Make extension state available through function

The extension state is not easily accessible in release builds, which
makes debugging issue with the loader very difficult. This commit
introduces a new schema `timescaledb_debug` and makes the function
`ts_extension_get_state` available also in release builds as
`timescaledb_debug.extension_state`.

See timescale#1682

sql/debug_utils.sql

@@ -13,3 +13,6 @@ AS '@MODULE_PATHNAME@', 'ts_debug_point_release';
 
 CREATE OR REPLACE FUNCTION debug_waitpoint_id(TEXT) RETURNS BIGINT LANGUAGE C VOLATILE STRICT
 AS '@MODULE_PATHNAME@', 'ts_debug_point_id';
+
+CREATE OR REPLACE FUNCTION timescaledb_debug.extension_state() RETURNS TEXT
+AS '@MODULE_PATHNAME@', 'ts_extension_get_state' LANGUAGE C;

sql/pre_install/schemas.sql

@@ -11,6 +11,16 @@ CREATE SCHEMA _timescaledb_cache;
 CREATE SCHEMA _timescaledb_config;
 CREATE SCHEMA timescaledb_experimental;
 CREATE SCHEMA timescaledb_information;
+CREATE SCHEMA timescaledb_debug;
 
-GRANT USAGE ON SCHEMA _timescaledb_cache, _timescaledb_catalog, _timescaledb_functions, _timescaledb_internal, _timescaledb_config, timescaledb_information, timescaledb_experimental TO PUBLIC;
+GRANT USAGE ON SCHEMA
+      _timescaledb_cache,
+      _timescaledb_catalog,
+      _timescaledb_functions,
+      _timescaledb_internal,
+      _timescaledb_config,
+      timescaledb_debug,
+      timescaledb_information,
+      timescaledb_experimental
+TO PUBLIC;
 

sql/updates/latest-dev.sql

@@ -316,3 +316,6 @@ ALTER TABLE _timescaledb_catalog.dimension
     ADD CONSTRAINT dimension_hypertable_id_fkey FOREIGN KEY (hypertable_id) REFERENCES _timescaledb_catalog.hypertable(id) ON DELETE CASCADE;
 ALTER TABLE _timescaledb_catalog.tablespace
     ADD CONSTRAINT tablespace_hypertable_id_fkey FOREIGN KEY (hypertable_id) REFERENCES _timescaledb_catalog.hypertable(id) ON DELETE CASCADE;
+
+CREATE SCHEMA timescaledb_debug;
+GRANT USAGE ON SCHEMA timescaledb_debug TO PUBLIC;

sql/updates/reverse-dev.sql

@@ -623,3 +623,5 @@ ALTER TABLE _timescaledb_catalog.hypertable_data_node
 ALTER TABLE _timescaledb_catalog.tablespace
     ADD CONSTRAINT tablespace_hypertable_id_fkey FOREIGN KEY (hypertable_id) REFERENCES _timescaledb_catalog.hypertable(id) ON DELETE CASCADE;
 
+DROP FUNCTION IF EXISTS timescaledb_debug.extension_state;
+DROP SCHEMA IF EXISTS timescaledb_debug;

src/extension.c

@@ -66,6 +66,13 @@ static enum ExtensionState extstate = EXTENSION_STATE_UNKNOWN;
  */
 static Oid ts_extension_oid = InvalidOid;
 
+static const char *extstate_str[] = {
+	[EXTENSION_STATE_UNKNOWN] = "unknown",
+	[EXTENSION_STATE_TRANSITIONING] = "transitioning",
+	[EXTENSION_STATE_CREATED] = "created",
+	[EXTENSION_STATE_NOT_INSTALLED] = "not installed",
+};
+
 static bool
 extension_loader_present()
 {
@@ -334,19 +341,10 @@ ts_extension_is_proxy_table_relid(Oid relid)
 	return relid == extension_proxy_oid;
 }
 
-#ifdef TS_DEBUG
-static const char *extstate_str[] = {
-	[EXTENSION_STATE_UNKNOWN] = "unknown",
-	[EXTENSION_STATE_TRANSITIONING] = "transitioning",
-	[EXTENSION_STATE_CREATED] = "created",
-	[EXTENSION_STATE_NOT_INSTALLED] = "not installed",
-};
-
 TS_FUNCTION_INFO_V1(ts_extension_get_state);
 
 Datum
 ts_extension_get_state(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_TEXT_P(cstring_to_text(extstate_str[extstate]));
 }
-#endif

tsl/test/shared/expected/extension.out

@@ -296,6 +296,7 @@ ORDER BY pronamespace::regnamespace::text COLLATE "C", p.oid::regprocedure::text
  time_bucket_gapfill(smallint,smallint,smallint,smallint)
  timescaledb_post_restore()
  timescaledb_pre_restore()
+ timescaledb_debug.extension_state()
  timescaledb_experimental.add_policies(regclass,boolean,"any","any","any","any")
  timescaledb_experimental.alter_policies(regclass,boolean,"any","any","any","any")
  timescaledb_experimental.remove_all_policies(regclass,boolean)