better plugin interface

[Quramy]

I think there are better names of each plugins and their methods.

Publisher:

Publisher plugin should have 2 methods named publish and fetch. They've been strongly influenced by the S3-plugin implementation and I feel uneasy.

• What does means fetch ? Some users wants this method to copy local files or refer a directory existing their repository.
• Should the fetch method be tied with the publish ? In the beginning I've not doubted that the location publish to / fetch from is same, is it correct ?

Key Generator

KeyGenerator has strongly tied 2 methods too, getExpectedKey and getActualKey.

Because the above reason, in other words I think separate publish / fetch to other interfaces, getExpectedKey and getActualKey should be declared at other interfaces rather than one interface.

The second, I think the term key and generate ain't good, but I cannot get better name than them... Is there nice one?

• identifier / key / snapshot-id / snapshot-key / etc,,,
• detect / create / determine / find / search / etc,,,