Everytime a mobile user that is connected to my node.js, socket.io server leaves their browser (maybe checks instagram or something) the socket disconnects due to "transport close".

When they return I want them to reconnect using their old socket so they can receive buffered packets and have access to their old data stored in said socket.

What actually happens is that they reconnect and a new socket is created when the "connection" event is emitted in the server. The old socket is deleted too, unless I store it somewhere.

Are there any simple ways (config or something) to just reuse an old socket when a reconnection happens?

This post helped me a bit: reuse socket id on reconnect, socket.io, node.js. However it doesn't show me how to reuse the actual old socket.

CodePudding user response：

Unfortunately after such event "transport close", by design the socket is destroyed. So at this point you should look to other alternatives. My suggestion is to introduce a new data structure which will store the messages in a list. My proposal involves:

1. A map where the key is the user id and value is a list which contains all user messages.
2. You can store an offset to the structure which holds the list which marks the messages sent before the connection problem
3. On reconnect you lookup the map with the userid and retrieve the user messages