From 813b456ea21d4cf57b124bf855ec019c7a8099a7 Mon Sep 17 00:00:00 2001
From: Teodor Sigaev <teodor@sigaev.ru>
Date: Tue, 12 Apr 2016 18:03:01 +0300
Subject: [PATCH] Add page id to bloom index
Added to ensure that bloom index pages can be distinguished from other pages
by pg_filedump. Because there wasn't any public/production versions before,
it doesn't pay attention to any compatibility issues.
Per notice from Tom Lane
---
contrib/bloom/bloom.h | 19 +++++++++++++++++--
contrib/bloom/blutils.c | 1 +
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/contrib/bloom/bloom.h b/contrib/bloom/bloom.h
index d5284f37253..cbf2eb78927 100644
--- a/contrib/bloom/bloom.h
+++ b/contrib/bloom/bloom.h
@@ -31,8 +31,13 @@
/* Opaque for bloom pages */
typedef struct BloomPageOpaqueData
{
- OffsetNumber maxoff;
- uint16 flags;
+ OffsetNumber maxoff; /* number of index tuples on page */
+ uint16 flags; /* see bit definitions below */
+ uint16 unused; /* placeholder to force maxaligning of size
+ * of BloomPageOpaqueData and to place
+ * bloom_page_id exactly at the end of page
+ */
+ uint16 bloom_page_id; /* for identification of BLOOM indexes */
} BloomPageOpaqueData;
typedef BloomPageOpaqueData *BloomPageOpaque;
@@ -41,6 +46,16 @@ typedef BloomPageOpaqueData *BloomPageOpaque;
#define BLOOM_META (1<<0)
#define BLOOM_DELETED (2<<0)
+/*
+ * The page ID is for the convenience of pg_filedump and similar utilities,
+ * which otherwise would have a hard time telling pages of different index
+ * types apart. It should be the last 2 bytes on the page. This is more or
+ * less "free" due to alignment considerations.
+ *
+ * See comments above GinPageOpaqueData.
+ */
+#define BLOOM_PAGE_ID 0xFF83
+
/* Macros for accessing bloom page structures */
#define BloomPageGetOpaque(page) ((BloomPageOpaque) PageGetSpecialPointer(page))
#define BloomPageGetMaxOffset(page) (BloomPageGetOpaque(page)->maxoff)
diff --git a/contrib/bloom/blutils.c b/contrib/bloom/blutils.c
index 6c7dc1d07d1..edfdfb934f6 100644
--- a/contrib/bloom/blutils.c
+++ b/contrib/bloom/blutils.c
@@ -359,6 +359,7 @@ BloomInitPage(Page page, uint16 flags)
opaque = BloomPageGetOpaque(page);
memset(opaque, 0, sizeof(BloomPageOpaqueData));
opaque->flags = flags;
+ opaque->bloom_page_id = BLOOM_PAGE_ID;
}
/*
--
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