Previously we'd open(path, O_NOATIME) and do a series of small read()
calls to just parse the header. I think this will trigger kernel readahead
into the compressed portion, but we don't care about that.
This should be more efficient.
This is an incompatible change to archive-z, thus it is now renamed to
archive-z2 and ostree will no longer parse archive-z.
I noticed in perf that we were spending some time zlib-decompressing
file headers, which is just inefficient. Rather than do this, keep
the headers uncompressed, and just zlib-compress content.
This is where loose content objects are stored as one compressed file,
instead of the two separate ones for regular archive mode. This mode
would be suitable for HTTP servers, beause only one HTTP request is
necessary, and the result would be compressed.
They're not a large efficiency win at the moment, because we don't
do any delta compression.
At the moment, they simply served to compress data, but we will change
the archive mode to do that by default.
This helps make things less confusing when we try to create a file not
owned by our uid, such as running ostree-pull as non-root on a
repository owned by root.
This will allow us to use hard links again for user-mode checkouts,
rather than the hackish link cache. It was pretty silly anyways to
have file objects be stored with just a small metadata header
prepended, but uncompressed.
Either they should be hardlinkable, or compressed (in pack files).
Rather than passing xattr/file_info for all objects, change the API to
assume we're passing the defined object stream for each type. Namely,
for OSTREE_OBJECT_TYPE_FILE, we're now giving the "archive file" data.
This significantly cleans up the code for committing to archive mode
repositories, at the cost of having to (at present) create an
intermediate temporary file when committing to raw repositories.
Having the archived vs not distinction in the object system wasn't
useful in light of pack files. In fact, we should probably move
towards generating a pack file per commit by default.
Don't expose GChecksum in APIs. Add a new stream class which allows
us to pass an input stream somewhere, but gather a checksum as it's
read.
Move some bits of the internals towards binary csums.
Continuing from 16c0cfe9b5, we now have
the problem that we're removing the executable bit, which obviously
breaks things when we chroot in for a build. Fix this by masking over
our bits.
If multiple files have the same hash, we need to ensure we're not
overwriting other tempfiles in the same transaction. Instead
just delete them, since we know they're in the repo.
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.
Colin Walters