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authorTom Lane2009-06-08 16:22:44 +0000
committerTom Lane2009-06-08 16:22:44 +0000
commit896d5ca8038b866c14b28b0edaf6e15b35052da4 (patch)
treec8644f263d58237baba51f59f248e9ae6effcd57
parent8378846fdffb329d33cb8b3732f56c5d9c92efc0 (diff)
Fix contrib/pageinspect to not create an ABI breakage between 8.3 and 8.4.
The original implementation of the 3-argument form of get_raw_page() risked core dumps if the 8.3 SQL function definition was mistakenly used with the 8.4 module, which is entirely likely after a dump-and-reload upgrade. To protect 8.4 beta testers against upgrade problems, add a check on PG_NARGS. In passing, fix missed additions to the uninstall script, and polish the docs a trifle.
-rw-r--r--contrib/pageinspect/pageinspect.sql.in8
-rw-r--r--contrib/pageinspect/rawpage.c56
-rw-r--r--contrib/pageinspect/uninstall_pageinspect.sql2
-rw-r--r--doc/src/sgml/pageinspect.sgml10
4 files changed, 63 insertions, 13 deletions
diff --git a/contrib/pageinspect/pageinspect.sql.in b/contrib/pageinspect/pageinspect.sql.in
index e320bec7e2..ca6406a6d3 100644
--- a/contrib/pageinspect/pageinspect.sql.in
+++ b/contrib/pageinspect/pageinspect.sql.in
@@ -6,15 +6,15 @@ SET search_path = public;
--
-- get_raw_page()
--
-CREATE OR REPLACE FUNCTION get_raw_page(text, text, int4)
+CREATE OR REPLACE FUNCTION get_raw_page(text, int4)
RETURNS bytea
AS 'MODULE_PATHNAME', 'get_raw_page'
LANGUAGE C STRICT;
-CREATE OR REPLACE FUNCTION get_raw_page(text, int4)
+CREATE OR REPLACE FUNCTION get_raw_page(text, text, int4)
RETURNS bytea
-AS $$ SELECT get_raw_page($1, 'main', $2); $$
-LANGUAGE SQL STRICT;
+AS 'MODULE_PATHNAME', 'get_raw_page_fork'
+LANGUAGE C STRICT;
--
-- page_header()
diff --git a/contrib/pageinspect/rawpage.c b/contrib/pageinspect/rawpage.c
index 08d61fab87..55ef637836 100644
--- a/contrib/pageinspect/rawpage.c
+++ b/contrib/pageinspect/rawpage.c
@@ -29,8 +29,13 @@
PG_MODULE_MAGIC;
Datum get_raw_page(PG_FUNCTION_ARGS);
+Datum get_raw_page_fork(PG_FUNCTION_ARGS);
Datum page_header(PG_FUNCTION_ARGS);
+static bytea *get_raw_page_internal(text *relname, ForkNumber forknum,
+ BlockNumber blkno);
+
+
/*
* get_raw_page
*
@@ -42,13 +47,56 @@ Datum
get_raw_page(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
+ uint32 blkno = PG_GETARG_UINT32(1);
+ bytea *raw_page;
+
+ /*
+ * We don't normally bother to check the number of arguments to a C
+ * function, but here it's needed for safety because early 8.4 beta
+ * releases mistakenly redefined get_raw_page() as taking three arguments.
+ */
+ if (PG_NARGS() != 2)
+ ereport(ERROR,
+ (errmsg("wrong number of arguments to get_raw_page()"),
+ errhint("Run the updated pageinspect.sql script.")));
+
+ raw_page = get_raw_page_internal(relname, MAIN_FORKNUM, blkno);
+
+ PG_RETURN_BYTEA_P(raw_page);
+}
+
+/*
+ * get_raw_page_fork
+ *
+ * Same, for any fork
+ */
+PG_FUNCTION_INFO_V1(get_raw_page_fork);
+
+Datum
+get_raw_page_fork(PG_FUNCTION_ARGS)
+{
+ text *relname = PG_GETARG_TEXT_P(0);
text *forkname = PG_GETARG_TEXT_P(1);
uint32 blkno = PG_GETARG_UINT32(2);
+ bytea *raw_page;
ForkNumber forknum;
- Relation rel;
- RangeVar *relrv;
+ forknum = forkname_to_number(text_to_cstring(forkname));
+
+ raw_page = get_raw_page_internal(relname, forknum, blkno);
+
+ PG_RETURN_BYTEA_P(raw_page);
+}
+
+/*
+ * workhorse
+ */
+static bytea *
+get_raw_page_internal(text *relname, ForkNumber forknum, BlockNumber blkno)
+{
bytea *raw_page;
+ RangeVar *relrv;
+ Relation rel;
char *raw_page_data;
Buffer buf;
@@ -57,8 +105,6 @@ get_raw_page(PG_FUNCTION_ARGS)
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use raw functions"))));
- forknum = forkname_to_number(text_to_cstring(forkname));
-
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
@@ -105,7 +151,7 @@ get_raw_page(PG_FUNCTION_ARGS)
relation_close(rel, AccessShareLock);
- PG_RETURN_BYTEA_P(raw_page);
+ return raw_page;
}
/*
diff --git a/contrib/pageinspect/uninstall_pageinspect.sql b/contrib/pageinspect/uninstall_pageinspect.sql
index f92b20ebe6..362c60449e 100644
--- a/contrib/pageinspect/uninstall_pageinspect.sql
+++ b/contrib/pageinspect/uninstall_pageinspect.sql
@@ -4,8 +4,10 @@
SET search_path = public;
DROP FUNCTION get_raw_page(text, int4);
+DROP FUNCTION get_raw_page(text, text, int4);
DROP FUNCTION page_header(bytea);
DROP FUNCTION heap_page_items(bytea);
DROP FUNCTION bt_metap(text);
DROP FUNCTION bt_page_stats(text, int4);
DROP FUNCTION bt_page_items(text, int4);
+DROP FUNCTION fsm_page_contents(bytea);
diff --git a/doc/src/sgml/pageinspect.sgml b/doc/src/sgml/pageinspect.sgml
index 8f4094439f..87028091c8 100644
--- a/doc/src/sgml/pageinspect.sgml
+++ b/doc/src/sgml/pageinspect.sgml
@@ -27,8 +27,9 @@
<function>get_raw_page</function> reads the specified block of the named
table and returns a copy as a <type>bytea</> value. This allows a
single time-consistent copy of the block to be obtained.
- <literal>fork</literal> should be <literal>'main'</literal> for the main
- data fork, or <literal>'fsm'</literal> for the FSM.
+ <replaceable>fork</replaceable> should be <literal>'main'</literal> for
+ the main data fork, or <literal>'fsm'</literal> for the free space map,
+ or <literal>'vm'</literal> for the visibility map.
</para>
</listitem>
</varlistentry>
@@ -40,8 +41,9 @@
<listitem>
<para>
- A shorthand of above, for reading from the main fork. Equal to
- <literal>get_raw_page(relname, 0, blkno)</literal>
+ A shorthand version of <function>get_raw_page</function>, for reading
+ from the main fork. Equivalent to
+ <literal>get_raw_page(relname, 'main', blkno)</literal>
</para>
</listitem>
</varlistentry>