ING_DB

WEGA/contrib/ingres/dbs/src/access/add_ovflo.c

@@ -0,0 +1,91 @@
+# include	"gen.h"
+# include	"../h/dbs.h"
+# include	"../h/access.h"
+# include	"../h/aux.h"
+# include	"../h/lock.h"
+
+/* ADD_OVFLO -- Allocates an overflow page which will be */
+/* 	attached to current page.  TID must be for current page. */
+/* 	TID will be updated to id of new overflow page. */
+AAadd_ovflo(d, tid)
+register DESC		*d;
+struct tup_id		*tid;
+{
+	register ACCBUF			*b;
+	register int			lk;
+	register int			i;
+	long				mpage;
+	long				newpage;
+	struct tup_id			tidx;
+	extern ACCBUF			*AAchoose_buf();
+
+	/* save main page pointer so that it may be used when */
+	/* setting up new overflow page. */
+	mpage = AAcc_head->mainpg;
+
+	if (lk = (AAcclock && (d->relopn < 0 )))
+	{
+		if (AAsetcsl(AAcc_head->rel_tupid) < 0)
+			return (AMTA_ERR);
+		AAcclock = FALSE;
+	}
+
+	/* Determine last page of the relation */
+	AAlast_page(d, &tidx, AAcc_head);
+	AApluck_page(&tidx, &newpage);
+	newpage++;
+
+	/* choose an available buffer as victim for setting up */
+	/* overflow page. */
+	if (!(b = AAchoose_buf(d, newpage)))
+	{
+		if (lk)
+		{
+			AAcclock = TRUE;
+			AAunlcs(AAcc_head->rel_tupid);
+		}
+		return (-1);
+	}
+
+	/* setup overflow page */
+	b->mainpg = mpage;
+	b->ovflopg = 0;
+	b->thispage = newpage;
+	b->linetab[LINETAB(0)] = b->firstup - (char *) b;
+	b->nxtlino = 0;
+	b->bufstatus |= BUF_DIRTY;
+	if (AApageflush(b))
+		return (-2);
+
+	/* now that overflow page has successfully been written, */
+	/* get the old current page back and link the new overflow page */
+	/* to it. */
+	/* If the relation is a heap then don't leave the old main */
+	/* page around in the buffers. This is done on the belief */
+	/* that it will never be accessed again. */
+	if (AAgetpage(d, tid))
+		return (-3);
+
+	AAcc_head->ovflopg = newpage;
+	AAcc_head->bufstatus |= BUF_DIRTY;
+	i = AApageflush(AAcc_head);
+	if (lk)
+	{
+		AAcclock = TRUE;
+		AAunlcs(AAcc_head->rel_tupid);
+	}
+	if (i)
+		return (-4);
+
+	if (abs(ctoi(d->reldum.relspec)) == M_HEAP)
+		AAresetacc(AAcc_head);	/* no error is possible */
+
+	/* now bring the overflow page back and make it current. */
+	/* if the overflow page is still in AM cache, then this will not */
+	/* cause any disk activity. */
+	AAstuff_page(tid, &newpage);
+	if (AAgetpage(d, tid))
+		return (-5);
+
+	return (0);
+}