Method decodeString

packages/socket.io-parser/lib/index.ts:225–296

* Decode a packet String (JSON data) * * @param {String} str * @return {Object} packet

(str)

   * @return {Object} packet
   */
  private decodeString(str): Packet {
    let i = 0;
    // look up type
    const p: any = {
      type: Number(str.charAt(0)),
    };

    if (PacketType[p.type] === undefined) {
      throw new Error("unknown packet type " + p.type);
    }

    // look up attachments if type binary
    if (
      p.type === PacketType.BINARY_EVENT ||
      p.type === PacketType.BINARY_ACK
    ) {
      const start = i + 1;
      while (str.charAt(++i) !== "-" && i != str.length) {}
      const buf = str.substring(start, i);
      if (buf != Number(buf) || str.charAt(i) !== "-") {
        throw new Error("Illegal attachments");
      }
      const n = Number(buf);
      if (!isInteger(n) || n < 0) {
        throw new Error("Illegal attachments");
      } else if (n > this.opts.maxAttachments) {
        throw new Error("too many attachments");
      }
      p.attachments = n;
    }

    // look up namespace (if any)
    if ("/" === str.charAt(i + 1)) {
      const start = i + 1;
      while (++i) {
        const c = str.charAt(i);
        if ("," === c) break;
        if (i === str.length) break;
      }
      p.nsp = str.substring(start, i);
    } else {
      p.nsp = "/";
    }

    // look up id
    const next = str.charAt(i + 1);
    if ("" !== next && Number(next) == next) {
      const start = i + 1;
      while (++i) {
        const c = str.charAt(i);
        if (null == c || Number(c) != c) {
          --i;
          break;
        }
        if (i === str.length) break;
      }
      p.id = Number(str.substring(start, i + 1));
    }