Home | History | Annotate | Line # | Download | only in mtree
only.c revision 1.1 
      1 /*	$NetBSD: only.c,v 1.1 2013/02/03 19:15:17 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of The NetBSD Foundation nor the names of its
     19  *    contributors may be used to endorse or promote products derived
     20  *    from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     32  * POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 #if HAVE_NBTOOL_CONFIG_H
     35 #include "nbtool_config.h"
     36 #endif
     37 
     38 #include <sys/cdefs.h>
     39 
     40 #if defined(__RCSID) && !defined(lint)
     41 __RCSID("$NetBSD: only.c,v 1.1 2013/02/03 19:15:17 christos Exp $");
     42 #endif
     43 
     44 #include <sys/param.h>
     45 
     46 #include <stdio.h>
     47 #include <stdlib.h>
     48 #include <string.h>
     49 #include <stdbool.h>
     50 #include <time.h>
     51 #include <err.h>
     52 #include <util.h>
     53 
     54 #include "extern.h"
     55 
     56 struct hentry {
     57 	char *str;
     58 	uint32_t hash;
     59 	struct hentry *next;
     60 };
     61 
     62 static struct hentry *table[1024];
     63 static bool loaded;
     64 
     65 static uint32_t
     66 hash_str(const char *str)
     67 {
     68 	const uint8_t *s = (const uint8_t *)str;
     69 	uint8_t c;
     70 	uint32_t hash = 0;
     71 	while ((c = *s++) != '\0')
     72 		hash = hash * 33 + c;           /* "perl": k=33, r=r+r/32 */
     73 	return hash + (hash >> 5);
     74 }
     75 
     76 static bool
     77 hash_find(const char *str, uint32_t *h)
     78 {
     79 	struct hentry *e;
     80 	*h = hash_str(str) % __arraycount(table);
     81 
     82 	for (e = table[*h]; e; e = e->next)
     83 		if (e->hash == *h && strcmp(e->str, str) == 0)
     84 			return true;
     85 	return false;
     86 }
     87 
     88 static void
     89 hash_insert(char *str)
     90 {
     91 	uint32_t h;
     92 	struct hentry *e;
     93 
     94 	if (hash_find(str, &h))
     95 		err(1, "Duplicate entry %s", str);
     96 
     97 	if ((e = malloc(sizeof(*e))) == NULL)
     98 		mtree_err("memory allocation error");
     99 
    100 	e->str = str;
    101 	e->hash = h;
    102 	e->next = table[h];
    103 	table[h] = e;
    104 }
    105 
    106 void
    107 load_only(const char *fname)
    108 {
    109 	FILE *fp;
    110 	char *line;
    111 	size_t len, lineno;
    112 
    113 	if ((fp = fopen(fname, "r")) == NULL)
    114 		err(1, "Cannot open `%s'", fname);
    115 
    116 	while ((line = fparseln(fp, &len, &lineno, NULL, FPARSELN_UNESCALL)))
    117 		hash_insert(line);
    118 
    119 	fclose(fp);
    120 	loaded = true;
    121 }
    122 
    123 bool
    124 find_only(const char *path)
    125 {
    126 	uint32_t h;
    127 
    128 	if (!loaded)
    129 		return true;
    130 	return hash_find(path, &h);
    131 }
    132