Function decodeFrameHybi17

lib/internal/debugger/inspect_client.js:103–168

(data)

}

function decodeFrameHybi17(data) {
  const dataAvailable = data.length;
  const notComplete = { closed: false, payload: null, rest: data };
  let payloadOffset = 2;
  if ((dataAvailable - payloadOffset) < 0) return notComplete;

  const firstByte = data[0];
  const secondByte = data[1];

  const final = (firstByte & kFinalBit) !== 0;
  const reserved1 = (firstByte & kReserved1Bit) !== 0;
  const reserved2 = (firstByte & kReserved2Bit) !== 0;
  const reserved3 = (firstByte & kReserved3Bit) !== 0;
  const opCode = firstByte & kOpCodeMask;
  const masked = (secondByte & kMaskBit) !== 0;
  const compressed = reserved1;
  if (compressed) {
    throw new ERR_DEBUGGER_ERROR('Compressed frames not supported');
  }
  if (!final || reserved2 || reserved3) {
    throw new ERR_DEBUGGER_ERROR('Only compression extension is supported');
  }

  if (masked) {
    throw new ERR_DEBUGGER_ERROR('Masked server frame - not supported');
  }

  let closed = false;
  switch (opCode) {
    case kOpCodeClose:
      closed = true;
      break;
    case kOpCodeText:
      break;
    default:
      throw new ERR_DEBUGGER_ERROR(`Unsupported op code ${opCode}`);
  }

  let payloadLength = secondByte & kPayloadLengthMask;
  switch (payloadLength) {
    case kTwoBytePayloadLengthField:
      payloadOffset += 2;
      payloadLength = (data[2] << 8) + data[3];
      break;

    case kEightBytePayloadLengthField:
      payloadOffset += 8;
      payloadLength = 0;
      for (let i = 0; i < 8; ++i) {
        payloadLength <<= 8;
        payloadLength |= data[2 + i];
      }
      break;

    default:
      // Nothing. We already have the right size.
  }
  if ((dataAvailable - payloadOffset - payloadLength) < 0) return notComplete;