This improves the borg special remote memory usage, by
letting it only load one archive's worth of filenames into memory at a
time, and building up a larger tree out of the chunks.
When a borg repository has many archives, git-annex could easily OOM
before. Now, it will use only memory proportional to the number of
annexed keys in an archive.
Minor implementation wart: Each new chunk re-opens the content
identifier database, and also a new vector clock is used for each chunk.
This is a minor innefficiency only; the use of continuations makes
it hard to avoid, although putting the database handle into a Reader
monad would be one way to fix it.
It may later be possible to extend the ImportableContentsChunkable
interface to remotes that are not third-party populated. However, that
would perhaps need an interface that does not use continuations.
The ImportableContentsChunkable interface currently does not allow
populating the top of the tree with anything other than subtrees. It
would be easy to extend it to allow putting files in that tree, but borg
doesn't need that so I left it out for now.
Sponsored-by: Noam Kremen on Patreon
Note that a key with no size field that is hard linked will
result in listImportableContents reporting a file size of 0,
rather than the actual size of the file. One result is that
the progress meter when getting the file will seem to get stuck
at 100%. Another is that the remote's preferred content expression,
if it tries to match against file size, will treat it as an empty file.
I don't see a way to improve the latter behavior, and the former behavior
is a minor enough problem.
This commit was sponsored by Jake Vosloo on Patreon.
Keys stored on the filesystem are mangled by keyFile to avoid problem
chars. So, that mangling has to be reversed when parsing files from a
borg backup back to a key.
The directory special remote also so mangles them. Some other special
remotes do not; eg S3 just serializes the key -- but S3 object names are
not limited to filesystem valid filenames anyway, so a S3 server must
not map them directly to files in any case. It seems unlikely that a
borg backup of some such special remote will get broken by this change.
This commit was sponsored by Graham Spencer on Patreon.
Still some issues to deal with, see TODO and XXX.
Here's what gets logged, for each key:
cid log:
1608582045.832799227s 6720ebad-b20e-4460-a8f2-2477361aea75 !MjAyMC0xMi0yMVQxMTozMzoxNw==:!MjAyMC0xMi0yMVQxMzowNzoyNg==
The "!Mj" are base64 encoded borg archive names, since mine were
dates and contained some characters not allowed in cid logs unescaped.
There were archives that each contained the key. This list will grow as
more borg backups are done and learned about.
tree generated:
120000 blob 5ef6a4615c084819b44cd4e3a31657664ddf643b x/dotgit/annex/objects/06/mv/SHA256E-s30--a5d8532e64ec28f5491e25e7a6c1cb68f80507c1be6c1b35f8ec53d25413e5da/SHA256E-s30--a5d8532e64ec28f5491e25e7a6c1cb68f80507c1be6c1b35f8ec53d25413e5da
120000 blob 063a139d3021c8db60f5c576d29fada2b824d91c x/dotgit/annex/objects/72/PP/SHA256E-s30--e80b09a854b4e4d99a76caaa6983b34272480e0b4fdb95d04234a54b4849b893/SHA256E-s30--e80b09a854b4e4d99a76caaa6983b34272480e0b4fdb95d04234a54b4849b893
120000 blob b53b54916fd6abf21fedf796deca08d5ac7a75af x/dotgit/annex/objects/Ww/pk/SHA256E-s30--6aac072a8ebf02a5807c4f15e77ed585a6c87b3b333ba625a3c8d6b4dc50a9f2/SHA256E-s30--6aac072a8ebf02a5807c4f15e77ed585a6c87b3b333ba625a3c8d6b4dc50a9f2
This commit was sponsored by Denis Dzyubenko on Patreon.
May actually work now.
Note that, importKey now has to add the size to the key if it's supposed
to have size. Remote.Directory relied on the importer adding the size,
which is no longer done, so it was changed; it was the only one.
This way, importKey does not need to behave differently between regular
and thirdpartypopulated imports.
2020-12-21 16:19:44 -04:00
Renamed from Remote/Helper/ThirdParty.hs (Browse further)
