1N/A/***********************************************************************
1N/A* *
1N/A* This software is part of the ast package *
1N/A* Copyright (c) 1985-2011 AT&T Intellectual Property *
1N/A* and is licensed under the *
1N/A* Common Public License, Version 1.0 *
1N/A* by AT&T Intellectual Property *
1N/A* *
1N/A* A copy of the License is available at *
1N/A* http://www.opensource.org/licenses/cpl1.0.txt *
1N/A* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
1N/A* *
1N/A* Information and Software Systems Research *
1N/A* AT&T Research *
1N/A* Florham Park NJ *
1N/A* *
1N/A* Glenn Fowler <gsf@research.att.com> *
1N/A* David Korn <dgk@research.att.com> *
1N/A* Phong Vo <kpv@research.att.com> *
1N/A* *
1N/A***********************************************************************/
1N/A#include "dthdr.h"
1N/A
1N/A/* Set a view path from dict to view.
1N/A**
1N/A** Written by Kiem-Phong Vo (5/25/96)
1N/A*/
1N/A
1N/A
1N/A#if __STD_C
1N/Astatic Void_t* dtvsearch(Dt_t* dt, reg Void_t* obj, reg int type)
1N/A#else
1N/Astatic Void_t* dtvsearch(dt,obj,type)
1N/ADt_t* dt;
1N/Areg Void_t* obj;
1N/Areg int type;
1N/A#endif
1N/A{
1N/A Dt_t *d, *p;
1N/A Void_t *o, *n, *ok, *nk;
1N/A int cmp, lk, sz, ky;
1N/A Dtcompar_f cmpf;
1N/A
1N/A /* these operations only happen at the top level */
1N/A if(type&(DT_INSERT|DT_DELETE|DT_CLEAR|DT_RENEW))
1N/A return (*(dt->meth->searchf))(dt,obj,type);
1N/A
1N/A if((type&(DT_MATCH|DT_SEARCH)) || /* order sets first/last done below */
1N/A ((type&(DT_FIRST|DT_LAST)) && !(dt->meth->type&(DT_OBAG|DT_OSET)) ) )
1N/A { for(d = dt; d; d = d->view)
1N/A if((o = (*(d->meth->searchf))(d,obj,type)) )
1N/A break;
1N/A dt->walk = d;
1N/A return o;
1N/A }
1N/A
1N/A if(dt->meth->type & (DT_OBAG|DT_OSET) )
1N/A { if(!(type & (DT_FIRST|DT_LAST|DT_NEXT|DT_PREV)) )
1N/A return NIL(Void_t*);
1N/A
1N/A n = nk = NIL(Void_t*); p = NIL(Dt_t*);
1N/A for(d = dt; d; d = d->view)
1N/A { if(!(o = (*d->meth->searchf)(d, obj, type)) )
1N/A continue;
1N/A _DTDSC(d->disc,ky,sz,lk,cmpf);
1N/A ok = _DTKEY(o,ky,sz);
1N/A
1N/A if(n) /* get the right one among all dictionaries */
1N/A { cmp = _DTCMP(d,ok,nk,d->disc,cmpf,sz);
1N/A if(((type & (DT_NEXT|DT_FIRST)) && cmp < 0) ||
1N/A ((type & (DT_PREV|DT_LAST)) && cmp > 0) )
1N/A goto a_dj;
1N/A }
1N/A else /* looks good for now */
1N/A { a_dj: p = d;
1N/A n = o;
1N/A nk = ok;
1N/A }
1N/A }
1N/A
1N/A dt->walk = p;
1N/A return n;
1N/A }
1N/A
1N/A /* non-ordered methods */
1N/A if(!(type & (DT_NEXT|DT_PREV)) )
1N/A return NIL(Void_t*);
1N/A
1N/A if(!dt->walk || obj != _DTOBJ(dt->walk->data->here, dt->walk->disc->link) )
1N/A { for(d = dt; d; d = d->view)
1N/A if((o = (*(d->meth->searchf))(d, obj, DT_SEARCH)) )
1N/A break;
1N/A dt->walk = d;
1N/A if(!(obj = o) )
1N/A return NIL(Void_t*);
1N/A }
1N/A
1N/A for(d = dt->walk, obj = (*d->meth->searchf)(d, obj, type);; )
1N/A { while(obj) /* keep moving until finding an uncovered object */
1N/A { for(p = dt; ; p = p->view)
1N/A { if(p == d) /* adjacent object is uncovered */
1N/A return obj;
1N/A if((*(p->meth->searchf))(p, obj, DT_SEARCH) )
1N/A break;
1N/A }
1N/A obj = (*d->meth->searchf)(d, obj, type);
1N/A }
1N/A
1N/A if(!(d = dt->walk = d->view) ) /* move on to next dictionary */
1N/A return NIL(Void_t*);
1N/A else if(type&DT_NEXT)
1N/A obj = (*(d->meth->searchf))(d,NIL(Void_t*),DT_FIRST);
1N/A else obj = (*(d->meth->searchf))(d,NIL(Void_t*),DT_LAST);
1N/A }
1N/A}
1N/A
1N/A#if __STD_C
1N/ADt_t* dtview(reg Dt_t* dt, reg Dt_t* view)
1N/A#else
1N/ADt_t* dtview(dt,view)
1N/Areg Dt_t* dt;
1N/Areg Dt_t* view;
1N/A#endif
1N/A{
1N/A reg Dt_t* d;
1N/A
1N/A UNFLATTEN(dt);
1N/A if(view)
1N/A { UNFLATTEN(view);
1N/A if(view->meth != dt->meth) /* must use the same method */
1N/A return NIL(Dt_t*);
1N/A }
1N/A
1N/A /* make sure there won't be a cycle */
1N/A for(d = view; d; d = d->view)
1N/A if(d == dt)
1N/A return NIL(Dt_t*);
1N/A
1N/A /* no more viewing lower dictionary */
1N/A if((d = dt->view) )
1N/A d->nview -= 1;
1N/A dt->view = dt->walk = NIL(Dt_t*);
1N/A
1N/A if(!view)
1N/A { dt->searchf = dt->meth->searchf;
1N/A return d;
1N/A }
1N/A
1N/A /* ok */
1N/A dt->view = view;
1N/A dt->searchf = dtvsearch;
1N/A view->nview += 1;
1N/A
1N/A return view;
1N/A}