Session class

A Zenoh session.

Wraps z_owned_session_t. Use Session.open to create a session, optionally passing a Config. Call close when done to gracefully shut down the session and release native resources.

This object holds a native handle, so it cannot cross an isolate boundary: a copy would share this one's native address while carrying its own fresh disposal flag, and the second release would be a use-after-free. Sending it throws ArgumentError naming the class.

⛔ No NativeFinalizer is attached to this class, deliberately: its release is documented UNDEFINED BEHAVIOUR from a finalizer callback: z_close drops closures that call Dart_PostCObject_DL, a Dart C API, and a finalizer callback runs with no current isolate. It is also collected while its children are still live. Releasing it explicitly is therefore the only thing that reclaims it.

Implemented types
Available extensions

Properties

hashCode → int
The hash code for this object.
no setterinherited
isClosed → bool
Whether this session has been closed.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
zid → ZenohId
Returns the ZenohId of this session.
no setter

Methods

close() → void
Gracefully closes the session and releases native resources.
declareAdvancedPublisher(Object keyExpr, {AdvancedPublisherOptions? options}) → AdvancedPublisher

Available on Session, provided by the AdvancedSession extension

Declares an advanced publisher on the given keyExpr.
declareAdvancedSubscriber(Object keyExpr, {AdvancedSubscriberOptions options = const AdvancedSubscriberOptions()}) → AdvancedSubscriber

Available on Session, provided by the AdvancedSession extension

Declares an advanced subscriber on the given keyExpr.
declareBackgroundLivelinessSubscriber(Object keyExpr, {bool history = false, bool retainPayload = false}) → Stream<Sample>
Declares a fire-and-forget background subscriber on liveliness tokens intersecting keyExpr.
declareBackgroundQueryable(Object keyExpr, {bool complete = false, Locality? allowedOrigin}) → Stream<Query>
Declares a fire-and-forget background queryable on the given keyExpr.
declareBackgroundSubscriber(Object keyExpr, {Locality? allowedOrigin, bool retainPayload = false}) → Stream<Sample>
Declares a background subscriber on the given keyExpr.
declareKeyExpr(Object keyExpr) → KeyExpr
Declares keyExpr on this session and returns an owned KeyExpr.
declareLivelinessSubscriber(Object keyExpr, {bool history = false, bool retainPayload = false}) → Subscriber
Declares a liveliness subscriber on the given keyExpr.
declareLivelinessToken(Object keyExpr) → LivelinessToken
Declares a liveliness token on the given keyExpr.
declarePublisher(Object keyExpr, {Encoding? encoding, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination, bool enableMatchingListener = false}) → Publisher
Declares a publisher on the given keyExpr.
declarePullLivelinessSubscriber(Object keyExpr, {required ChannelKind kind, required int capacity, bool history = false, bool retainPayload = false}) → PullSubscriber
Declares a liveliness subscriber whose transitions land in a bounded channel, and returns the shipped PullSubscriber to take them out of.
declarePullQueryable(Object keyExpr, {required ChannelKind kind, required int capacity, bool complete = false, Locality? allowedOrigin}) → PullQueryable
Declares a queryable whose queries land in a bounded channel instead of a stream, and returns a PullQueryable to take them out of.
declarePullSubscriber(Object keyExpr, {ChannelKind kind = ChannelKind.ring, int capacity = 256, Locality? allowedOrigin, bool retainPayload = false}) → PullSubscriber
Declares a pull subscriber on the given keyExpr.
declareQuerier(Object keyExpr, {QueryTarget target = QueryTarget.bestMatching, ConsolidationMode consolidation = ConsolidationMode.auto, Duration? timeout, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination, ReplyKeyExpr? acceptReplies, bool enableMatchingListener = false}) → Querier
Declares a querier on the given keyExpr.
declareQueryable(Object keyExpr, {bool complete = false, Locality? allowedOrigin}) → Queryable
Declares a queryable on the given keyExpr.
declareSubscriber(Object keyExpr, {Locality? allowedOrigin, bool retainPayload = false}) → Subscriber
Declares a subscriber on the given keyExpr.
deleteResource(Object keyExpr, {Timestamp? timestamp, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination}) → void
Deletes a resource on the given keyExpr.
get(Object selector, {String? parameters, ZBytes? payload, Encoding? encoding, ZBytes? attachment, QueryTarget target = QueryTarget.bestMatching, ConsolidationMode consolidation = ConsolidationMode.auto, Duration? timeout, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination, ReplyKeyExpr? acceptReplies, bool retainPayload = false}) → Stream<Reply>
Sends a query on the given selector and returns a stream of replies.
livelinessGet(Object keyExpr, {Duration? timeout, bool retainPayload = false}) → Stream<Reply>
Queries liveliness tokens matching the given keyExpr.
newTimestamp() → Timestamp
Creates a new timestamp from this session's HLC clock.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
peersZid() → List<ZenohId>
Returns the ZenohIds of all connected peers.
pullGet(Object selector, {required ChannelKind kind, required int capacity, String? parameters, ZBytes? payload, Encoding? encoding, ZBytes? attachment, QueryTarget target = QueryTarget.bestMatching, ConsolidationMode consolidation = ConsolidationMode.auto, Duration? timeout, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination, ReplyKeyExpr? acceptReplies, bool retainPayload = false}) → PullReplies
Sends a query whose replies land in a bounded channel instead of a stream, and returns a PullReplies handle to take them out of.
pullLivelinessGet(Object keyExpr, {required ChannelKind kind, required int capacity, Duration? timeout, bool retainPayload = false}) → PullReplies
Queries liveliness tokens, with replies landing in a bounded channel instead of a stream.
put(Object keyExpr, String value, {Encoding? encoding, ZBytes? attachment, Timestamp? timestamp, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination}) → void
Publishes a string value on the given keyExpr.
putBytes(Object keyExpr, ZBytes payload, {Encoding? encoding, ZBytes? attachment, Timestamp? timestamp, CongestionControl? congestionControl, Priority? priority, bool? isExpress, Locality? allowedDestination}) → void
Publishes a ZBytes payload on the given keyExpr.
routersZid() → List<ZenohId>
Returns the ZenohIds of all connected routers.
toString() → String
A string representation of this object.
inherited
undeclareKeyExpr(KeyExpr keyExpr) → void
Undeclares keyExpr from this session, releasing its numerical id.

Operators

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

Static Methods

open({Config? config}) → Future<Session>
Opens a Zenoh session without blocking the calling isolate.