rule.py 文件源码

def get_expired_rules(total_workers, worker_number, limit=100, blacklisted_rules=[], session=None):
    """
    Get expired rules.

    :param total_workers:      Number of total workers.
    :param worker_number:      id of the executing worker.
    :param limit:              Maximum number of rules to return.
    :param backlisted_rules:   List of blacklisted rules.
    :param session:            Database session in use.
    """

    query = session.query(models.ReplicationRule.id, models.ReplicationRule.rse_expression).filter(models.ReplicationRule.expires_at < datetime.utcnow(),
                                                                                                   models.ReplicationRule.locked == False,
                                                                                                   models.ReplicationRule.child_rule_id == None).\
        with_hint(models.ReplicationRule, "index(rules RULES_EXPIRES_AT_IDX)", 'oracle').\
        order_by(models.ReplicationRule.expires_at)  # NOQA

    if session.bind.dialect.name == 'oracle':
        bindparams = [bindparam('worker_number', worker_number),
                      bindparam('total_workers', total_workers)]
        query = query.filter(text('ORA_HASH(name, :total_workers) = :worker_number', bindparams=bindparams))
    elif session.bind.dialect.name == 'mysql':
        query = query.filter(text('mod(md5(name), %s) = %s' % (total_workers + 1, worker_number)))
    elif session.bind.dialect.name == 'postgresql':
        query = query.filter(text('mod(abs((\'x\'||md5(name))::bit(32)::int), %s) = %s' % (total_workers + 1, worker_number)))

    if limit:
        fetched_rules = query.limit(limit).all()
        filtered_rules = [rule for rule in fetched_rules if rule[0] not in blacklisted_rules]
        if len(fetched_rules) == limit and len(filtered_rules) == 0:
            return get_expired_rules(total_workers=total_workers,
                                     worker_number=worker_number,
                                     limit=None,
                                     blacklisted_rules=blacklisted_rules,
                                     session=session)
        else:
            return filtered_rules
    else:
        return [rule for rule in query.all() if rule[0] not in blacklisted_rules]