Rather than offering high level "commit directory", instead perform
operations on a mtree. Commits are treated more like regular objects.
Change the commit builtin to drive this all at a lower level.
ostbuild will generate two artifacts: foo-runtime.tar.gz and
foo-devel.tar.gz in the general case. When committing to the devel
tree, it'd be lame (i.e. slower and not atomic) to have to commit
twice.
This will allow us to have hardlink checkouts of archives. A key use
case here is an archive repo of an OS (with root-owned files etc.)
where we want to do builds in a user tree.
A positive side effect of doing things this way is that now the SHA256
checksums for a given file should be identical regardless of whether
it's stored in an archive or bare repository.
We really want the ability to take a .tar.gz and directly import
it into a repository, without creating a temporary filesystem tree.
First, doing it this way is significantly faster. Also, this allows
us to handle importing tar files with e.g. uid 0 files into packed
repositories as non-root, which is very useful for tests and builds.
The default is always ignore_exists. Also port the internals here
to use more GIO code, and stop using *at syscall variants since they're
only useful if used 100%.
This necessitated a large set of changes.
We now support an "archive" mode for repositories. In this mode,
files are stored "packed" rather than hard linked. This allows one to
e.g. store an OSTree repository with root-owned files as non-root. It
is also used as the basis for serving repositories via HTTP.
While doing this I realized that GVariant is endianness-dependent; I
decided to just store all data in big endian.
Colin Walters