从 websocket 接收似乎是封装的 JSON 的内容。 我如何处理这种格式？

Question

Every received message starts with a number followed by what appears to be encapsulated JSON.

JSON.parse() obviously doesn't work here.

0{"sid":"ZH4b_LP4asdas","upgrades":[],"pingInterval":25000,"pingTimeout":5000}
40
42["request","{\"api_key\":\"blablabla\",\"version\":2,\"step\":{\"type\":\"CATCHER\",\"params\":{},\".......\"}"]
3
3 .......

Does this data format has some common name or specification and how do I go about decoding it?

PS: I'm using node.js ws websocket and have to send "2" pings in order to maintain the connection.

Answer 1

Done it the crude way. You would be wrong to assume I couldn't. But if there is another way, let me know! :)

EDIT : of course, had to add strip slashes as well for the actual data.

function stripslashes(str) {
    str = str.replace(/\\'/g, '\'');
    str = str.replace(/\\"/g, '"');
    str = str.replace(/\\0/g, '\0');
    str = str.replace(/\\\\/g, '\\');
    return str;
}

var data= '0{"sid":"ZH4b_LP4asdas","upgrades":[],"pingInterval":25000,"pingTimeout":5000}'
var match = data.match(/^\d+/);
if (!match) {console.log('corrupted data'); return}
var channel = match[0]; //channel
var message = data.slice(match[0].length);
if (!message) {console.log('empty message'); return}
message=message.replace(/^\[.*?,"|"\]$/g, "");  //extracting from array formation
message=stripslashes(message);
data=JSON.parse(message);
console.log(data);  //log the data
if (typeof data.step != 'undefined' && typeof data.step.data != 'undefined' && typeof data.step.data.body != 'undefined')
console.log(Buffer.from(data.step.data.body,'base64').toString());  //extract base64 body of the message within