This document describes the current stable version of Celery (5.2). For development docs, go here.

Source code for

"""Sending/Receiving Messages (Kombu integration)."""
import numbers
from collections import namedtuple
from import Mapping
from datetime import timedelta
from weakref import WeakValueDictionary

from kombu import Connection, Consumer, Exchange, Producer, Queue, pools
from kombu.common import Broadcast
from kombu.utils.functional import maybe_list
from kombu.utils.objects import cached_property

from celery import signals
from celery.utils.nodenames import anon_nodename
from celery.utils.saferepr import saferepr
from celery.utils.text import indent as textindent
from celery.utils.time import maybe_make_aware

from . import routes as _routes

__all__ = ('AMQP', 'Queues', 'task_message')

#: earliest date supported by time.mktime.
INT_MIN = -2147483648

#: Human readable queue declaration.
.> {<16} exchange={}({}) \

task_message = namedtuple('task_message',
                          ('headers', 'properties', 'body', 'sent_event'))

def utf8dict(d, encoding='utf-8'):
    return {k.decode(encoding) if isinstance(k, bytes) else k: v
            for k, v in d.items()}

[docs]class Queues(dict): """Queue name⇒ declaration mapping. Arguments: queues (Iterable): Initial list/tuple or dict of queues. create_missing (bool): By default any unknown queues will be added automatically, but if this flag is disabled the occurrence of unknown queues in `wanted` will raise :exc:`KeyError`. max_priority (int): Default x-max-priority for queues with none set. """ #: If set, this is a subset of queues to consume from. #: The rest of the queues are then used for routing only. _consume_from = None def __init__(self, queues=None, default_exchange=None, create_missing=True, autoexchange=None, max_priority=None, default_routing_key=None): super().__init__() self.aliases = WeakValueDictionary() self.default_exchange = default_exchange self.default_routing_key = default_routing_key self.create_missing = create_missing self.autoexchange = Exchange if autoexchange is None else autoexchange self.max_priority = max_priority if queues is not None and not isinstance(queues, Mapping): queues = { q for q in queues} queues = queues or {} for name, q in queues.items(): self.add(q) if isinstance(q, Queue) else self.add_compat(name, **q) def __getitem__(self, name): try: return self.aliases[name] except KeyError: return super().__getitem__(name) def __setitem__(self, name, queue): if self.default_exchange and not = self.default_exchange super().__setitem__(name, queue) if queue.alias: self.aliases[queue.alias] = queue def __missing__(self, name): if self.create_missing: return self.add(self.new_missing(name)) raise KeyError(name)
[docs] def add(self, queue, **kwargs): """Add new queue. The first argument can either be a :class:`kombu.Queue` instance, or the name of a queue. If the former the rest of the keyword arguments are ignored, and options are simply taken from the queue instance. Arguments: queue (kombu.Queue, str): Queue to add. exchange (kombu.Exchange, str): if queue is str, specifies exchange name. routing_key (str): if queue is str, specifies binding key. exchange_type (str): if queue is str, specifies type of exchange. **options (Any): Additional declaration options used when queue is a str. """ if not isinstance(queue, Queue): return self.add_compat(queue, **kwargs) return self._add(queue)
[docs] def add_compat(self, name, **options): # docs used to use binding_key as routing key options.setdefault('routing_key', options.get('binding_key')) if options['routing_key'] is None: options['routing_key'] = name return self._add(Queue.from_dict(name, **options))
def _add(self, queue): if is None or == '': = self.default_exchange if not queue.routing_key: queue.routing_key = self.default_routing_key if self.max_priority is not None: if queue.queue_arguments is None: queue.queue_arguments = {} self._set_max_priority(queue.queue_arguments) self[] = queue return queue def _set_max_priority(self, args): if 'x-max-priority' not in args and self.max_priority is not None: return args.update({'x-max-priority': self.max_priority})
[docs] def format(self, indent=0, indent_first=True): """Format routing table into string for log dumps.""" active = self.consume_from if not active: return '' info = [QUEUE_FORMAT.strip().format(q) for _, q in sorted(active.items())] if indent_first: return textindent('\n'.join(info), indent) return info[0] + '\n' + textindent('\n'.join(info[1:]), indent)
[docs] def select_add(self, queue, **kwargs): """Add new task queue that'll be consumed from. The queue will be active even when a subset has been selected using the :option:`celery worker -Q` option. """ q = self.add(queue, **kwargs) if self._consume_from is not None: self._consume_from[] = q return q
[docs] def select(self, include): """Select a subset of currently defined queues to consume from. Arguments: include (Sequence[str], str): Names of queues to consume from. """ if include: self._consume_from = { name: self[name] for name in maybe_list(include) }
[docs] def deselect(self, exclude): """Deselect queues so that they won't be consumed from. Arguments: exclude (Sequence[str], str): Names of queues to avoid consuming from. """ if exclude: exclude = maybe_list(exclude) if self._consume_from is None: # using all queues return for k in self if k not in exclude) # using selection for queue in exclude: self._consume_from.pop(queue, None)
[docs] def new_missing(self, name): return Queue(name, self.autoexchange(name), name)
@property def consume_from(self): if self._consume_from is not None: return self._consume_from return self
[docs]class AMQP: """App AMQP API: app.amqp.""" Connection = Connection Consumer = Consumer Producer = Producer #: compat alias to Connection BrokerConnection = Connection queues_cls = Queues #: Cached and prepared routing table. _rtable = None #: Underlying producer pool instance automatically #: set by the :attr:`producer_pool`. _producer_pool = None # Exchange class/function used when defining automatic queues. # For example, you can use ``autoexchange = lambda n: None`` to use the # AMQP default exchange: a shortcut to bypass routing # and instead send directly to the queue named in the routing key. autoexchange = None #: Max size of positional argument representation used for #: logging purposes. argsrepr_maxsize = 1024 #: Max size of keyword argument representation used for logging purposes. kwargsrepr_maxsize = 1024 def __init__(self, app): = app self.task_protocols = { 1: self.as_task_v1, 2: self.as_task_v2, } @cached_property def create_task_message(self): return self.task_protocols[] @cached_property def send_task_message(self): return self._create_task_sender()
[docs] def Queues(self, queues, create_missing=None, autoexchange=None, max_priority=None): # Create new :class:`Queues` instance, using queue defaults # from the current configuration. conf = default_routing_key = conf.task_default_routing_key if create_missing is None: create_missing = conf.task_create_missing_queues if max_priority is None: max_priority = conf.task_queue_max_priority if not queues and conf.task_default_queue: queues = (Queue(conf.task_default_queue, exchange=self.default_exchange, routing_key=default_routing_key),) autoexchange = (self.autoexchange if autoexchange is None else autoexchange) return self.queues_cls( queues, self.default_exchange, create_missing, autoexchange, max_priority, default_routing_key, )
[docs] def Router(self, queues=None, create_missing=None): """Return the current task router.""" return _routes.Router(self.routes, queues or self.queues,'task_create_missing_queues', create_missing),
[docs] def flush_routes(self): self._rtable = _routes.prepare(
def TaskConsumer(self, channel, queues=None, accept=None, **kw): if accept is None: accept = return self.Consumer( channel, accept=accept, queues=queues or list(self.queues.consume_from.values()), **kw ) def as_task_v2(self, task_id, name, args=None, kwargs=None, countdown=None, eta=None, group_id=None, group_index=None, expires=None, retries=0, chord=None, callbacks=None, errbacks=None, reply_to=None, time_limit=None, soft_time_limit=None, create_sent_event=False, root_id=None, parent_id=None, shadow=None, chain=None, now=None, timezone=None, origin=None, ignore_result=False, argsrepr=None, kwargsrepr=None): args = args or () kwargs = kwargs or {} if not isinstance(args, (list, tuple)): raise TypeError('task args must be a list or tuple') if not isinstance(kwargs, Mapping): raise TypeError('task keyword arguments must be a mapping') if countdown: # convert countdown to ETA self._verify_seconds(countdown, 'countdown') now = now or timezone = timezone or eta = maybe_make_aware( now + timedelta(seconds=countdown), tz=timezone, ) if isinstance(expires, numbers.Real): self._verify_seconds(expires, 'expires') now = now or timezone = timezone or expires = maybe_make_aware( now + timedelta(seconds=expires), tz=timezone, ) if not isinstance(eta, str): eta = eta and eta.isoformat() # If we retry a task `expires` will already be ISO8601-formatted. if not isinstance(expires, str): expires = expires and expires.isoformat() if argsrepr is None: argsrepr = saferepr(args, self.argsrepr_maxsize) if kwargsrepr is None: kwargsrepr = saferepr(kwargs, self.kwargsrepr_maxsize) if not root_id: # empty root_id defaults to task_id root_id = task_id return task_message( headers={ 'lang': 'py', 'task': name, 'id': task_id, 'shadow': shadow, 'eta': eta, 'expires': expires, 'group': group_id, 'group_index': group_index, 'retries': retries, 'timelimit': [time_limit, soft_time_limit], 'root_id': root_id, 'parent_id': parent_id, 'argsrepr': argsrepr, 'kwargsrepr': kwargsrepr, 'origin': origin or anon_nodename(), 'ignore_result': ignore_result, }, properties={ 'correlation_id': task_id, 'reply_to': reply_to or '', }, body=( args, kwargs, { 'callbacks': callbacks, 'errbacks': errbacks, 'chain': chain, 'chord': chord, }, ), sent_event={ 'uuid': task_id, 'root_id': root_id, 'parent_id': parent_id, 'name': name, 'args': argsrepr, 'kwargs': kwargsrepr, 'retries': retries, 'eta': eta, 'expires': expires, } if create_sent_event else None, ) def as_task_v1(self, task_id, name, args=None, kwargs=None, countdown=None, eta=None, group_id=None, group_index=None, expires=None, retries=0, chord=None, callbacks=None, errbacks=None, reply_to=None, time_limit=None, soft_time_limit=None, create_sent_event=False, root_id=None, parent_id=None, shadow=None, now=None, timezone=None, **compat_kwargs): args = args or () kwargs = kwargs or {} utc = self.utc if not isinstance(args, (list, tuple)): raise TypeError('task args must be a list or tuple') if not isinstance(kwargs, Mapping): raise TypeError('task keyword arguments must be a mapping') if countdown: # convert countdown to ETA self._verify_seconds(countdown, 'countdown') now = now or eta = now + timedelta(seconds=countdown) if isinstance(expires, numbers.Real): self._verify_seconds(expires, 'expires') now = now or expires = now + timedelta(seconds=expires) eta = eta and eta.isoformat() expires = expires and expires.isoformat() return task_message( headers={}, properties={ 'correlation_id': task_id, 'reply_to': reply_to or '', }, body={ 'task': name, 'id': task_id, 'args': args, 'kwargs': kwargs, 'group': group_id, 'group_index': group_index, 'retries': retries, 'eta': eta, 'expires': expires, 'utc': utc, 'callbacks': callbacks, 'errbacks': errbacks, 'timelimit': (time_limit, soft_time_limit), 'taskset': group_id, 'chord': chord, }, sent_event={ 'uuid': task_id, 'name': name, 'args': saferepr(args), 'kwargs': saferepr(kwargs), 'retries': retries, 'eta': eta, 'expires': expires, } if create_sent_event else None, ) def _verify_seconds(self, s, what): if s < INT_MIN: raise ValueError(f'{what} is out of range: {s!r}') return s def _create_task_sender(self): default_retry = default_policy = default_delivery_mode = default_queue = self.default_queue queues = self.queues send_before_publish = signals.before_task_publish.send before_receivers = signals.before_task_publish.receivers send_after_publish = signals.after_task_publish.send after_receivers = signals.after_task_publish.receivers send_task_sent = signals.task_sent.send # XXX compat sent_receivers = signals.task_sent.receivers default_evd = self._event_dispatcher default_exchange = self.default_exchange default_rkey = default_serializer = default_compressor = def send_task_message(producer, name, message, exchange=None, routing_key=None, queue=None, event_dispatcher=None, retry=None, retry_policy=None, serializer=None, delivery_mode=None, compression=None, declare=None, headers=None, exchange_type=None, **kwargs): retry = default_retry if retry is None else retry headers2, properties, body, sent_event = message if headers: headers2.update(headers) if kwargs: properties.update(kwargs) qname = queue if queue is None and exchange is None: queue = default_queue if queue is not None: if isinstance(queue, str): qname, queue = queue, queues[queue] else: qname = if delivery_mode is None: try: delivery_mode = except AttributeError: pass delivery_mode = delivery_mode or default_delivery_mode if exchange_type is None: try: exchange_type = except AttributeError: exchange_type = 'direct' # convert to anon-exchange, when exchange not set and direct ex. if (not exchange or not routing_key) and exchange_type == 'direct': exchange, routing_key = '', qname elif exchange is None: # not topic exchange, and exchange not undefined exchange = or default_exchange routing_key = routing_key or queue.routing_key or default_rkey if declare is None and queue and not isinstance(queue, Broadcast): declare = [queue] # merge default and custom policy retry = default_retry if retry is None else retry _rp = (dict(default_policy, **retry_policy) if retry_policy else default_policy) if before_receivers: send_before_publish( sender=name, body=body, exchange=exchange, routing_key=routing_key, declare=declare, headers=headers2, properties=properties, retry_policy=retry_policy, ) ret = producer.publish( body, exchange=exchange, routing_key=routing_key, serializer=serializer or default_serializer, compression=compression or default_compressor, retry=retry, retry_policy=_rp, delivery_mode=delivery_mode, declare=declare, headers=headers2, **properties ) if after_receivers: send_after_publish(sender=name, body=body, headers=headers2, exchange=exchange, routing_key=routing_key) if sent_receivers: # XXX deprecated if isinstance(body, tuple): # protocol version 2 send_task_sent( sender=name, task_id=headers2['id'], task=name, args=body[0], kwargs=body[1], eta=headers2['eta'], taskset=headers2['group'], ) else: # protocol version 1 send_task_sent( sender=name, task_id=body['id'], task=name, args=body['args'], kwargs=body['kwargs'], eta=body['eta'], taskset=body['taskset'], ) if sent_event: evd = event_dispatcher or default_evd exname = exchange if isinstance(exname, Exchange): exname = sent_event.update({ 'queue': qname, 'exchange': exname, 'routing_key': routing_key, }) evd.publish('task-sent', sent_event, producer, retry=retry, retry_policy=retry_policy) return ret return send_task_message @cached_property def default_queue(self): return self.queues[] @cached_property def queues(self): """Queue name⇒ declaration mapping.""" return self.Queues( @queues.setter def queues(self, queues): return self.Queues(queues) @property def routes(self): if self._rtable is None: self.flush_routes() return self._rtable @cached_property def router(self): return self.Router() @router.setter def router(self, value): return value @property def producer_pool(self): if self._producer_pool is None: self._producer_pool = pools.producers[] self._producer_pool.limit = return self._producer_pool publisher_pool = producer_pool # compat alias @cached_property def default_exchange(self): return Exchange(, @cached_property def utc(self): return @cached_property def _event_dispatcher(self): # We call Dispatcher.publish with a custom producer # so don't need the diuspatcher to be enabled. return def _handle_conf_update(self, *args, **kwargs): if ('task_routes' in kwargs or 'task_routes' in args): self.flush_routes() self.router = self.Router() return