fs: git: use pygit2 (#5559)

dvc/fs/git.py

@@ -158,12 +158,6 @@ class GitFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
                 errno.ENOENT, os.strerror(errno.ENOENT), path
             )
 
-    @property
-    def hash_jobs(self):  # pylint: disable=invalid-overridden-method
-        # NOTE: gitpython is not threadsafe. See
-        # https://github.com/iterative/dvc/issues/4079
-        return 1
-
     def walk_files(self, top):  # pylint: disable=arguments-differ
         for root, _, files in self.walk(top):
             for file in files:

dvc/scm/git/__init__.py

@@ -352,7 +352,7 @@ class Git(Base):
         from .objects import GitTrie
 
         resolved = self.resolve_rev(rev)
-        tree_obj = self._backend_func("get_tree_obj", rev=resolved)
+        tree_obj = self.pygit2.get_tree_obj(rev=resolved)
         trie = GitTrie(tree_obj, resolved)
         return GitFileSystem(self.root_dir, trie, **kwargs)
 

dvc/scm/git/backend/pygit2.py

@@ -1,6 +1,7 @@
 import locale
 import logging
 import os
+import stat
 from io import BytesIO, StringIO
 from typing import Callable, Iterable, List, Mapping, Optional, Tuple, Union
 
@@ -31,6 +32,8 @@ class Pygit2Object(GitObject):
 
     @property
     def mode(self):
+        if not self.obj.filemode and self.obj.type_str == "tree":
+            return stat.S_IFDIR
         return self.obj.filemode
 
     def scandir(self) -> Iterable["Pygit2Object"]: