The desiredSize read-only property of the WritableStreamDefaultWriter interface returns the desired size required to fill the stream's internal queue.
WritableStreamDefaultWriter: desiredSize property
Value
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.
Exceptions
-
TypeError -
The writer's lock is released.
Examples
js
const writableStream = new WritableStream(
{
write(chunk) {
// ...
},
close() {
// ...
},
abort(err) {
// ...
},
},
queuingStrategy,
);
// ...
const writer = writableStream.getWriter();
// ...
// return stream's desired size
let size = writer.desiredSize;
Specifications
| Specification |
|---|
| Streams Standard # ref-for-default-writer-desired-size⑥ |
Browser compatibility
| 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