Implement EventHandler capable of proxying between TFW and named pipes

lib/tfw/components/pipe_io_event_handler.py

@@ -0,0 +1,35 @@
+from json import loads, dumps, JSONDecodeError
+
+from tfw import EventHandlerBase
+from tfw.config.logs import logging
+
+from .pipe_io_server import PipeIOServer
+
+LOG = logging.getLogger(__name__)
+
+
+class PipeIOEventHandler(EventHandlerBase):
+    def __init__(self, key, in_pipe_path, out_pipe_path):
+        super().__init__(key)
+        self._pipe_io_server = JSONProxyPipeIOServer(in_pipe_path, out_pipe_path, self.server_connector.send)
+        self._pipe_io_server.start()
+
+    def cleanup(self):
+        self._pipe_io_server.stop()
+
+    def handle_event(self, message):
+        json_bytes = dumps(message).encode()
+        self._pipe_io_server.send_message(json_bytes)
+
+
+class JSONProxyPipeIOServer(PipeIOServer):
+    def __init__(self, in_pipe_path, out_pipe_path, proxy_method):
+        super().__init__(in_pipe_path, out_pipe_path)
+        self.proxy = proxy_method
+
+    def handle_message(self, message):
+        try:
+            json = loads(message)
+            self.proxy(json)
+        except JSONDecodeError:
+            LOG.debug("Invalid JSON received on %s! Ignoring...", self._in_pipe)