use new syscache for pg_extension

Author: okbob

src/catalog.c

@@ -11,13 +11,7 @@
 
 #include "plpgsql_check.h"
 
-#include "access/genam.h"
-
-#include "access/htup_details.h"
-#include "access/table.h"
-
 #include "catalog/pg_extension.h"
-#include "catalog/indexing.h"
 #include "catalog/pg_language.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_proc.h"
@@ -31,10 +25,24 @@
 #include "utils/syscache.h"
 #include "utils/regproc.h"
 
-#include "utils/rel.h"
 #include "catalog/pg_proc.h"
 #include "utils/syscache.h"
 
+/*
+ * Pre pg 18 doesn't support system cache for pg_extension,
+ * we need to manipulate with table on low level.
+ */
+#if PG_VERSION_NUM < 180000
+
+#include "access/genam.h"
+
+#include "access/htup_details.h"
+#include "access/table.h"
+#include "catalog/indexing.h"
+#include "utils/rel.h"
+
+#endif
+
 static Oid plpgsql_check_PLpgSQLlanguageId = InvalidOid;
 
 /*
@@ -216,6 +224,8 @@ get_extension_schema(Oid ext_oid)
 
 #endif
 
+#if PG_VERSION_NUM < 180000
+
 /*
  * get_extension_version - given an extension OID, look up the version
  *
@@ -266,6 +276,39 @@ get_extension_version(Oid ext_oid)
 	return result;
 }
 
+#else
+
+/*
+ * Returns a palloc'd string, or NULL if no such extension.
+ * Use extension syscache from PostgreSQL 18+
+ */
+char *
+get_extension_version2(Oid ext_oid)
+{
+	HeapTuple extTuple;
+	Datum	extversiondatum;
+	char	   *result;
+	bool		isnull;
+
+	extTuple = SearchSysCache1(EXTENSIONOID, ObjectIdGetDatum(ext_oid));
+	if (!HeapTupleIsValid(extTuple))
+		elog(ERROR, "cache lookup failed for extension %u", ext_oid);
+
+	extversiondatum = SysCacheGetAttr(EXTENSIONOID, extTuple,
+									  Anum_pg_extension_extversion, &isnull);
+
+	if (isnull)
+		elog(ERROR, "extversion is null");
+
+	result = TextDatumGetCString(extversiondatum);
+
+	ReleaseSysCache(extTuple);
+
+	return result;
+}
+
+#endif
+
 /*
  * Returns oid of pragma function. It is used for elimination
  * pragma function from volatility tests.

src/plpgsql_check.c

@@ -35,6 +35,13 @@
 #include "utils/guc.h"
 #include "utils/memutils.h"
 
+#if PG_VERSION_NUM >= 180000
+
+#include "utils/inval.h"
+#include "utils/syscache.h"
+
+#endif
+
 #ifdef PG_MODULE_MAGIC
 PG_MODULE_MAGIC;
 #endif
@@ -109,6 +116,15 @@ plpgsql_check__ns_lookup_t plpgsql_check__ns_lookup_p;
 
 static bool is_expected_extversion = false;
 
+#if PG_VERSION_NUM >= 180000
+
+static void
+pg_extension_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+	is_expected_extversion = false;
+}
+
+#endif
 
 /*
  * load_external_function retursn PGFunctions - we need generic function, so
@@ -129,8 +145,16 @@ plpgsql_check_check_ext_version(Oid fn_oid)
 		extoid = getExtensionOfObject(ProcedureRelationId, fn_oid);
 		Assert(OidIsValid(extoid));
 
+#if PG_VERSION_NUM >= 180000
+
+		extver = get_extension_version2(extoid);
+
+#else
+
 		extver = get_extension_version(extoid);
 
+#endif
+
 		Assert(extver);
 
 		if (strcmp(EXPECTED_EXTVERSION, extver) != 0)
@@ -421,6 +445,14 @@ _PG_init(void)
 	plpgsql_check_tracer_init();
 	plpgsql_check_cursors_leaks_init();
 
+
+#if PG_VERSION_NUM >= 180000
+
+	CacheRegisterSyscacheCallback(EXTENSIONOID,
+								  pg_extension_cache_callback,
+								  (Datum) 0);
+
+#endif
 	inited = true;
 }
 

src/plpgsql_check.h

@@ -230,8 +230,16 @@ extern char *plpgsql_check_get_src(HeapTuple procTuple);
 extern Oid plpgsql_check_pragma_func_oid(void);
 extern bool plpgsql_check_is_plpgsql_function(Oid foid);
 extern Oid plpgsql_check_get_op_namespace(Oid opno);
+
+#if PG_VERSION_NUM < 180000
+
 extern char *get_extension_version(Oid ext_oid);
 
+#else
+
+extern char *get_extension_version2(Oid ext_oid);
+
+#endif
 
 /*
  * functions from tablefunc.c