impl_mongodb.py 文件源码

def update_ttl(ttl, ttl_index_name, index_field, coll):
        """Update or create time_to_live indexes.

        :param ttl: time to live in seconds.
        :param ttl_index_name: name of the index we want to update or create.
        :param index_field: field with the index that we need to update.
        :param coll: collection which indexes need to be updated.
        """
        indexes = coll.index_information()
        if ttl <= 0:
            if ttl_index_name in indexes:
                coll.drop_index(ttl_index_name)
            return

        if ttl_index_name in indexes:
            return coll.database.command(
                'collMod', coll.name,
                index={'keyPattern': {index_field: pymongo.ASCENDING},
                       'expireAfterSeconds': ttl})

        coll.create_index([(index_field, pymongo.ASCENDING)],
                          expireAfterSeconds=ttl,
                          name=ttl_index_name)