev_hashtable = NULL;
86}
87#else
88void reset_ino_dev_hashtable(void);
89#endif
90