Improve coding of log_heap_clean() and heap_xlog_clean().

src/backend/access/heap/heapam.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.150 2003/02/13 05:35:07 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.151 2003/02/23 20:32:11 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -1891,36 +1891,40 @@ heap_restrpos(HeapScanDesc scan)
 }
 
 XLogRecPtr
-log_heap_clean(Relation reln, Buffer buffer, char *unused, int unlen)
+log_heap_clean(Relation reln, Buffer buffer, OffsetNumber *unused, int uncnt)
 {
 	xl_heap_clean xlrec;
 	XLogRecPtr	recptr;
-	XLogRecData rdata[3];
+	XLogRecData rdata[2];
 
 	/* Caller should not call me on a temp relation */
 	Assert(!reln->rd_istemp);
 
 	xlrec.node = reln->rd_node;
 	xlrec.block = BufferGetBlockNumber(buffer);
+
 	rdata[0].buffer = InvalidBuffer;
 	rdata[0].data = (char *) &xlrec;
 	rdata[0].len = SizeOfHeapClean;
 	rdata[0].next = &(rdata[1]);
 
-	if (unlen > 0)
-	{
+	/*
+	 * The unused-offsets array is not actually in the buffer, but pretend
+	 * that it is.  When XLogInsert stores the whole buffer, the offsets
+	 * array need not be stored too.
+	 */
 	rdata[1].buffer = buffer;
-		rdata[1].data = unused;
-		rdata[1].len = unlen;
-		rdata[1].next = &(rdata[2]);
+	if (uncnt > 0)
+	{
+		rdata[1].data = (char *) unused;
+		rdata[1].len = uncnt * sizeof(OffsetNumber);
 	}
 	else
-		rdata[0].next = &(rdata[2]);
-
-	rdata[2].buffer = buffer;
-	rdata[2].data = NULL;
-	rdata[2].len = 0;
-	rdata[2].next = NULL;
+	{
+		rdata[1].data = NULL;
+		rdata[1].len = 0;
+	}
+	rdata[1].next = NULL;
 
 	recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_CLEAN, rdata);
 
@@ -2032,7 +2036,6 @@ heap_xlog_clean(bool redo, XLogRecPtr lsn, XLogRecord *record)
 		return;
 
 	reln = XLogOpenRelation(redo, RM_HEAP_ID, xlrec->node);
-
 	if (!RelationIsValid(reln))
 		return;
 
@@ -2052,18 +2055,14 @@ heap_xlog_clean(bool redo, XLogRecPtr lsn, XLogRecord *record)
 
 	if (record->xl_len > SizeOfHeapClean)
 	{
-		OffsetNumber unbuf[BLCKSZ / sizeof(OffsetNumber)];
-		OffsetNumber *unused = unbuf;
-		char	   *unend;
+		OffsetNumber *unused;
+		OffsetNumber *unend;
 		ItemId		lp;
 
-		Assert((record->xl_len - SizeOfHeapClean) <= BLCKSZ);
-		memcpy((char *) unbuf,
-			   (char *) xlrec + SizeOfHeapClean,
-			   record->xl_len - SizeOfHeapClean);
-		unend = (char *) unbuf + (record->xl_len - SizeOfHeapClean);
+		unused = (OffsetNumber *) ((char *) xlrec + SizeOfHeapClean);
+		unend = (OffsetNumber *) ((char *) xlrec + record->xl_len);
 
-		while ((char *) unused < unend)
+		while (unused < unend)
 		{
 			lp = PageGetItemId(page, *unused + 1);
 			lp->lp_flags &= ~LP_USED;

src/backend/commands/vacuum.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.248 2003/02/22 00:45:05 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.249 2003/02/23 20:32:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2386,8 +2386,7 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 		if (vacpage->blkno == (blkno - 1) &&
 			vacpage->offsets_free > 0)
 		{
-			OffsetNumber unbuf[BLCKSZ / sizeof(OffsetNumber)];
-			OffsetNumber *unused = unbuf;
+			OffsetNumber unused[BLCKSZ / sizeof(OffsetNumber)];
 			int			uncnt;
 
 			buf = ReadBuffer(onerel, vacpage->blkno);
@@ -2430,8 +2429,7 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 			{
 				XLogRecPtr	recptr;
 
-				recptr = log_heap_clean(onerel, buf, (char *) unused,
-						  (char *) (&(unused[uncnt])) - (char *) unused);
+				recptr = log_heap_clean(onerel, buf, unused, uncnt);
 				PageSetLSN(page, recptr);
 				PageSetSUI(page, ThisStartUpID);
 			}
@@ -2555,8 +2553,7 @@ vacuum_heap(VRelStats *vacrelstats, Relation onerel, VacPageList vacuum_pages)
 static void
 vacuum_page(Relation onerel, Buffer buffer, VacPage vacpage)
 {
-	OffsetNumber unbuf[BLCKSZ / sizeof(OffsetNumber)];
-	OffsetNumber *unused = unbuf;
+	OffsetNumber unused[BLCKSZ / sizeof(OffsetNumber)];
 	int			uncnt;
 	Page		page = BufferGetPage(buffer);
 	ItemId		itemid;
@@ -2580,8 +2577,7 @@ vacuum_page(Relation onerel, Buffer buffer, VacPage vacpage)
 	{
 		XLogRecPtr	recptr;
 
-		recptr = log_heap_clean(onerel, buffer, (char *) unused,
-						  (char *) (&(unused[uncnt])) - (char *) unused);
+		recptr = log_heap_clean(onerel, buffer, unused, uncnt);
 		PageSetLSN(page, recptr);
 		PageSetSUI(page, ThisStartUpID);
 	}

src/backend/commands/vacuumlazy.c

@@ -31,7 +31,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuumlazy.c,v 1.24 2003/02/22 00:45:05 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuumlazy.c,v 1.25 2003/02/23 20:32:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -497,8 +497,7 @@ static int
 lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 				 int tupindex, LVRelStats *vacrelstats)
 {
-	OffsetNumber unbuf[BLCKSZ / sizeof(OffsetNumber)];
-	OffsetNumber *unused = unbuf;
+	OffsetNumber unused[BLCKSZ / sizeof(OffsetNumber)];
 	int			uncnt;
 	Page		page = BufferGetPage(buffer);
 	ItemId		itemid;
@@ -524,8 +523,7 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 	{
 		XLogRecPtr	recptr;
 
-		recptr = log_heap_clean(onerel, buffer, (char *) unused,
-						  (char *) (&(unused[uncnt])) - (char *) unused);
+		recptr = log_heap_clean(onerel, buffer, unused, uncnt);
 		PageSetLSN(page, recptr);
 		PageSetSUI(page, ThisStartUpID);
 	}

src/include/access/heapam.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: heapam.h,v 1.80 2003/02/13 05:35:11 momjian Exp $
+ * $Id: heapam.h,v 1.81 2003/02/23 20:32:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -173,7 +173,7 @@ extern void heap_redo(XLogRecPtr lsn, XLogRecord *rptr);
 extern void heap_undo(XLogRecPtr lsn, XLogRecord *rptr);
 extern void heap_desc(char *buf, uint8 xl_info, char *rec);
 extern XLogRecPtr log_heap_clean(Relation reln, Buffer buffer,
-			   char *unused, int unlen);
+								 OffsetNumber *unused, int uncnt);
 extern XLogRecPtr log_heap_move(Relation reln, Buffer oldbuf,
 			  ItemPointerData from,
 			  Buffer newbuf, HeapTuple newtup);