usr/src/cmd/sgs/crle/common/hash.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2000 by Sun Microsystems, Inc.
  24  * All rights reserved.
  25  */
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include        <stdio.h>
  29 #include        <stdlib.h>
  30 #include        <string.h>
  31 #include        <libelf.h>
  32 #include        "_crle.h"
  33
  34 Hash_tbl *
  35 make_hash(int size, Hash_type type, ulong_t ident)
  36 {
  37         Hash_tbl *      tbl;
  38
  39         if ((tbl = malloc(sizeof (Hash_tbl))) == 0)
  40                 return (0);
  41
  42         if ((tbl->t_entry = calloc((unsigned)(sizeof (Hash_ent *)), size)) == 0)
  43                 return (0);
  44
  45         tbl->t_ident = ident;
  46         tbl->t_type = type;
  47         tbl->t_size = size;
  48
  49         return (tbl);
  50 }
  51
  52
  53 Hash_ent *
  54 get_hash(Hash_tbl * tbl, Addr key, Half id, int mode)
  55 {
  56         int             bucket;
  57         Hash_ent *      ent;
  58         Word            hashval;
  59
  60         if (tbl->t_type == HASH_STR)
  61                 hashval = elf_hash((const char *)key);
  62         else
  63                 hashval = key;
  64
  65         bucket = hashval % tbl->t_size;
  66
  67         if (mode & HASH_FND_ENT) {
  68                 for (ent = tbl->t_entry[bucket]; ent != NULL;
  69                     ent = ent->e_next) {
  70                         if (tbl->t_type == HASH_STR) {
  71                                 if ((strcmp((const char *)ent->e_key,
  72                                     (const char *)key) == 0) && ((id == 0) ||
  73                                     (id == ent->e_id)))
  74                                         return (ent);
  75                         } else {
  76                                 if (ent->e_key == key)
  77                                         return (ent);
  78                         }
  79                 }
  80         }
  81         if (!(mode & HASH_ADD_ENT))
  82                 return (0);
  83
  84         /*
  85          * Key not found in this hash table ... insert new entry into bucket.
  86          */
  87         if ((ent = calloc(sizeof (Hash_ent), 1)) == 0)
  88                 return (0);
  89
  90         ent->e_key = key;
  91         ent->e_hash = hashval;
  92
  93         /*
  94          * Hook into bucket chain
  95          */
  96         ent->e_next = tbl->t_entry[bucket];
  97         tbl->t_entry[bucket] = ent;
  98
  99         return (ent);
 100 }