ReadableStreamDefaultController: desiredSize property

{{APIRef("Streams")}}{{AvailableInWorkers}}

The desiredSize read-only property of the {{domxref("ReadableStreamDefaultController")}} interface returns the desired size required to fill the stream's internal queue.

Value

An integer. Note that this can be negative if the queue is over-full.

Examples

The A readable stream with an underlying push source and backpressure support example in the spec provides a good example of using desiredSize to manually detect when the stream is full and apply backpressure, and also of using {{domxref("ReadableStreamDefaultController.error()")}} to manually trigger a stream error if another part of the system it relies on fails.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Using readable streams
• {{domxref("ReadableStreamDefaultController")}}