freebsd-src/contrib/mtree/only.c
Bryan Drewery 62a4b30239 mtree -O: Fix not descending on hash collisions
MFC after:	2 weeks
Obtained from:	NetBSD (nakayama)
2019-09-12 20:46:46 +00:00

154 lines
3.7 KiB
C

/* $NetBSD: only.c,v 1.3 2017/09/07 04:04:13 nakayama Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
__RCSID("$NetBSD: only.c,v 1.3 2017/09/07 04:04:13 nakayama Exp $");
#endif
#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <time.h>
#include <err.h>
#include <util.h>
#include "extern.h"
struct hentry {
char *str;
uint32_t hash;
struct hentry *next;
};
static struct hentry *table[1024];
static bool loaded;
static uint32_t
hash_str(const char *str)
{
const uint8_t *s = (const uint8_t *)str;
uint8_t c;
uint32_t hash = 0;
while ((c = *s++) != '\0')
hash = hash * 33 + c; /* "perl": k=33, r=r+r/32 */
return hash + (hash >> 5);
}
static bool
hash_find(const char *str, uint32_t *h)
{
struct hentry *e;
*h = hash_str(str) % __arraycount(table);
for (e = table[*h]; e; e = e->next)
if (e->hash == *h && strcmp(e->str, str) == 0)
return true;
return false;
}
static void
hash_insert(char *str, uint32_t h)
{
struct hentry *e;
char *x;
if ((e = malloc(sizeof(*e))) == NULL)
mtree_err("memory allocation error");
if ((x = strdup(str)) == NULL)
mtree_err("memory allocation error");
e->str = x;
e->hash = h;
e->next = table[h];
table[h] = e;
}
static void
fill(char *str)
{
uint32_t h;
char *ptr = strrchr(str, '/');
if (ptr == NULL)
return;
*ptr = '\0';
if (!hash_find(str, &h)) {
hash_insert(str, h);
fill(str);
}
*ptr = '/';
}
void
load_only(const char *fname)
{
FILE *fp;
char *line;
size_t len, lineno;
if ((fp = fopen(fname, "r")) == NULL)
err(1, "Cannot open `%s'", fname);
while ((line = fparseln(fp, &len, &lineno, NULL, FPARSELN_UNESCALL))) {
uint32_t h;
if (hash_find(line, &h))
err(1, "Duplicate entry %s", line);
hash_insert(line, h);
fill(line);
free(line);
}
fclose(fp);
loaded = true;
}
bool
find_only(const char *path)
{
uint32_t h;
if (!loaded)
return true;
return hash_find(path, &h);
}