This avoids querying the database when the content file doen't exist
(or otherwise fails the provided check). However, it does add overhead of
querying the database, and will certianly impact performance.
The Keys database can hold multiple inode caches for a given key. One for
the annex object, and one for each pointer file, which may not be hard
linked to it.
Inode caches for a key are recorded when its content is added to the annex,
but only if it has known pointer files. This is to avoid the overhead of
maintaining the database when not needed.
When the smudge filter outputs a file's content, the inode cache is not
updated, because git's smudge interface doesn't let us write the file. So,
dropping will fall back to doing an expensive verification then. Ideally,
git's interface would be improved, and then the inode cache could be
updated then too.
This removes ambiguity, because while someone might have "WORM--foo" in a
file that's not intended to be a git-annex pointer file,
"annex/objects/WORM--foo" is less likely.
Also, 664cc987e8 had a caveat about symlink
targets being parsed as pointer files, and now the same parser is used for
both.
I did not include any hash directories before the key in the pointer file,
as they're not needed. However, if they were included, the parser would
still work ok.
Note that this changes the default behavior of git add in a newly
initialized repository; it will add files to the annex.
Don't like that this could break workflows, but it's necessary in order for
any pointer files in the repo to be handled by git-annex.
Since all places where a repo is used in direct mode need to have git-annex
upgraded before the repo can safely be converted to v6, the upgrade needs
to be manual for now.
I suppose that at some point I'll want to drop all the direct mode support
code. At that point, will stop supporting v5, and will need to auto-upgrade
any remaining v5 repos. If possible, I'd like to carry the direct mode
support for say, a year or so, to give people plenty of time to upgrade and
avoid disruption.
