Web/API/CountQueuingStrategy

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The CountQueuingStrategy interface of the the Streams API provides a built-in chunk counting queuing strategy that can be used when constructing streams.

Constructor

CountQueuingStrategy(): Creates a new CountQueuingStrategy object instance.

Properties

None.

Methods

CountQueuingStrategy.size(): Returns 1.

Examples

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

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

var size = queueingStrategy.size();

Specifications

Specification	Status	Comment
StreamsThe definition of 'CountQueuingStrategy' in that specification.	Living Standard	Initial definition.

Browser Compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`CountQueuingStrategy` Experimental'	Chrome Full support 59	Edge Full support 16	Firefox Full support 57 Disabled' Full support 57 Disabled' Disabled' From version 57: this feature is behind the `dom.streams.enabled` preference (needs to be set to `true`) and the `javascript.options.streams` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 46	Safari ?	WebView Android Full support 59	Chrome Android Full support 59	Firefox Android Full support 57 Disabled' Full support 57 Disabled' Disabled' From version 57: this feature is behind the `dom.streams.enabled` preference (needs to be set to `true`) and the `javascript.options.streams` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android Full support 43	Safari iOS ?	Samsung Internet Android Full support 7.0
`CountQueuingStrategy()` constructor Experimental'	Chrome Full support 59	Edge Full support 16	Firefox Full support 57 Disabled' Full support 57 Disabled' Disabled' From version 57: this feature is behind the `dom.streams.enabled` preference (needs to be set to `true`) and the `javascript.options.streams` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 46	Safari ?	WebView Android Full support 59	Chrome Android Full support 59	Firefox Android Full support 57 Disabled' Full support 57 Disabled' Disabled' From version 57: this feature is behind the `dom.streams.enabled` preference (needs to be set to `true`) and the `javascript.options.streams` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android Full support 43	Safari iOS ?	Samsung Internet Android Full support 7.0
`size` Experimental'	Chrome Full support 59	Edge Full support 16	Firefox Full support 57 Disabled' Full support 57 Disabled' Disabled' From version 57: this feature is behind the `dom.streams.enabled` preference (needs to be set to `true`) and the `javascript.options.streams` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 46	Safari ?	WebView Android Full support 59	Chrome Android Full support 59	Firefox Android Full support 57 Disabled' Full support 57 Disabled' Disabled' From version 57: this feature is behind the `dom.streams.enabled` preference (needs to be set to `true`) and the `javascript.options.streams` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android Full support 43	Safari iOS ?	Samsung Internet Android Full support 7.0

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.': User must explicitly enable this feature.

CountQueuingStrategy by Mozilla Contributors is licensed under CC-BY-SA 2.5.