ReadableByteStreamController: close() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Note: This feature is available inWeb Workers.

Theclose() method of theReadableByteStreamController interface closes the associated stream.

This might be called by the underlying source when its data source has been exhausted/completed.

Note:Readers will still be able to read any previously-enqueued chunks from the stream, but once those are read, the stream will become closed.However if there is an outstanding and partially writtenbyobRequest whenclose() is called, the stream will be errored.

Syntax

close()

Parameters

None.

Return value

None (undefined).

Exceptions

TypeError: Thrown if the source object is not aReadableByteStreamController, it is already closed, or the stream is not readable for some other reason.

Examples

The example inUsing readable byte streams > Creating a readable socket push byte stream how we might close the stream when there is no more data.

The relevant code is reproduced below.This relies on the hypotheticalreadInto() method returning 0 bytes only when there is no more data.

bytesRead = socket.readInto(v.buffer, v.byteOffset, v.byteLength);if (bytesRead === 0) {  controller.close();}

After calling close, the stream will be closed, and any consumers signalled.For example if using aReadableStreamBYOBReader anyread() requests would resolve withdone: true and the promise fromReadableStreamBYOBReader.closed would also be resolved.