1da2e3ebdSchin /***********************************************************************
2da2e3ebdSchin *                                                                      *
3da2e3ebdSchin *               This software is part of the ast package               *
4*b30d1939SAndy Fiddaman *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5da2e3ebdSchin *                      and is licensed under the                       *
6*b30d1939SAndy Fiddaman *                 Eclipse Public License, Version 1.0                  *
77c2fbfb3SApril Chin *                    by AT&T Intellectual Property                     *
8da2e3ebdSchin *                                                                      *
9da2e3ebdSchin *                A copy of the License is available at                 *
10*b30d1939SAndy Fiddaman *          http://www.eclipse.org/org/documents/epl-v10.html           *
11*b30d1939SAndy Fiddaman *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12da2e3ebdSchin *                                                                      *
13da2e3ebdSchin *              Information and Software Systems Research               *
14da2e3ebdSchin *                            AT&T Research                             *
15da2e3ebdSchin *                           Florham Park NJ                            *
16da2e3ebdSchin *                                                                      *
17da2e3ebdSchin *                 Glenn Fowler <gsf@research.att.com>                  *
18da2e3ebdSchin *                  David Korn <dgk@research.att.com>                   *
19da2e3ebdSchin *                   Phong Vo <kpv@research.att.com>                    *
20da2e3ebdSchin *                                                                      *
21da2e3ebdSchin ***********************************************************************/
22da2e3ebdSchin #pragma prototyped
23da2e3ebdSchin /*
24da2e3ebdSchin  * Glenn Fowler
25da2e3ebdSchin  * AT&T Bell Laboratories
26da2e3ebdSchin  *
27da2e3ebdSchin  * hash table library
28da2e3ebdSchin  */
29da2e3ebdSchin 
30da2e3ebdSchin #include "hashlib.h"
31da2e3ebdSchin 
32da2e3ebdSchin /*
33da2e3ebdSchin  * push/pop/query hash table scope
34da2e3ebdSchin  *
35da2e3ebdSchin  *	bot==0		pop top scope
36da2e3ebdSchin  *	bot==top	query
37da2e3ebdSchin  *	bot!=0		push top on bot
38da2e3ebdSchin  *
39da2e3ebdSchin  * scope table pointer returned
40da2e3ebdSchin  */
41da2e3ebdSchin 
42da2e3ebdSchin Hash_table_t*
hashview(Hash_table_t * top,Hash_table_t * bot)43da2e3ebdSchin hashview(Hash_table_t* top, Hash_table_t* bot)
44da2e3ebdSchin {
45da2e3ebdSchin 	register Hash_bucket_t*		b;
46da2e3ebdSchin 	register Hash_bucket_t*		p;
47da2e3ebdSchin 	register Hash_bucket_t**	sp;
48da2e3ebdSchin 	register Hash_bucket_t**	sx;
49da2e3ebdSchin 
50da2e3ebdSchin 	if (!top || top->frozen)
51da2e3ebdSchin 		bot = 0;
52da2e3ebdSchin 	else if (top == bot)
53da2e3ebdSchin 		bot = top->scope;
54da2e3ebdSchin 	else if (bot)
55da2e3ebdSchin 	{
56da2e3ebdSchin 		if (top->scope)
57da2e3ebdSchin 			bot = 0;
58da2e3ebdSchin 		else
59da2e3ebdSchin 		{
60da2e3ebdSchin 			sx = &top->table[top->size];
61da2e3ebdSchin 			sp = &top->table[0];
62da2e3ebdSchin 			while (sp < sx)
63da2e3ebdSchin 				for (b = *sp++; b; b = b->next)
64da2e3ebdSchin 					if (p = (Hash_bucket_t*)hashlook(bot, b->name, HASH_LOOKUP, NiL))
65da2e3ebdSchin 					{
66da2e3ebdSchin 						b->name = (p->hash & HASH_HIDES) ? p->name : (char*)b;
67da2e3ebdSchin 						b->hash |= HASH_HIDES;
68da2e3ebdSchin 					}
69da2e3ebdSchin 			top->scope = bot;
70da2e3ebdSchin 			bot->frozen++;
71da2e3ebdSchin 		}
72da2e3ebdSchin 	}
73da2e3ebdSchin 	else if (bot = top->scope)
74da2e3ebdSchin 	{
75da2e3ebdSchin 		sx = &top->table[top->size];
76da2e3ebdSchin 		sp = &top->table[0];
77da2e3ebdSchin 		while (sp < sx)
78da2e3ebdSchin 			for (b = *sp++; b; b = b->next)
79da2e3ebdSchin 				if (b->hash & HASH_HIDES)
80da2e3ebdSchin 				{
81da2e3ebdSchin 					b->hash &= ~HASH_HIDES;
82da2e3ebdSchin 					b->name = ((Hash_bucket_t*)b->name)->name;
83da2e3ebdSchin 				}
84da2e3ebdSchin 		top->scope = 0;
85da2e3ebdSchin 		bot->frozen--;
86da2e3ebdSchin 	}
87da2e3ebdSchin 	return(bot);
88da2e3ebdSchin }
89