Convert contrib modules to use the extension facility.

This isn't fully tested as yet, in particular I'm not sure that the
"foo--unpackaged--1.0.sql" scripts are OK.  But it's time to get some
buildfarm cycles on it.

sepgsql is not converted to an extension, mainly because it seems to
require a very nonstandard installation process.

Dimitri Fontaine and Tom Lane

contrib/pg_buffercache/.gitignore

@@ -1 +0,0 @@
-/pg_buffercache.sql

contrib/pg_buffercache/Makefile

@@ -3,8 +3,8 @@
 MODULE_big = pg_buffercache
 OBJS = pg_buffercache_pages.o
 
-DATA_built = pg_buffercache.sql
-DATA = uninstall_pg_buffercache.sql
+EXTENSION = pg_buffercache
+DATA = pg_buffercache--1.0.sql pg_buffercache--unpackaged--1.0.sql
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config

contrib/pg_buffercache/pg_buffercache--1.0.sql

@@ -1,7 +1,4 @@
-/* contrib/pg_buffercache/pg_buffercache.sql.in */
-
--- Adjust this setting to control where the objects get created.
-SET search_path = public;
+/* contrib/pg_buffercache/pg_buffercache--1.0.sql */
 
 -- Register the function.
 CREATE OR REPLACE FUNCTION pg_buffercache_pages()
@@ -15,6 +12,6 @@ CREATE VIEW pg_buffercache AS
 	(bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,
 	 relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2);
 
--- Don't want these to be available at public.
+-- Don't want these to be available to public.
 REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC;
 REVOKE ALL ON pg_buffercache FROM PUBLIC;

contrib/pg_buffercache/pg_buffercache--unpackaged--1.0.sql

@@ -0,0 +1,4 @@
+/* contrib/pg_buffercache/pg_buffercache--unpackaged--1.0.sql */
+
+ALTER EXTENSION pg_buffercache ADD function pg_buffercache_pages();
+ALTER EXTENSION pg_buffercache ADD view pg_buffercache;

contrib/pg_buffercache/pg_buffercache.control

@@ -0,0 +1,5 @@
+# pg_buffercache extension
+comment = 'examine the shared buffer cache'
+default_version = '1.0'
+module_pathname = '$libdir/pg_buffercache'
+relocatable = true

contrib/pg_buffercache/uninstall_pg_buffercache.sql

@@ -1,8 +0,0 @@
-/* contrib/pg_buffercache/uninstall_pg_buffercache.sql */
-
--- Adjust this setting to control where the objects get dropped.
-SET search_path = public;
-
-DROP VIEW pg_buffercache;
-
-DROP FUNCTION pg_buffercache_pages();