OutboundQueue class

A single FIFO for every outbound frame, with two admission lanes.

Constructors

OutboundQueue({required Future<void> send(Uint8List bytes), bool isReady()?, bool canSend(Uint8List bytes)?, bool Function() createSendGuard(Uint8List bytes)?, bool Function() createDecodedSendGuard(String type, Map<String, Object?> payload)?, void onDropped(String type)?, Uint8List? substituteOnReject(String type, Uint8List bytes, String reason)?, int? maxPayloadBytes, int maxAttempts = 3, Duration backoffBase = const Duration(milliseconds: 200), int lossyCap = 32, int guaranteedCap = 64, Duration readyPoll = const Duration(milliseconds: 250), Future<void> sleep(Duration)?})

Properties

backoffBase → Duration

final

canSend → bool Function(Uint8List bytes)?

Rechecked at delivery time, including retries, so policy changes while offline cannot release an old UI frame after reconnecting.

final

createDecodedSendGuard → bool Function() Function(String type, Map<String, Object?> payload)?

createSendGuard for producers that already hold the decoded frame (see enqueue's payload): the guard reads the map instead of decoding the bytes a second time. Takes precedence when a payload is supplied; otherwise createSendGuard (if any) is used.

final

createSendGuard → bool Function() Function(Uint8List bytes)?

Called once at enqueue to freeze origin context for this frame. The resulting guard is rechecked before every delivery attempt, alongside canSend, so later frames cannot overwrite an older frame's identity.

final

droppedGuaranteed ↔ int

Guaranteed frames lost to overflow or attempt exhaustion — should be 0 in any healthy session; a nonzero value is a real signal.

getter/setter pair

droppedLossy ↔ int

Lossy frames evicted or exhausted (Android droppedFrames).

getter/setter pair

guaranteedCap → int

final

hashCode → int

The hash code for this object.

no setter, inherited

isReady → bool Function()?

Transport readiness (room Connected).

final

lossyCap → int

final

maxAttempts → int

final

maxPayloadBytes → int?

Optional final transport guard for all frame types, measured on the encoded bytes. Producers may trim/chunk beforehand; the queue only drops.

final

onDropped → void Function(String type)?

Called with the frame type when a frame is discarded under cap pressure, policy, or exhausted retries. A missing ui_diff and its queued dependents produce one notification to request a replacement baseline.

final

readyPoll → Duration

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

send → Future<void> Function(Uint8List bytes)

Deliver one frame.

final

substituteOnReject → Uint8List? Function(String type, Uint8List bytes, String reason)?

Asked when POLICY (not transport) rejects a guaranteed frame, at enqueue size check or at delivery. A non-null result is delivered in its place, without the policy guard — it must carry no screen content. This is how a request/response frame the backend is waiting on (info_query_response, find_candidates_response) becomes an explicit failure instead of a silent drop that leaves the agent waiting for a timeout.

final

Methods

dispose() → void

enqueue(String type, Uint8List bytes, {Map<String, Object?>? payload}) → void

Enqueue by wire type. payload is the already-decoded frame when the producer has it — passed to createDecodedSendGuard so no frame is decoded more than once on its way out.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited