xref: /onnv-gate/usr/src/lib/libast/common/cdt/dtrenew.c (revision 4887:feebf9260c2e)
1*4887Schin /***********************************************************************
2*4887Schin *                                                                      *
3*4887Schin *               This software is part of the ast package               *
4*4887Schin *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5*4887Schin *                      and is licensed under the                       *
6*4887Schin *                  Common Public License, Version 1.0                  *
7*4887Schin *                      by AT&T Knowledge Ventures                      *
8*4887Schin *                                                                      *
9*4887Schin *                A copy of the License is available at                 *
10*4887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
11*4887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*4887Schin *                                                                      *
13*4887Schin *              Information and Software Systems Research               *
14*4887Schin *                            AT&T Research                             *
15*4887Schin *                           Florham Park NJ                            *
16*4887Schin *                                                                      *
17*4887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
18*4887Schin *                  David Korn <dgk@research.att.com>                   *
19*4887Schin *                   Phong Vo <kpv@research.att.com>                    *
20*4887Schin *                                                                      *
21*4887Schin ***********************************************************************/
22*4887Schin #include	"dthdr.h"
23*4887Schin 
24*4887Schin 
25*4887Schin /*	Renew the object at the current finger.
26*4887Schin **
27*4887Schin **	Written by Kiem-Phong Vo (5/25/96)
28*4887Schin */
29*4887Schin 
30*4887Schin #if __STD_C
31*4887Schin Void_t* dtrenew(Dt_t* dt, reg Void_t* obj)
32*4887Schin #else
33*4887Schin Void_t* dtrenew(dt, obj)
34*4887Schin Dt_t*		dt;
35*4887Schin reg Void_t*	obj;
36*4887Schin #endif
37*4887Schin {
38*4887Schin 	reg Void_t*	key;
39*4887Schin 	reg Dtlink_t	*e, *t, **s;
40*4887Schin 	reg Dtdisc_t*	disc = dt->disc;
41*4887Schin 
42*4887Schin 	UNFLATTEN(dt);
43*4887Schin 
44*4887Schin 	if(!(e = dt->data->here) || _DTOBJ(e,disc->link) != obj)
45*4887Schin 		return NIL(Void_t*);
46*4887Schin 
47*4887Schin 	if(dt->data->type&(DT_STACK|DT_QUEUE|DT_LIST))
48*4887Schin 		return obj;
49*4887Schin 	else if(dt->data->type&(DT_OSET|DT_OBAG) )
50*4887Schin 	{	if(!e->right )	/* make left child the new root */
51*4887Schin 			dt->data->here = e->left;
52*4887Schin 		else		/* make right child the new root */
53*4887Schin 		{	dt->data->here = e->right;
54*4887Schin 
55*4887Schin 			/* merge left subtree to right subtree */
56*4887Schin 			if(e->left)
57*4887Schin 			{	for(t = e->right; t->left; t = t->left)
58*4887Schin 					;
59*4887Schin 				t->left = e->left;
60*4887Schin 			}
61*4887Schin 		}
62*4887Schin 	}
63*4887Schin 	else /*if(dt->data->type&(DT_SET|DT_BAG))*/
64*4887Schin 	{	s = dt->data->htab + HINDEX(dt->data->ntab,e->hash);
65*4887Schin 		if((t = *s) == e)
66*4887Schin 			*s = e->right;
67*4887Schin 		else
68*4887Schin 		{	for(; t->right != e; t = t->right)
69*4887Schin 				;
70*4887Schin 			t->right = e->right;
71*4887Schin 		}
72*4887Schin 		key = _DTKEY(obj,disc->key,disc->size);
73*4887Schin 		e->hash = _DTHSH(dt,key,disc,disc->size);
74*4887Schin 		dt->data->here = NIL(Dtlink_t*);
75*4887Schin 	}
76*4887Schin 
77*4887Schin 	dt->data->size -= 1;
78*4887Schin 	return (*dt->meth->searchf)(dt,(Void_t*)e,DT_RENEW) ? obj : NIL(Void_t*);
79*4887Schin }
80