1 /* hash.c -- hash table routines
2 Copyright (C) 1993, 1994, 1998, 2001 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, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
28 /* Obstack allocation and deallocation routines. */
29 #define obstack_chunk_alloc xmalloc
30 #define obstack_chunk_free free
32 /* The default number of entries to use when creating a hash table. */
33 #define DEFAULT_SIZE 1009
35 /* Create a new hash table, given a number of entries. */
38 hash_table_init_n (table, newfunc, hash, comp, size)
39 struct hash_table *table;
40 struct hash_entry *(*newfunc) PARAMS ((struct hash_entry *,
43 unsigned long (*hash) PARAMS ((hash_table_key));
44 bool (*comp) PARAMS ((hash_table_key, hash_table_key));
49 alloc = size * sizeof (struct hash_entry *);
50 obstack_begin (&table->memory, alloc);
51 table->table = ((struct hash_entry **)
52 obstack_alloc (&table->memory, alloc));
53 memset ((PTR) table->table, 0, alloc);
55 table->newfunc = newfunc;
60 /* Create a new hash table with the default number of entries. */
63 hash_table_init (table, newfunc, hash, comp)
64 struct hash_table *table;
65 struct hash_entry *(*newfunc) PARAMS ((struct hash_entry *,
68 unsigned long (*hash) PARAMS ((hash_table_key));
69 bool (*comp) PARAMS ((hash_table_key, hash_table_key));
71 hash_table_init_n (table, newfunc, hash, comp, DEFAULT_SIZE);
74 /* Free a hash table. */
77 hash_table_free (table)
78 struct hash_table *table;
80 obstack_free (&table->memory, (PTR) NULL);
83 /* Look up KEY in TABLE. If CREATE is non-NULL a new entry is
84 created if one does not previously exist. */
87 hash_lookup (table, key, create, copy)
88 struct hash_table *table;
91 hash_table_key (*copy) PARAMS ((struct obstack* memory,
94 register unsigned long hash;
95 struct hash_entry *hashp;
98 hash = (*table->hash)(key);
100 index = hash % table->size;
101 for (hashp = table->table[index]; hashp != 0; hashp = hashp->next)
102 if (hashp->hash == hash
103 && (*table->comp)(hashp->key, key))
109 hashp = (*table->newfunc) ((struct hash_entry *) NULL, table, key);
114 key = (*copy) (&table->memory, key);
118 hashp->next = table->table[index];
119 table->table[index] = hashp;
124 /* Base method for creating a new hash table entry. */
127 hash_newfunc (entry, table, p)
128 struct hash_entry *entry;
129 struct hash_table *table;
130 hash_table_key p ATTRIBUTE_UNUSED;
133 entry = ((struct hash_entry *)
134 hash_allocate (table, sizeof (struct hash_entry)));
138 /* Allocate space in a hash table. */
141 hash_allocate (table, size)
142 struct hash_table *table;
145 return obstack_alloc (&table->memory, size);
148 /* Traverse a hash table. */
151 hash_traverse (table, func, info)
152 struct hash_table *table;
153 bool (*func) PARAMS ((struct hash_entry *, hash_table_key));
157 struct hash_entry *p;
159 for (i = 0; i < table->size; i++)
160 for (p = table->table[i]; p != 0; p = p->next)
161 if (! (*func) (p, info))
165 /* Hash a string. Return a hash-code for the string. */
171 const unsigned char *s;
176 s = (const unsigned char *) k;
180 while ((c = *s++) != '\0')
182 hash += c + (c << 17);
187 hash += len + (len << 17);
193 /* Compare two strings. Return non-zero iff the two strings are
197 string_compare (k1, k2)
201 return (strcmp ((char*) k1, (char*) k2) == 0);
204 /* Copy K to OBSTACK. */
207 string_copy (memory, k)
208 struct obstack *memory;
212 char *string = (char *) k;
214 new = (char *) obstack_alloc (memory, strlen (string) + 1);
215 strcpy (new, string);