This PR is the final change, where all backends are now purely implemented with async interfaces.
The code changes here replace the LIST call with an async version. This affect all backends (and then some) but the changes are mostly mechanical rewrites of the code.
In many places, the backeds were already prepared for async output, in other some glue was needed.
To reduce the scope of this change, some backends simply report a synchronous result as an async list.
By changing to IEnumerable, it is possible to iterate only a portion of the list, which is useful when not all entries are needed (e.g., when testing a connection).
All existing backends have been updated, and any which were able to be changed to yield return results in a straightforward way now do.
Many backends had a try/catch in the List() method. Due to the fact that yield returns can't be placed within a try/catch block, these have been refactored to either scope the try/catch to the parts that (should) be the only places throwing exceptions, so that exceptions are still caught and handled.
Note that lazy evaluation may cause some changes in behavior - exceptions that were previously thrown at the point of invokation of List() may now be thrown while it is being enumerated.
I believe this will not be problematic though, as the only well-known exception seems to be FolderMissingException, which should be thrown by Test(), but TestList() attempts to enumerate the list to force this exception.
Any places that require the legacy behavior can get it by simply converting the lazy enumerable to a List()
This was based on the idea that the interfaces should remain static.
I hope this change is enough to ensure stable interfaces until release 1.2.
Overview of changes:
Moved all interfaces into the same dll.
Encryption and compression is now plugable modules, just as the backends.
Encryption/compression can now register an UI.
Encryption now uses AESCrypt as a default.
GPG does not default to using the --armor option.
Added support for generic modules, but none are written yet.
Added support for plugable settings pages in the "Options" dialog.
Fixed issue #148.
Duplicati now uses AESCrypt as the default encryption format.
Fixed issue #199.
GPG now supports custom commandline options.
Fixed issue #207.
Encryption modules are now plugable.
Fixed issue #118.
S3 credentials are now stored.
Fixed issue #151.
Backends can now register system wide options.
git-svn-id: https://duplicati.googlecode.com/svn/trunk@427 59da171f-624f-0410-aa54-27559c288bec
Kenneth Skovhede