Make State class immutable

homeassistant/core.py

@@ -10,6 +10,7 @@ import time
 import logging
 import signal
 import threading
+from types import MappingProxyType
 import enum
 import functools as ft
 from collections import namedtuple
@@ -353,7 +354,7 @@ class State(object):
 
         self.entity_id = entity_id.lower()
         self.state = state
-        self.attributes = attributes or {}
+        self.attributes = MappingProxyType(attributes or {})
         self.last_updated = dt_util.strip_microseconds(
             last_updated or dt_util.utcnow())
 
@@ -381,12 +382,6 @@ class State(object):
             self.attributes.get(ATTR_FRIENDLY_NAME) or
             self.object_id.replace('_', ' '))
 
-    def copy(self):
-        """Return a copy of the state."""
-        return State(self.entity_id, self.state,
-                     dict(self.attributes), self.last_changed,
-                     self.last_updated)
-
     def as_dict(self):
         """Return a dict representation of the State.
 
@@ -395,7 +390,7 @@ class State(object):
         """
         return {'entity_id': self.entity_id,
                 'state': self.state,
-                'attributes': self.attributes,
+                'attributes': dict(self.attributes),
                 'last_changed': dt_util.datetime_to_str(self.last_changed),
                 'last_updated': dt_util.datetime_to_str(self.last_updated)}
 
@@ -459,14 +454,11 @@ class StateMachine(object):
     def all(self):
         """Create a list of all states."""
         with self._lock:
-            return [state.copy() for state in self._states.values()]
+            return list(self._states.values())
 
     def get(self, entity_id):
         """Retrieve state of entity_id or None if not found."""
-        state = self._states.get(entity_id.lower())
-
-        # Make a copy so people won't mutate the state
-        return state.copy() if state else None
+        return self._states.get(entity_id.lower())
 
     def is_state(self, entity_id, state):
         """Test if entity exists and is specified state."""