use a channel pool

Author: Mike Prosser

src/nipanel/_panel.py

@@ -5,9 +5,10 @@
 from types import TracebackType
 from typing import TYPE_CHECKING, Optional, Type
 
-from grpc import RpcError, StatusCode, insecure_channel
+from grpc import RpcError, StatusCode
 from ni.pythonpanel.v1.python_panel_service_pb2 import ConnectRequest, DisconnectRequest
 from ni.pythonpanel.v1.python_panel_service_pb2_grpc import PythonPanelServiceStub
+from ni_measurement_plugin_sdk_service.grpc.channelpool import GrpcChannelPool
 
 from nipanel._panel_not_found_error import PanelNotFoundError
 
@@ -21,14 +22,16 @@
 class Panel(ABC):
     """This class allows you to connect to a panel and specify values for its controls."""
 
+    _channel_pool: GrpcChannelPool
     _stub: PythonPanelServiceStub | None
     _panel_id: str
     _panel_uri: str
 
-    __slots__ = ["_stub", "_panel_id", "_panel_uri", "__weakref__"]
+    __slots__ = ["_channel_pool", "_stub", "_panel_id", "_panel_uri", "__weakref__"]
 
     def __init__(self, panel_id: str, panel_uri: str) -> None:
         """Initialize the panel."""
+        self._channel_pool = GrpcChannelPool()
         self._panel_id = panel_id
         self._panel_uri = panel_uri
 
@@ -59,8 +62,8 @@ def __exit__(
 
     def connect(self) -> None:
         """Connect to the panel and open it."""
-        # TODO: use the channel pool
-        channel = insecure_channel(self._resolve_service_address())
+        address = self._resolve_service_address()
+        channel = self._channel_pool.get_channel(address)
         self._stub = PythonPanelServiceStub(channel)
         connect_request = ConnectRequest(panel_id=self._panel_id, panel_uri=self._panel_uri)
 
@@ -88,7 +91,7 @@ def disconnect(self) -> None:
                 raise
 
         self._stub = None
-        # TODO: channel pool cleanup?
+        self._channel_pool.close()
 
     def get_value(self, value_id: str) -> object:
         """Get the value for a control on the panel.

tests/utils/_port_panel.py

@@ -2,18 +2,18 @@
 
 
 class PortPanel(Panel):
-    """This class allows you to connect to the PythonPanelService with a specified port, for testing."""
+    """This class allows you to connect to the PythonPanelService with a specified port."""
 
     def __init__(self, port: int, panel_id: str, panel_uri: str) -> None:
-        """Create a panel and connect to a specified port, for testing.
+        """Create a panel and connect to a specified port.
 
         Args:
             port: The port number for the gRPC server.
             panel_id: A unique identifier for the panel.
             panel_uri: The file path of the panel script.
 
         Returns:
-            A new FakePanel instance.
+            A new PortPanel instance.
         """
         super().__init__(panel_id, panel_uri)
         self.port = port