Function createPacketDecoderStream

packages/socket.io/client-dist/socket.io.js:437–499

(maxPayload, binaryType)

    return buffer;
  }
  function createPacketDecoderStream(maxPayload, binaryType) {
    if (!TEXT_DECODER) {
      TEXT_DECODER = new TextDecoder();
    }
    var chunks = [];
    var state = 0 /* State.READ_HEADER */;
    var expectedLength = -1;
    var isBinary = false;
    return new TransformStream({
      transform: function transform(chunk, controller) {
        chunks.push(chunk);
        while (true) {
          if (state === 0 /* State.READ_HEADER */) {
            if (totalLength(chunks) < 1) {
              break;
            }
            var header = concatChunks(chunks, 1);
            isBinary = (header[0] & 0x80) === 0x80;
            expectedLength = header[0] & 0x7f;
            if (expectedLength < 126) {
              state = 3 /* State.READ_PAYLOAD */;
            } else if (expectedLength === 126) {
              state = 1 /* State.READ_EXTENDED_LENGTH_16 */;
            } else {
              state = 2 /* State.READ_EXTENDED_LENGTH_64 */;
            }
          } else if (state === 1 /* State.READ_EXTENDED_LENGTH_16 */) {
            if (totalLength(chunks) < 2) {
              break;
            }
            var headerArray = concatChunks(chunks, 2);
            expectedLength = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length).getUint16(0);
            state = 3 /* State.READ_PAYLOAD */;
          } else if (state === 2 /* State.READ_EXTENDED_LENGTH_64 */) {
            if (totalLength(chunks) < 8) {
              break;
            }
            var _headerArray = concatChunks(chunks, 8);
            var view = new DataView(_headerArray.buffer, _headerArray.byteOffset, _headerArray.length);
            var n = view.getUint32(0);
            if (n > Math.pow(2, 53 - 32) - 1) {
              // the maximum safe integer in JavaScript is 2^53 - 1
              controller.enqueue(ERROR_PACKET);
              break;
            }
            expectedLength = n * Math.pow(2, 32) + view.getUint32(4);
            state = 3 /* State.READ_PAYLOAD */;
          } else {
            if (totalLength(chunks) < expectedLength) {
              break;
            }
            var data = concatChunks(chunks, expectedLength);
            controller.enqueue(decodePacket(isBinary ? data : TEXT_DECODER.decode(data), binaryType));
            state = 0 /* State.READ_HEADER */;
          }
          if (expectedLength === 0 || expectedLength > maxPayload) {
            controller.enqueue(ERROR_PACKET);
            break;