1 files changed, 121 insertions, 0 deletions
diff --git a/src/backend/catalog/pg_cast.c b/src/backend/catalog/pg_cast.c
new file mode 100644
index 0000000..4857f64
--- /dev/null
+++ b/src/backend/catalog/pg_cast.c
@@ -0,0 +1,121 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_cast.c
+ *	  routines to support manipulation of the pg_cast relation
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/catalog/pg_cast.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/htup_details.h"
+#include "access/table.h"
+#include "catalog/catalog.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_cast.h"
+#include "catalog/pg_proc.h"
+#include "catalog/pg_type.h"
+#include "utils/builtins.h"
+#include "utils/rel.h"
+#include "utils/syscache.h"
+
+/*
+ * ----------------------------------------------------------------
+ *		CastCreate
+ *
+ * Forms and inserts catalog tuples for a new cast being created.
+ * Caller must have already checked privileges, and done consistency
+ * checks on the given datatypes and cast function (if applicable).
+ *
+ * 'behavior' indicates the types of the dependencies that the new
+ * cast will have on its input and output types and the cast function.
+ * ----------------------------------------------------------------
+ */
+ObjectAddress
+CastCreate(Oid sourcetypeid, Oid targettypeid, Oid funcid, char castcontext,
+		   char castmethod, DependencyType behavior)
+{
+	Relation	relation;
+	HeapTuple	tuple;
+	Oid			castid;
+	Datum		values[Natts_pg_cast];
+	bool		nulls[Natts_pg_cast];
+	ObjectAddress myself,
+				referenced;
+	ObjectAddresses *addrs;
+
+	relation = table_open(CastRelationId, RowExclusiveLock);
+
+	/*
+	 * Check for duplicate.  This is just to give a friendly error message,
+	 * the unique index would catch it anyway (so no need to sweat about race
+	 * conditions).
+	 */
+	tuple = SearchSysCache2(CASTSOURCETARGET,
+							ObjectIdGetDatum(sourcetypeid),
+							ObjectIdGetDatum(targettypeid));
+	if (HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("cast from type %s to type %s already exists",
+						format_type_be(sourcetypeid),
+						format_type_be(targettypeid))));
+
+	/* ready to go */
+	castid = GetNewOidWithIndex(relation, CastOidIndexId, Anum_pg_cast_oid);
+	values[Anum_pg_cast_oid - 1] = ObjectIdGetDatum(castid);
+	values[Anum_pg_cast_castsource - 1] = ObjectIdGetDatum(sourcetypeid);
+	values[Anum_pg_cast_casttarget - 1] = ObjectIdGetDatum(targettypeid);
+	values[Anum_pg_cast_castfunc - 1] = ObjectIdGetDatum(funcid);
+	values[Anum_pg_cast_castcontext - 1] = CharGetDatum(castcontext);
+	values[Anum_pg_cast_castmethod - 1] = CharGetDatum(castmethod);
+
+	MemSet(nulls, false, sizeof(nulls));
+
+	tuple = heap_form_tuple(RelationGetDescr(relation), values, nulls);
+
+	CatalogTupleInsert(relation, tuple);
+
+	addrs = new_object_addresses();
+
+	/* make dependency entries */
+	ObjectAddressSet(myself, CastRelationId, castid);
+
+	/* dependency on source type */
+	ObjectAddressSet(referenced, TypeRelationId, sourcetypeid);
+	add_exact_object_address(&referenced, addrs);
+
+	/* dependency on target type */
+	ObjectAddressSet(referenced, TypeRelationId, targettypeid);
+	add_exact_object_address(&referenced, addrs);
+
+	/* dependency on function */
+	if (OidIsValid(funcid))
+	{
+		ObjectAddressSet(referenced, ProcedureRelationId, funcid);
+		add_exact_object_address(&referenced, addrs);
+	}
+
+	record_object_address_dependencies(&myself, addrs, behavior);
+	free_object_addresses(addrs);
+
+	/* dependency on extension */
+	recordDependencyOnCurrentExtension(&myself, false);
+
+	/* Post creation hook for new cast */
+	InvokeObjectPostCreateHook(CastRelationId, castid, 0);
+
+	heap_freetuple(tuple);
+
+	table_close(relation, RowExclusiveLock);
+
+	return myself;
+}