first comit

venv/lib/python3.10/site-packages/ipykernel/inprocess/channels.py

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+"""A kernel client for in-process kernels."""
+
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+from typing import List
+
+from jupyter_client.channelsabc import HBChannelABC
+
+# -----------------------------------------------------------------------------
+# Channel classes
+# -----------------------------------------------------------------------------
+
+
+class InProcessChannel:
+    """Base class for in-process channels."""
+
+    proxy_methods: List[object] = []
+
+    def __init__(self, client=None):
+        """Initialize the channel."""
+        super().__init__()
+        self.client = client
+        self._is_alive = False
+
+    def is_alive(self):
+        """Test if the channel is alive."""
+        return self._is_alive
+
+    def start(self):
+        """Start the channel."""
+        self._is_alive = True
+
+    def stop(self):
+        """Stop the channel."""
+        self._is_alive = False
+
+    def call_handlers(self, msg):
+        """This method is called in the main thread when a message arrives.
+
+        Subclasses should override this method to handle incoming messages.
+        """
+        msg = "call_handlers must be defined in a subclass."
+        raise NotImplementedError(msg)
+
+    def flush(self, timeout=1.0):
+        """Flush the channel."""
+
+    def call_handlers_later(self, *args, **kwds):
+        """Call the message handlers later.
+
+        The default implementation just calls the handlers immediately, but this
+        method exists so that GUI toolkits can defer calling the handlers until
+        after the event loop has run, as expected by GUI frontends.
+        """
+        self.call_handlers(*args, **kwds)
+
+    def process_events(self):
+        """Process any pending GUI events.
+
+        This method will be never be called from a frontend without an event
+        loop (e.g., a terminal frontend).
+        """
+        raise NotImplementedError
+
+
+class InProcessHBChannel:
+    """A dummy heartbeat channel interface for in-process kernels.
+
+    Normally we use the heartbeat to check that the kernel process is alive.
+    When the kernel is in-process, that doesn't make sense, but clients still
+    expect this interface.
+    """
+
+    time_to_dead = 3.0
+
+    def __init__(self, client=None):
+        """Initialize the channel."""
+        super().__init__()
+        self.client = client
+        self._is_alive = False
+        self._pause = True
+
+    def is_alive(self):
+        """Test if the channel is alive."""
+        return self._is_alive
+
+    def start(self):
+        """Start the channel."""
+        self._is_alive = True
+
+    def stop(self):
+        """Stop the channel."""
+        self._is_alive = False
+
+    def pause(self):
+        """Pause the channel."""
+        self._pause = True
+
+    def unpause(self):
+        """Unpause the channel."""
+        self._pause = False
+
+    def is_beating(self):
+        """Test if the channel is beating."""
+        return not self._pause
+
+
+HBChannelABC.register(InProcessHBChannel)