Hardlink or copy (#5502)

* Fall back to making copies when we can't link

* Changelog

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed the docstring information for the `FBetaMultiLabelMeasure` metric.
 - Various fixes for Python 3.9
 - Fixed the name that the `push-to-hf` command uses to store weights.
+- Support for inferior operating systems when making hardlinks
 
 ### Removed
 

allennlp/common/file_utils.py

@@ -42,6 +42,7 @@
     find_latest_cached as _find_latest_cached,
 )
 from cached_path.cache_file import CacheFile
+from cached_path.common import PathOrStr
 from cached_path.file_lock import FileLock
 from cached_path.meta import Meta as _Meta
 import torch
@@ -606,3 +607,13 @@ def inspect_cache(patterns: List[str] = None, cache_dir: Union[str, Path] = None
 
 def filename_is_safe(filename: str) -> bool:
     return all(c in SAFE_FILENAME_CHARS for c in filename)
+
+
+def hardlink_or_copy(source: PathOrStr, dest: PathOrStr):
+    try:
+        os.link(source, dest)
+    except OSError as e:
+        if e.errno in {18, 95}:  # Cross-device link and Windows
+            shutil.copy(source, dest)
+        else:
+            raise

allennlp/common/sqlite_sparse_sequence.py

@@ -1,9 +1,8 @@
-import os
-import shutil
 from os import PathLike
 from typing import MutableSequence, Any, Union, Iterable
 from sqlitedict import SqliteDict
 
+from allennlp.common.file_utils import hardlink_or_copy
 from allennlp.common.sequences import SlicedSequence
 
 
@@ -95,10 +94,4 @@ def close(self) -> None:
             self.table = None
 
     def copy_to(self, target: Union[str, PathLike]):
-        try:
-            os.link(self.table.filename, target)
-        except OSError as e:
-            if e.errno == 18:  # Cross-device link
-                shutil.copy(self.table.filename, target)
-            else:
-                raise
+        hardlink_or_copy(self.table.filename, target)

allennlp/training/gradient_descent_trainer.py

@@ -16,6 +16,7 @@
 
 from allennlp.common.checks import ConfigurationError, check_for_gpu
 from allennlp.common import util as common_util, Tqdm, Lazy
+from allennlp.common.file_utils import hardlink_or_copy
 from allennlp.data.data_loaders.data_loader import DataLoader, TensorDict
 from allennlp.models.model import Model
 from allennlp.nn.parallel import DdpAccelerator, DdpWrappedModel, TorchDdpAccelerator
@@ -913,7 +914,7 @@ def _try_train(self) -> Tuple[Dict[str, Any], int]:
                             model_state_file, _ = last_checkpoint
                             if os.path.exists(self._best_model_filename):
                                 os.remove(self._best_model_filename)
-                            os.link(model_state_file, self._best_model_filename)
+                            hardlink_or_copy(model_state_file, self._best_model_filename)
                         else:
                             self._save_model_state(self._best_model_filename)
                     else: