/*      $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);
}