Direct dependence of storage client code on the RIStorageServer RemoteReference creates tight coupling and inflexibility

[exarkun]

allmydata.storage_client.NativeStorageClient provides the functionality to *get* a RemoteReference for the server-published RIStorageServer but offers little or not abstractions beyond that.

All storage client application code has get_rref and callRemote calls sprinkled throughout.

This couples all of that storage client application code tightly to both the RemoteReference and RIStorageServer interfaces. In turn, this makes it difficult to make changes to either of these.

If we want Tahoe-LAFS to switch to an HTTP-based protocol then tight coupling to RemoteReference is an undesirable thing.

If we want to enhance the storage server protocol then tight coupling to RIStoragerServer is also an undesirable thing.

[exarkun]

Fixed in ​https://github.com/tahoe-lafs/tahoe-lafs/commit/a07426b2e99988a38d42ee52a95144723f2e4cfa