The desiredSize read-only property of the WritableStreamDefaultWriter interface returns the desired size required to fill the stream's internal queue.
The desiredSize read-only property of the WritableStreamDefaultWriter interface returns the desired size required to fill the stream's internal queue.
An integer. Note that this can be negative if the queue is over-full.
The value will be null if the stream cannot be successfully written to (due to either being errored, or having an abort queued up), and zero if the stream is closed.
TypeErrorThe writer's lock is released.
js
const writableStream = new WritableStream( { write(chunk) { // ... }, close() { // ... }, abort(err) { // ... }, }, queuingStrategy, ); // ... const writer = writableStream.getWriter(); // ... // return stream's desired size let size = writer.desiredSize;
| Specification |
|---|
| Streams Standard # ref-for-default-writer-desired-size⑥ |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
desiredSize |
59 | 16 | 100 | No | 46 | 14.1 | 59 | 59 | 100 | 43 | 14.5 | 7.0 |
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https://developer.mozilla.org/en-US/docs/Web/API/WritableStreamDefaultWriter/desiredSize