Class BodyReadable

lib/api/readable.js:27–363

* @class * @extends {Readable} * @see https://fetch.spec.whatwg.org/#body

 * @see https://fetch.spec.whatwg.org/#body
 */
class BodyReadable extends Readable {
  /**
   * @param {object} opts
   * @param {(this: Readable, size: number) => void} opts.resume
   * @param {() => (void | null)} opts.abort
   * @param {string} [opts.contentType = '']
   * @param {number} [opts.contentLength]
   * @param {number} [opts.highWaterMark = 64 * 1024]
   */
  constructor ({
    resume,
    abort,
    contentType = '',
    contentLength,
    highWaterMark = 64 * 1024 // Same as nodejs fs streams.
  }) {
    super({
      autoDestroy: true,
      read: resume,
      highWaterMark
    })

    this._readableState.dataEmitted = false

    this[kAbort] = abort

    /** @type {Consume | null} */
    this[kConsume] = null

    /** @type {number} */
    this[kBytesRead] = 0

    /** @type {ReadableStream|null} */
    this[kBody] = null

    /** @type {boolean} */
    this[kUsed] = false

    /** @type {string} */
    this[kContentType] = contentType

    /** @type {number|null} */
    this[kContentLength] = Number.isFinite(contentLength) ? contentLength : null

    /**
     * Is stream being consumed through Readable API?
     * This is an optimization so that we avoid checking
     * for 'data' and 'readable' listeners in the hot path
     * inside push().
     *
     * @type {boolean}
     */
    this[kReading] = false
  }

  /**
   * @param {Error|null} err
   * @param {(error:(Error|null)) => void} callback