Class Future (2.2.0)

Future(completed=None)

This future object is returned from asychronous Pub/Sub publishing calls.

Calling result will resolve the future by returning the message ID, unless an error occurs.

Methods

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.

Parameter
Name	Description
`callback`	`Callable` The function to call.

cancel()

Actions in Pub/Sub generally may not be canceled.

This method always returns False.

cancelled()

Actions in Pub/Sub generally may not be canceled.

This method always returns False.

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.

Parameter
Name	Description
`timeout`	`Union[int, float]` The number of seconds before this call times out and raises TimeoutError.

Exceptions
Type	Description
`concurrent.futures.TimeoutError`	If the request times out.

Returns
Type	Description
`Exception`	The exception raised by the call, if any.

result(timeout=None)

Return the message ID or raise an exception.

This blocks until the message has been published successfully and returns the message ID unless an exception is raised.

Parameter
Name	Description
`timeout`	`Union[int, float]` The number of seconds before this call times out and raises TimeoutError.

Exceptions
Type	Description
`concurrent.futures.TimeoutError`	If the request times out.
`Exception`	For undefined exceptions in the underlying call execution.

Returns
Type	Description
`str`	The message ID.

running()

Actions in Pub/Sub generally may not be canceled.

Returns
Type	Description
`bool`	`True` if this method has not yet completed, or `False` if it has completed.

set_exception(exception)

Set the result of the future to the given exception.

Parameter
Name	Description
`exception`	`Exception` The exception raised.

set_result(result)

Set the result of the future to the provided result.

Parameter
Name	Description
`result`	`Any` The result