dtmethod.c revision 3e14f97f673e8a630f076077de35afdd43dc1587
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2010 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#include "dthdr.h"
/* Change search method.
**
** Written by Kiem-Phong Vo (05/25/96)
*/
#if __STD_C
Dtmethod_t* dtmethod(Dt_t* dt, Dtmethod_t* meth)
#else
Dtmethod_t* dtmethod(dt, meth)
Dt_t* dt;
Dtmethod_t* meth;
#endif
{
reg Dtlink_t *list, *r;
reg Dtdisc_t* disc = dt->disc;
reg Dtmethod_t* oldmeth = dt->meth;
if(!meth || meth->type == oldmeth->type)
return oldmeth;
if(disc->eventf &&
(*disc->eventf)(dt,DT_METH,(Void_t*)meth,disc) < 0)
return NIL(Dtmethod_t*);
dt->data->minp = 0;
/* get the list of elements */
list = dtflatten(dt);
if(dt->data->type&(DT_LIST|DT_STACK|DT_QUEUE) )
dt->data->head = NIL(Dtlink_t*);
else if(dt->data->type&(DT_SET|DT_BAG) )
{ if(dt->data->ntab > 0)
(*dt->memoryf)(dt,(Void_t*)dt->data->htab,0,disc);
dt->data->ntab = 0;
dt->data->htab = NIL(Dtlink_t**);
}
dt->data->here = NIL(Dtlink_t*);
dt->data->type = (dt->data->type&~(DT_METHODS|DT_FLATTEN)) | meth->type;
dt->meth = meth;
if(dt->searchf == oldmeth->searchf)
dt->searchf = meth->searchf;
if(meth->type&(DT_LIST|DT_STACK|DT_QUEUE) )
{ if(!(oldmeth->type&(DT_LIST|DT_STACK|DT_QUEUE)) )
{ if((r = list) )
{ reg Dtlink_t* t;
for(t = r->right; t; r = t, t = t->right )
t->left = r;
list->left = r;
}
}
dt->data->head = list;
}
else if(meth->type&(DT_OSET|DT_OBAG))
{ dt->data->size = 0;
while(list)
{ r = list->right;
(*meth->searchf)(dt,(Void_t*)list,DT_RENEW);
list = r;
}
}
else if(!((meth->type&DT_BAG) && (oldmeth->type&DT_SET)) )
{ int rehash;
if((meth->type&(DT_SET|DT_BAG)) && !(oldmeth->type&(DT_SET|DT_BAG)))
rehash = 1;
else rehash = 0;
dt->data->size = dt->data->loop = 0;
while(list)
{ r = list->right;
if(rehash)
{ reg Void_t* key = _DTOBJ(list,disc->link);
key = _DTKEY(key,disc->key,disc->size);
list->hash = _DTHSH(dt,key,disc,disc->size);
}
(void)(*meth->searchf)(dt,(Void_t*)list,DT_RENEW);
list = r;
}
}
return oldmeth;
}