ota_cache: integrate to use multidict

src/ota_proxy/ota_cache.py

@@ -26,7 +26,7 @@
 from urllib.parse import SplitResult, quote, urlsplit
 
 import aiohttp
-from multidict import CIMultiDictProxy
+from multidict import CIMultiDict, CIMultiDictProxy
 
 from otaclient_common.common import get_backoff
 from otaclient_common.typing import StrOrPath
@@ -409,7 +409,7 @@ async def _do_request() -> AsyncIterator[bytes]:
 
     async def _retrieve_file_by_cache(
         self, cache_identifier: str, *, retry_cache: bool
-    ) -> Optional[Tuple[AsyncIterator[bytes], Mapping[str, str]]]:
+    ) -> tuple[AsyncIterator[bytes], CIMultiDict[str]] | None:
         """
         Returns:
             A tuple of bytes iterator and headers dict for back to client.
@@ -458,7 +458,8 @@ async def _retrieve_file_by_cache(
 
     async def _retrieve_file_by_external_cache(
         self, client_cache_policy: OTAFileCacheControl
-    ) -> tuple[AsyncIterator[bytes], Mapping[str, str]] | None:
+    ) -> tuple[AsyncIterator[bytes], CIMultiDict[str]] | None:
+        # skip if not external cache or otaclient doesn't sent valid file_sha256
         if not self._external_cache_data_dir or not client_cache_policy.file_sha256:
             return
 
@@ -469,26 +470,31 @@ async def _retrieve_file_by_external_cache(
         )
 
         if cache_file_zst.is_file():
-            return read_file(cache_file_zst, executor=self._executor), {
-                HEADER_OTA_FILE_CACHE_CONTROL: OTAFileCacheControl.export_kwargs_as_header(
+            _header = CIMultiDict()
+            _header[HEADER_OTA_FILE_CACHE_CONTROL] = (
+                OTAFileCacheControl.export_kwargs_as_header(
                     file_sha256=cache_identifier,
                     file_compression_alg=cfg.EXTERNAL_CACHE_STORAGE_COMPRESS_ALG,
                 )
-            }
-        elif cache_file.is_file():
-            return read_file(cache_file, executor=self._executor), {
-                HEADER_OTA_FILE_CACHE_CONTROL: OTAFileCacheControl.export_kwargs_as_header(
+            )
+            return read_file(cache_file_zst, executor=self._executor), _header
+
+        if cache_file.is_file():
+            _header = CIMultiDict()
+            _header[HEADER_OTA_FILE_CACHE_CONTROL] = (
+                OTAFileCacheControl.export_kwargs_as_header(
                     file_sha256=cache_identifier
                 )
-            }
+            )
+            return read_file(cache_file, executor=self._executor), _header
 
     # exposed API
 
     async def retrieve_file(
         self,
         raw_url: str,
         headers_from_client: Dict[str, str],
-    ) -> Optional[Tuple[AsyncIterator[bytes], Mapping[str, str]]]:
+    ) -> tuple[AsyncIterator[bytes], CIMultiDict[str] | CIMultiDictProxy[str]] | None:
         """Retrieve a file descriptor for the requested <raw_url>.
 
         This method retrieves a file descriptor for incoming client request.