如何使用Go和gorilla websocket仅发送给一个客户端，而不是所有客户端

Question

I am trying to learn websockets with Go. I have been looking at examples with gorilla websocket.

I have checked out these 2 examples that show how to use gorilla websocket:

https://github.com/gorilla/websocket/tree/master/examples

https://www.youtube.com/watch?v=ysAZ_oqPOo0

All of these examples show how to connect to a websocket server, send and receive texts. But what I don't understand is how you can send to only one client. Because in a real world application you will have users, and we don't want all users to receive the same message and same data. Is there a way for me to get the unique id of a connection which I can save in a database like redis and link it to a user id in the same database, and then use that websocket id to send back to a specific client if that user id received a message or a notification? Is this how one would go about and achieve something like this? If that is the case, how would I that?

Answer 1

Is there a way for me to get the unique id of a connection which I can save in a database like redis and link it to a user id in the same database, and then use that websocket id to send back to a specific client if that user id received a message or a notification?

Sure! You can generate Id by yourself while user registering. Just add userId field in connection structure

In chat example you have hub, which contains connections pool. That pool is using to broadcast messages to all users:

case m := <-h.broadcast:
    for c := range h.connections {
        select {
        case c.send <- m:
        default:
            close(c.send)
            delete(h.connections, c)
        }
    }
}

So there you go. You should make method to send private message, depend on userId