CountQueuingStrategy: CountQueuingStrategy() constructor

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since June 2022.

Note: This feature is available in Web Workers.

The CountQueuingStrategy() constructor creates and returns a CountQueuingStrategy object instance.

Syntax

new CountQueuingStrategy(options)

Parameters

options

An object with the following property:

highWaterMark: The total number of chunks that can be contained in the internal queue before backpressure is applied.

Return value

An instance of the CountQueuingStrategy object.

Exceptions

None.

Examples

const queuingStrategy = new CountQueuingStrategy({ highWaterMark: 1 });

const writableStream = new WritableStream(
  {
    // Implement the sink
    write(chunk) {
      // …
    },
    close() {
      // …
    },
    abort(err) {
      console.log("Sink error:", err);
    },
  },
  queuingStrategy,
);

const size = queuingStrategy.size();

Specifications

Specification
Streams # ref-for-cqs-constructor①