Skip to main content

Saga

agentmux_launcher::saga

Trait Saga 

Source 
pub trait Saga: Send {
    // Required methods
    fn start(&mut self, ctx: &SagaCtx) -> SagaAction;
    fn on_event(&mut self, event: &Event, ctx: &SagaCtx) -> SagaAction;
    fn name(&self) -> &'static str;

    // Provided methods
    fn input_snapshot(&self) -> Value { ... }
    fn timeout(&self) -> Duration { ... }
}
Expand description

A multi-step, multi-reducer state machine. Implementations describe one logical operation (tear-off, pool-respawn, etc.).

Lifecycle: coordinator calls start once when the saga is added to in_flight. After that, every event on the bus is passed to on_event. The saga inspects the event, advances its internal state, returns the next action.

Identification: sagas know which events belong to them by inspecting saga_id in lifecycle events or by matching patterns in event payloads (e.g. specific labels). F.5 sagas correlate by event type only (pool_respawn matches any PoolWindowAdded after start). Per-variant saga_id tagging on commands/events is deferred until concurrent same-type sagas are needed.

Required Methods§

Source

fn start(&mut self, ctx: &SagaCtx) -> SagaAction

Source

fn on_event(&mut self, event: &Event, ctx: &SagaCtx) -> SagaAction

Source

fn name(&self) -> &'static str

Provided Methods§

Source

fn input_snapshot(&self) -> Value

LSD-2 — saga’s input arguments serialized for the durable log’s input_json column. The coordinator calls this once at spawn_saga time (before start) and writes the result via LauncherSagaLog::start_saga. Operators see this in --diag sagas output (e.g. {"closed_label":"win-3"}) so they can tell which window’s cleanup a recovered-failed saga belonged to.

Default Value::Null — sagas with no input fields can ignore it. Concrete sagas should override with a serde_json::json! of their constructor args.

Source

fn timeout(&self) -> Duration

CPD-3 — per-saga deadline budget for completing all IssueCmd+wait cycles. Coordinator arms a timer when the saga registers; if the saga is still in_flight when timeout() elapses, it is force-failed (SagaFailed { reason: "saga timeout" }) and removed from the registry.

Default 5s — fits class-C single-step host dispatch (e.g. pool respawn). WindowCleanupCascade overrides to 30s because pane drain on a workspace with many panes can legitimately take that long. Per spec §3.10.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§