Version: 4.x

自定义解析器

从 Socket.IO v2.0.0 开始，现在可以提供自己的解析器，以控制数据包的编组/解组。

¥Since Socket.IO v2.0.0, it is now possible to provide your own parser, in order to control the marshalling / unmarshalling of packets.

服务器

¥Server

import { Server } from "socket.io";

const io = new Server({
  parser: myParser
});

客户端

¥Client

import { io } from "socket.io-client";

const socket = io({
  parser: myParser
});

可用的解析器

¥Available parsers

除了默认解析器之外，以下是可用解析器的列表：

¥Besides the default parser, here is the list of available parsers:

包	描述
`socket.io-circular-parser`	与默认解析器类似，但处理循环引用。
`socket.io-msgpack-parser`	使用 MessagePack 对数据包进行编码（基于 `notepack.io` 包）。
`@skgdev/socket.io-msgpack-javascript`	使用 MessagePack 对数据包进行编码（基于 `@msgpack/msgpack` 包）。
`socket.io-json-parser`	使用 `JSON.stringify()` 和 `JSON.parse()` 对数据包进行编码。
`socket.io-cbor-x-parser`	使用 cbor-x 对数据包进行编码。
`@socket.io/devalue-parser`	使用 devalue 对数据包进行编码。

实现你自己的解析器

¥Implementing your own parser

下面是一个使用 JSON.stringify() 和 JSON.parse() 方法的解析器的基本示例：

¥Here is a basic example with a parser that uses the JSON.stringify() and JSON.parse() methods:

import { Emitter } from "@socket.io/component-emitter"; // polyfill of Node.js EventEmitter in the browser

class Encoder {
  /**

   * Encode a packet into a list of strings/buffers
   */
  encode(packet) {
    return [JSON.stringify(packet)];
  }
}

function isObject(value) {
  return Object.prototype.toString.call(value) === "[object Object]";
}

class Decoder extends Emitter {
  /**

   * Receive a chunk (string or buffer) and optionally emit a "decoded" event with the reconstructed packet
   */
  add(chunk) {
    const packet = JSON.parse(chunk);
    if (this.isPacketValid(packet)) {
      this.emit("decoded", packet);
    } else {
      throw new Error("invalid format");
    }
  }
  isPacketValid({ type, data, nsp, id }) {
    const isNamespaceValid = typeof nsp === "string";
    const isAckIdValid = id === undefined || Number.isInteger(id);
    if (!isNamespaceValid || !isAckIdValid) {
      return false;
    }
    switch (type) {
      case 0: // CONNECT
        return data === undefined || isObject(data);
      case 1: // DISCONNECT
        return data === undefined;
      case 2: // EVENT
        return Array.isArray(data) && typeof data[0] === "string";
      case 3: // ACK
        return Array.isArray(data);
      case 4: // CONNECT_ERROR
        return isObject(data);
      default:
        return false;
    }
  }
  /**

   * Clean up internal buffers
   */
  destroy() {}
}

export const parser = { Encoder, Decoder };

默认解析器

¥The default parser

默认解析器（socket.io-parser 包）的源代码可以在这里找到：https://github.com/socketio/socket.io-parser

¥The source code of the default parser (the socket.io-parser package) can be found here: https://github.com/socketio/socket.io-parser

输出示例：

¥Example of output:

基本触发
¥basic emit

socket.emit("test", 42);

将被编码为：

¥will be encoded as:

2["test",42]
||
|└─ JSON-encoded payload
└─ packet type (2 => EVENT)

使用二进制、确认和自定义命名空间触发
¥emit with binary, acknowledgement and custom namespace

socket.emit("test", Uint8Array.from([42]), () => {
  console.log("ack received");
});

将被编码为：

¥will be encoded as:

51-/admin,13["test",{"_placeholder":true,"num":0}]
||||     || └─ JSON-encoded payload with placeholders for binary attachments
||||     |└─ acknowledgement id
||||     └─ separator
|||└─ namespace (not included when it's the main namespace)
||└─ separator
|└─ number of binary attachments
└─ packet type (5 => BINARY EVENT)

and an additional attachment (the extracted Uint8Array)

优点：

¥Pros:

然后对二进制附件进行 Base64 编码，因此该解析器与不支持数组缓冲区的浏览器兼容，例如 IE9
¥the binary attachments is then base64-encoded, so this parser is compatible with browsers that do not support Arraybuffers, like IE9

缺点：

¥Cons:

具有二进制内容的数据包作为两个不同的 WebSocket 帧发送（如果已建立 WebSocket 连接）
¥packets with binary content are sent as two distinct WebSocket frames (if the WebSocket connection is established)

msgpack 解析器

¥The msgpack parser

该解析器使用 MessagePack 序列化格式。

¥This parser uses the MessagePack serialization format.

该解析器的源代码可以在这里找到：https://github.com/socketio/socket.io-msgpack-parser

¥The source code of this parser can be found here: https://github.com/socketio/socket.io-msgpack-parser

使用示例：

¥Sample usage:

服务器

¥Server

import { Server } from "socket.io";
import customParser from "socket.io-msgpack-parser";

const io = new Server({
  parser: customParser
});

客户端（Node.js）

¥Client (Node.js)

import { io } from "socket.io-client";
import customParser from "socket.io-msgpack-parser";

const socket = io("https://example.com", {
  parser: customParser
});

在浏览器中，现在有一个包含此解析器的官方包：

¥In the browser, there is now an official bundle which includes this parser:

在这种情况下，你不需要指定 parser 选项。

¥In that case, you don't need to specify the parser option.

优点：

¥Pros:

包含二进制内容的数据包作为单个 WebSocket 帧发送（如果已建立 WebSocket 连接）
¥packets with binary content are sent as one single WebSocket frame (if the WebSocket connection is established)
可能会导致较小的有效负载（尤其是在使用大量数字时）
¥may result in smaller payloads (especially when using a lot of numbers)

缺点：

¥Cons:

与不支持数组缓冲区的浏览器不兼容，例如 IE9
¥incompatible with browsers that do not support Arraybuffers, like IE9
在浏览器的“网络”选项卡中更难调试
¥harder to debug in the Network tab of the browser

info

请注意，socket.io-msgpack-parser 依赖于 notepack.io MessagePack 实现。此实现主要关注性能和最小包大小，因此不支持扩展类型等功能。对于基于官方 JavaScript 实现的解析器，请检查这个包。

¥Please note that socket.io-msgpack-parser relies on the notepack.io MessagePack implementation. This implementation mainly focuses on performance and minimal bundle size, and thus does not support features like extension types. For a parser based on the official JavaScript implementation, please check this package.

可用的解析器​

实现你自己的解析器​

默认解析器​

msgpack 解析器​

可用的解析器

实现你自己的解析器

默认解析器

msgpack 解析器