Orphaned file segments remain when a large object is overwritten

[joel-wright]

When a large object overwritten, either by another large object with a different size, or by a small object, the original segments that made up the file are left on the storage system in /.file-segments. This has the effect that every time a large object is overwritten the disk space used is not reclaimed. This can lead to a misunderstanding because the file-segments folder is hidden, and the user cannot see why their storage usage increases unless they show hidden files and have an understanding of swift large objects.

It would be nice if orphaned segments were cleaned up in a similar way to when a large object is deleted.

I have attached a simple patch against svn revision 14153 that implements the cleanup and can be disabled/enables using the Preferences object.

[joel-wright]

Upload Cleanup Patch

[dkocher]

This patch will remove segments from the previous large object before the new upload is complete.

[dkocher]

In r14156. I have revised the patch to work both when overwriting with a segmented or single upload and no cleanup is made if appending to a previously interrupted large upload.