Cache the mime type of static files (#103281)

homeassistant/components/http/static.py

@@ -1,7 +1,8 @@
 """Static file handling for HTTP component."""
 from __future__ import annotations
 
-from collections.abc import Mapping
+from collections.abc import Mapping, MutableMapping
+import mimetypes
 from pathlib import Path
 from typing import Final
 
@@ -16,10 +17,11 @@ from homeassistant.core import HomeAssistant
 from .const import KEY_HASS
 
 CACHE_TIME: Final = 31 * 86400  # = 1 month
-CACHE_HEADERS: Final[Mapping[str, str]] = {
-    hdrs.CACHE_CONTROL: f"public, max-age={CACHE_TIME}"
-}
-PATH_CACHE = LRU(512)
+CACHE_HEADER = f"public, max-age={CACHE_TIME}"
+CACHE_HEADERS: Mapping[str, str] = {hdrs.CACHE_CONTROL: CACHE_HEADER}
+PATH_CACHE: MutableMapping[
+    tuple[str, Path, bool], tuple[Path | None, str | None]
+] = LRU(512)
 
 
 def _get_file_path(rel_url: str, directory: Path, follow_symlinks: bool) -> Path | None:
@@ -48,7 +50,7 @@ class CachingStaticResource(StaticResource):
         """Return requested file from disk as a FileResponse."""
         rel_url = request.match_info["filename"]
         key = (rel_url, self._directory, self._follow_symlinks)
-        if (filepath := PATH_CACHE.get(key)) is None:
+        if (filepath_content_type := PATH_CACHE.get(key)) is None:
             hass: HomeAssistant = request.app[KEY_HASS]
             try:
                 filepath = await hass.async_add_executor_job(_get_file_path, *key)
@@ -62,13 +64,24 @@ class CachingStaticResource(StaticResource):
                 # perm error or other kind!
                 request.app.logger.exception(error)
                 raise HTTPNotFound() from error
-            PATH_CACHE[key] = filepath
 
-        if filepath:
+            content_type: str | None = None
+            if filepath is not None:
+                content_type = (mimetypes.guess_type(rel_url))[
+                    0
+                ] or "application/octet-stream"
+            PATH_CACHE[key] = (filepath, content_type)
+        else:
+            filepath, content_type = filepath_content_type
+
+        if filepath and content_type:
             return FileResponse(
                 filepath,
                 chunk_size=self._chunk_size,
-                headers=CACHE_HEADERS,
+                headers={
+                    hdrs.CACHE_CONTROL: CACHE_HEADER,
+                    hdrs.CONTENT_TYPE: content_type,
+                },
             )
 
         return await super()._handle(request)