| """Default classes for Comm and CommManager, for usage in IPython.""" |
|
|
| |
| |
| from __future__ import annotations |
|
|
| import contextlib |
| import logging |
| import typing as t |
| import uuid |
|
|
| import comm |
|
|
| if t.TYPE_CHECKING: |
| from zmq.eventloop.zmqstream import ZMQStream |
|
|
| logger = logging.getLogger("Comm") |
|
|
| MessageType = t.Dict[str, t.Any] |
| MaybeDict = t.Optional[t.Dict[str, t.Any]] |
| BuffersType = t.Optional[t.List[bytes]] |
| CommCallback = t.Callable[[MessageType], None] |
| CommTargetCallback = t.Callable[["BaseComm", MessageType], None] |
|
|
|
|
| class BaseComm: |
| """Class for communicating between a Frontend and a Kernel |
| |
| Must be subclassed with a publish_msg method implementation which |
| sends comm messages through the iopub channel. |
| """ |
|
|
| def __init__( |
| self, |
| target_name: str = "comm", |
| data: MaybeDict = None, |
| metadata: MaybeDict = None, |
| buffers: BuffersType = None, |
| comm_id: str | None = None, |
| primary: bool = True, |
| target_module: str | None = None, |
| topic: bytes | None = None, |
| _open_data: MaybeDict = None, |
| _close_data: MaybeDict = None, |
| **kwargs: t.Any, |
| ) -> None: |
| super().__init__(**kwargs) |
|
|
| self.comm_id = comm_id if comm_id else uuid.uuid4().hex |
| self.primary = primary |
| self.target_name = target_name |
| self.target_module = target_module |
| self.topic = topic if topic else (f"comm-{self.comm_id}").encode("ascii") |
|
|
| self._open_data = _open_data if _open_data else {} |
| self._close_data = _close_data if _close_data else {} |
|
|
| self._msg_callback: CommCallback | None = None |
| self._close_callback: CommCallback | None = None |
|
|
| self._closed = True |
|
|
| if self.primary: |
| |
| self.open(data=data, metadata=metadata, buffers=buffers) |
| else: |
| self._closed = False |
|
|
| def publish_msg( |
| self, |
| msg_type: str, |
| data: MaybeDict = None, |
| metadata: MaybeDict = None, |
| buffers: BuffersType = None, |
| **keys: t.Any, |
| ) -> None: |
| msg = "publish_msg Comm method is not implemented" |
| raise NotImplementedError(msg) |
|
|
| def __del__(self) -> None: |
| """trigger close on gc""" |
| with contextlib.suppress(Exception): |
| |
| |
| self.close(deleting=True) |
|
|
| |
|
|
| def open( |
| self, data: MaybeDict = None, metadata: MaybeDict = None, buffers: BuffersType = None |
| ) -> None: |
| """Open the frontend-side version of this comm""" |
|
|
| if data is None: |
| data = self._open_data |
| comm_manager = comm.get_comm_manager() |
| if comm_manager is None: |
| msg = "Comms cannot be opened without a comm_manager." |
| raise RuntimeError(msg) |
|
|
| comm_manager.register_comm(self) |
| try: |
| self.publish_msg( |
| "comm_open", |
| data=data, |
| metadata=metadata, |
| buffers=buffers, |
| target_name=self.target_name, |
| target_module=self.target_module, |
| ) |
| self._closed = False |
| except Exception: |
| comm_manager.unregister_comm(self) |
| raise |
|
|
| def close( |
| self, |
| data: MaybeDict = None, |
| metadata: MaybeDict = None, |
| buffers: BuffersType = None, |
| deleting: bool = False, |
| ) -> None: |
| """Close the frontend-side version of this comm""" |
| if self._closed: |
| |
| return |
| self._closed = True |
| if data is None: |
| data = self._close_data |
| self.publish_msg( |
| "comm_close", |
| data=data, |
| metadata=metadata, |
| buffers=buffers, |
| ) |
| if not deleting: |
| |
| comm.get_comm_manager().unregister_comm(self) |
|
|
| def send( |
| self, data: MaybeDict = None, metadata: MaybeDict = None, buffers: BuffersType = None |
| ) -> None: |
| """Send a message to the frontend-side version of this comm""" |
| self.publish_msg( |
| "comm_msg", |
| data=data, |
| metadata=metadata, |
| buffers=buffers, |
| ) |
|
|
| |
|
|
| def on_close(self, callback: CommCallback | None) -> None: |
| """Register a callback for comm_close |
| |
| Will be called with the `data` of the close message. |
| |
| Call `on_close(None)` to disable an existing callback. |
| """ |
| self._close_callback = callback |
|
|
| def on_msg(self, callback: CommCallback | None) -> None: |
| """Register a callback for comm_msg |
| |
| Will be called with the `data` of any comm_msg messages. |
| |
| Call `on_msg(None)` to disable an existing callback. |
| """ |
| self._msg_callback = callback |
|
|
| |
|
|
| def handle_close(self, msg: MessageType) -> None: |
| """Handle a comm_close message""" |
| logger.debug("handle_close[%s](%s)", self.comm_id, msg) |
| if self._close_callback: |
| self._close_callback(msg) |
|
|
| def handle_msg(self, msg: MessageType) -> None: |
| """Handle a comm_msg message""" |
| logger.debug("handle_msg[%s](%s)", self.comm_id, msg) |
| if self._msg_callback: |
| from IPython import get_ipython |
|
|
| shell = get_ipython() |
| if shell: |
| shell.events.trigger("pre_execute") |
| self._msg_callback(msg) |
| if shell: |
| shell.events.trigger("post_execute") |
|
|
|
|
| class CommManager: |
| """Default CommManager singleton implementation for Comms in the Kernel""" |
|
|
| |
|
|
| def __init__(self) -> None: |
| self.comms: dict[str, BaseComm] = {} |
| self.targets: dict[str, CommTargetCallback] = {} |
|
|
| def register_target(self, target_name: str, f: CommTargetCallback | str) -> None: |
| """Register a callable f for a given target name |
| |
| f will be called with two arguments when a comm_open message is received with `target`: |
| |
| - the Comm instance |
| - the `comm_open` message itself. |
| |
| f can be a Python callable or an import string for one. |
| """ |
| if isinstance(f, str): |
| parts = f.rsplit(".", 1) |
| if len(parts) == 2: |
| |
| package, obj = parts |
| module = __import__(package, fromlist=[obj]) |
| try: |
| f = getattr(module, obj) |
| except AttributeError as e: |
| error_msg = f"No module named {obj}" |
| raise ImportError(error_msg) from e |
| else: |
| |
| f = __import__(parts[0]) |
|
|
| self.targets[target_name] = t.cast(CommTargetCallback, f) |
|
|
| def unregister_target(self, target_name: str, f: CommTargetCallback) -> CommTargetCallback: |
| """Unregister a callable registered with register_target""" |
| return self.targets.pop(target_name) |
|
|
| def register_comm(self, comm: BaseComm) -> str: |
| """Register a new comm""" |
| comm_id = comm.comm_id |
| self.comms[comm_id] = comm |
| return comm_id |
|
|
| def unregister_comm(self, comm: BaseComm) -> None: |
| """Unregister a comm, and close its counterpart""" |
| |
| comm = self.comms.pop(comm.comm_id) |
|
|
| def get_comm(self, comm_id: str) -> BaseComm | None: |
| """Get a comm with a particular id |
| |
| Returns the comm if found, otherwise None. |
| |
| This will not raise an error, |
| it will log messages if the comm cannot be found. |
| """ |
| try: |
| return self.comms[comm_id] |
| except KeyError: |
| logger.warning("No such comm: %s", comm_id) |
| if logger.isEnabledFor(logging.DEBUG): |
| |
| logger.debug("Current comms: %s", list(self.comms.keys())) |
| return None |
|
|
| |
|
|
| def comm_open(self, stream: ZMQStream, ident: str, msg: MessageType) -> None: |
| """Handler for comm_open messages""" |
| from comm import create_comm |
|
|
| content = msg["content"] |
| comm_id = content["comm_id"] |
| target_name = content["target_name"] |
| f = self.targets.get(target_name, None) |
| comm = create_comm( |
| comm_id=comm_id, |
| primary=False, |
| target_name=target_name, |
| ) |
| self.register_comm(comm) |
| if f is None: |
| logger.error("No such comm target registered: %s", target_name) |
| else: |
| try: |
| f(comm, msg) |
| return |
| except Exception: |
| logger.error("Exception opening comm with target: %s", target_name, exc_info=True) |
|
|
| |
| try: |
| comm.close() |
| except Exception: |
| logger.error( |
| """Could not close comm during `comm_open` failure |
| clean-up. The comm may not have been opened yet.""", |
| exc_info=True, |
| ) |
|
|
| def comm_msg(self, stream: ZMQStream, ident: str, msg: MessageType) -> None: |
| """Handler for comm_msg messages""" |
| content = msg["content"] |
| comm_id = content["comm_id"] |
| comm = self.get_comm(comm_id) |
| if comm is None: |
| return |
|
|
| try: |
| comm.handle_msg(msg) |
| except Exception: |
| logger.error("Exception in comm_msg for %s", comm_id, exc_info=True) |
|
|
| def comm_close(self, stream: ZMQStream, ident: str, msg: MessageType) -> None: |
| """Handler for comm_close messages""" |
| content = msg["content"] |
| comm_id = content["comm_id"] |
| comm = self.get_comm(comm_id) |
| if comm is None: |
| return |
|
|
| self.comms[comm_id]._closed = True |
| del self.comms[comm_id] |
|
|
| try: |
| comm.handle_close(msg) |
| except Exception: |
| logger.error("Exception in comm_close for %s", comm_id, exc_info=True) |
|
|
|
|
| __all__ = ["BaseComm", "CommManager"] |
|
|