ByteLengthQueuingStrategy: highWaterMark property

Note: This feature is available in Web Workers.

Note: Unlike CountQueuingStrategy() where the highWaterMark property specifies a simple count of the number of chunks, with ByteLengthQueuingStrategy(), the highWaterMark parameter specifies a number of bytes — specifically, given a stream of chunks, how many bytes worth of those chunks (rather than a count of how many of those chunks) can be contained in the internal queue before backpressure is applied.

const queuingStrategy = new ByteLengthQueuingStrategy({
 highWaterMark: 1 * 1024,
});
const readableStream = new ReadableStream(
 {
 start(controller) {
 // ...
 },
 pull(controller) {
 // ...
 },
 cancel(err) {
 console.log("stream error:", err);
 },
 },
 queuingStrategy,
);
const size = queuingStrategy.size(chunk);
console.log(`highWaterMark value: ${queuingStrategy.highWaterMark}$`);

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This page was last modified on ⁨Jul 26, 2024⁩ by MDN contributors.