Data fetch inside of socket event listeners on the server side.

[janghanp]

I am making a simple chat app with React and Socket Io(NodeJS) but currently, I fetch data from a database inside of socket event listeners about 2 or 3 times in an event listener. (e.g To set previous messages in a chat room etc)

socket.on('join_room', async (data) => {
  const chat = awiat prisma.chat.findUnique({
    where: {
      name: data.roomName,
    },
    include: { 
      messages: {
        include: {
          sender: true,
        },
      },
      users: true,
    },
  })

  const messages = chat.messages;
 
  const users = chat?.users.map((user) => {
	// eslint-disable-next-line @typescript-eslint/ban-ts-comment
	// @ts-ignore
	delete user.password;
	// eslint-disable-next-line @typescript-eslint/ban-ts-comment
	// @ts-ignore
	delete user.createdAt;
	// eslint-disable-next-line @typescript-eslint/ban-ts-comment
	// @ts-ignore
	delete user.updatedAt;

	return user;
   });

  socket.emit('setMessagesAndMemebers', { messages, users })

// Check if a user joined the room for the first time.
const userInChat = await prisma.chat.findFirst({
  where: {
       AND: [
	     {
		 name: data.roomName,
	     },
             {
		users: {
		    some: {
		        username: data.username,
		},
	    },
	}, 
     ],
  },
});

// A new member to the room.
if (!userInChat) {
   // Connect a user to the existing chat.
   await prisma.chat.update({
      where: {
	    name: data.roomName,
       },
	data: {
	   users: {
	      connect: {
		username: data.username,
	      },
	   },
        },
   });

const newUser = await prisma.user.findUnique({
  where: {
    username: data.username,
    },
 });

if (newUser) {
   // eslint-disable-next-line @typescript-eslint/ban-ts-comment
   // @ts-ignore
  delete newUser.password;

  io.to(data.roomName).emit('enter_new_member', { newUser });
  })
}

However, it looks like it is a lot of work to do for a socket. I think communication between sockets should be as fast as possible.

My thought possibly be wrong so I would appreciate any thoughts about this problem.