1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2011 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Eclipse Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.eclipse.org/org/documents/epl-v10.html *
11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
12 * *
13 * Information and Software Systems Research *
14 * AT&T Research *
15 * Florham Park NJ *
16 * *
17 * Glenn Fowler <gsf@research.att.com> *
18 * David Korn <dgk@research.att.com> *
19 * Phong Vo <kpv@research.att.com> *
20 * *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24 * Glenn Fowler
25 * AT&T Research
26 *
27 * hash table library
28 */
29
30 #include "hashlib.h"
31
32 /*
33 * change table size and rehash
34 * size must be a power of 2
35 */
36
37 void
hashsize(register Hash_table_t * tab,int size)38 hashsize(register Hash_table_t* tab, int size)
39 {
40 register Hash_bucket_t** old_s;
41 register Hash_bucket_t** new_s;
42 register Hash_bucket_t* old_b;
43 register Hash_bucket_t* new_b;
44 Hash_bucket_t** old_sx;
45 unsigned int index;
46 Hash_region_f region;
47 void* handle;
48
49 if (size > 0 && size != tab->size && !(size & (size - 1)))
50 {
51 if (region = tab->root->local->region)
52 {
53 handle = tab->root->local->handle;
54 new_s = (Hash_bucket_t**)(*region)(handle, NiL, sizeof(Hash_bucket_t*) * size, 0);
55 }
56 else new_s = newof(0, Hash_bucket_t*, size, 0);
57 if (!new_s) tab->flags |= HASH_FIXED;
58 else
59 {
60 old_sx = (old_s = tab->table) + tab->size;
61 tab->size = size;
62 while (old_s < old_sx)
63 {
64 old_b = *old_s++;
65 while (old_b)
66 {
67 new_b = old_b;
68 old_b = old_b->next;
69 index = new_b->hash;
70 HASHMOD(tab, index);
71 new_b->next = new_s[index];
72 new_s[index] = new_b;
73 }
74 }
75 if ((tab->flags & (HASH_RESIZE|HASH_STATIC)) != HASH_STATIC)
76 {
77 if (region) (*region)(handle, tab->table, 0, 0);
78 else free(tab->table);
79 }
80 tab->table = new_s;
81 tab->flags |= HASH_RESIZE;
82 }
83 }
84 }
85