hashsize.c revision 7c2fbfb345896881c631598ee3852ce9ce33fb07
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2008 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* hash table library
*/
#include "hashlib.h"
/*
* change table size and rehash
* size must be a power of 2
*/
void
hashsize(register Hash_table_t* tab, int size)
{
register Hash_bucket_t** old_s;
register Hash_bucket_t** new_s;
register Hash_bucket_t* old_b;
register Hash_bucket_t* new_b;
Hash_bucket_t** old_sx;
unsigned int index;
Hash_region_f region;
void* handle;
if (size > 0 && size != tab->size && !(size & (size - 1)))
{
if (region = tab->root->local->region)
{
handle = tab->root->local->handle;
new_s = (Hash_bucket_t**)(*region)(handle, NiL, sizeof(Hash_bucket_t*) * size, 0);
}
else new_s = newof(0, Hash_bucket_t*, size, 0);
if (!new_s) tab->flags |= HASH_FIXED;
else
{
old_sx = (old_s = tab->table) + tab->size;
tab->size = size;
while (old_s < old_sx)
{
old_b = *old_s++;
while (old_b)
{
new_b = old_b;
old_b = old_b->next;
index = new_b->hash;
HASHMOD(tab, index);
new_b->next = new_s[index];
new_s[index] = new_b;
}
}
if ((tab->flags & (HASH_RESIZE|HASH_STATIC)) != HASH_STATIC)
{
if (region) (*region)(handle, tab->table, 0, 0);
else free(tab->table);
}
tab->table = new_s;
tab->flags |= HASH_RESIZE;
}
}
}