1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                      by AT&T Knowledge Ventures                      *
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 #include	"dthdr.h"
23 
24 /*	Change discipline.
25 **	dt :	dictionary
26 **	disc :	discipline
27 **
28 **	Written by Kiem-Phong Vo (5/26/96)
29 */
30 
31 #if __STD_C
32 static Void_t* dtmemory(Dt_t* dt,Void_t* addr,size_t size,Dtdisc_t* disc)
33 #else
34 static Void_t* dtmemory(dt, addr, size, disc)
35 Dt_t* 		dt;	/* dictionary			*/
36 Void_t* 	addr;	/* address to be manipulate	*/
37 size_t		size;	/* size to obtain		*/
38 Dtdisc_t* 	disc;	/* discipline			*/
39 #endif
40 {
41 	if(addr)
42 	{	if(size == 0)
43 		{	free(addr);
44 			return NIL(Void_t*);
45 		}
46 		else	return realloc(addr,size);
47 	}
48 	else	return size > 0 ? malloc(size) : NIL(Void_t*);
49 }
50 
51 #if __STD_C
52 Dtdisc_t* dtdisc(Dt_t* dt, Dtdisc_t* disc, int type)
53 #else
54 Dtdisc_t* dtdisc(dt,disc,type)
55 Dt_t*		dt;
56 Dtdisc_t*	disc;
57 int		type;
58 #endif
59 {
60 	reg Dtsearch_f	searchf;
61 	reg Dtlink_t	*r, *t;
62 	reg char*	k;
63 	reg Dtdisc_t*	old;
64 
65 	if(!(old = dt->disc) )	/* initialization call from dtopen() */
66 	{	dt->disc = disc;
67 		if(!(dt->memoryf = disc->memoryf) )
68 			dt->memoryf = dtmemory;
69 		return disc;
70 	}
71 
72 	if(!disc)	/* only want to know current discipline */
73 		return old;
74 
75 	searchf = dt->meth->searchf;
76 
77 	UNFLATTEN(dt);
78 
79 	if(old->eventf && (*old->eventf)(dt,DT_DISC,(Void_t*)disc,old) < 0)
80 		return NIL(Dtdisc_t*);
81 
82 	dt->disc = disc;
83 	if(!(dt->memoryf = disc->memoryf) )
84 		dt->memoryf = dtmemory;
85 
86 	if(dt->data->type&(DT_STACK|DT_QUEUE|DT_LIST))
87 		goto done;
88 	else if(dt->data->type&DT_BAG)
89 	{	if(type&DT_SAMEHASH)
90 			goto done;
91 		else	goto dt_renew;
92 	}
93 	else if(dt->data->type&(DT_SET|DT_BAG))
94 	{	if((type&DT_SAMEHASH) && (type&DT_SAMECMP))
95 			goto done;
96 		else	goto dt_renew;
97 	}
98 	else /*if(dt->data->type&(DT_OSET|DT_OBAG))*/
99 	{	if(type&DT_SAMECMP)
100 			goto done;
101 	dt_renew:
102 		r = dtflatten(dt);
103 		dt->data->type &= ~DT_FLATTEN;
104 		dt->data->here = NIL(Dtlink_t*);
105 		dt->data->size = 0;
106 
107 		if(dt->data->type&(DT_SET|DT_BAG))
108 		{	reg Dtlink_t	**s, **ends;
109 			ends = (s = dt->data->htab) + dt->data->ntab;
110 			while(s < ends)
111 				*s++ = NIL(Dtlink_t*);
112 		}
113 
114 		/* reinsert them */
115 		while(r)
116 		{	t = r->right;
117 			if(!(type&DT_SAMEHASH))	/* new hash value */
118 			{	k = (char*)_DTOBJ(r,disc->link);
119 				k = _DTKEY((Void_t*)k,disc->key,disc->size);
120 				r->hash = _DTHSH(dt,k,disc,disc->size);
121 			}
122 			(void)(*searchf)(dt,(Void_t*)r,DT_RENEW);
123 			r = t;
124 		}
125 	}
126 
127 done:
128 	return old;
129 }
130