make functions get_pathman_config_params_relid() & get_pathman_config_relid() safer

Author: funbringer

src/hooks.c

@@ -592,7 +592,7 @@ pathman_relcache_hook(Datum arg, Oid relid)
 		return;
 
 	/* Invalidation event for PATHMAN_CONFIG table (probably DROP) */
-	if (relid == get_pathman_config_relid())
+	if (relid == get_pathman_config_relid(false))
 		delay_pathman_shutdown();
 
 	/* Invalidate PartParentInfo cache if needed */

src/init.c

@@ -661,7 +661,7 @@ pathman_config_contains_relation(Oid relid, Datum *values, bool *isnull,
 				ObjectIdGetDatum(relid));
 
 	/* Open PATHMAN_CONFIG with latest snapshot available */
-	rel = heap_open(get_pathman_config_relid(), AccessShareLock);
+	rel = heap_open(get_pathman_config_relid(false), AccessShareLock);
 
 	/* Check that 'partrel' column is if regclass type */
 	Assert(RelationGetDescr(rel)->
@@ -735,7 +735,7 @@ read_pathman_params(Oid relid, Datum *values, bool *isnull)
 				BTEqualStrategyNumber, F_OIDEQ,
 				ObjectIdGetDatum(relid));
 
-	rel = heap_open(get_pathman_config_params_relid(), AccessShareLock);
+	rel = heap_open(get_pathman_config_params_relid(false), AccessShareLock);
 	snapshot = RegisterSnapshot(GetLatestSnapshot());
 	scan = heap_beginscan(rel, snapshot, 1, key);
 
@@ -774,7 +774,7 @@ read_pathman_config(void)
 	HeapTuple		htup;
 
 	/* Open PATHMAN_CONFIG with latest snapshot available */
-	rel = heap_open(get_pathman_config_relid(), AccessShareLock);
+	rel = heap_open(get_pathman_config_relid(false), AccessShareLock);
 
 	/* Check that 'partrel' column is if regclass type */
 	Assert(RelationGetDescr(rel)->

src/pathman.h

@@ -85,8 +85,8 @@ extern Oid	pathman_config_params_relid;
 /*
  * Just to clarify our intentions (return the corresponding relid).
  */
-Oid get_pathman_config_relid(void);
-Oid get_pathman_config_params_relid(void);
+Oid get_pathman_config_relid(bool invalid_is_ok);
+Oid get_pathman_config_params_relid(bool invalid_is_ok);
 
 /*
  * pg_pathman's global state structure.

src/pg_pathman.c

@@ -1884,16 +1884,32 @@ generate_mergeappend_paths(PlannerInfo *root, RelOptInfo *rel,
  * Get cached PATHMAN_CONFIG relation Oid.
  */
 Oid
-get_pathman_config_relid(void)
+get_pathman_config_relid(bool invalid_is_ok)
 {
+	/* Raise ERROR if Oid is invalid */
+	if (!OidIsValid(pathman_config_relid) && !invalid_is_ok)
+		elog(ERROR,
+			 (!IsPathmanInitialized() ?
+				"pg_pathman is not initialized yet" :
+				"unexpected error in function "
+						  CppAsString(get_pathman_config_relid)));
+
 	return pathman_config_relid;
 }
 
 /*
  * Get cached PATHMAN_CONFIG_PARAMS relation Oid.
  */
 Oid
-get_pathman_config_params_relid(void)
+get_pathman_config_params_relid(bool invalid_is_ok)
 {
+	/* Raise ERROR if Oid is invalid */
+	if (!OidIsValid(pathman_config_relid) && !invalid_is_ok)
+		elog(ERROR,
+			 (!IsPathmanInitialized() ?
+				"pg_pathman is not initialized yet" :
+				"unexpected error in function "
+						  CppAsString(get_pathman_config_params_relid)));
+
 	return pathman_config_params_relid;
 }

src/pl_funcs.c

@@ -285,7 +285,7 @@ show_partition_list_internal(PG_FUNCTION_ARGS)
 		usercxt = (show_partition_list_cxt *) palloc(sizeof(show_partition_list_cxt));
 
 		/* Open PATHMAN_CONFIG with latest snapshot available */
-		usercxt->pathman_config = heap_open(get_pathman_config_relid(),
+		usercxt->pathman_config = heap_open(get_pathman_config_relid(false),
 											AccessShareLock);
 		usercxt->snapshot = RegisterSnapshot(GetLatestSnapshot());
 		usercxt->pathman_config_scan = heap_beginscan(usercxt->pathman_config,
@@ -637,7 +637,7 @@ add_to_pathman_config(PG_FUNCTION_ARGS)
 	isnull[Anum_pathman_config_range_interval - 1]	= PG_ARGISNULL(2);
 
 	/* Insert new row into PATHMAN_CONFIG */
-	pathman_config = heap_open(get_pathman_config_relid(), RowExclusiveLock);
+	pathman_config = heap_open(get_pathman_config_relid(false), RowExclusiveLock);
 	htup = heap_form_tuple(RelationGetDescr(pathman_config), values, isnull);
 	simple_heap_insert(pathman_config, htup);
 	indstate = CatalogOpenIndexes(pathman_config);
@@ -685,14 +685,17 @@ Datum
 pathman_config_params_trigger_func(PG_FUNCTION_ARGS)
 {
 	TriggerData	   *trigdata = (TriggerData *) fcinfo->context;
-	Oid				pathman_config_params = get_pathman_config_params_relid();
+	Oid				pathman_config_params;
 	Oid				partrel;
 	Datum			partrel_datum;
 	bool			partrel_isnull;
 
-    /* Handle pg_pathman disabled case */
-    if (!OidIsValid(pathman_config_params))
-        goto _return;
+	/* Fetch Oid of PATHMAN_CONFIG_PARAMS */
+	pathman_config_params = get_pathman_config_params_relid(true);
+
+	/* Handle "pg_pathman.enabled = t" case */
+	if (!OidIsValid(pathman_config_params))
+		goto pathman_config_params_trigger_func_return;
 
 	/* Handle user calls */
 	if (!CALLED_AS_TRIGGER(fcinfo))
@@ -722,8 +725,8 @@ pathman_config_params_trigger_func(PG_FUNCTION_ARGS)
 	if (check_relation_exists(partrel))
 		CacheInvalidateRelcacheByRelid(partrel);
 
+pathman_config_params_trigger_func_return:
 	/* Return the tuple we've been given */
-_return:
 	if (trigdata->tg_event & TRIGGER_EVENT_UPDATE)
 		PG_RETURN_POINTER(trigdata->tg_newtuple);
 	else

src/relation_info.c

@@ -415,7 +415,7 @@ finish_delayed_invalidation(void)
 
 			/* Check that PATHMAN_CONFIG table has indeed been dropped */
 			if (cur_pathman_config_relid == InvalidOid ||
-				cur_pathman_config_relid != get_pathman_config_relid())
+				cur_pathman_config_relid != get_pathman_config_relid(true))
 			{
 				/* Ok, let's unload pg_pathman's config */
 				unload_config();