WebTransportSession class

Manages the state of a single WebTransport session over HTTP/3.

A WebTransportSession represents one WebTransport session mapped onto a QUIC bidirectional stream (the session's control stream). Per RFC 9220, endpoints exchange typed capsules on this stream to open streams, send datagrams, drain, or close the session.

The session tracks incoming capsules via onCapsuleReceived, surfacing registered stream IDs and received datagrams. Callers can initiate a graceful close with initiateClose, or send a drain signal with initiateDrain.

Example

final session = WebTransportSession(0);

// Process an incoming datagram WebTransportCapsule.
session.onCapsuleReceived(WebTransportCapsule(
  type: CapsuleType.datagram,
  payload: Uint8List.fromList([1, 2, 3]),
));
print('Datagrams: ${session.receivedDatagrams.length}');

// Gracefully close the session with an error code.
final closeCapsule = session.initiateClose(
  errorCode: 0,
  reasonPhrase: 'done',
);
print('Session closed: ${session.isClosed}');

Constructors

WebTransportSession(int _sessionId): Creates a WebTransport session identified by sessionId.

Properties

hashCode → int: The hash code for this object.
no setterinherited
isActive → bool: Whether the session is still active (not draining and not closed).
no setter
isClosed → bool: Whether the session is fully closed.
no setter
isDraining → bool: Whether the peer has initiated a drain.
no setter
receivedDatagrams → List<Uint8List>: Datagrams received via CapsuleType.datagram capsules.
no setter
receivedGoaway → bool: Whether a GOAWAY WebTransportCapsule has been received from the peer.
no setter
registeredBidirectionalStreams → List<int>: Bidirectional stream IDs registered by the peer.
no setter
registeredUnidirectionalStreams → List<int>: Unidirectional stream IDs registered by the peer.
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
sessionId → int: The QUIC stream ID that serves as this session's identifier.
no setter

Methods

initiateClose({int errorCode = 0, String? reasonPhrase}) → WebTransportCapsule: Initiate a graceful close of this session.
initiateDrain() → WebTransportCapsule: Initiate a drain of this session.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
onCapsuleReceived(WebTransportCapsule capsule) → void: Handle an incoming WebTransportCapsule on the session's control stream.
onCloseAcknowledged() → void: Called when the locally-initiated CLOSE has been acknowledged.
sendDatagram(Uint8List data) → WebTransportCapsule: Send a datagram via a WebTransportCapsule of type CapsuleType.datagram.
sendGoaway({int? streamId}) → GoawayCapsule: Send a GOAWAY WebTransportCapsule to signal that no new sessions will be accepted.
toString() → String: A string representation of this object.
inherited

Operators

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