ext: Add getter methods for cache, config and data directories

Methods do get or create directories

mopidy/ext.py

@@ -2,10 +2,12 @@ from __future__ import absolute_import, unicode_literals
 
 import collections
 import logging
+import os
 
 import pkg_resources
 
 from mopidy import config as config_lib, exceptions
+from mopidy.internal import path
 
 
 logger = logging.getLogger(__name__)
@@ -58,6 +60,42 @@ class Extension(object):
         schema['enabled'] = config_lib.Boolean()
         return schema
 
+    def get_cache_dir(self, config):
+        """Get or create cache directory for extension and return path
+
+        :param config: Loaded configuration
+        :return: string
+        """
+        assert self.ext_name is not None
+        cache_dir_path = bytes(os.path.join(config['core']['cache_dir'],
+                                            self.ext_name))
+        path.get_or_create_dir(cache_dir_path)
+        return cache_dir_path
+
+    def get_config_dir(self, config):
+        """Get or create configuration directory for extension and return path
+
+        :param config: Loaded configuration
+        :return: string
+        """
+        assert self.ext_name is not None
+        config_dir_path = bytes(os.path.join(config['core']['config_dir'],
+                                             self.ext_name))
+        path.get_or_create_dir(config_dir_path)
+        return config_dir_path
+
+    def get_data_dir(self, config):
+        """Get or create data directory for extension and return path
+
+        :param config: Loaded configuration
+        :returns: string
+        """
+        assert self.ext_name is not None
+        data_dir_path = bytes(os.path.join(config['core']['data_dir'],
+                                           self.ext_name))
+        path.get_or_create_dir(data_dir_path)
+        return data_dir_path
+
     def get_command(self):
         """Command to expose to command line users running ``mopidy``.