WritableStreamDefaultWriter: desiredSize property
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since May 2022.
Note: This feature is available in Web Workers.
The desiredSize read-only property of the
WritableStreamDefaultWriter 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.
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
const size = writer.desiredSize;
Specifications
| Specification |
|---|
| Streams # ref-for-default-writer-desired-size⑥ |
Browser compatibility
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desiredSize
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