The naive approach to creating a ReadableStream from a Buffer is to use the ReadableStream constructor and enqueue the entire array as a single chunk. For a large buffer, this may be undesirable as this approach does not "streaming" the data in smaller chunks.
const buf = Buffer.from("hello world");
const stream = new ReadableStream({
start(controller) {
controller.enqueue(buf);
controller.close();
},
});
To stream the data in smaller chunks, first create a Blob instance from the Buffer. Then use the Blob.stream() method to create a ReadableStream that streams the data in chunks of a specified size.
const buf = Buffer.from("hello world");
const blob = new Blob([buf]);
const stream = blob.stream();
The chunk size can be set by passing a number to the .stream() method.
const buf = Buffer.from("hello world");
const blob = new Blob([buf]);
// set chunk size of 1024 bytes
const stream = blob.stream(1024);
See Docs > API > Binary Data for complete documentation on manipulating binary data with Bun.