Function cast_value

gpcontrib/orafce/dbms_sql.c:1536–1573

* Apply cast rules to a value */

 * Apply cast rules to a value
 */
static Datum
cast_value(CastCacheData *ccast, Datum value, bool isnull)
{
	if (!isnull && !ccast->without_cast)
	{
		if (ccast->path == COERCION_PATH_FUNC)
			value = FunctionCall1(&ccast->finfo, value);
		else if (ccast->path == COERCION_PATH_RELABELTYPE)
		{
			/* do nothing */
		}
		else if (ccast->path == COERCION_PATH_COERCEVIAIO)
		{
			char *str;

			str = OutputFunctionCall(&ccast->finfo_out, value);
			value = InputFunctionCall(&ccast->finfo_in,
									  str,
									  ccast->typIOParam,
									  ccast->targettypmod);
		}
		else
			ereport(ERROR,
				    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				     errmsg("unsupported cast path yet %d", ccast->path)));

		if (ccast->targettypmod != -1 && ccast->path_typmod == COERCION_PATH_FUNC)
			value = FunctionCall3(&ccast->finfo_typmod,
								  value,
								  Int32GetDatum(ccast->targettypmod),
								  BoolGetDatum(true));
	}

	if (ccast->targettypid != InvalidOid)
		domain_check(value, isnull, ccast->targettypid, NULL, NULL);

	return value;
}

/*
 * CALL statement is relatily slow in PLpgSQL - due repated parsing, planning.