hdmetor / go-chat

Chat server in golang

As a way to get my feet wet with go I decided to implement a chat service.

To try it:

• clone the repo

• in the repo folder do go run main.go. The chat server should start

• open a new terminal window and do nc localhost 6677 and follow the instructions

• repeat the last step (once for each new user)

• ???

• Profit!

How it works:

There are two main data structure, one for the chat room, and one for a user.

The chat room

type Room struct {
    // map to keep track of connected users
    users map[string]*User
    // incoming messages
    incoming chan string
    // users joining
    joins chan *User
    // users disconnecting
    disconnects chan string
}

The Room contains global information about the chat room:

• users is a map that associates each username to its User object

• incoming is the channel for incoming messages (that are broadcast to the whole room)

• joins is a channel where each new User object is put when a physical user joins the room

• disconnects is the channel that contains the users disconnecting

The user

type User struct {
    name       string
    connection net.Conn
    disconnect bool
    sending    chan string
    writer     *bufio.Writer
    reader     *bufio.Reader
}

The user struct contains information about each user:

• name contains the name that the user selected when it joined

• connection does the actual connection with the socket

• disconnect is set to true when the user disconnects

• sending is a chan with the user outgoing messages

• writer / reader are the object to write / read to and from the socket

Special commands:

When typing /users as a chat message, the chat will list all the currently active users. Such list is not broadcast to other users.

Note that is not possible for a username to start with '/'.