Futures#

class google.cloud.pubsub_v1.subscriber.futures.StreamingPullFuture(manager)[source]#

Represents a process that asynchronously performs streaming pull and schedules messages to be processed.

This future is resolved when the process is stopped (via cancel()) or if it encounters an unrecoverable error. Calling .result() will cause the calling thread to block indefinitely.

add_done_callback(callback)#

Attach the provided callable to the future.

The provided function is called, with this future as its only argument, when the future finishes running.

Parameters

callback (Callable) – The function to call.

Returns

None

cancel()[source]#

Stops pulling messages and shutdowns the background thread consuming messages.

cancelled()[source]#
Returns

True if the subscription has been cancelled.

Return type

bool

done()#

Return True the future is done, False otherwise.

This still returns True in failure cases; checking result() or exception() is the canonical way to assess success or failure.

exception(timeout=None)#

Return the exception raised by the call, if any.

Parameters

timeout (Union[int, float]) – The number of seconds before this call times out and raises TimeoutError.

Raises

concurrent.futures.TimeoutError – If the request times out.

Returns

The exception raised by the call, if any.

Return type

Exception

result(timeout=None)#

Resolve the future and return a value where appropriate.

Parameters

timeout (Union[int, float]) – The number of seconds before this call times out and raises TimeoutError.

Raises
running()#

Actions in Pub/Sub generally may not be canceled.

Returns

True if this method has not yet completed, or

False if it has completed.

Return type

bool

set_exception(exception)#

Set the result of the future to the given exception.

Parameters

exception (Exception) – The exception raised.

set_result(result)#

Set the result of the future to the provided result.

Parameters

result (Any) – The result