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Joey Hess 2016-02-09 13:45:40 -04:00
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@ -7,26 +7,46 @@ Consider two use cases:
2. [[todo/hide_missing_files]]
Both of these could be met by making `git-annex sync` maintain an adjusted
version of the HEAD branch. This could be a detached HEAD or a branch named
eg `adjusted/master`.
version of the original branch, eg `adjusted/master`.
[[!toc]]
## filters
There would be a filter function. For #1 above it would simply convert all
annex symlinks to annex file pointers. For #2 above it would omit files
whose content is not currently in the annex. Sometimes, both #1 and #2 would
be wanted.
## merge
When merging changes from a remote, apply the filter to the head of the
remote branch, resulting in a commit with its changes. Merge in that
commit. Note that it's possible to control the metadata of the commit such
that 2 users who have the same adjusted branch checked out, both generate
the same commit sha.
This would be done by `git annex merge` and `git annex sync`.
Since the adjusted/master branch is not present on the remote, if the user
does a `git pull`, it won't merge in changes from origin/master. Which is
good because the filter needs to be applied first.
However, if the user does `git merge origin/master`, they'll get into a
state where the filter has not been applied. The post-merge hook could be
used to clean up after that. Or, let the user foot-shoot this way; they can
always reset back once they notice the mistake.
## annex object add/remove
When objects are added/removed from the annex, the associated file has to
be looked up, and the filter applied to it. So, dropping a file with the
missing file filter would cause it to be removed from the adjusted branch,
and receiving a file's content would cause it to appear in the adjusted
branch.
## commit
When committing changes, a commit is made as usual to the adjusted branch.
So, the user can `git commit` (or `git annex sync`). This does not touch
the original branch yet.
@ -59,11 +79,7 @@ It might be useful to have a post-commit hook that generates the
reverse-filtered commit and updates the original branch. And/or
`git-annex sync` could do it.
The new master branch can then be pushed out to remotes. The
adjusted/master branch is not pushed to remotes. `git-annex sync` should
automatically push master when adjusted/master is checked out.
## problems
## reverse filtering
Reversing filter #1 would mean only converting pointer files to
symlinks when the file was originally a symlink. This is problimatic when a
@ -71,6 +87,21 @@ file is renamed. Would it be ok, if foo is renamed to bar and bar is
committed, for it to be committed as an unlocked file, even if foo was
originally locked?
Reversing filter #2 would mean not deleting removed files whose content was
not present. When the commit includes deletion of files that were removed
due to their content not being present, those deletions are not propigated.
When the user deletes an unlocked file, the content is still
present in annex, so reversing the filter should propigate the file
deletion.
## push
The new master branch can then be pushed out to remotes. The
adjusted/master branch is not pushed to remotes. `git-annex sync` should
automatically push master when adjusted/master is checked out.
## problems
Using `git checkout` when in an adjusted branch is problimatic, because a
non-adjusted branch would then be checked out. But, we can just say, if
you want to get into an adjusted branch, you have to run some command.