ext: support queries like insert/update/delete/etc

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>

Makefile

@@ -1,5 +1,5 @@
 MODULE_big = pg_zlog
-OBJS = pg_zlog.o
+OBJS = pg_zlog.o ruleutils_94.o ruleutils_95.o ruleutils_96.o
 EXTENSION = pg_zlog
 DATA = pg_zlog--0.1.sql
 
@@ -18,7 +18,7 @@ testdb:
 		= 'pg_zlog'/" testdb_data/postgresql.conf
 
 testdbrun:
-	postgres -D testdb_data
+	postgres -D testdb_data -d 1
 
 testdbinit:
 	echo 'CREATE EXTENSION pg_zlog;' | psql postgres

pg_zlog--0.1.sql

@@ -33,13 +33,19 @@ BEGIN
 END;
 $BODY$ LANGUAGE plpgsql;
 
-CREATE FUNCTION pgzlog_apply_update(log_name text, query text, pos bigint)
+CREATE FUNCTION pgzlog_start_update(log_name text)
 RETURNS void
 as $BODY$
 BEGIN
-	PERFORM pg_advisory_xact_lock(29030, hashtext(log_name));
+    PERFORM pg_advisory_xact_lock(29030, hashtext(log_name));
+    SET LOCAL pg_zlog.enabled TO false;
+END;
+$BODY$ LANGUAGE 'plpgsql';
 
-	SET LOCAL pg_zlog.enabled TO false;
+CREATE FUNCTION pgzlog_apply_update(log_name text, query text, pos bigint)
+RETURNS void
+as $BODY$
+BEGIN
 
     RAISE DEBUG 'Executing: %', query;
 
@@ -53,3 +59,11 @@ BEGIN
     WHERE name = log_name;
 END;
 $BODY$ LANGUAGE 'plpgsql';
+
+/*
+ * zlog_execute executes a query locally, by-passing the query logging logic.
+ */
+CREATE FUNCTION zlog_execute(INTERNAL)
+RETURNS void
+LANGUAGE C
+AS 'MODULE_PATHNAME', $$zlog_execute$$;