Remove redundant IndexTupleDSize macro.

Use IndexTupleSize everywhere, instead.  Also, remove IndexTupleSize's
internal typecast, as that's not really needed and might mask coding
errors.  Change some pointer variable datatypes in the call sites
to compensate for that and make it clearer what we're assuming.

Ildar Musin, Robert Haas, Stephen Frost

Discussion: https://postgr.es/m/0274288e-9e88-13b6-c61c-7b36928bf221@postgrespro.ru

src/backend/access/hash/hash_xlog.c

@@ -558,7 +558,7 @@ hash_xlog_move_page_contents(XLogReaderState *record)
 				Size		itemsz;
 				OffsetNumber l;
 
-				itemsz = IndexTupleDSize(*itup);
+				itemsz = IndexTupleSize(itup);
 				itemsz = MAXALIGN(itemsz);
 
 				data += itemsz;
@@ -686,7 +686,7 @@ hash_xlog_squeeze_page(XLogReaderState *record)
 				Size		itemsz;
 				OffsetNumber l;
 
-				itemsz = IndexTupleDSize(*itup);
+				itemsz = IndexTupleSize(itup);
 				itemsz = MAXALIGN(itemsz);
 
 				data += itemsz;

src/backend/access/hash/hashinsert.c

@@ -55,7 +55,7 @@ _hash_doinsert(Relation rel, IndexTuple itup, Relation heapRel)
 	hashkey = _hash_get_indextuple_hashkey(itup);
 
 	/* compute item size too */
-	itemsz = IndexTupleDSize(*itup);
+	itemsz = IndexTupleSize(itup);
 	itemsz = MAXALIGN(itemsz);	/* be safe, PageAddItem will do this but we
 								 * need to be consistent */
 
@@ -222,7 +222,7 @@ restart_insert:
 		XLogRegisterBuffer(1, metabuf, REGBUF_STANDARD);
 
 		XLogRegisterBuffer(0, buf, REGBUF_STANDARD);
-		XLogRegisterBufData(0, (char *) itup, IndexTupleDSize(*itup));
+		XLogRegisterBufData(0, (char *) itup, IndexTupleSize(itup));
 
 		recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_INSERT);
 
@@ -309,7 +309,7 @@ _hash_pgaddmultitup(Relation rel, Buffer buf, IndexTuple *itups,
 	{
 		Size		itemsize;
 
-		itemsize = IndexTupleDSize(*itups[i]);
+		itemsize = IndexTupleSize(itups[i]);
 		itemsize = MAXALIGN(itemsize);
 
 		/* Find where to insert the tuple (preserving page's hashkey ordering) */

src/backend/access/hash/hashovfl.c

@@ -891,7 +891,7 @@ readpage:
 
 			itup = (IndexTuple) PageGetItem(rpage,
 											PageGetItemId(rpage, roffnum));
-			itemsz = IndexTupleDSize(*itup);
+			itemsz = IndexTupleSize(itup);
 			itemsz = MAXALIGN(itemsz);
 
 			/*

src/backend/access/hash/hashpage.c

@@ -1173,7 +1173,7 @@ _hash_splitbucket(Relation rel,
 				 * the current page in the new bucket, we must allocate a new
 				 * overflow page and place the tuple on that page instead.
 				 */
-				itemsz = IndexTupleDSize(*new_itup);
+				itemsz = IndexTupleSize(new_itup);
 				itemsz = MAXALIGN(itemsz);
 
 				if (PageGetFreeSpaceForMultipleTuples(npage, nitups + 1) < (all_tups_size + itemsz))

src/backend/access/heap/hio.c

@@ -67,9 +67,9 @@ RelationPutHeapTuple(Relation relation,
 	if (!token)
 	{
 		ItemId		itemId = PageGetItemId(pageHeader, offnum);
-		Item		item = PageGetItem(pageHeader, itemId);
+		HeapTupleHeader item = (HeapTupleHeader) PageGetItem(pageHeader, itemId);
 
-		((HeapTupleHeader) item)->t_ctid = tuple->t_self;
+		item->t_ctid = tuple->t_self;
 	}
 }
 

src/backend/access/nbtree/nbtinsert.c

@@ -558,7 +558,7 @@ _bt_findinsertloc(Relation rel,
 
 	lpageop = (BTPageOpaque) PageGetSpecialPointer(page);
 
-	itemsz = IndexTupleDSize(*newtup);
+	itemsz = IndexTupleSize(newtup);
 	itemsz = MAXALIGN(itemsz);	/* be safe, PageAddItem will do this but we
 								 * need to be consistent */
 
@@ -755,7 +755,7 @@ _bt_insertonpg(Relation rel,
 		elog(ERROR, "cannot insert to incompletely split page %u",
 			 BufferGetBlockNumber(buf));
 
-	itemsz = IndexTupleDSize(*itup);
+	itemsz = IndexTupleSize(itup);
 	itemsz = MAXALIGN(itemsz);	/* be safe, PageAddItem will do this but we
 								 * need to be consistent */
 
@@ -914,7 +914,7 @@ _bt_insertonpg(Relation rel,
 									sizeof(IndexTupleData));
 			}
 			else
-				XLogRegisterBufData(0, (char *) itup, IndexTupleDSize(*itup));
+				XLogRegisterBufData(0, (char *) itup, IndexTupleSize(itup));
 
 			recptr = XLogInsert(RM_BTREE_ID, xlinfo);
 

src/backend/access/nbtree/nbtsort.c

@@ -813,7 +813,7 @@ _bt_buildadd(BTWriteState *wstate, BTPageState *state, IndexTuple itup)
 	last_off = state->btps_lastoff;
 
 	pgspc = PageGetFreeSpace(npage);
-	itupsz = IndexTupleDSize(*itup);
+	itupsz = IndexTupleSize(itup);
 	itupsz = MAXALIGN(itupsz);
 
 	/*

src/backend/access/nbtree/nbtxlog.c

@@ -51,9 +51,15 @@ _bt_restore_page(Page page, char *from, int len)
 	i = 0;
 	while (from < end)
 	{
-		/* Need to copy tuple header due to alignment considerations */
+		/*
+		 * As we step through the items, 'from' won't always be properly
+		 * aligned, so we need to use memcpy().  Further, we use Item (which
+		 * is just a char*) here for our items array for the same reason;
+		 * wouldn't want the compiler or anyone thinking that an item is
+		 * aligned when it isn't.
+		 */
 		memcpy(&itupdata, from, sizeof(IndexTupleData));
-		itemsz = IndexTupleDSize(itupdata);
+		itemsz = IndexTupleSize(&itupdata);
 		itemsz = MAXALIGN(itemsz);
 
 		items[i] = (Item) from;
@@ -205,7 +211,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 	BTPageOpaque ropaque;
 	char	   *datapos;
 	Size		datalen;
-	Item		left_hikey = NULL;
+	IndexTuple	left_hikey = NULL;
 	Size		left_hikeysz = 0;
 	BlockNumber leftsib;
 	BlockNumber rightsib;
@@ -248,7 +254,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 	{
 		ItemId		hiItemId = PageGetItemId(rpage, P_FIRSTDATAKEY(ropaque));
 
-		left_hikey = PageGetItem(rpage, hiItemId);
+		left_hikey = (IndexTuple) PageGetItem(rpage, hiItemId);
 		left_hikeysz = ItemIdGetLength(hiItemId);
 	}
 
@@ -272,7 +278,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 		Page		lpage = (Page) BufferGetPage(lbuf);
 		BTPageOpaque lopaque = (BTPageOpaque) PageGetSpecialPointer(lpage);
 		OffsetNumber off;
-		Item		newitem = NULL;
+		IndexTuple	newitem = NULL;
 		Size		newitemsz = 0;
 		Page		newlpage;
 		OffsetNumber leftoff;
@@ -281,7 +287,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 
 		if (onleft)
 		{
-			newitem = (Item) datapos;
+			newitem = (IndexTuple) datapos;
 			newitemsz = MAXALIGN(IndexTupleSize(newitem));
 			datapos += newitemsz;
 			datalen -= newitemsz;
@@ -290,7 +296,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 		/* Extract left hikey and its size (assuming 16-bit alignment) */
 		if (!isleaf)
 		{
-			left_hikey = (Item) datapos;
+			left_hikey = (IndexTuple) datapos;
 			left_hikeysz = MAXALIGN(IndexTupleSize(left_hikey));
 			datapos += left_hikeysz;
 			datalen -= left_hikeysz;
@@ -301,7 +307,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 
 		/* Set high key */
 		leftoff = P_HIKEY;
-		if (PageAddItem(newlpage, left_hikey, left_hikeysz,
+		if (PageAddItem(newlpage, (Item) left_hikey, left_hikeysz,
 						P_HIKEY, false, false) == InvalidOffsetNumber)
 			elog(PANIC, "failed to add high key to left page after split");
 		leftoff = OffsetNumberNext(leftoff);
@@ -310,12 +316,12 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 		{
 			ItemId		itemid;
 			Size		itemsz;
-			Item		item;
+			IndexTuple	item;
 
 			/* add the new item if it was inserted on left page */
 			if (onleft && off == xlrec->newitemoff)
 			{
-				if (PageAddItem(newlpage, newitem, newitemsz, leftoff,
+				if (PageAddItem(newlpage, (Item) newitem, newitemsz, leftoff,
 								false, false) == InvalidOffsetNumber)
 					elog(ERROR, "failed to add new item to left page after split");
 				leftoff = OffsetNumberNext(leftoff);
@@ -323,8 +329,8 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 
 			itemid = PageGetItemId(lpage, off);
 			itemsz = ItemIdGetLength(itemid);
-			item = PageGetItem(lpage, itemid);
+			item = (IndexTuple) PageGetItem(lpage, itemid);
-			if (PageAddItem(newlpage, item, itemsz, leftoff,
+			if (PageAddItem(newlpage, (Item) item, itemsz, leftoff,
 							false, false) == InvalidOffsetNumber)
 				elog(ERROR, "failed to add old item to left page after split");
 			leftoff = OffsetNumberNext(leftoff);
@@ -333,7 +339,7 @@ btree_xlog_split(bool onleft, XLogReaderState *record)
 		/* cope with possibility that newitem goes at the end */
 		if (onleft && off == xlrec->newitemoff)
 		{
-			if (PageAddItem(newlpage, newitem, newitemsz, leftoff,
+			if (PageAddItem(newlpage, (Item) newitem, newitemsz, leftoff,
 							false, false) == InvalidOffsetNumber)
 				elog(ERROR, "failed to add new item to left page after split");
 			leftoff = OffsetNumberNext(leftoff);

src/include/access/itup.h

@@ -67,8 +67,7 @@ typedef IndexAttributeBitMapData * IndexAttributeBitMap;
 #define INDEX_VAR_MASK	0x4000
 #define INDEX_NULL_MASK 0x8000
 
-#define IndexTupleSize(itup)		((Size) (((IndexTuple) (itup))->t_info & INDEX_SIZE_MASK))
+#define IndexTupleSize(itup)		((Size) ((itup)->t_info & INDEX_SIZE_MASK))
-#define IndexTupleDSize(itup)		((Size) ((itup).t_info & INDEX_SIZE_MASK))
 #define IndexTupleHasNulls(itup)	((((IndexTuple) (itup))->t_info & INDEX_NULL_MASK))
 #define IndexTupleHasVarwidths(itup) ((((IndexTuple) (itup))->t_info & INDEX_VAR_MASK))