get: use Repo.open instead of external_repo

This should use `Repo.open` just like `dvc import`, to benefit from
handling local repos without cloning and redundant downloaads.

dvc/repo/get.py

@@ -4,7 +4,6 @@ from typing import TYPE_CHECKING, Union
 
 from dvc.exceptions import DvcException
 from dvc.utils import resolve_output
-from dvc.utils.fs import remove
 
 if TYPE_CHECKING:
     from dvc.fs.dvc import DVCFileSystem
@@ -21,63 +20,38 @@ class GetDVCFileError(DvcException):
 
 
 def get(url, path, out=None, rev=None, jobs=None, force=False):
-    import shortuuid
-
     from dvc.dvcfile import is_valid_filename
     from dvc.fs.callbacks import Callback
-    from dvc.repo.open_repo import external_repo
+    from dvc.repo import Repo
 
     out = resolve_output(path, out, force=force)
 
     if is_valid_filename(out):
         raise GetDVCFileError()
 
-    # Creating a directory right beside the output to make sure that they
-    # are on the same filesystem, so we could take the advantage of
-    # reflink and/or hardlink. Not using tempfile.TemporaryDirectory
-    # because it will create a symlink to tmpfs, which defeats the purpose
-    # and won't work with reflink/hardlink.
-    dpath = os.path.dirname(os.path.abspath(out))
-    tmp_dir = os.path.join(dpath, "." + str(shortuuid.uuid()))
+    with Repo.open(
+        url=url,
+        rev=rev,
+        subrepos=True,
+        uninitialized=True,
+    ) as repo:
+        from dvc.fs.data import DataFileSystem
 
-    # Try any links possible to avoid data duplication.
-    #
-    # Not using symlink, because we need to remove cache after we
-    # are done, and to make that work we would have to copy data
-    # over anyway before removing the cache, so we might just copy
-    # it right away.
-    #
-    # Also, we can't use theoretical "move" link type here, because
-    # the same cache file might be used a few times in a directory.
-    cache_types = ["reflink", "hardlink", "copy"]
-    try:
-        with external_repo(
-            url=url,
-            rev=rev,
-            subrepos=True,
-            uninitialized=True,
-            cache_dir=tmp_dir,
-            cache_types=cache_types,
-        ) as repo:
-            from dvc.fs.data import DataFileSystem
+        fs: Union[DataFileSystem, "DVCFileSystem"]
+        if os.path.isabs(path):
+            fs = DataFileSystem(index=repo.index.data["local"])
+            fs_path = fs.from_os_path(path)
+        else:
+            fs = repo.dvcfs
+            fs_path = fs.from_os_path(path)
 
-            fs: Union[DataFileSystem, "DVCFileSystem"]
-            if os.path.isabs(path):
-                fs = DataFileSystem(index=repo.index.data["local"])
-                fs_path = fs.from_os_path(path)
-            else:
-                fs = repo.dvcfs
-                fs_path = fs.from_os_path(path)
-
-            with Callback.as_tqdm_callback(
-                desc=f"Downloading {fs.path.name(path)}",
-                unit="files",
-            ) as cb:
-                fs.get(
-                    fs_path,
-                    os.path.abspath(out),
-                    batch_size=jobs,
-                    callback=cb,
-                )
-    finally:
-        remove(tmp_dir)
+        with Callback.as_tqdm_callback(
+            desc=f"Downloading {fs.path.name(path)}",
+            unit="files",
+        ) as cb:
+            fs.get(
+                fs_path,
+                os.path.abspath(out),
+                batch_size=jobs,
+                callback=cb,
+            )

dvc/repo/open_repo.py

@@ -3,7 +3,7 @@ import os
 import tempfile
 import threading
 from contextlib import contextmanager
-from typing import TYPE_CHECKING, Collection, Dict, Iterator, Optional, Tuple
+from typing import TYPE_CHECKING, Dict, Iterator, Optional, Tuple
 
 from funcy import retry, wrap_with
 
@@ -14,7 +14,6 @@ from dvc.utils import relpath
 
 if TYPE_CHECKING:
     from dvc.scm import Git
-    from dvc.types import StrPath
 
 logger = logging.getLogger(__name__)
 
@@ -25,8 +24,6 @@ def external_repo(
     url,
     rev: Optional[str] = None,
     for_write: bool = False,
-    cache_dir: Optional["StrPath"] = None,
-    cache_types: Optional[Collection[str]] = None,
     **kwargs,
 ) -> Iterator["Repo"]:
     logger.debug("Creating external repo %s@%s", url, rev)
@@ -36,12 +33,8 @@ def external_repo(
     # the tip of the default branch
     rev = rev or "refs/remotes/origin/HEAD"
 
-    cache_config = {
-        "cache": {"dir": cache_dir or _get_cache_dir(url), "type": cache_types}
-    }
-
     config = _get_remote_config(url) if os.path.isdir(url) else {}
-    config.update(cache_config)
+    config.update({"cache": {"dir": _get_cache_dir(url)}})
     config.update(kwargs.pop("config", None) or {})
 
     main_root = "/"
@@ -54,7 +47,7 @@ def external_repo(
         root_dir=path,
         url=url,
         config=config,
-        repo_factory=erepo_factory(url, main_root, cache_config),
+        repo_factory=erepo_factory(url, main_root, {"cache": config["cache"]}),
         rev=rev,
         **kwargs,
     )

tests/unit/repo/test_open_repo.py

@@ -65,8 +65,7 @@ def test_subrepo_is_constructed_properly(
         str(tmp_dir),
         subrepos=True,
         uninitialized=True,
-        cache_dir=str(cache_dir),
-        cache_types=["symlink"],
+        config={"cache": {"dir": str(cache_dir), "type": ["symlink"]}},
     ) as repo:
         spy = mocker.spy(repo.dvcfs.fs, "repo_factory")