Throttling

When you pass the throttle option (in milliseconds) when constructing a Tabus, emit() limits how often messages are actually sent through the transport.

interface TabusOptions {
  throttle?: number; // minimum ms between emitted messages (default: 0, no throttle)
  trailing?: boolean; // emit the last pending message when the window expires (default: true)
}

Leading + trailing edge

Leading edge: the first call within a “window” is emitted immediately.
Subsequent calls within the window: aren’t emitted instantly; instead they replace a pending message (only the last one is kept).
Trailing edge (if trailing !== false): when the window expires, the saved pending message is emitted automatically.
If trailing: false, intermediate messages are silently dropped and only the leading edge is honored.
destroy() cancels any pending trailing timer and discards the pending message — nothing is emitted after the instance is destroyed.

Example: cursor at ~60fps

const bus = new Tabus("canvas", { throttle: 16 }); // ~60fps

// If called many times in a row (e.g. on mousemove):
bus.emit("cursor", { x: 10, y: 20 }); // emitted RIGHT NOW (leading edge)
bus.emit("cursor", { x: 11, y: 21 }); // saved as pending
bus.emit("cursor", { x: 12, y: 22 }); // replaces the previous pending one
// ...once 16ms have passed since the last leading emit,
// the LAST pending payload is emitted automatically: { x: 12, y: 22 }

With trailing: false, only { x: 10, y: 20 } would be emitted and the rest would be lost.

When to use `trailing: false`

Use it when the intermediate value doesn’t matter and the only thing that’s relevant is reacting quickly to the first event of a burst — for example, a “something changed” notice where you don’t care about the last state, only that it happened.

Next step

Check out the full real-time cursor example, which uses this same throttle pattern on a mousemove.