socket.io-parser.js

/*

slightly modified from socket.io-parser

Copyright (c) 2014 Guillermo Rauch <guillermo@learnboost.com>

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the 'Software'), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/
var withNativeArrayBuffer = typeof ArrayBuffer === "function";
var isView = (obj) => {
  return typeof ArrayBuffer.isView === "function"
    ? ArrayBuffer.isView(obj)
    : obj.buffer instanceof ArrayBuffer;
};
var toString = Object.prototype.toString;
var withNativeBlob =
  typeof Blob === "function" ||
  (typeof Blob !== "undefined" &&
    toString.call(Blob) === "[object BlobConstructor]");
var withNativeFile =
  typeof File === "function" ||
  (typeof File !== "undefined" &&
    toString.call(File) === "[object FileConstructor]");
function isBinary(obj) {
  return (
    (withNativeArrayBuffer && (obj instanceof ArrayBuffer || isView(obj))) ||
    (withNativeBlob && obj instanceof Blob) ||
    (withNativeFile && obj instanceof File)
  );
}
function hasBinary(obj, toJSON) {
  if (!obj || typeof obj !== "object") {
    return false;
  }
  if (Array.isArray(obj)) {
    for (let i = 0, l = obj.length; i < l; i++) {
      if (hasBinary(obj[i])) {
        return true;
      }
    }
    return false;
  }
  if (isBinary(obj)) {
    return true;
  }
  if (
    obj.toJSON &&
    typeof obj.toJSON === "function" &&
    arguments.length === 1
  ) {
    return hasBinary(obj.toJSON(), true);
  }
  for (const key in obj) {
    if (Object.prototype.hasOwnProperty.call(obj, key) && hasBinary(obj[key])) {
      return true;
    }
  }
  return false;
}

function deconstructPacket(packet) {
  const buffers = [];
  const packetData = packet.data;
  const pack = packet;
  pack.data = _deconstructPacket(packetData, buffers);
  pack.attachments = buffers.length;
  return { packet: pack, buffers };
}
function _deconstructPacket(data, buffers) {
  if (!data) return data;
  if (isBinary(data)) {
    const placeholder = { _placeholder: true, num: buffers.length };
    buffers.push(data);
    return placeholder;
  } else if (Array.isArray(data)) {
    const newData = new Array(data.length);
    for (let i = 0; i < data.length; i++) {
      newData[i] = _deconstructPacket(data[i], buffers);
    }
    return newData;
  } else if (typeof data === "object" && !(data instanceof Date)) {
    const newData = {};
    for (const key in data) {
      if (Object.prototype.hasOwnProperty.call(data, key)) {
        newData[key] = _deconstructPacket(data[key], buffers);
      }
    }
    return newData;
  }
  return data;
}
function reconstructPacket(packet, buffers) {
  packet.data = _reconstructPacket(packet.data, buffers);
  delete packet.attachments;
  return packet;
}
function _reconstructPacket(data, buffers) {
  if (!data) return data;
  if (data && data._placeholder === true) {
    const isIndexValid =
      typeof data.num === "number" &&
      data.num >= 0 &&
      data.num < buffers.length;
    if (isIndexValid) {
      return buffers[data.num];
    } else {
      throw new Error("illegal attachments");
    }
  } else if (Array.isArray(data)) {
    for (let i = 0; i < data.length; i++) {
      data[i] = _reconstructPacket(data[i], buffers);
    }
  } else if (typeof data === "object") {
    for (const key in data) {
      if (Object.prototype.hasOwnProperty.call(data, key)) {
        data[key] = _reconstructPacket(data[key], buffers);
      }
    }
  }
  return data;
}

var protocol = 5;
var PacketType;
(function (PacketType2) {
  PacketType2[(PacketType2["CONNECT"] = 0)] = "CONNECT";
  PacketType2[(PacketType2["DISCONNECT"] = 1)] = "DISCONNECT";
  PacketType2[(PacketType2["EVENT"] = 2)] = "EVENT";
  PacketType2[(PacketType2["ACK"] = 3)] = "ACK";
  PacketType2[(PacketType2["CONNECT_ERROR"] = 4)] = "CONNECT_ERROR";
  PacketType2[(PacketType2["BINARY_EVENT"] = 5)] = "BINARY_EVENT";
  PacketType2[(PacketType2["BINARY_ACK"] = 6)] = "BINARY_ACK";
})(PacketType || (PacketType = {}));
var Encoder = class {
  /**
   * Encoder constructor
   *
   * @param {function} replacer - custom replacer to pass down to JSON.parse
   */
  constructor(replacer) {
    this.replacer = replacer;
  }
  /**
   * Encode a packet as a single string if non-binary, or as a
   * buffer sequence, depending on packet type.
   *
   * @param {Object} obj - packet object
   */
  encode(obj) {
    if (obj.type === PacketType.EVENT || obj.type === PacketType.ACK) {
      if (hasBinary(obj)) {
        return this.encodeAsBinary({
          type:
            obj.type === PacketType.EVENT
              ? PacketType.BINARY_EVENT
              : PacketType.BINARY_ACK,
          nsp: obj.nsp,
          data: obj.data,
          id: obj.id,
        });
      }
    }
    return [this.encodeAsString(obj)];
  }
  /**
   * Encode packet as string.
   */
  encodeAsString(obj) {
    let str = "" + obj.type;
    if (
      obj.type === PacketType.BINARY_EVENT ||
      obj.type === PacketType.BINARY_ACK
    ) {
      str += obj.attachments + "-";
    }
    if (obj.nsp && "/" !== obj.nsp) {
      str += obj.nsp + ",";
    }
    if (null != obj.id) {
      str += obj.id;
    }
    if (null != obj.data) {
      str += JSON.stringify(obj.data, this.replacer);
    }
    return str;
  }
  /**
   * Encode packet as 'buffer sequence' by removing blobs, and
   * deconstructing packet into object with placeholders and
   * a list of buffers.
   */
  encodeAsBinary(obj) {
    const deconstruction = deconstructPacket(obj);
    const pack = this.encodeAsString(deconstruction.packet);
    const buffers = deconstruction.buffers;
    buffers.unshift(pack);
    return buffers;
  }
};
var Decoder = class extends EventTarget {
  /**
   * Decoder constructor
   *
   * @param {function} reviver - custom reviver to pass down to JSON.stringify
   */
  constructor(reviver) {
    super();
    this.reviver = reviver;
  }
  /**
   * Decodes an encoded packet string into packet JSON.
   *
   * @param {String} obj - encoded packet
   */
  add(obj) {
    let packet;
    if (typeof obj === "string") {
      if (this.reconstructor) {
        throw new Error("got plaintext data when reconstructing a packet");
      }
      packet = this.decodeString(obj);
      const isBinaryEvent = packet.type === PacketType.BINARY_EVENT;
      if (isBinaryEvent || packet.type === PacketType.BINARY_ACK) {
        packet.type = isBinaryEvent ? PacketType.EVENT : PacketType.ACK;
        this.reconstructor = new BinaryReconstructor(packet);
        if (packet.attachments === 0) {
          super.dispatchEvent(new CustomEvent("decoded", { detail: packet }));
        }
      } else {
        super.dispatchEvent(new CustomEvent("decoded", { detail: packet }));
      }
    } else if (isBinary(obj) || obj.base64) {
      if (!this.reconstructor) {
        throw new Error("got binary data when not reconstructing a packet");
      } else {
        packet = this.reconstructor.takeBinaryData(obj);
        if (packet) {
          this.reconstructor = null;
          super.dispatchEvent(new CustomEvent("decoded", { detail: packet }));
        }
      }
    } else {
      throw new Error("Unknown type: " + obj);
    }
  }
  /**
   * Decode a packet String (JSON data)
   *
   * @param {String} str
   * @return {Object} packet
   */
  decodeString(str) {
    let i = 0;
    const p = {
      type: Number(str.charAt(0)),
    };
    if (PacketType[p.type] === void 0) {
      throw new Error("unknown packet type " + p.type);
    }
    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");
      }
      p.attachments = Number(buf);
    }
    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 = "/";
    }
    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));
    }
    if (str.charAt(++i)) {
      const payload = this.tryParse(str.substr(i));
      if (Decoder.isPayloadValid(p.type, payload)) {
        p.data = payload;
      } else {
        throw new Error("invalid payload");
      }
    }
    return p;
  }
  tryParse(str) {
    try {
      return JSON.parse(str, this.reviver);
    } catch (e) {
      return false;
    }
  }
  static isPayloadValid(type, payload) {
    switch (type) {
      case PacketType.CONNECT:
        return typeof payload === "object";
      case PacketType.DISCONNECT:
        return payload === void 0;
      case PacketType.CONNECT_ERROR:
        return typeof payload === "string" || typeof payload === "object";
      case PacketType.EVENT:
      case PacketType.BINARY_EVENT:
        return Array.isArray(payload) && payload.length > 0;
      case PacketType.ACK:
      case PacketType.BINARY_ACK:
        return Array.isArray(payload);
    }
  }
  /**
   * Deallocates a parser's resources
   */
  destroy() {
    if (this.reconstructor) {
      this.reconstructor.finishedReconstruction();
      this.reconstructor = null;
    }
  }
};
var BinaryReconstructor = class {
  constructor(packet) {
    this.packet = packet;
    this.buffers = [];
    this.reconPack = packet;
  }
  /**
   * Method to be called when binary data received from connection
   * after a BINARY_EVENT packet.
   *
   * @param {Buffer | ArrayBuffer} binData - the raw binary data received
   * @return {null | Object} returns null if more binary data is expected or
   *   a reconstructed packet object if all buffers have been received.
   */
  takeBinaryData(binData) {
    this.buffers.push(binData);
    if (this.buffers.length === this.reconPack.attachments) {
      const packet = reconstructPacket(this.reconPack, this.buffers);
      this.finishedReconstruction();
      return packet;
    }
    return null;
  }
  /**
   * Cleans up binary packet reconstruction variables.
   */
  finishedReconstruction() {
    this.reconPack = null;
    this.buffers = [];
  }
};
export { Decoder, Encoder, PacketType, protocol };