From e577e89b081b1e0b666a22699febe9cfcf612c8f Mon Sep 17 00:00:00 2001
From: Victorien VANROYE <victorien.vanroye@gmail.com>
Date: Thu, 18 Nov 2021 22:30:47 +0100
Subject: [PATCH] docs(connection_manager): #13 document connection manager

---
 .../service/device/connection_manager.py      | 36 +++++++++++++------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/src/application/service/device/connection_manager.py b/src/application/service/device/connection_manager.py
index 2526c3e..f375007 100644
--- a/src/application/service/device/connection_manager.py
+++ b/src/application/service/device/connection_manager.py
@@ -1,10 +1,12 @@
 from fastapi import WebSocket
 from typing import Dict
-from asyncio import gather
+import logging
 
 from application.cache import Cache
 
 
+logger = logging.getLogger(__package__)
+
 class ConnectionManager:
     """
     Connection Manager is responsible to manage and store reference of device's connection
@@ -38,22 +40,34 @@ async def unregister_application(self) -> None:
         # TODO : How manage the crash of application ? (liveness probing)
         pass
 
-    def _get_device_key(self, device_id: str):
+    def _get_device_key(self, device_id: str) -> str:
         """
-        Format Device Key for Redis
+        Format Device Key for Redis.
+
+        Returns:
+            String representing the Key in Redis for a device.
         """
         return f"{self.PREFIX_KEY_DEVICE}{device_id}"
 
-    async def register_connection(self, websocket: WebSocket, device_id: str):
+    async def register_connection(self, websocket: WebSocket, device_id: str) -> bool:
         """
-        Register Connection for Device Connected to this specific instance
+        Register Connection for Device Connected to this specific instance.
+
+        Returns:
+            Success Execution
         """
-        async with self.cache.acquire() as _cache_connection:
-            await _cache_connection.set(
-                key=self._get_device_key(device_id=device_id), 
-                value=self.application_instance_name
-            )
-        self.local_device_store[device_id] = websocket
+        try:
+            async with self.cache.acquire() as _cache_connection:
+                await _cache_connection.set(
+                    key=self._get_device_key(device_id=device_id), 
+                    value=self.application_instance_name
+                )
+            self.local_device_store[device_id] = websocket
+        except RuntimeError as e:
+            logger.exception(e)
+            return False
+        else:
+            return True
 
     async def unregister_connection(self, websocket: WebSocket, device_id: str):
         """