具有多个嵌套函数的ndb.Tasklet和SyncTasklet

Question

我正在尝试高效地调用tasklet和子tasklet：

@ndb.tasklet
def getBeds(bed_key):
    bed = yield bed_key.get_asyn()
    bed_info = {}
    ......
    raise ndb.Return(bed_info)

@ndb.tasklet
def getRoom(room_key):
    room = yield room_key.get_async()
    room_info = {}
    ..........
    beds_in_room = map(getBeds,room.beds)
    room_info["beds"] = beds_in_room
    raise ndb.Return(room_info)

@ndb.tasklet
def getBuilding(build_key):
    build = yield build_key.get_async()
    build_info = {}
    ...........
    rooms_in_build = map(getRoom,build.rooms)
    build_info["rooms"] = rooms_in_build

@ndb.toplevel
def getHotel(hotel_obj)
    hotel_inf = {}
    .........
    buildings_in_hotel = map(getBuilding,hotel_obj.buildings)
    hotel_inf["buildings"] = buildings_in_hotel
    return hotel_inf

出于某种原因，我认为@ndb.toplevel会暂停getHotel，直到一切都完成。不幸的是，buildings_in_hotel返回了一个期货列表...

我如何让它完成？

Answer 1

你投降了！

当调用一个微线程时，你总是得到一个未来，然后让步来获得结果。还有一个并行的输出，你可以产生一个微线程的元组或列表(有时被称为屏障)。

beds_in_room = yield map(getBeds,room.beds)

和

rooms_in_build = yield map(getRoom,build.rooms)

和

buildings_in_hotel = yield map(getBuilding,hotel_obj.buildings)