Cache transient templates compiles provided via api

partially fixes #89047 (there is more going on here)

homeassistant/components/api/__init__.py

@@ -1,5 +1,6 @@
 """Rest API for Home Assistant."""
 import asyncio
+from functools import lru_cache
 from http import HTTPStatus
 import logging
 
@@ -350,6 +351,9 @@ class APIComponentsView(HomeAssistantView):
         return self.json(request.app["hass"].config.components)
 
 
+_cached_template = lru_cache(template.Template)
+
+
 class APITemplateView(HomeAssistantView):
     """View to handle Template requests."""
 
@@ -362,7 +366,8 @@ class APITemplateView(HomeAssistantView):
             raise Unauthorized()
         try:
             data = await request.json()
-            tpl = template.Template(data["template"], request.app["hass"])
+            tpl = _cached_template(data["template"])
+            tpl.hass = request.app["hass"]
             return tpl.async_render(variables=data.get("variables"), parse_result=False)
         except (ValueError, TemplateError) as ex:
             return self.json_message(

homeassistant/components/mobile_app/webhook.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 import asyncio
 from collections.abc import Callable, Coroutine
 from contextlib import suppress
-from functools import wraps
+from functools import lru_cache, wraps
 from http import HTTPStatus
 import logging
 import secrets
@@ -365,6 +365,9 @@ async def webhook_stream_camera(
     return webhook_response(resp, registration=config_entry.data)
 
 
+_cached_template = lru_cache(template.Template)
+
+
 @WEBHOOK_COMMANDS.register("render_template")
 @validate_schema(
     {
@@ -381,7 +384,8 @@ async def webhook_render_template(
     resp = {}
     for key, item in data.items():
         try:
-            tpl = template.Template(item[ATTR_TEMPLATE], hass)
+            tpl = _cached_template(item[ATTR_TEMPLATE])
+            tpl.hass = hass
             resp[key] = tpl.async_render(item.get(ATTR_TEMPLATE_VARIABLES))
         except TemplateError as ex:
             resp[key] = {"error": str(ex)}

homeassistant/components/websocket_api/commands.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 from collections.abc import Callable
 from contextlib import suppress
 import datetime as dt
+from functools import lru_cache
 import json
 from typing import Any, cast
 
@@ -424,6 +425,9 @@ def handle_ping(
     connection.send_message(pong_message(msg["id"]))
 
 
+_cached_template = lru_cache(template.Template)
+
+
 @decorators.websocket_command(
     {
         vol.Required("type"): "render_template",
@@ -440,7 +444,8 @@ async def handle_render_template(
 ) -> None:
     """Handle render_template command."""
     template_str = msg["template"]
-    template_obj = template.Template(template_str, hass)
+    template_obj = _cached_template(template_str)
+    template_obj.hass = hass
     variables = msg.get("variables")
     timeout = msg.get("timeout")
     info = None