SyncDriver class

Full-duplex reliable-sync loop driver (spec § SyncDriver).

One driver drives one peer connection over a caller-supplied IpcSink / IpcSource pair. It composes the three pure-protocol pieces into the loop shape the spec pins:

  1. resync-on-reconnect — onReconnect arms a replay of the unacked outbox suffix from the peer's ack cursor and re-advertises our receiver cursor, so a dropped-frame gap converges;
  2. drain — pop host-enqueued outbound data frames, DurableOutbox.append each before sending (at-least-once durability), send via the sink;
  3. retain-on-fail — a send error leaves the frame in the outbox (unacked) and stops the drain; it is re-sent on the next reconnect;
  4. receive — read inbound frames, route control frames (OutboxAck → advance retention; ResyncRequest → answer with a provider snapshot) and feed data frames through the ResyncCoordinator.

The driver owns no threads, no clock source, and no storage engine — the host injects all three (Clock, the transport pair, the outbox) and decides the tick cadence.

Constructors

SyncDriver({required IpcSink sink, required IpcSource source, required DurableOutbox outbox, required Clock clock, required SnapshotProvider provider, Epoch lastEpoch = 0})
A driver whose receiver has already applied through lastEpoch (0 = fresh; a Snapshot seeds the first epoch — resume otherwise).

Properties

hashCode → int
The hash code for this object.
no setterinherited
outbox → DurableOutbox
The underlying outbox (diagnostics / durable-store flush).
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

enqueue(Epoch epoch, IpcMessage msg) → void
Stage an outbound data frame at epoch for the next tick's drain. epoch is the frame's accepted-event count (Delta.epoch / Snapshot.epoch); it becomes the outbox retention key.
isStalled() → bool
Whether the sink is currently stalled (last send failed, awaiting reconnect).
lastEpoch() → int
The receiver's current applied epoch.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
onReconnect() → void
Signal that the transport was re-established; the next tick replays the unacked outbox suffix and re-advertises our receiver cursor.
stalledFor(int now) → int
Millis the sink has been stalled as of now, or 0 when healthy — a backoff signal for the host scheduler (which owns cadence/backoff policy).
tick() → Progress
Run one loop pass. See the class docs for the resync → drain → retain → receive shape. Sink failures retain-and-stall (not an error); only an inbound source read failure throws DriverError.
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited