Drainer

Result draining service.

Attributes

Attribute	Type	Description
result_consumer	object	The consumer instance used to drain and process incoming events from the message broker.

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Constructor

Signature

def Drainer(
    result_consumer: Any
) - > null

Parameters

Name	Type	Description
result_consumer	Any	The consumer object responsible for handling or draining results.

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Signature

def Drainer(
    result_consumer: [ResultConsumer](../rpc/resultconsumer.md?sid=celery_backends_rpc_resultconsumer)
)

Parameters

Name	Type	Description
result_consumer	[ResultConsumer](../rpc/resultconsumer.md?sid=celery_backends_rpc_resultconsumer)	The consumer instance responsible for managing event streams and draining operations

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Methods

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start()

@classmethod
def start() - > null

Starts the result draining service.

Returns

Type	Description
null	null

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stop()

@classmethod
def stop() - > null

Stops the result draining service.

Returns

Type	Description
null	null

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drain_events_until()

@classmethod
def drain_events_until(
    p: Predicate,
    timeout: float = None,
    interval: float = 1,
    on_interval: callable = None,
    wait: callable = None
) - > generator

Yields results while draining events until a specific condition is met or a timeout occurs. This method handles recoverable connection errors by logging and retrying after a set interval.

Parameters

Name	Type	Description
p	Predicate	An object with a 'ready' attribute used to determine when the draining loop should terminate
timeout	float = None	The maximum number of seconds to wait before raising a socket.timeout exception
interval	float = 1	The duration in seconds to wait during each individual drain attempt and between retries after connection errors
on_interval	callable = None	An optional callback function executed after each drain attempt regardless of success
wait	callable = None	The underlying function used to drain events, defaulting to the result consumer's drain_events method

Returns

Type	Description
generator	A generator yielding results from the wait_for method until the predicate condition is satisfied

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wait_for()

@classmethod
def wait_for(
    p: Predicate,
    wait: callable,
    timeout: float = None
) - > null

Invokes the provided wait function to block for incoming events until the specified timeout.

Parameters

Name	Type	Description
p	Predicate	The predicate object associated with the event wait operation
wait	callable	The blocking function to call for event processing
timeout	float = None	The maximum time in seconds to block during this specific wait call

Returns

Type	Description
null	null

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