Merge pull request #4060 from catap/atomic-move

Introduce atomic move and write of file

beets/util/__init__.py

@@ -19,6 +19,7 @@ import sys
 import errno
 import locale
 import re
+import tempfile
 import shutil
 import fnmatch
 import functools
@@ -478,6 +479,11 @@ def move(path, dest, replace=False):
     instead, in which case metadata will *not* be preserved. Paths are
     translated to system paths.
     """
+    if os.path.isdir(path):
+        raise FilesystemError(u'source is directory', 'move', (path, dest))
+    if os.path.isdir(dest):
+        raise FilesystemError(u'destination is directory', 'move',
+                              (path, dest))
     if samefile(path, dest):
         return
     path = syspath(path)
@@ -487,15 +493,23 @@ def move(path, dest, replace=False):
 
     # First, try renaming the file.
     try:
-        os.rename(path, dest)
+        os.replace(path, dest)
     except OSError:
-        # Otherwise, copy and delete the original.
+        tmp = tempfile.mktemp(suffix='.beets',
+                              prefix=py3_path(b'.' + os.path.basename(dest)),
+                              dir=py3_path(os.path.dirname(dest)))
+        tmp = syspath(tmp)
         try:
-            shutil.copyfile(path, dest)
+            shutil.copyfile(path, tmp)
+            os.replace(tmp, dest)
+            tmp = None
             os.remove(path)
         except OSError as exc:
             raise FilesystemError(exc, 'move', (path, dest),
                                   traceback.format_exc())
+        finally:
+            if tmp is not None:
+                os.remove(tmp)
 
 
 def link(path, dest, replace=False):