This fixes the restore issues as all sources will now appear as if they were originally part of the source file system.
The backend implementation has now been simplified so the backends only return names of entries with no path information. Most backends already do this, but the S3 backends did not, so this was fixed as well.
This also clears up the interfaces, so the backend does not know about the `ISourceProviderEntry`. All mapping is done by the `BackendSourceProvider`, making it simpler to support other backends as sources.
With this interface it is possible to wrap the current support for snapshots and USN and simplify the enumeration.
This makes a number of assumptions into fields such as `IsMetaEntry` and `IsRootEntry` that removes code that was checking for various properties.
This first commit has support for VSS and USN as well as "naked" files, keeping feature parity.
There is also an experimental support for loading a backend-as-a-source. The support for this is currently limited as the backends need to be extended to support a folder concept.
Macos and Linux were working, ubuntu errors with 'close_nointr(fd) != -EBADF
It seems to be related to both FileStream behavior around closing handles when a SafeFilehandle is provided by an fopen call.
This is inspired largely by the new (/ returning) feature of OneDrive in Windows 10 Fall Creator's Update, which downloads files on-demand.
A side effect of that change is that the OneDrive folder (and subfolders of it) are marked as reparse points, even though they are not technically standard symlinks.
With this change, a new extension method IsSymlink is added for ISnapshotService and ISystemIO, which checks both the file attributes (for reparse point) and the symlink target path (if null, the path is not treated as a symlink).
All places that previously checked only the file attributes have been updated to use either this method (or at least the same logic, in the case of the core BackupHandler file check).
One side effect of this change is that '--symlink-policy=store' no longer ignores empty symlinks - they are now treated as regular files.
If there are empty symlinks, they will now be backed up as if they were regular files, but I don't know what the conditions are that create symlinks like that, so this might not effect anything in practice.
Still needs a work over in terms of error handling, progress reporting, warning output, refactoring etc.
Also misses the volume reuse/reclaim algorithms.
But it passes the unit tests now, with and without a local database.
git-svn-id: https://duplicati.googlecode.com/svn/sandboxes/Kenneth/ForestHash@1526 59da171f-624f-0410-aa54-27559c288bec