blatann.waitables.waitable module¶
- class blatann.waitables.waitable.Waitable(n_args=1)¶
Bases:
object
Base class for an object which can be waited on for an operation to complete. This is a similar concept to
concurrent.futures.Future
where asynchronous operations can block the current thread, or register a handler to be called when it completes.- wait(timeout=None, exception_on_timeout=True)¶
Waits for the asynchronous operation to complete
Warning
If this call times out, it cannot be (successfully) called again as it will clean up all event handlers for the waitable. This is done to remove lingering references to the waitable object through event subscriptions
- then(callback)¶
Registers a function callback that will be called when the asynchronous operation completes
Note
Only a single callback is supported– subsequent calls to this method will overwrite previous callbacks
- Parameters
callback (
Callable
) – The function to call when the async operation completes- Returns
This waitable object
- class blatann.waitables.waitable.GenericWaitable(n_args=1)¶
Bases:
Waitable
Simple wrapper of a Waitable object which exposes a
notify
method so external objects can signal/trigger the waitable’s response- notify(*results)¶
- class blatann.waitables.waitable.EmptyWaitable(*args)¶
Bases:
Waitable
Waitable class which will immediately return the args provided when waited on or when a callback function is registered
- wait(timeout=None, exception_on_timeout=True)¶
Waits for the asynchronous operation to complete
Warning
If this call times out, it cannot be (successfully) called again as it will clean up all event handlers for the waitable. This is done to remove lingering references to the waitable object through event subscriptions
- Parameters
timeout – How long to wait, or
None
to wait indefinitelyexception_on_timeout – Flag to either throw an exception on timeout, or instead return
None
object(s)
- Returns
The result of the asynchronous operation
- Raises
TimeoutError
- then(callback)¶
Registers a function callback that will be called when the asynchronous operation completes
Note
Only a single callback is supported– subsequent calls to this method will overwrite previous callbacks
- Parameters
callback – The function to call when the async operation completes
- Returns
This waitable object