I see when analyzing a delta here that due to byteswapping a negative
compression ratio of 540%, 66%, and 28%. Let's arbitrarily pick 20%
as a threshold for detecting byetswapping.
If the average object size is greater than 4GiB, let's assume we're
dealing with opposite endianness. I'm fairly confident no one is
going to be shipping peta- or exa- byte size ostree deltas, period.
Past the gigabyte scale you really want bittorrent or something.
xdg-app passed this a filename directly, and in this case it should be
used as is. This regressed to always look for "superblock" in the same
directory as the passed in filename.
https://bugzilla.gnome.org/show_bug.cgi?id=762617
Some Docker layers are just metadata in the `layer.json`. If one is
mapping Docker layers to OSTree commits, one needs to create a dummy
root directory, because OSTree doesn't support metadata-only commits.
Let's just push that logic down here because it's easier than special
casing it in higher levels.
One of the design goals with deltas was not just wire efficiency,
but also having all the data up front about how much data would
be transferred before starting.
Let's expose that better by adding a `dry-run` option to the pull API.
This requires static deltas to be useful. Basically we simply call
the progress callback once with the data from the superblock.
For a production release repository, most OS vendors would want
to just always use static deltas. Add the ability for the pulls to
require it.
(I think I'll also add a summary key for this actually in addition,
so the repo manager can force it too)
If ostree is run in a test setup where it operates as root in a tmp
directory, it might cause issues to flag the deployments as immutable.
The test harness might simply be doing an `rm -rf` (effectively the case
for gnome-desktop-testing-runner), which will then fail.
We add a new debug option to the ostree_sysroot object using GLib's
GDebugKey functionality to allow our tests to communicate to ostree that
we don't want immutable deployments.
This is a more flexible version of the previous
ostree_repo_write_archive_to_mtree() which took a file reference.
This has an extensible options structure, and in particular
now supports `ignore_unsupported_content`.
I plan to use this for importing Docker images which contain device
nodes. (There's no reason for container images to have those, so
we'll just ignore them).
Also here, just like the export variant, the caller is responsible for
setting up libarchive.
I was going to add new API for importing, and it was really confusing
that what I think of now as import and export both had "write" in the
name. It's just clearer to talk about the direction.
At the same time, include `Export` in the options structure.
This isn't an ABI break as the API isn't in a release.
I was getting a compilation error with the GCC hardening flags which
look for a missing mode with `O_CREAT`. The right fix here is to drop
`O_CREAT`, as truncate() should throw `ENOENT` if the file doesn't
exist.
For rofiles-fuse. Eventually what we should really do is split out
the shared library from the binaries? A minimal system shouldn't need
rofiles-fuse, it's mainly for doing layered packages and that sort of
thing.
I don't know why we didn't do this a long time ago. This extends the
pull API to allow grabbing a specific commit, and will set the branch
to it. There's some support for this in the deploy engine, but there
are a lot of reasons to support it for raw pulls (such as subset
mirroring cases).
In fact I'm thinking we should also have the override-version logic
here too.
NOTE: One thing I debated here is inventing a new syntax on the
command line. Git doesn't seem to have this functionality (probably
because it'd be rarely used). The '@' character at least doesn't
conflict with anything.
Anyways, I wanted this for some other test cases. Without this,
writing tests that go between different commits is more awkward as one
must generate the content in one repo, then pull downstream, then
generate more content, then pull again. But now I can just keep track
of commit IDs and do exactly what I want without synchronizing the
tests.
At the moment I'm looking at using rpm-ostree to manage RPM inputs
which can then be converted into Docker images. It's most convenient
if we can stream directly out of libostree rather than doing a
checkout + tar combination.
There are also backup/debugging etc. reasons to implement `export` as
well.
While it's not strictly tied to OSTree, let's move
https://github.com/cgwalters/rofiles-fuse in here because:
- It's *very* useful in concert with OSTree
- It's tiny
- We can reuse OSTree's test, documentation, etc. infrastructure
One thing to consider also is that at some point we could experiment
with writing a FUSE filesystem for OSTree. This could internalize a
better equivalent of `--link-checkout-speedup`, but on the other hand,
the cost of walking filesystem trees for these types of operations is
really quite small.
But if we did decide to do more FUSE things in OSTree, this is a step
towards that too.
Now we display stats on the individual parts, such as the blob size
and the number of each type of opcode. Most interesting to me is
things like how many bsdiff opcodes there are vs new objects, etc.
We had code to deal with opening/checksumming/decompressing static
deltas in a few places. I'd like to teach `ostree static-delta show`
how to display more information, and this will allow it to just use
`_ostree_static_delta_part_open()` too.
Simon McVittie
Colin Walters
Alexander Larsson
Joaquim Rocha
Jonathan Lebon
Matthew Barnes
Giuseppe Scrivano