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Room

Source code in pycrdt_websocket/yroom.py 
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class YRoom:

    clients: list
    ydoc: Doc
    ystore: BaseYStore | None
    _on_message: Callable[[bytes], Awaitable[bool] | bool] | None
    _update_send_stream: MemoryObjectSendStream
    _update_receive_stream: MemoryObjectReceiveStream
    _ready: bool
    _task_group: TaskGroup | None
    _started: Event | None
    _starting: bool

    def __init__(
        self, ready: bool = True, ystore: BaseYStore | None = None, log: Logger | None = None
    ):
        """Initialize the object.

        The YRoom instance should preferably be used as an async context manager:
        ```py
        async with room:
            ...
        ```
        However, a lower-level API can also be used:
        ```py
        task = asyncio.create_task(room.start())
        await room.started.wait()
        ...
        room.stop()
        ```

        Arguments:
            ready: Whether the internal YDoc is ready to be synchronized right away.
            ystore: An optional store in which to persist document updates.
            log: An optional logger.
        """
        self.ydoc = Doc()
        self.awareness = Awareness(self.ydoc)
        self._update_send_stream, self._update_receive_stream = create_memory_object_stream(
            max_buffer_size=65536
        )
        self._ready = False
        self.ready = ready
        self.ystore = ystore
        self.log = log or getLogger(__name__)
        self.clients = []
        self._on_message = None
        self._started = None
        self._starting = False
        self._task_group = None

    @property
    def started(self):
        """An async event that is set when the YRoom provider has started."""
        if self._started is None:
            self._started = Event()
        return self._started

    @property
    def ready(self) -> bool:
        """
        Returns:
            True is the internal YDoc is ready to be synchronized.
        """
        return self._ready

    @ready.setter
    def ready(self, value: bool) -> None:
        """
        Arguments:
            value: True if the internal YDoc is ready to be synchronized, False otherwise."""
        self._ready = value
        if value:
            self.ydoc.observe(partial(put_updates, self._update_send_stream))

    @property
    def on_message(self) -> Callable[[bytes], Awaitable[bool] | bool] | None:
        """
        Returns:
            The optional callback to call when a message is received.
        """
        return self._on_message

    @on_message.setter
    def on_message(self, value: Callable[[bytes], Awaitable[bool] | bool] | None):
        """
        Arguments:
            value: An optional callback to call when a message is received. If the callback returns True, the message is skipped.
        """
        self._on_message = value

    async def _broadcast_updates(self):
        if self.ystore is not None and not self.ystore.started.is_set():
            self._task_group.start_soon(self.ystore.start)

        async with self._update_receive_stream:
            async for update in self._update_receive_stream:
                if self._task_group.cancel_scope.cancel_called:
                    return
                # broadcast internal ydoc's update to all clients, that includes changes from the
                # clients and changes from the backend (out-of-band changes)
                for client in self.clients:
                    self.log.debug("Sending Y update to client with endpoint: %s", client.path)
                    message = create_update_message(update)
                    self._task_group.start_soon(client.send, message)
                if self.ystore:
                    self.log.debug("Writing Y update to YStore")
                    self._task_group.start_soon(self.ystore.write, update)

    async def __aenter__(self) -> YRoom:
        if self._task_group is not None:
            raise RuntimeError("YRoom already running")

        async with AsyncExitStack() as exit_stack:
            tg = create_task_group()
            self._task_group = await exit_stack.enter_async_context(tg)
            self._exit_stack = exit_stack.pop_all()
            tg.start_soon(self._broadcast_updates)
            self.started.set()

        return self

    async def __aexit__(self, exc_type, exc_value, exc_tb):
        if self._task_group is None:
            raise RuntimeError("YRoom not running")

        self._task_group.cancel_scope.cancel()
        self._task_group = None
        return await self._exit_stack.__aexit__(exc_type, exc_value, exc_tb)

    async def start(self, *, task_status: TaskStatus[None] = TASK_STATUS_IGNORED):
        """Start the room.

        Arguments:
            task_status: The status to set when the task has started.
        """
        if self._starting:
            return
        else:
            self._starting = True

        if self._task_group is not None:
            raise RuntimeError("YRoom already running")

        async with create_task_group() as self._task_group:
            self._task_group.start_soon(self._broadcast_updates)
            self.started.set()
            self._starting = False
            task_status.started()

    def stop(self):
        """Stop the room."""
        if self._task_group is None:
            raise RuntimeError("YRoom not running")

        self._task_group.cancel_scope.cancel()
        self._task_group = None

    async def serve(self, websocket: Websocket):
        """Serve a client.

        Arguments:
            websocket: The WebSocket through which to serve the client.
        """
        async with create_task_group() as tg:
            self.clients.append(websocket)
            await sync(self.ydoc, websocket, self.log)
            try:
                async for message in websocket:
                    # filter messages (e.g. awareness)
                    skip = False
                    if self.on_message:
                        _skip = self.on_message(message)
                        skip = await _skip if isawaitable(_skip) else _skip
                    if skip:
                        continue
                    message_type = message[0]
                    if message_type == YMessageType.SYNC:
                        # update our internal state in the background
                        # changes to the internal state are then forwarded to all clients
                        # and stored in the YStore (if any)
                        tg.start_soon(
                            process_sync_message, message[1:], self.ydoc, websocket, self.log
                        )
                    elif message_type == YMessageType.AWARENESS:
                        # forward awareness messages from this client to all clients,
                        # including itself, because it's used to keep the connection alive
                        self.log.debug(
                            "Received %s message from endpoint: %s",
                            YMessageType.AWARENESS.name,
                            websocket.path,
                        )
                        for client in self.clients:
                            self.log.debug(
                                "Sending Y awareness from client with endpoint %s to client with endpoint: %s",
                                websocket.path,
                                client.path,
                            )
                            tg.start_soon(client.send, message)
            except Exception as e:
                self.log.debug("Error serving endpoint: %s", websocket.path, exc_info=e)

            # remove this client
            self.clients = [c for c in self.clients if c != websocket]

on_message: Callable[[bytes], Awaitable[bool] | bool] | None property writable

Returns:

Type Description
Callable[[bytes], Awaitable[bool] | bool] | None

The optional callback to call when a message is received.

ready: bool property writable

Returns:

Type Description
bool

True is the internal YDoc is ready to be synchronized.

started property

An async event that is set when the YRoom provider has started.

__init__(ready=True, ystore=None, log=None)

Initialize the object.

The YRoom instance should preferably be used as an async context manager: 

async with room:
    ...
However, a lower-level API can also be used: 
task = asyncio.create_task(room.start())
await room.started.wait()
...
room.stop()

Parameters:

Name Type Description Default
ready bool

Whether the internal YDoc is ready to be synchronized right away.

 True
ystore BaseYStore | None

An optional store in which to persist document updates.

 None
log Logger | None

An optional logger.

 None
Source code in pycrdt_websocket/yroom.py 
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def __init__(
    self, ready: bool = True, ystore: BaseYStore | None = None, log: Logger | None = None
):
    """Initialize the object.

    The YRoom instance should preferably be used as an async context manager:
    ```py
    async with room:
        ...
    ```
    However, a lower-level API can also be used:
    ```py
    task = asyncio.create_task(room.start())
    await room.started.wait()
    ...
    room.stop()
    ```

    Arguments:
        ready: Whether the internal YDoc is ready to be synchronized right away.
        ystore: An optional store in which to persist document updates.
        log: An optional logger.
    """
    self.ydoc = Doc()
    self.awareness = Awareness(self.ydoc)
    self._update_send_stream, self._update_receive_stream = create_memory_object_stream(
        max_buffer_size=65536
    )
    self._ready = False
    self.ready = ready
    self.ystore = ystore
    self.log = log or getLogger(__name__)
    self.clients = []
    self._on_message = None
    self._started = None
    self._starting = False
    self._task_group = None

serve(websocket) async

Serve a client.

Parameters:

Name Type Description Default
websocket Websocket

The WebSocket through which to serve the client.

 required
Source code in pycrdt_websocket/yroom.py 
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async def serve(self, websocket: Websocket):
    """Serve a client.

    Arguments:
        websocket: The WebSocket through which to serve the client.
    """
    async with create_task_group() as tg:
        self.clients.append(websocket)
        await sync(self.ydoc, websocket, self.log)
        try:
            async for message in websocket:
                # filter messages (e.g. awareness)
                skip = False
                if self.on_message:
                    _skip = self.on_message(message)
                    skip = await _skip if isawaitable(_skip) else _skip
                if skip:
                    continue
                message_type = message[0]
                if message_type == YMessageType.SYNC:
                    # update our internal state in the background
                    # changes to the internal state are then forwarded to all clients
                    # and stored in the YStore (if any)
                    tg.start_soon(
                        process_sync_message, message[1:], self.ydoc, websocket, self.log
                    )
                elif message_type == YMessageType.AWARENESS:
                    # forward awareness messages from this client to all clients,
                    # including itself, because it's used to keep the connection alive
                    self.log.debug(
                        "Received %s message from endpoint: %s",
                        YMessageType.AWARENESS.name,
                        websocket.path,
                    )
                    for client in self.clients:
                        self.log.debug(
                            "Sending Y awareness from client with endpoint %s to client with endpoint: %s",
                            websocket.path,
                            client.path,
                        )
                        tg.start_soon(client.send, message)
        except Exception as e:
            self.log.debug("Error serving endpoint: %s", websocket.path, exc_info=e)

        # remove this client
        self.clients = [c for c in self.clients if c != websocket]

start(*, task_status=TASK_STATUS_IGNORED) async

Start the room.

Parameters:

Name Type Description Default
task_status TaskStatus[None]

The status to set when the task has started.

 TASK_STATUS_IGNORED
Source code in pycrdt_websocket/yroom.py 
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async def start(self, *, task_status: TaskStatus[None] = TASK_STATUS_IGNORED):
    """Start the room.

    Arguments:
        task_status: The status to set when the task has started.
    """
    if self._starting:
        return
    else:
        self._starting = True

    if self._task_group is not None:
        raise RuntimeError("YRoom already running")

    async with create_task_group() as self._task_group:
        self._task_group.start_soon(self._broadcast_updates)
        self.started.set()
        self._starting = False
        task_status.started()

stop()

Stop the room.

Source code in pycrdt_websocket/yroom.py 
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def stop(self):
    """Stop the room."""
    if self._task_group is None:
        raise RuntimeError("YRoom not running")

    self._task_group.cancel_scope.cancel()
    self._task_group = None