Fix filename too long when downloading to local folder (#2789)

Author: Wauplin

src/huggingface_hub/_local_folder.py

@@ -49,6 +49,8 @@
 ```
 """
 
+import base64
+import hashlib
 import logging
 import os
 import time
@@ -84,7 +86,7 @@ class LocalDownloadFilePaths:
 
     def incomplete_path(self, etag: str) -> Path:
         """Return the path where a file will be temporarily downloaded before being moved to `file_path`."""
-        return self.metadata_path.with_suffix(f".{etag}.incomplete")
+        return self.metadata_path.parent / f"{_short_hash(self.metadata_path.name)}.{etag}.incomplete"
 
 
 @dataclass(frozen=True)
@@ -424,3 +426,7 @@ def _huggingface_dir(local_dir: Path) -> Path:
         except OSError:
             pass
     return path
+
+
+def _short_hash(filename: str) -> str:
+    return base64.urlsafe_b64encode(hashlib.sha1(filename.encode()).digest()).decode()

tests/test_local_folder.py

@@ -79,13 +79,17 @@ def test_local_download_paths(tmp_path: Path):
     assert paths.metadata_path.parent.is_dir()
     assert paths.lock_path.parent.is_dir()
 
-    # Incomplete path are etag-based
-    assert (
-        paths.incomplete_path("etag123")
-        == tmp_path / ".cache" / "huggingface" / "download" / "path" / "in" / "repo.txt.etag123.incomplete"
-    )
+    # Incomplete paths are etag-based
+    incomplete_path = paths.incomplete_path("etag123")
+    assert incomplete_path.parent == tmp_path / ".cache" / "huggingface" / "download" / "path" / "in"
+    assert incomplete_path.name.endswith(".etag123.incomplete")
     assert paths.incomplete_path("etag123").parent.is_dir()
 
+    # Incomplete paths are unique per file per etag
+    other_paths = get_local_download_paths(tmp_path, "path/in/repo_other.txt")
+    other_incomplete_path = other_paths.incomplete_path("etag123")
+    assert incomplete_path != other_incomplete_path  # different .incomplete files to prevent concurrency issues
+
 
 def test_local_download_paths_are_recreated_each_time(tmp_path: Path):
     paths1 = get_local_download_paths(tmp_path, "path/in/repo.txt")