__init__.py

@@ -142,28 +142,34 @@ class property_cache_pickle(object):
         :param default: value to be returned, if key does not exists.
         :returns: value for a given key or default value.
         """
-        if key in self._source_instance.keys() and key not in self._source_get_keys:
-            if self._cached_props is None:
-                self._init_cache()
-            if self._max_age is None:
-                cache_old = False
-            else:
-                cache_old = time.time() - self._cached_props[self.AGE_TAG].get(self._key_filter(key), 0) > self._max_age
-                if cache_old:
-                    logger.debug("The cached value is old, cached value will be ignored")
-            if self._key_filter(key) not in self._cached_props[self.DATA_TAG] or cache_old:
-                logger.debug("Loading property for key='%s' from source instance", key)
-                val = self._source_instance.get(key, None)
-                if self._store_on_get:
-                    tm = int(time.time())
-                    logger.debug("Adding key=%s, value=%s with timestamp=%d to chache", key, val, tm)
-                    self._cached_props[self.DATA_TAG][self._key_filter(key)] = val
-                    self._cached_props[self.AGE_TAG][self._key_filter(key)] = tm
-                    self._save_cache()
-                else:
-                    return val
+        # Init cache
+        if self._cached_props is None:
+            self._init_cache()
+        # Identify old cache
+        if self._max_age is None:
+            cache_old = False
+        else:
+            cache_old = time.time() - self._cached_props[self.AGE_TAG].get(self._key_filter(key), 0) > self._max_age
+            if cache_old:
+                logger.debug("The cached value is old, cached value will be ignored")
+        # Return cached value
+        if not cache_old and key not in self._source_get_keys and self._key_filter(key) in self._cached_props[self.DATA_TAG]:
+            logger.debug("Providing property for '%s' from cache", key)
+            rv = self._cached_props[self.DATA_TAG].get(self._key_filter(key), default)
+            if rv is not None or not self._return_source_on_none:
+                return rv
+        # Create cache and return value
+        if key in self._source_instance.keys():
+            logger.debug("Loading property for key='%s' from source instance", key)
+            val = self._source_instance.get(key, None)
+            if self._store_on_get:
+                tm = int(time.time())
+                logger.debug("Adding key=%s, value=%s with timestamp=%d to chache", key, val, tm)
+                self._cached_props[self.DATA_TAG][self._key_filter(key)] = val
+                self._cached_props[self.AGE_TAG][self._key_filter(key)] = tm
+                self._save_cache()
             else:
-                logger.debug("Providing property for '%s' from cache", key)
+                return val
             cached_data = self._cached_props[self.DATA_TAG].get(self._key_filter(key), default)
             if cached_data is None and self._return_source_on_none:
                 return self._source_instance.get(key, default)