better structure

backend/src/overpass/overpass.py

@@ -1,5 +1,6 @@
 """Module allowing connexion to overpass api and fectch data from OSM."""
 import os
+import time
 import urllib
 import math
 import logging
@@ -153,7 +154,7 @@ class Overpass :
             - If no conditions are provided, the query will just use the `selector` to filter the OSM 
             elements without additional constraints.
         """
-        query = '[out:json];('
+        query = '[out:json][timeout:20];('
 
         # convert the bbox to string.
         bbox_str = f"({','.join(map(str, bbox))})"
@@ -399,18 +400,25 @@ def fill_cache():
     """
     overpass = Overpass()
 
+    n_files = 0
+    total = 0
+
     with os.scandir(OSM_CACHE_DIR) as it:
         for entry in it:
             if entry.is_file() and entry.name.startswith('hollow_'):
-
+                total += 1
                 try :
                     # Read the whole file content as a string
                     with open(entry.path, 'r', encoding='utf-8') as f:
                         # load data and fill the cache with the query and key
                         json_data = json.load(f)
                         overpass.fill_cache(json_data)
+                        n_files += 1
+                        time.sleep(1)
                     # Now delete the file as the cache is filled
                     os.remove(entry.path)
 
                 except Exception as exc :
                     overpass.logger.error(f'An error occured while parsing file {entry.path} as .json file: {str(exc)}')
+
+    overpass.logger.info(f"Successfully filled {n_files}/{total} cache files.")