The desiredSize read-only property of the ReadableStreamDefaultController interface returns the desired size required to fill the stream's internal queue.
ReadableStreamDefaultController.desiredSize
Value
An integer. Note that this can be negative if the queue is over-full.
Examples
The A readable stream with an underlying push source and backpressure support example in the spec provides a good example of using desiredSize to manually detect when the stream is full and apply backpressure, and also of using ReadablestreamDefaultController.error() to manually trigger a stream error if another part of the system it relies on fails.
Specifications
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 |
89
|
89
|
65
|
No
|
75
|
No
|
89
|
89
|
65
|
63
|
No
|
15.0
|
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https://developer.mozilla.org/en-US/docs/Web/API/ReadableStreamDefaultController/desiredSize
