1 /* hash.c -- hash table routines
2 Copyright (C) 1993, 94 Free Software Foundation, Inc.
3 Written by Steve Chamberlain <sac@cygnus.com>
5 This file was lifted from BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
25 #include "gansidecl.h"
28 /* Obstack allocation and deallocation routines. */
29 #define obstack_chunk_alloc xmalloc
30 #define obstack_chunk_free free
32 extern char * xmalloc ();
34 /* The default number of entries to use when creating a hash table. */
35 #define DEFAULT_SIZE (1009)
37 /* Create a new hash table, given a number of entries. */
40 hash_table_init_n (table, newfunc, size)
41 struct hash_table *table;
42 struct hash_entry *(*newfunc) PARAMS ((struct hash_entry *,
49 alloc = size * sizeof (struct hash_entry *);
50 if (!obstack_begin (&table->memory, alloc))
55 table->table = ((struct hash_entry **)
56 obstack_alloc (&table->memory, alloc));
62 memset ((PTR) table->table, 0, alloc);
64 table->newfunc = newfunc;
68 /* Create a new hash table with the default number of entries. */
71 hash_table_init (table, newfunc)
72 struct hash_table *table;
73 struct hash_entry *(*newfunc) PARAMS ((struct hash_entry *,
77 return hash_table_init_n (table, newfunc, DEFAULT_SIZE);
80 /* Free a hash table. */
83 hash_table_free (table)
84 struct hash_table *table;
86 obstack_free (&table->memory, (PTR) NULL);
89 /* Look up a string in a hash table. */
92 hash_lookup (table, string, create, copy)
93 struct hash_table *table;
98 register const unsigned char *s;
99 register unsigned long hash;
100 register unsigned int c;
101 struct hash_entry *hashp;
107 s = (const unsigned char *) string;
108 while ((c = *s++) != '\0')
110 hash += c + (c << 17);
114 hash += len + (len << 17);
117 index = hash % table->size;
118 for (hashp = table->table[index];
119 hashp != (struct hash_entry *) NULL;
122 if (hashp->hash == hash
123 && strcmp (hashp->string, string) == 0)
128 return (struct hash_entry *) NULL;
130 hashp = (*table->newfunc) ((struct hash_entry *) NULL, table, string);
131 if (hashp == (struct hash_entry *) NULL)
132 return (struct hash_entry *) NULL;
137 new = (char *) obstack_alloc (&table->memory, len + 1);
141 return (struct hash_entry *) NULL;
143 strcpy (new, string);
146 hashp->string = string;
148 hashp->next = table->table[index];
149 table->table[index] = hashp;
154 /* Base method for creating a new hash table entry. */
158 hash_newfunc (entry, table, string)
159 struct hash_entry *entry;
160 struct hash_table *table;
163 if (entry == (struct hash_entry *) NULL)
164 entry = ((struct hash_entry *)
165 hash_allocate (table, sizeof (struct hash_entry)));
169 /* Allocate space in a hash table. */
172 hash_allocate (table, size)
173 struct hash_table *table;
178 ret = obstack_alloc (&table->memory, size);
179 if (ret == NULL && size != 0)
184 /* Traverse a hash table. */
187 hash_traverse (table, func, info)
188 struct hash_table *table;
189 boolean (*func) PARAMS ((struct hash_entry *, PTR));
194 for (i = 0; i < table->size; i++)
196 struct hash_entry *p;
198 for (p = table->table[i]; p != NULL; p = p->next)
200 if (! (*func) (p, info))