This is a new git subcommand, that does a generic union merge operation
between two refs, storing the result in a branch. It operates efficiently
without touching the working tree. It does need to write out a temporary
index file, and may need to write out some other temp files as well.
This could be useful for anything that stores data in a branch,
and needs to merge changes into that branch without actually checking the
branch out. Since conflict handling can't be done without a working copy,
the merge type is always a union merge, which is fine for data stored in
log format (as git-annex does), or in non-conflicting files
(as pristine-tar does).
This probably belongs in git proper, but it will live in git-annex for now.
---
Plan is to move .git-annex/ to a git-annex branch, and use git-union-merge
to handle merging changes when pulling from remotes.
Some preliminary benchmarking using real .git-annex/ data indicates
that it's quite fast, except for the "git add" call, which is as slow
as "git add" tends to be with a big index.
ghc 7 produces these warnings http://hackage.haskell.org/trac/ghc/ticket/4288
The specialization is enabled by -O2, and the default limit of 3 is
there to avoid specialization blowing up binary size. Perhaps that default
is a little low? I needed 4 to avoid a warning on Unused.hs, and 5 to avoid
warnings on test.hs
The test suite will not be run if it cannot be compiled.
It may be possible later to split off the quickcheck using tests into
a separate program and keep most of the tests using just hunit.
So, it would be nicer to just use Cabal and take advantage
of its conditional compilation support. But, Cabal seems to
lack good support for a package with an internal library that is used by
multiple executables. It wants to build everything twice or more.
That's too slow for me.
Anyway, fairly soon, I expect to upgrade hS3 to a requirment, and I
can just revert this.
It compiles. It sorta works. Several subcommands are FIXME marked and
broken, because things that used to accept separate --backend and --key
params need to be changed to accept just a --key that encodes all the key
info, now that there is metadata in keys.
When adding files to the annex, the symlinks pointing at the annexed
content are made to have the same mtime as the original file. While git
does not preserve that information, this allows a tool like metastore to be
used with annexed files.
The option cause it to always build to build/Main.o, no matter what
binary it was building. This caused extra work, and in some cases,
could cause the wrong code to be put into the final binary.
