Supporting multiple directory hash types will allow converting to a
different one, without a flag day.
gitAnnexLocation now checks which of the possible locations have a file.
This means more statting of files. Several places currently use
gitAnnexLocation and immediately check if the returned file exists;
those need to be optimised.
Many functions took the repo as their first parameter. Changing it
consistently to be the last parameter allows doing some useful things with
currying, that reduce boilerplate.
In particular, g <- gitRepo is almost never needed now, instead
use inRepo to run an IO action in the repo, and fromRepo to get
a value from the repo.
This also provides more opportunities to use monadic and applicative
combinators.
Checks location log information, and file contents.
Does not check that numcopies is satisfied, as .gitattributes information
about numcopies is not available in a bare repository. In practice, that
should not be a problem, since fsck is also run in a checkout and will
check numcopies there.
This new approach allows filtering out checks from the default set that are
not appropriate for a command, rather than having to list every check
that is appropriate. It also reduces some boilerplate.
Haskell does not define Eq for functions, so I had to go a long way around
with each check having a unique id. Meh.
The only remaining vestiage of backends is different types of keys. These
are still called "backends", mostly to avoid needing to change user interface
and configuration. But everything to do with storing keys in different
backends was gone; instead different types of remotes are used.
In the refactoring, lots of code was moved out of odd corners like
Backend.File, to closer to where it's used, like Command.Drop and
Command.Fsck. Quite a lot of dead code was removed. Several data structures
became simpler, which may result in better runtime efficiency. There should
be no user-visible changes.
This was a real PITA to fix, since location logs can be staged in
both the current repo, as well as in local remote's repos, in
which case the cwd will not be in the repo. And git add needs different
params in both cases, when absolute paths are not used.
In passing, git annex fsck now stages location log fixes.
