As rpm-ostree evolves, it keeps driving API additions to libostree.
This creates a relatively tight coupling.
However, if delivering via e.g. RPM, unless one manually remembers to
increment the `Requires:` in the spec file, it's possible for the two
to become desynchronized.
RPM handles versioned symbols and will ensure a dependency if the
application starts using a newer version.
To implement this, switch to `-fvisibility=hidden`, along with an
annotation in the header, and finally add a `.sym` file.
This matches what other projects like systemd and libvirt do.
Although rather than attempting to retroactively version symbols, glom
them all onto the current one.
A fast way to generate new OSTree content using an existing
tree is to checkout (as hard links), add/replace files, then
call `ostree_repo_scan_hardlinks()`, then commit.
But `ostree_repo_scan_hardlinks()` scans the entire repo, which
can be slow if you have a lot of content.
All we really need is a mapping of (device,inode) -> checksum
just for the objects we checked out, then use that mapping
for commits.
This patch adds API so that callers can create a mapping via
`ostree_repo_devino_cache_new()`, then pass it to
`ostree_repo_checkout_tree_at()` which will populate it, and then
`ostree_repo_write_directory_to_mtree()` can consume it.
I plan to use this in rpm-ostree for package layering work.
Notes:
- The old `ostree_repo_scan_hardlinks()` API still works.
- I tweaked the cache to be a set with the checksum colocated with
the key, to avoid a separate malloc block per entry.
https://github.com/GNOME/ostree/pull/167
It's better if this is independent from the OstreeSysroot; for
example, a policy is active in a given deployment root at once, not
for a sysroot globally.
We can also collect SELinux-related API in one place.
Unfortunately at the moment there can be only one instance of this
class per process.
Colin Walters
Giuseppe Scrivano