metadata.py 文件源码

def _add_table_metadata(self, table_metadata):
        old_indexes = {}
        old_meta = self.tables.get(table_metadata.name, None)
        if old_meta:
            # views are not queried with table, so they must be transferred to new
            table_metadata.views = old_meta.views
            # indexes will be updated with what is on the new metadata
            old_indexes = old_meta.indexes

        # note the intentional order of add before remove
        # this makes sure the maps are never absent something that existed before this update
        for index_name, index_metadata in six.iteritems(table_metadata.indexes):
            self.indexes[index_name] = index_metadata

        for index_name in (n for n in old_indexes if n not in table_metadata.indexes):
            self.indexes.pop(index_name, None)

        self.tables[table_metadata.name] = table_metadata