From d2a52230ff4e1863b7e867196e6f7db21b217c42 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 4 Sep 2023 15:51:19 -0500
Subject: [PATCH] Speed up responding to states being polled via API (#99621)

* Speed up responding to states being polled via API

Switch to using `as_dict_json` to avoid serializing states over and over when the
states api is polled since the mobile app is already building the cache as it also
polls the states via the websocket_api

* Speed up responding to states being polled via API

Switch to using `as_dict_json` to avoid serializing states over and over when the
states api is polled since the mobile app is already building the cache as it also
polls the states via the websocket_api

* fix json

* cover
---
 homeassistant/components/api/__init__.py | 29 ++++++++++++++++--------
 tests/components/api/test_init.py        |  4 +++-
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/homeassistant/components/api/__init__.py b/homeassistant/components/api/__init__.py
index b427341546e..10cf63b701d 100644
--- a/homeassistant/components/api/__init__.py
+++ b/homeassistant/components/api/__init__.py
@@ -14,6 +14,7 @@ from homeassistant.auth.permissions.const import POLICY_READ
 from homeassistant.bootstrap import DATA_LOGGING
 from homeassistant.components.http import HomeAssistantView, require_admin
 from homeassistant.const import (
+    CONTENT_TYPE_JSON,
     EVENT_HOMEASSISTANT_STOP,
     MATCH_ALL,
     URL_API,
@@ -195,15 +196,19 @@ class APIStatesView(HomeAssistantView):
         user: User = request["hass_user"]
         hass: HomeAssistant = request.app["hass"]
         if user.is_admin:
-            return self.json([state.as_dict() for state in hass.states.async_all()])
-        entity_perm = user.permissions.check_entity
-        return self.json(
-            [
-                state.as_dict()
+            states = (state.as_dict_json() for state in hass.states.async_all())
+        else:
+            entity_perm = user.permissions.check_entity
+            states = (
+                state.as_dict_json()
                 for state in hass.states.async_all()
                 if entity_perm(state.entity_id, "read")
-            ]
+            )
+        response = web.Response(
+            body=f'[{",".join(states)}]', content_type=CONTENT_TYPE_JSON
         )
+        response.enable_compression()
+        return response
 
 
 class APIEntityStateView(HomeAssistantView):
@@ -213,14 +218,18 @@ class APIEntityStateView(HomeAssistantView):
     name = "api:entity-state"
 
     @ha.callback
-    def get(self, request, entity_id):
+    def get(self, request: web.Request, entity_id: str) -> web.Response:
         """Retrieve state of entity."""
-        user = request["hass_user"]
+        user: User = request["hass_user"]
+        hass: HomeAssistant = request.app["hass"]
         if not user.permissions.check_entity(entity_id, POLICY_READ):
             raise Unauthorized(entity_id=entity_id)
 
-        if state := request.app["hass"].states.get(entity_id):
-            return self.json(state)
+        if state := hass.states.get(entity_id):
+            return web.Response(
+                body=state.as_dict_json(),
+                content_type=CONTENT_TYPE_JSON,
+            )
         return self.json_message("Entity not found.", HTTPStatus.NOT_FOUND)
 
     async def post(self, request, entity_id):
diff --git a/tests/components/api/test_init.py b/tests/components/api/test_init.py
index f61988eff5a..38528b335b0 100644
--- a/tests/components/api/test_init.py
+++ b/tests/components/api/test_init.py
@@ -575,11 +575,13 @@ async def test_states(
 ) -> None:
     """Test fetching all states as admin."""
     hass.states.async_set("test.entity", "hello")
+    hass.states.async_set("test.entity2", "hello")
     resp = await mock_api_client.get(const.URL_API_STATES)
     assert resp.status == HTTPStatus.OK
     json = await resp.json()
-    assert len(json) == 1
+    assert len(json) == 2
     assert json[0]["entity_id"] == "test.entity"
+    assert json[1]["entity_id"] == "test.entity2"
 
 
 async def test_states_view_filters(