Function transformGenericOptions

src/backend/commands/foreigncmds.c:120–216

* Transform a list of DefElem into text array format. This is substantially * the same thing as optionListToArray(), except we recognize SET/ADD/DROP * actions for modifying an existing list of options, which is passed in * Datum form as oldOptions. Also, if fdwvalidator isn't InvalidOid * it specifies a validator function to call on the result. * * Returns the array in the form of a Datum

 * FOREIGN TABLE.
 */
Datum
transformGenericOptions(Oid catalogId,
						Datum oldOptions,
						List *options,
						Oid fdwvalidator)
{
	List	   *resultOptions = untransformRelOptions(oldOptions);
	ListCell   *optcell;
	Datum		result;

	foreach(optcell, options)
	{
		DefElem    *od = lfirst(optcell);
		ListCell   *cell;

		/*
		 * Find the element in resultOptions.  We need this for validation in
		 * all cases.
		 */
		foreach(cell, resultOptions)
		{
			DefElem    *def = lfirst(cell);

			if (strcmp(def->defname, od->defname) == 0)
				break;
		}

		/*
		 * It is possible to perform multiple SET/DROP actions on the same
		 * option.  The standard permits this, as long as the options to be
		 * added are unique.  Note that an unspecified action is taken to be
		 * ADD.
		 */
		switch (od->defaction)
		{
			case DEFELEM_DROP:
				if (!cell)
					ereport(ERROR,
							(errcode(ERRCODE_UNDEFINED_OBJECT),
							 errmsg("option \"%s\" not found",
									od->defname)));
				resultOptions = list_delete_cell(resultOptions, cell);
				break;

			case DEFELEM_SET:
				if (!cell)
					ereport(ERROR,
							(errcode(ERRCODE_UNDEFINED_OBJECT),
							 errmsg("option \"%s\" not found",
									od->defname)));
				lfirst(cell) = od;
				break;

			case DEFELEM_ADD:
			case DEFELEM_UNSPEC:
				if (cell)
					ereport(ERROR,
							(errcode(ERRCODE_DUPLICATE_OBJECT),