xref: /titanic_41/usr/src/lib/libast/common/hash/hashfree.c (revision e802abbda8c322f24d47835734f4a793ef15ddc8)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2008 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
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  * free (remove) a hash table
34  * can be called for partially constructed tables
35  * scope covered table pointer is returned
36  * root info freed when last reference freed
37  */
38 
39 Hash_table_t*
40 hashfree(register Hash_table_t* tab)
41 {
42 	register Hash_bucket_t**	sp;
43 	register Hash_bucket_t*		b;
44 	register Hash_bucket_t*		p;
45 	Hash_bucket_t**			sx;
46 	Hash_root_t*			rp;
47 	Hash_table_t*			tp;
48 	Hash_free_f			freevalue;
49 	Hash_free_f			freebucket;
50 	Hash_region_f			region;
51 	void*				handle;
52 
53 	if (!tab) return(0);
54 	if (tab->table)
55 	{
56 		freebucket = 0;
57 		freevalue = 0;
58 		if (tab->root->local->free)
59 		{
60 			if (tab->root->flags & HASH_BUCKET) freebucket = tab->root->local->free;
61 			else freevalue = tab->root->local->free;
62 		}
63 		if (region = tab->root->local->region)
64 			handle = tab->root->local->handle;
65 		sx = &tab->table[tab->size];
66 		sp = &tab->table[0];
67 		while (sp < sx)
68 		{
69 			b = *sp++;
70 			while (b)
71 			{
72 				p = b;
73 				b = b->next;
74 				if (freebucket) (*freebucket)((char*)p);
75 				else if (freevalue && p->value) (*freevalue)(p->value);
76 				if (p->hash & HASH_FREENAME)
77 				{
78 					p->hash &= ~HASH_FREENAME;
79 					if (region) (*region)(handle, p->name, 0, 0);
80 					else free(p->name);
81 				}
82 				if (!(p->hash & HASH_KEEP))
83 				{
84 					if (region) (*region)(handle, p, 0, 0);
85 					else free(p);
86 				}
87 				else if (p->hash & HASH_HIDES)
88 				{
89 					p->hash &= ~HASH_HIDES;
90 					p->name = ((Hash_bucket_t*)p->name)->name;
91 				}
92 			}
93 		}
94 		if ((tab->flags & (HASH_RESIZE|HASH_STATIC)) != HASH_STATIC)
95 		{
96 			if (region) (*region)(handle, tab->table, 0, 0);
97 			else free(tab->table);
98 		}
99 	}
100 	else region = 0;
101 	if (tab->root)
102 	{
103 		if (!region)
104 		{
105 			/*
106 			 * remove from the table lists
107 			 */
108 
109 			if ((tp = tab->root->references) != tab)
110 			{
111 				for (; tp; tp = tp->next)
112 					if (tp->next == tab)
113 					{
114 						tp->next = tab->next;
115 						break;
116 					}
117 			}
118 			else if (!(tab->root->references = tp->next))
119 			{
120 				if ((rp = hash_info.list) != tab->root)
121 				{
122 					for (; rp; rp = rp->next)
123 						if (rp->next == tab->root)
124 						{
125 							rp->next = tab->root->next;
126 							break;
127 						}
128 				}
129 				else hash_info.list = rp->next;
130 			}
131 		}
132 		if (!(tab->root->references))
133 		{
134 			if (tab->root->local)
135 				free(tab->root->local);
136 			if (region) (*region)(handle, tab->root, 0, 0);
137 			else free(tab->root);
138 		}
139 	}
140 	if (tp = tab->scope) tp->frozen--;
141 	if (region) (*region)(handle, tab, 0, 0);
142 	else free(tab);
143 	return(tp);
144 }
145