Reactor

A Reactor is the long-lived process that binds a set of named Accumulators to a Computation Graph, maintains an input cache from the Boundary events they emit, and fires the graph when its criteria are satisfied. The firing criterion is a top-level primitive: a graph subscribes to a reactor by name.

Mental model

A reactor declares which accumulators feed it and a criterion: when_any (fire when any source has new data) or when_all (wait for all).
It keeps an input cache and an input strategy — latest (overwrite with newest) or sequential.
When the criterion is met, it calls the compiled graph with the current cache.

Interfaces

Rust

#[reactor] declares the reactor as a top-level primitive on a struct:

#[cloacina_macros::reactor(
    name = "pricing_reactor",
    accumulators = [orderbook],
    criteria = when_any(orderbook),
)]
pub struct PricingReactor;

(The lower-level runtime exposes Reactor::new(graph_fn, ReactionCriteria::WhenAny, InputStrategy::Latest, …) — see the embedded tutorials.)

Python

@cloaca.reactor decorates a class; criteria is the mode argument:

import cloaca

@cloaca.reactor(
    name="pricing_reactor",
    accumulators=["orderbook"],
    mode="when_any",        # or "when_all"
)
class PricingReactor:
    pass

Key facts

Criteria: when_any / when_all over the named accumulator sources.
Input strategy: latest or sequential (Rust InputStrategy).
Naming: the accumulators names must match the accumulator source names and the graph’s entry-node source names.

Reactor

Reactor

Mental model

Interfaces

Key facts

See also