Code review for HeapTupleHeader changes. Add version number to page headers

(overlaying low byte of page size) and add HEAP_HASOID bit to t_infomask,
per earlier discussion.  Simplify scheme for overlaying fields in tuple
header (no need for cmax to live in more than one place).  Don't try to
clear infomask status bits in tqual.c --- not safe to do it there.  Don't
try to force output table of a SELECT INTO to have OIDs, either.  Get rid
of unnecessarily complex three-state scheme for TupleDesc.tdhasoids, which
has already caused one recent failure.  Improve documentation.

1 files changed, 11 insertions, 19 deletions

diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c
index 5735da26d46..884db0ad21f 100644
--- a/src/backend/access/common/heaptuple.c
+++ b/src/backend/access/common/heaptuple.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/common/heaptuple.c,v 1.80 2002/08/25 17:20:00 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/common/heaptuple.c,v 1.81 2002/09/02 01:05:03 tgl Exp $
  *
  * NOTES
  *	  The old interface functions have been converted to macros
@@ -80,7 +80,7 @@ DataFill(char *data,
 		bitmask = CSIGNBIT;
 	}
 
-	*infomask &= HEAP_XACT_MASK;
+	*infomask &= ~(HEAP_HASNULL | HEAP_HASVARWIDTH | HEAP_HASEXTENDED);
 
 	for (i = 0; i < numberOfAttributes; i++)
 	{
@@ -584,8 +584,6 @@ heap_formtuple(TupleDesc tupleDescriptor,
 		elog(ERROR, "heap_formtuple: numberOfAttributes %d exceeds limit %d",
 			 numberOfAttributes, MaxTupleAttributeNumber);
 
-	AssertTupleDescHasOidIsValid(tupleDescriptor);
-
 	for (i = 0; i < numberOfAttributes; i++)
 	{
 		if (nulls[i] != ' ')
@@ -600,7 +598,7 @@ heap_formtuple(TupleDesc tupleDescriptor,
 	if (hasnull)
 		len += BITMAPLEN(numberOfAttributes);
 
-	if (tupleDescriptor->tdhasoid == WITHOID)
+	if (tupleDescriptor->tdhasoid)
 		len += sizeof(Oid);
 
 	hoff = len = MAXALIGN(len); /* align user data safely */
@@ -626,6 +624,9 @@ heap_formtuple(TupleDesc tupleDescriptor,
 			 &td->t_infomask,
 			 (hasnull ? td->t_bits : NULL));
 
+	if (tupleDescriptor->tdhasoid)
+		td->t_infomask |= HEAP_HASOID;
+
 	td->t_infomask |= HEAP_XMAX_INVALID;
 
 	return tuple;
@@ -651,7 +652,6 @@ heap_modifytuple(HeapTuple tuple,
 	char	   *nulls;
 	bool		isNull;
 	HeapTuple	newTuple;
-	uint8		infomask;
 
 	/*
 	 * sanity checks
@@ -702,18 +702,10 @@ heap_modifytuple(HeapTuple tuple,
 							  nulls);
 
 	/*
-	 * copy the header except for t_len, t_natts, t_hoff, t_bits,
-	 * t_infomask
+	 * copy the identification info of the old tuple: t_ctid, t_self,
+	 * and OID (if any)
 	 */
-	infomask = newTuple->t_data->t_infomask;
-	/*
-	 * copy t_xmin, t_cid, t_xmax, t_ctid, t_natts, t_infomask
-	 */
-	memmove((char *) newTuple->t_data,	/* XXX */
-			(char *) tuple->t_data,
-			offsetof(HeapTupleHeaderData, t_hoff));	/* XXX */
-	newTuple->t_data->t_infomask = infomask;
-	newTuple->t_data->t_natts = numberOfAttributes;
+	newTuple->t_data->t_ctid = tuple->t_data->t_ctid;
 	newTuple->t_self = tuple->t_self;
 	newTuple->t_tableOid = tuple->t_tableOid;
 	if (relation->rd_rel->relhasoids)
@@ -776,11 +768,11 @@ heap_addheader(int natts,		/* max domain index */
 	tuple->t_datamcxt = CurrentMemoryContext;
 	tuple->t_data = td = (HeapTupleHeader) ((char *) tuple + HEAPTUPLESIZE);
 
-	MemSet((char *) td, 0, len);
+	MemSet((char *) td, 0, hoff);
 
 	td->t_hoff = hoff;
 	td->t_natts = natts;
-	td->t_infomask = HEAP_XMAX_INVALID; /* XXX sufficient? */
+	td->t_infomask = withoid ? (HEAP_XMAX_INVALID | HEAP_HASOID) : HEAP_XMAX_INVALID;
 
 	memcpy((char *) td + hoff, structure, structlen);