refactor: Elide BatchDownloader logic into Downloader

BatchDownloader is a wrapper class over Downloader that is effectively
a glorified for loop. It doesn't need to exist.

Author: ichard26

src/pip/_internal/network/download.py

@@ -172,6 +172,14 @@ def __init__(
         self._progress_bar = progress_bar
         self._resume_retries = resume_retries
 
+    def batch(
+        self, links: Iterable[Link], location: str
+    ) -> Iterable[tuple[Link, tuple[str, str]]]:
+        """Download the files given by links into location."""
+        for link in links:
+            filepath, content_type = self(link, location)
+            yield link, (filepath, content_type)
+
     def __call__(self, link: Link, location: str) -> tuple[str, str]:
         """Download the file given by link into location."""
         resp = _http_get_download(self._session, link)
@@ -297,21 +305,3 @@ def _reset_download_state(
         etag_or_last_modified = _get_http_response_etag_or_last_modified(resp)
 
         return bytes_received, total_length, etag_or_last_modified
-
-
-class BatchDownloader:
-    def __init__(
-        self,
-        session: PipSession,
-        progress_bar: str,
-        resume_retries: int,
-    ) -> None:
-        self._downloader = Downloader(session, progress_bar, resume_retries)
-
-    def __call__(
-        self, links: Iterable[Link], location: str
-    ) -> Iterable[tuple[Link, tuple[str, str]]]:
-        """Download the files given by links into location."""
-        for link in links:
-            filepath, content_type = self._downloader(link, location)
-            yield link, (filepath, content_type)

src/pip/_internal/operations/prepare.py

@@ -29,7 +29,7 @@
 from pip._internal.models.direct_url import ArchiveInfo
 from pip._internal.models.link import Link
 from pip._internal.models.wheel import Wheel
-from pip._internal.network.download import BatchDownloader, Downloader
+from pip._internal.network.download import Downloader
 from pip._internal.network.lazy_wheel import (
     HTTPRangeRequestUnsupported,
     dist_from_wheel_url,
@@ -245,7 +245,6 @@ def __init__(
         self.build_tracker = build_tracker
         self._session = session
         self._download = Downloader(session, progress_bar, resume_retries)
-        self._batch_download = BatchDownloader(session, progress_bar, resume_retries)
         self.finder = finder
 
         # Where still-packed archives should be written to. If None, they are
@@ -468,10 +467,7 @@ def _complete_partial_requirements(
             assert req.link
             links_to_fully_download[req.link] = req
 
-        batch_download = self._batch_download(
-            links_to_fully_download.keys(),
-            temp_dir,
-        )
+        batch_download = self._download.batch(links_to_fully_download.keys(), temp_dir)
         for link, (filepath, _) in batch_download:
             logger.debug("Downloading link %s to %s", link, filepath)
             req = links_to_fully_download[link]