Method read

lib/internal/webstreams/readablestream.js:1024–1082

* @param {ArrayBufferView} view * @param {{ * min? : number * }} [options] * @returns {Promise<{ * value : ArrayBufferView, * done : boolean, * }>}

(view, options = kEmptyObject)

   * }>}
   */
  async read(view, options = kEmptyObject) {
    if (!isReadableStreamBYOBReader(this))
      throw new ERR_INVALID_THIS('ReadableStreamBYOBReader');
    if (!isArrayBufferView(view)) {
      throw new ERR_INVALID_ARG_TYPE(
        'view',
        [
          'Buffer',
          'TypedArray',
          'DataView',
        ],
        view,
      );
    }
    validateObject(options, 'options', kValidateObjectAllowObjectsAndNull);

    const viewByteLength = ArrayBufferViewGetByteLength(view);
    const viewBuffer = ArrayBufferViewGetBuffer(view);

    if (isSharedArrayBuffer(viewBuffer)) {
      throw new ERR_INVALID_ARG_VALUE(
        'view',
        view,
        'must not be backed by a SharedArrayBuffer',
      );
    }

    const viewBufferByteLength = ArrayBufferPrototypeGetByteLength(viewBuffer);

    if (viewByteLength === 0 || viewBufferByteLength === 0) {
      throw new ERR_INVALID_STATE.TypeError(
        'View or Viewed ArrayBuffer is zero-length or detached');
    }

    // Supposed to assert here that the view's buffer is not
    // detached, but there's no API available to use to check that.

    const min = options?.min ?? 1;
    if (typeof min !== 'number')
      throw new ERR_INVALID_ARG_TYPE('options.min', 'number', min);
    if (!NumberIsInteger(min))
      throw new ERR_INVALID_ARG_VALUE('options.min', min, 'must be an integer');
    if (min <= 0)
      throw new ERR_INVALID_ARG_VALUE('options.min', min, 'must be greater than 0');
    if (!isDataView(view)) {
      if (min > TypedArrayPrototypeGetLength(view)) {
        throw new ERR_OUT_OF_RANGE('options.min', '<= view.length', min);
      }
    } else if (min > viewByteLength) {
      throw new ERR_OUT_OF_RANGE('options.min', '<= view.byteLength', min);
    }

    if (this[kState].stream === undefined) {
      throw new ERR_INVALID_STATE.TypeError('The reader is not attached to a stream');
    }
    const readIntoRequest = new ReadIntoRequest();
    readableStreamBYOBReaderRead(this, view, min, readIntoRequest);
    return readIntoRequest.promise;