Simplify PipeIOHandlerBase by using meghod assignment

tfw/components/pipe_io/pipe_io_handler.py

@@ -1,7 +1,7 @@
 import logging
 from abc import abstractmethod
 from json import loads, dumps
-from subprocess import run, PIPE, Popen
+from subprocess import PIPE, Popen
 from functools import partial
 from os import getpgid, killpg
 from os.path import join
@@ -21,14 +21,21 @@ class PipeIOHandlerBase:
 
     def __init__(self, in_pipe_path, out_pipe_path, permissions=DEFAULT_PERMISSIONS):
         self.connector = None
-        self.pipe_io = CallbackPipeIOServer(
+        self._in_pipe = in_pipe_path
+        self.pipe_io = PipeIOServer(
             in_pipe_path,
             out_pipe_path,
-            self.handle_pipe_event,
             permissions
         )
+        self.pipe_io.handle_message = self._server_handle_message
         self.pipe_io.start()
 
+    def _server_handle_message(self, message):
+        try:
+            self.handle_pipe_event(message)
+        except:  # pylint: disable=bare-except
+            LOG.exception('Failed to handle message %s from pipe %s!', message, self._in_pipe)
+
     @abstractmethod
     def handle_pipe_event(self, message_bytes):
         raise NotImplementedError()
@@ -37,18 +44,6 @@ class PipeIOHandlerBase:
         self.pipe_io.stop()
 
 
-class CallbackPipeIOServer(PipeIOServer):
-    def __init__(self, in_pipe_path, out_pipe_path, callback, permissions):
-        super().__init__(in_pipe_path, out_pipe_path, permissions)
-        self.callback = callback
-
-    def handle_message(self, message):
-        try:
-            self.callback(message)
-        except:  # pylint: disable=bare-except
-            LOG.exception('Failed to handle message %s from pipe %s!', message, self.in_pipe)
-
-
 class PipeIOHandler(PipeIOHandlerBase):
     def handle_event(self, message, _):
         json_bytes = dumps(message).encode()