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  5. ReadableStream BYOBReader

ReadableStreamBYOBReader

​​ Background

BYOB is an abbreviation of bring your own buffer. A ReadableStreamBYOBReader allows reading into a developer-supplied buffer, thus minimizing copies.

An instance of ReadableStreamBYOBReader is functionally identical to ReadableStreamDefaultReader with the exception of the read method.

A ReadableStreamBYOBReader is not instantiated via its constructor. Rather, it is retrieved from a ReadableStream:


const { readable, writable } = new TransformStream();

const reader = readable.getReader({ mode: 'byob' });

​​ Methods

  • read(bufferArrayBufferView) : Promise<ReadableStreamBYOBReadResult>

    • Returns a promise with the next available chunk of data read into a passed-in buffer.

  • readAtLeast(minBytes, bufferArrayBufferView) : Promise<ReadableStreamBYOBReadResult>

    • Returns a promise with the next available chunk of data read into a passed-in buffer. The promise will not resolve until at least minBytes have been read.

​​ Common issues