eri24816 / Topicsync

A tool helps syncing states in multi-client applications

ChatRoom

TODOs

Introduction

ChatRoom is a communication tool for multi-client applications where clients' states need to be syncronized in real-time, such as real-time collaborative tools or multiplayer games. ChatRoom provides a topic system and a service system. The topic system manages Topic. Each Topic has its value that is avaliable to all clients that subscribes to it and is changable from every client.

Topics

A topic stores a piece of data that is synchronized across clients. Clients can subscribe to topics and update topics. When one client makes a change on a topic's value, all clients subscribed to that topic will receive the change.

Special Topics

Special topics are those with their names begin with _topicsync/.

• _topicsync/server_status

  A status string describing the server's nearest event.

• _topicsync/client_message/<client_id>

  Debug messages (string) to clients. Clients subscribe to it to receive debug messages.

Services

Using a service, a client can call a function in another client and get the return value.

Special Services

Special services are those with their names begin with _topicsync/.

Debugging

Set DEBUG environment variable to true to enable debug mode. Debugger listens on http://localhost:8800.

Development

To publish

cz bump
poetry build
poetry publish

## Internal Communication API (Outdated, need to be updated later)

The communication between a ChatRoom server and a client is done via a WebSocket connection. Every message has the following format:

```json
{
    "type": "<message_type>",
    "content": {
        "<field1>": "<value1>",
        "<field2>": "<value2>",
        ...
    }
}

Where type is the type of message and content is the actual content of the message. For each message type, there are specified fields that should be in the content.

These are all message types used in ChatRoom:

Message Types (server -> client)

hello

• id : The given id of the client.

update

• topic_name : The topic that was updated.
• change : A dictionary that contains the serialized information of the Change object.

reject_update

• topic_name : The topic that was rejected.
• change : The change that was rejected.
• reason : A string describing why the update is rejected.

request

• service_name : The service to call.
• args : The argument to pass to the service.
• request_id : A unique id of the request.

response

• response : The response content.
• request_id : The same id as in the request message.

Message Types (client -> server)

request

• service_name : The service to call.
• args : The argument to pass to the service.
• request_id : A unique id of the request.

response

• response : The response content.
• request_id : The same id as in the request message.

register_service

• service_name : The name of the registered service.

unregister_service

• service_name : The name of the unregistered service.

subscribe

• topic_name : The subscribed topic.
• type : In case of the subcribed topic has not exist, the server will initialize the topic with this type.

unsubscribe

• topic_name : The unsubscribed topic.

update

• topic_name : The updated topic.
• change : A dictionary that contains the serialized information of the Change object.