Avoid hashing attributes when they are already in the cache

homeassistant/components/recorder/__init__.py

@@ -985,7 +985,7 @@ def _process_one_event(self, event):
         if event.event_type == EVENT_STATE_CHANGED:
             try:
                 dbstate = States.from_event(event)
-                dbstate_attributes = StateAttributes.from_event(event)
+                shared_attrs = StateAttributes.shared_attrs_from_event(event)
             except (TypeError, ValueError) as ex:
                 _LOGGER.warning(
                     "State is not JSON serializable: %s: %s",
@@ -995,27 +995,33 @@ def _process_one_event(self, event):
                 return
 
             dbstate.attributes = None
-            shared_attrs = dbstate_attributes.shared_attrs
             # Matching attributes found in the pending commit
             if pending_attributes := self._pending_state_attributes.get(shared_attrs):
                 dbstate.state_attributes = pending_attributes
             # Matching attributes id found in the cache
             elif attributes_id := self._state_attributes_ids.get(shared_attrs):
                 dbstate.attributes_id = attributes_id
-            # Matching attributes found in the database
-            elif (
-                attributes := self.event_session.query(StateAttributes.attributes_id)
-                .filter(StateAttributes.hash == dbstate_attributes.hash)
-                .filter(StateAttributes.shared_attrs == shared_attrs)
-                .first()
-            ):
-                dbstate.attributes_id = attributes[0]
-                self._state_attributes_ids[shared_attrs] = attributes[0]
-            # No matching attributes found, save them in the DB
             else:
-                dbstate.state_attributes = dbstate_attributes
-                self._pending_state_attributes[shared_attrs] = dbstate_attributes
-                self.event_session.add(dbstate_attributes)
+                attr_hash = StateAttributes.hash_shared_attrs(shared_attrs)
+                # Matching attributes found in the database
+                if (
+                    attributes := self.event_session.query(
+                        StateAttributes.attributes_id
+                    )
+                    .filter(StateAttributes.hash == attr_hash)
+                    .filter(StateAttributes.shared_attrs == shared_attrs)
+                    .first()
+                ):
+                    dbstate.attributes_id = attributes[0]
+                    self._state_attributes_ids[shared_attrs] = attributes[0]
+                # No matching attributes found, save them in the DB
+                else:
+                    dbstate_attributes = StateAttributes(
+                        shared_attrs=shared_attrs, hash=attr_hash
+                    )
+                    dbstate.state_attributes = dbstate_attributes
+                    self._pending_state_attributes[shared_attrs] = dbstate_attributes
+                    self.event_session.add(dbstate_attributes)
 
             if old_state := self._old_states.pop(dbstate.entity_id, None):
                 if old_state.state_id:

homeassistant/components/recorder/const.py

@@ -1,5 +1,11 @@
 """Recorder constants."""
 
+from functools import partial
+import json
+from typing import Final
+
+from homeassistant.helpers.json import JSONEncoder
+
 DATA_INSTANCE = "recorder_instance"
 SQLITE_URL_PREFIX = "sqlite://"
 DOMAIN = "recorder"
@@ -17,3 +23,5 @@
 MAX_ROWS_TO_PURGE = 998
 
 DB_WORKER_PREFIX = "DbWorker"
+
+JSON_DUMP: Final = partial(json.dumps, cls=JSONEncoder, separators=(",", ":"))

homeassistant/components/recorder/models.py

@@ -4,7 +4,7 @@
 from datetime import datetime, timedelta
 import json
 import logging
-from typing import TypedDict, overload
+from typing import Any, TypedDict, overload
 
 from fnvhash import fnv1a_32
 from sqlalchemy import (
@@ -35,9 +35,10 @@
     MAX_LENGTH_STATE_STATE,
 )
 from homeassistant.core import Context, Event, EventOrigin, State, split_entity_id
-from homeassistant.helpers.json import JSONEncoder
 import homeassistant.util.dt as dt_util
 
+from .const import JSON_DUMP
+
 # SQLAlchemy Schema
 # pylint: disable=invalid-name
 Base = declarative_base()
@@ -116,8 +117,7 @@ def from_event(event, event_data=None):
         """Create an event database object from a native event."""
         return Events(
             event_type=event.event_type,
-            event_data=event_data
-            or json.dumps(event.data, cls=JSONEncoder, separators=(",", ":")),
+            event_data=event_data or JSON_DUMP(event.data),
             origin=str(event.origin.value),
             time_fired=event.time_fired,
             context_id=event.context.id,
@@ -186,15 +186,13 @@ def __repr__(self) -> str:
         )
 
     @staticmethod
-    def from_event(event):
+    def from_event(event) -> States:
         """Create object from a state_changed event."""
         entity_id = event.data["entity_id"]
-        state = event.data.get("new_state")
-
-        dbstate = States(entity_id=entity_id)
-        dbstate.attributes = None
+        state: State | None = event.data.get("new_state")
+        dbstate = States(entity_id=entity_id, attributes=None)
 
-        # State got deleted
+        # None state means the state was removed from the state machine
         if state is None:
             dbstate.state = ""
             dbstate.domain = split_entity_id(entity_id)[0]
@@ -208,7 +206,7 @@ def from_event(event):
 
         return dbstate
 
-    def to_native(self, validate_entity_id=True):
+    def to_native(self, validate_entity_id: bool = True) -> State | None:
         """Convert to an HA state object."""
         try:
             return State(
@@ -221,7 +219,7 @@ def to_native(self, validate_entity_id=True):
                 process_timestamp(self.last_updated),
                 # Join the events table on event_id to get the context instead
                 # as it will always be there for state_changed events
-                context=Context(id=None),
+                context=Context(id=None),  # type: ignore[arg-type]
                 validate_entity_id=validate_entity_id,
             )
         except ValueError:
@@ -251,23 +249,29 @@ def __repr__(self) -> str:
         )
 
     @staticmethod
-    def from_event(event):
+    def from_event(event: Event) -> StateAttributes:
         """Create object from a state_changed event."""
-        state = event.data.get("new_state")
-        dbstate = StateAttributes()
-        # State got deleted
-        if state is None:
-            dbstate.shared_attrs = "{}"
-        else:
-            dbstate.shared_attrs = json.dumps(
-                dict(state.attributes),
-                cls=JSONEncoder,
-                separators=(",", ":"),
-            )
-        dbstate.hash = fnv1a_32(dbstate.shared_attrs.encode("utf-8"))
+        state: State | None = event.data.get("new_state")
+        # None state means the state was removed from the state machine
+        dbstate = StateAttributes(
+            shared_attrs="{}" if state is None else JSON_DUMP(state.attributes)
+        )
+        dbstate.hash = StateAttributes.hash_shared_attrs(dbstate.shared_attrs)
         return dbstate
 
-    def to_native(self):
+    @staticmethod
+    def shared_attrs_from_event(event: Event) -> str:
+        """Create shared_attrs from a state_changed event."""
+        state: State | None = event.data.get("new_state")
+        # None state means the state was removed from the state machine
+        return "{}" if state is None else JSON_DUMP(state.attributes)
+
+    @staticmethod
+    def hash_shared_attrs(shared_attrs: str) -> int:
+        """Return the hash of json encoded shared attributes."""
+        return fnv1a_32(shared_attrs.encode("utf-8"))
+
+    def to_native(self) -> dict[str, Any]:
         """Convert to an HA state object."""
         try:
             return json.loads(self.shared_attrs)