import asyncio
import warnings
from collections import defaultdict
from itertools import chain
from typing import Any, DefaultDict, Dict, MutableSet, Optional, Type, Union
from warnings import warn
from weakref import WeakSet
import aiormq
from .abc import (
AbstractConnection, AbstractRobustChannel, AbstractRobustExchange,
AbstractRobustQueue, TimeoutType,
)
from .channel import Channel
from .exchange import Exchange, ExchangeType
from .log import get_logger
from .queue import Queue
from .robust_exchange import RobustExchange
from .robust_queue import RobustQueue
from .tools import CallbackCollection
log = get_logger(__name__)
[docs]
class RobustChannel(Channel, AbstractRobustChannel): # type: ignore
""" Channel abstraction """
QUEUE_CLASS: Type[Queue] = RobustQueue
EXCHANGE_CLASS: Type[Exchange] = RobustExchange
RESTORE_RETRY_DELAY: int = 2
_exchanges: DefaultDict[str, MutableSet[AbstractRobustExchange]]
_queues: DefaultDict[str, MutableSet[RobustQueue]]
default_exchange: RobustExchange
def __init__(
self,
connection: AbstractConnection,
channel_number: Optional[int] = None,
publisher_confirms: bool = True,
on_return_raises: bool = False,
):
"""
:param connection: :class:`aio_pika.adapter.AsyncioConnection` instance
:param loop:
Event loop (:func:`asyncio.get_event_loop()` when :class:`None`)
:param future_store: :class:`aio_pika.common.FutureStore` instance
:param publisher_confirms:
False if you don't need delivery confirmations
(in pursuit of performance)
"""
super().__init__(
connection=connection,
channel_number=channel_number,
publisher_confirms=publisher_confirms,
on_return_raises=on_return_raises,
)
self._exchanges = defaultdict(WeakSet)
self._queues = defaultdict(WeakSet)
self._prefetch_count: int = 0
self._prefetch_size: int = 0
self._global_qos: bool = False
self.reopen_callbacks: CallbackCollection = CallbackCollection(self)
self.__restore_lock = asyncio.Lock()
self.__restored = asyncio.Event()
self.close_callbacks.add(self.__close_callback)
async def ready(self) -> None:
await self._connection.ready()
await self.__restored.wait()
async def get_underlay_channel(self) -> aiormq.abc.AbstractChannel:
await self._connection.ready()
return await super().get_underlay_channel()
async def restore(self, channel: Any = None) -> None:
if channel is not None:
warnings.warn(
"Channel argument will be ignored because you "
"don't need to pass this anymore.",
DeprecationWarning,
)
async with self.__restore_lock:
if self.__restored.is_set():
return
await self.reopen()
self.__restored.set()
async def __close_callback(self, _: Any, exc: BaseException) -> None:
if isinstance(exc, asyncio.CancelledError):
# This happens only if the channel is forced to close from the
# outside, for example, if the connection is closed.
# Of course, here you need to exit from this function
# as soon as possible and to avoid a recovery attempt.
self.__restored.clear()
return
in_restore_state = not self.__restored.is_set()
self.__restored.clear()
if self._closed or in_restore_state:
return
await self.restore()
async def reopen(self) -> None:
await super().reopen()
await self.reopen_callbacks()
async def _on_open(self) -> None:
if not hasattr(self, "default_exchange"):
await super()._on_open()
exchanges = tuple(chain(*self._exchanges.values()))
queues = tuple(chain(*self._queues.values()))
channel = await self.get_underlay_channel()
await channel.basic_qos(
prefetch_count=self._prefetch_count,
prefetch_size=self._prefetch_size,
)
for exchange in exchanges:
await exchange.restore()
for queue in queues:
await queue.restore()
if hasattr(self, "default_exchange"):
self.default_exchange.channel = self
self.__restored.set()
async def set_qos(
self,
prefetch_count: int = 0,
prefetch_size: int = 0,
global_: bool = False,
timeout: TimeoutType = None,
all_channels: Optional[bool] = None,
) -> aiormq.spec.Basic.QosOk:
if all_channels is not None:
warn('Use "global_" instead of "all_channels"', DeprecationWarning)
global_ = all_channels
await self.ready()
self._prefetch_count = prefetch_count
self._prefetch_size = prefetch_size
self._global_qos = global_
return await super().set_qos(
prefetch_count=prefetch_count,
prefetch_size=prefetch_size,
global_=global_,
timeout=timeout,
)
[docs]
async def declare_exchange(
self,
name: str,
type: Union[ExchangeType, str] = ExchangeType.DIRECT,
durable: bool = False,
auto_delete: bool = False,
internal: bool = False,
passive: bool = False,
arguments: Optional[Dict[str, Any]] = None,
timeout: TimeoutType = None,
robust: bool = True,
) -> AbstractRobustExchange:
await self.ready()
exchange = (
await super().declare_exchange(
name=name,
type=type,
durable=durable,
auto_delete=auto_delete,
internal=internal,
passive=passive,
arguments=arguments,
timeout=timeout,
)
)
if not internal and robust:
# noinspection PyTypeChecker
self._exchanges[name].add(exchange) # type: ignore
return exchange # type: ignore
async def exchange_delete(
self,
exchange_name: str,
timeout: TimeoutType = None,
if_unused: bool = False,
nowait: bool = False,
) -> aiormq.spec.Exchange.DeleteOk:
await self.ready()
result = await super().exchange_delete(
exchange_name=exchange_name,
timeout=timeout,
if_unused=if_unused,
nowait=nowait,
)
self._exchanges.pop(exchange_name, None)
return result
[docs]
async def declare_queue(
self,
name: Optional[str] = None,
*,
durable: bool = False,
exclusive: bool = False,
passive: bool = False,
auto_delete: bool = False,
arguments: Optional[Dict[str, Any]] = None,
timeout: TimeoutType = None,
robust: bool = True,
) -> AbstractRobustQueue:
await self.ready()
queue: RobustQueue = await super().declare_queue( # type: ignore
name=name,
durable=durable,
exclusive=exclusive,
passive=passive,
auto_delete=auto_delete,
arguments=arguments,
timeout=timeout,
)
if robust:
self._queues[queue.name].add(queue)
return queue
async def queue_delete(
self,
queue_name: str,
timeout: TimeoutType = None,
if_unused: bool = False,
if_empty: bool = False,
nowait: bool = False,
) -> aiormq.spec.Queue.DeleteOk:
await self.ready()
result = await super().queue_delete(
queue_name=queue_name,
timeout=timeout,
if_unused=if_unused,
if_empty=if_empty,
nowait=nowait,
)
self._queues.pop(queue_name, None)
return result
__all__ = ("RobustChannel",)