feat: cache managenent utility

multi_user/preferences.py

@@ -20,6 +20,9 @@ import logging
 import bpy
 import string
 import re
+import os
+
+from pathlib import Path
 
 from . import bl_types, environment, addon_updater_ops, presence, ui
 from .utils import get_preferences, get_expanded_icon
@@ -68,6 +71,16 @@ def update_port(self, context):
         self['ipc_port'] = random.randrange(self.port+4, 10000)
 
 
+def update_directory(self, context):
+    new_dir = Path(self.cache_directory)
+    if new_dir.exists() and any(Path(self.cache_directory).iterdir()):
+        logging.error("The folder is not empty, choose another one.")
+        self['cache_directory'] = environment.DEFAULT_CACHE_DIR
+    elif not new_dir.exists():
+        logging.info("Target cache folder doesn't exist, creating it.")
+        os.makedirs(self.cache_directory, exist_ok=True)
+
+
 def set_log_level(self, value):
     logging.getLogger().setLevel(value)
 
@@ -136,7 +149,8 @@ class SessionPrefs(bpy.types.AddonPreferences):
     cache_directory: bpy.props.StringProperty(
         name="cache directory",
         subtype="DIR_PATH",
-        default=environment.DEFAULT_CACHE_DIR)
+        default=environment.DEFAULT_CACHE_DIR,
+        update=update_directory)
     connection_timeout: bpy.props.IntProperty(
         name='connection timeout',
         description='connection timeout before disconnection',