"""Hashes a file in a separate thread, returning a deferred that will callback with the result."""
file.restat(False)
if not file.exists():
- df = defer.Deferred()
- df.errback(HashError("file not found"))
- return df
+ return defer.fail(HashError("file not found"))
df = threads.deferToThread(self._hashInThread, file)
return df