hashview.c revision 3e14f97f673e8a630f076077de35afdd43dc1587
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2010 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 Bell Laboratories
*
* hash table library
*/
#include "hashlib.h"
/*
* push/pop/query hash table scope
*
* bot==0 pop top scope
* bot==top query
* bot!=0 push top on bot
*
* scope table pointer returned
*/
Hash_table_t*
hashview(Hash_table_t* top, Hash_table_t* bot)
{
register Hash_bucket_t* b;
register Hash_bucket_t* p;
register Hash_bucket_t** sp;
register Hash_bucket_t** sx;
if (!top || top->frozen)
bot = 0;
else if (top == bot)
bot = top->scope;
else if (bot)
{
if (top->scope)
bot = 0;
else
{
sx = &top->table[top->size];
sp = &top->table[0];
while (sp < sx)
for (b = *sp++; b; b = b->next)
if (p = (Hash_bucket_t*)hashlook(bot, b->name, HASH_LOOKUP, NiL))
{
b->name = (p->hash & HASH_HIDES) ? p->name : (char*)b;
b->hash |= HASH_HIDES;
}
top->scope = bot;
bot->frozen++;
}
}
else if (bot = top->scope)
{
sx = &top->table[top->size];
sp = &top->table[0];
while (sp < sx)
for (b = *sp++; b; b = b->next)
if (b->hash & HASH_HIDES)
{
b->hash &= ~HASH_HIDES;
b->name = ((Hash_bucket_t*)b->name)->name;
}
top->scope = 0;
bot->frozen--;
}
return(bot);
}