hush/libbb/inode_hash.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) many different people. If you wrote this, please
* acknowledge your work.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include <stdio.h>
#include <stdlib.h>
2001-03-23 17:02:05 +00:00
#include <string.h>
#include "libbb.h"
#define HASH_SIZE 311 /* Should be prime */
#define hash_inode(i) ((i) % HASH_SIZE)
typedef struct ino_dev_hash_bucket_struct {
struct ino_dev_hash_bucket_struct *next;
ino_t ino;
dev_t dev;
char name[1];
} ino_dev_hashtable_bucket_t;
static ino_dev_hashtable_bucket_t *ino_dev_hashtable[HASH_SIZE];
/*
* Return 1 if statbuf->st_ino && statbuf->st_dev are recorded in
* `ino_dev_hashtable', else return 0
*
* If NAME is a non-NULL pointer to a character pointer, and there is
* a match, then set *NAME to the value of the name slot in that
* bucket.
*/
int is_in_ino_dev_hashtable(const struct stat *statbuf, char **name)
{
ino_dev_hashtable_bucket_t *bucket;
bucket = ino_dev_hashtable[hash_inode(statbuf->st_ino)];
while (bucket != NULL) {
if ((bucket->ino == statbuf->st_ino) &&
(bucket->dev == statbuf->st_dev))
{
if (name) *name = bucket->name;
return 1;
}
bucket = bucket->next;
}
return 0;
}
/* Add statbuf to statbuf hash table */
void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name)
{
int i;
size_t s;
ino_dev_hashtable_bucket_t *bucket;
i = hash_inode(statbuf->st_ino);
s = name ? strlen(name) : 0;
bucket = xmalloc(sizeof(ino_dev_hashtable_bucket_t) + s);
bucket->ino = statbuf->st_ino;
bucket->dev = statbuf->st_dev;
if (name)
strcpy(bucket->name, name);
else
bucket->name[0] = '\0';
bucket->next = ino_dev_hashtable[i];
ino_dev_hashtable[i] = bucket;
}
/* Clear statbuf hash table */
void reset_ino_dev_hashtable(void)
{
int i;
ino_dev_hashtable_bucket_t *bucket;
for (i = 0; i < HASH_SIZE; i++) {
while (ino_dev_hashtable[i] != NULL) {
bucket = ino_dev_hashtable[i]->next;
free(ino_dev_hashtable[i]);
ino_dev_hashtable[i] = bucket;
}
}
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/