Common Utilities - kombu.common

kombu.common

Common Utilities.

class kombu.common.Broadcast(name=None, queue=None, **kwargs)

Convenience class used to define broadcast queues.

Every queue instance will have a unique name, and both the queue and exchange is configured with auto deletion.

Parameters:

• name – This is used as the name of the exchange.
• queue – By default a unique id is used for the queue name for every consumer. You can specify a custom queue name here.
• **kwargs – See Queue for a list of additional keyword arguments supported.

kombu.common.maybe_declare(entity, channel=None, retry=False, **retry_policy)

kombu.common.uuid()

Generate a unique id, having - hopefully - a very small chance of collision.

For now this is provided by uuid.uuid4().

kombu.common.itermessages(conn, channel, queue, limit=1, timeout=None, callbacks=None, **kwargs)

kombu.common.send_reply(exchange, req, msg, producer=None, retry=False, retry_policy=None, **props)

Send reply for request.

Parameters:

• exchange – Reply exchange
• req – Original request, a message with a reply_to property.
• producer – Producer instance
• retry – If true must retry according to reply_policy argument.
• retry_policy – Retry settings.
• props – Extra properties

kombu.common.collect_replies(conn, channel, queue, *args, **kwargs)

Generator collecting replies from queue

kombu.common.insured(pool, fun, args, kwargs, errback=None, on_revive=None, **opts)

Ensures function performing broker commands completes despite intermittent connection failures.

kombu.common.drain_consumer(consumer, limit=1, timeout=None, callbacks=None)

kombu.common.eventloop(conn, limit=None, timeout=None, ignore_timeouts=False)

Best practice generator wrapper around Connection.drain_events.

Able to drain events forever, with a limit, and optionally ignoring timeout errors (a timeout of 1 is often used in environments where the socket can get “stuck”, and is a best practice for Kombu consumers).

Examples

eventloop is a generator:

from kombu.common import eventloop

def run(connection):
    it = eventloop(connection, timeout=1, ignore_timeouts=True)
    next(it)   # one event consumed, or timed out.

    for _ in eventloop(connection, timeout=1, ignore_timeouts=True):
        pass  # loop forever.

It also takes an optional limit parameter, and timeout errors are propagated by default:

for _ in eventloop(connection, limit=1, timeout=1):
    pass

See also

itermessages(), which is an event loop bound to one or more consumers, that yields any messages received.