SharedResourceSubscriptions class

Reference-counted resources/subscribe over a client several consumers share.

A device subscription is a property of the LINK, not of whoever asked for it: the server knows only "subscribed" or "not". Once one connection per device is shared — a device's own screen and a composed tile naming the same device — two consumers end up on one subscription, and the first to release it stops the stream for the other. Observed as a composed tile that streamed until the device's own screen was visited and closed, after which it froze and only moved one step per manual Subscribe.

So the wire call is made when the count goes 0 → 1, and again when it returns to 0. Everything in between is bookkeeping.

Counts hang off the client itself (an Expando), so they are shared by every consumer of that client without threading a registry through, and they disappear with it — no map to clean up when a device goes away.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

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

Static Methods

countFor(Client client, String uri) → int

How many consumers currently hold uri. For tests and diagnostics.

subscribe(Client client, String uri) → Future<void>

Subscribes on the wire only for the FIRST consumer of uri.

unsubscribe(Client client, String uri) → Future<void>

Unsubscribes on the wire only when the LAST consumer of uri releases.