4.3BSD/usr/ingres/source/iutil/getequal.c

# include	<ingres.h>
# include	<access.h>
# include	<sccs.h>

SCCSID(@(#)getequal.c	8.1	12/31/84)


/*
**	getequal - get the first tuple equal to the provided key
**	
**	GETEQUAL is used to do a keyed retrieval of a single
**	tuple in cases where the calling program knows the key to
**	be unique.  SETKEY must be called first to set all desired
**	domain values.  GETEQUAL will return the first tuple with
**	equality on all of the specified domains.
**	The tuple is returned in TUPLE.
**	
** NOTE:
**	This function used to call get() for the scan, I have exploded the
**	call for efficency reasons. I also call get_page only when we leave a
**	page boundary.
**
**	function values:
**	
**		<0 fatal error
**		 0  success
**		 1  no match
**
**	Trace Flags:
**		23.8-15
*/


getequal(d, keyval, tupleval, tid)
register DESC	*d;
char		keyval[MAXTUP];
char		tupleval[MAXTUP];
register	TID		*tid;
{
	auto		long	lpageid,pageid;
	TID		limtid;
	register	char	*tuple;
	register	char	*key;
	register	int	i;

	key = keyval;
	tuple = tupleval;

#	ifdef xATR1
	if (tTf(23, 8))
	{
		printf("getequal: %.14s,", d->reldum.relid);
		printdesc(d);
		printup(d, key);
	}
#	endif
	if (i = find(d, EXACTKEY, tid, &limtid, key))
		return (i);

	pluck_page(&limtid,&lpageid);
	if (i = get_page(d, tid))
		return ( i );

	for (;;)
	{

		do
		{
			while (((++(tid->line_id)) & I1MASK) >= Acc_head->nxtlino)
			{
				tid->line_id = -1;
				pageid = Acc_head->ovflopg;
				stuff_page(tid, &pageid);
				if (pageid == 0)
				{
					pageid = Acc_head->mainpg;
					stuff_page(tid, &pageid);
					if (pageid == 0 || pageid == lpageid + 1)
						return (1);
				}
				if (i = resetacc(Acc_head))
					return (i);
				if (i = get_page(d, tid))
					return (i);
			}
		} while (!Acc_head->linetab[-(tid->line_id & I1MASK)]);

		get_tuple(d,tid,tuple);

		if (!kcompare(d, key, tuple))
		{
#			ifdef xATR2
			if (tTf(23, 9))
			{
				printf("getequal: ");
				dumptid(tid);
				printf("getequal: ");
				printup(d, tuple);
			}
#			endif
			return (0);
		}
	}
}