Readable.prototype.read = function()

in digital-shadow/demo-car/js/aws-iot/aws-iot.js [8120:8182]

• 49 lines of code
• 25 McCabe index (conditional complexity)

Readable.prototype.read = function (n) {
  debug('read', n);
  n = parseInt(n, 10);
  var state = this._readableState;
  var nOrig = n;

  if (n !== 0) state.emittedReadable = false;

  if (n === 0 && state.needReadable && (state.length >= state.highWaterMark || state.ended)) {
    debug('read: emitReadable', state.length, state.ended);
    if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
    return null;
  }

  n = howMuchToRead(n, state);

  if (n === 0 && state.ended) {
    if (state.length === 0) endReadable(this);
    return null;
  }


  var doRead = state.needReadable;
  debug('need readable', doRead);

  if (state.length === 0 || state.length - n < state.highWaterMark) {
    doRead = true;
    debug('length less than watermark', doRead);
  }

  if (state.ended || state.reading) {
    doRead = false;
    debug('reading or ended', doRead);
  } else if (doRead) {
    debug('do read');
    state.reading = true;
    state.sync = true;
    if (state.length === 0) state.needReadable = true;
    this._read(state.highWaterMark);
    state.sync = false;
    if (!state.reading) n = howMuchToRead(nOrig, state);
  }

  var ret;
  if (n > 0) ret = fromList(n, state);else ret = null;

  if (ret === null) {
    state.needReadable = true;
    n = 0;
  } else {
    state.length -= n;
  }

  if (state.length === 0) {
    if (!state.ended) state.needReadable = true;

    if (nOrig !== n && state.ended) endReadable(this);
  }

  if (ret !== null) this.emit('data', ret);

  return ret;
};