Clean up the use of some page-header-access macros: principally, use

SizeOfPageHeaderData instead of sizeof(PageHeaderData) in places where that
makes the code clearer, and avoid casting between Page and PageHeader where
possible.  Zdenek Kotala, with some additional cleanup by Heikki Linnakangas.

I did not apply the parts of the proposed patch that would have resulted in
slightly changing the on-disk format of hash indexes; it seems to me that's
not a win as long as there's any chance of having in-place upgrade for 8.4.

2 files changed, 9 insertions, 9 deletions

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 2e832db4b15..72e531d3dc3 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.315 2008/06/30 22:10:43 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.316 2008/07/13 20:45:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1017,19 +1017,19 @@ static bool
 XLogCheckBuffer(XLogRecData *rdata, bool doPageWrites,
 				XLogRecPtr *lsn, BkpBlock *bkpb)
 {
-	PageHeader	page;
+	Page		page;
 
-	page = (PageHeader) BufferGetBlock(rdata->buffer);
+	page = BufferGetPage(rdata->buffer);
 
 	/*
 	 * XXX We assume page LSN is first data on *every* page that can be passed
 	 * to XLogInsert, whether it otherwise has the standard page layout or
 	 * not.
 	 */
-	*lsn = page->pd_lsn;
+	*lsn = PageGetLSN(page);
 
 	if (doPageWrites &&
-		XLByteLE(page->pd_lsn, RedoRecPtr))
+		XLByteLE(PageGetLSN(page), RedoRecPtr))
 	{
 		/*
 		 * The page needs to be backed up, so set up *bkpb
@@ -1040,8 +1040,8 @@ XLogCheckBuffer(XLogRecData *rdata, bool doPageWrites,
 		if (rdata->buffer_std)
 		{
 			/* Assume we can omit data between pd_lower and pd_upper */
-			uint16		lower = page->pd_lower;
-			uint16		upper = page->pd_upper;
+			uint16		lower = ((PageHeader) page)->pd_lower;
+			uint16		upper = ((PageHeader) page)->pd_upper;
 
 			if (lower >= SizeOfPageHeaderData &&
 				upper > lower &&
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index 9a2f18d5318..3e2d5046da6 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.56 2008/06/19 00:46:03 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.57 2008/07/13 20:45:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -279,7 +279,7 @@ XLogReadBuffer(RelFileNode rnode, BlockNumber blkno, bool init)
 		/* check that page has been initialized */
 		Page		page = (Page) BufferGetPage(buffer);
 
-		if (PageIsNew((PageHeader) page))
+		if (PageIsNew(page))
 		{
 			UnlockReleaseBuffer(buffer);
 			log_invalid_page(rnode, blkno, true);