Struct WindowCleanupCascade 

pub struct WindowCleanupCascade {
    closed_label: String,
    drained_pool: Option<bool>,
    phase: Phase,
}

Window-cleanup-cascade saga: fires once per window close, drives the implicit pane-reap + pool-drain-decision flow into an explicit two-step state machine, then completes.

Fields

closed_label: String

Label of the window that closed (the trigger event’s payload). The saga uses this for label-matching on terminal events: PanesReaped { label } only advances Step 1 when label matches; same for PoolDrained/PoolNotLast in Step 2.

Note: under the coordinator’s evict-and-replace policy, only one window-cleanup-cascade saga is ever in flight at a time, so label-matching is technically redundant for correctness. Keep it anyway as cheap defense-in-depth + a clear invariant-statement: “this saga belongs to this window’s cleanup, not whoever’s terminal event happens to land first.”

drained_pool: Option<bool>

Whether the host’s drain decision said “yes, that was the last window” (PoolDrained arm) or “no, more windows remain” (PoolNotLast arm). None until Step 2 resolves. Exported for tests.

phase: Phase

Implementations

impl WindowCleanupCascade

pub fn new(closed_label: String) -> Self

Construct a fresh saga for a close of closed_label. Coordinator allocates the saga_id and calls start once.

Trait Implementations

impl Saga for WindowCleanupCascade

fn input_snapshot(&self) -> Value

LSD-2 — record the closing window’s label for --diag sagas. drained_pool is None at start (only known after Step 2) so we don’t include it; the durable log captures the inputs the saga was constructed with, not its evolving state — that lives in step rows.

fn timeout(&self) -> Duration

CPD-3 — override the default 5s saga timeout. Pane drain (Stage 1 of wrr’s two-stage close cascade) on a workspace with many panes can legitimately take longer than 5s. Per SPEC_CROSS_PROCESS_DISPATCH §3.10.

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

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

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