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.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index 4d8cd79e9a8..0dab2b6ae91 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -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/include/access/hash.h,v 1.88 2008/06/19 00:46:05 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/access/hash.h,v 1.89 2008/07/13 20:45:47 tgl Exp $
  *
  * NOTES
  *		modeled after Margo Seltzer's hash implementation for unix.
@@ -166,10 +166,10 @@ typedef HashMetaPageData *HashMetaPage;
  * Maximum size of a hash index item (it's okay to have only one per page)
  */
 #define HashMaxItemSize(page) \
-	(PageGetPageSize(page) - \
-	 sizeof(PageHeaderData) - \
-	 MAXALIGN(sizeof(HashPageOpaqueData)) - \
-	 sizeof(ItemIdData))
+	MAXALIGN_DOWN(PageGetPageSize(page) - \
+				  SizeOfPageHeaderData - \
+				  sizeof(ItemIdData) - \
+				  MAXALIGN(sizeof(HashPageOpaqueData)))
 
 #define HASH_MIN_FILLFACTOR			10
 #define HASH_DEFAULT_FILLFACTOR		75