Struct mz_timely_util::activator::RcActivator

pub struct RcActivator { /* private fields */ }

An shared handle to multiple activators with support for triggering and acknowledging activations.

Activations are only triggered once the activate function has been called at least threshold times, and then not again until ack is called. This way, the RcActivator ensures two properties:

• It does not enqueue more than one activation per activator, if there is only one activator registered with this RcActivator. Once multiple activators are registered, any ack will enable more activations.
• The threshold to activation avoids activations purely caused by previous activations. Each scheduling of a logging dataflow potentially creates additional log data, which needs to be processed. The threshold should ensure that multiple activations under no load cause the dataflow to be scheduled. For Materialize’s log dataflows, this number seems to be larger than 32, below we might risk that we do not cause monotonically decreasing work. A value of 64 or larger is recommended, as there is no harm in bigger values. The log dataflow will still pick up all its inputs once every introspection interval, and this activator only creates additional activations.

Implementations

impl RcActivator

pub fn new(name: String, threshold: usize) -> Self

Construct a new RcActivator with the given name and threshold.

The threshold determines now many activations to ignore until scheduling the activation.

pub fn register(&self, activator: Activator)

Register an additional Activator with this RcActivator.

pub fn activate(&self)

Activate all contained activators.

The implementation is free to ignore activations and only release them once a sufficient volume has been accumulated.

pub fn ack(&self)

Acknowledge the activation, which enables new activations to be scheduled.

Trait Implementations

impl ActivatorTrait for RcActivator

fn activate(&self)

Trigger an activation of operators behind this activator.

fn ack(&self)

Acknowledge the receipt of activations from within an operator.

fn register<S: Scope>(&self, scope: &mut S, path: &[usize])

Register a new operator with its path with this activator.

impl Clone for RcActivator

fn clone(&self) -> RcActivator

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RcActivator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.