Avoiding using a callback simplifies this and should make it easier to
implement incremental checksumming, which will need to happen partly in
writeRetrievedContent and partly in retrieveChunks.
This benchmarks only slightly faster than the old git-annex. Eg, for a 1
gb file, 14.56s vs 15.57s. (On a ram disk; there would certianly be
more of an effect if the file was written to disk and didn't stay in
cache.)
Commenting out the updateIncremental calls make the same run in 6.31s.
May be that overhead in the implementation, other than the actual
checksumming, is slowing it down. Eg, MVar access.
(I also tried using 10x larger chunks, which did not change the speed.)
This is groundwork for calculating checksums while copying, rather than
in a separate pass, but that's not done yet. For now, avoid using rsync
(and cp on Windows), and instead read and write the file ourselves, with
resume handling.
Benchmarking vs old git-annex that used rsync, this is faster,
at least once the file size is larger than a couple of MB.
Changing to the P2P protocol broke this, because preseedTmp copies
the local copy of the object to the temp file, and then the P2P transfer
sees the right length file and uses it as-is.
When git-annex-shell is too old and rsync is used, it did verify the
content, and when the local repo does not have the object it did verify the
content.
This could perhaps have caused a hard link to be made when the content
of the object was modified. I don't think that actually happened,
because the annexed file would have to be unlocked, with annex.thin, for
the object to get modified, and in that case, a hard link is not made.
However, to be sure, run the check.
Note that it seemed best to run the check only once, although the
current implementation is fast and safe to run repeatedly.
Checksum as content is received from a remote git-annex repository, rather
than doing it in a second pass.
Not tested at all yet, but I imagine it will work!
Not implemented for any special remotes, and also not implemented for
copies from local remotes. It may be that, for local remotes, it will
suffice to use rsync, rely on its checksumming, and simply return Verified.
(It would still make a checksumming pass when cp is used for COW, I guess.)
See my comment in the next commit for some details about why
Verified needs a hash with preimage resistance. As far as tahoe goes,
it's fully cryptographically secure.
I think that bup could also return Verified. However, the Retriever
interface does not currenly support that.
When a git remote is configured with an absolute path, use that path,
rather than making it relative. If it's configured with a relative path,
use that.
Git.Construct.fromPath changed to preserve the path as-is,
rather than making it absolute. And Annex.new changed to not
convert the path to relative. Instead, Git.CurrentRepo.get
generates a relative path.
A few things that used fromAbsPath unncessarily were changed in passing to
use fromPath instead. I'm seeing fromAbsPath as a security check,
while before it was being used in some cases when the path was
known absolute already. It may be that fromAbsPath is not really needed,
but only git-annex-shell uses it now, and I'm not 100% sure that there's
not some input that would cause a relative path to be used, opening a
security hole, without the security check. So left it as-is.
Test suite passes and strace shows the configured remote url is used
unchanged in the path into it. I can't be 100% sure there's not some code
somewhere that takes an absolute path to the repo and converts it to
relative and uses it, but it seems pretty unlikely that the code paths used
for a git remote would call such code. One place I know of is gitAnnexLink,
but I'm pretty sure that git remotes never deal with annex symlinks. If
that did get called, it generates a path relative to cwd, which would have
been wrong before this change as well, when operating on a remote.
When annex.stalldetection is not enabled, and a likely stall is detected,
display a suggestion to enable it.
Note that the progress meter display is not taken down when displaying
the message, so it will display like this:
0% 8 B 0 B/s
Transfer seems to have stalled. To handle stalling transfers, configure annex.stalldetection
0% 10 B 0 B/s
Although of course if it's really stalled, it will never update
again after the message. Taking down the progress meter and starting
a new one doesn't seem too necessary given how unusual this is,
also this does help show the state it was at when it stalled.
Use of uninterruptibleCancel here is ok, the thread it's canceling
only does STM transactions and sleeps. The annex thread that gets
forked off is separate to avoid it being canceled, so that it
can be joined back at the end.
A module cycle required moving from dupState the precaching of the
remote list. Doing it at startConcurrency should cover all the cases
where the remote list is used in concurrent actions.
This commit was sponsored by Kevin Mueller on Patreon.
Don't accept the cid of the temp file that the content has just been
written to as something we will accept if another file has that same
content. There's no reason to, and on FAT, due to mtime resolution,
the test suite hit just such a case.
This fixes a reversion from 73df633a62
which removed inode from the ContentIdentifier.
Directory special remotes with importtree=yes now avoid unncessary overhead
when inodes of files have changed, as happens whenever a FAT filesystem
gets remounted.
A few unusual edge cases of modifications won't be detected and
imported. I think they're unusual enough not to be a concern. It would
be possible to add a config setting that controls whether to compare
inodes too, but does not seem worth bothering the user about currently.
I chose to continue to use the InodeCache serialization, just with the
inode zeroed. This way, if I later change my mind or make it
configurable, can parse it back to an InodeCache and operate on it. The
overhead of storing a 0 in the content identifier log seems worth it.
There is a one-time cost to this change; all directory special remotes
with importtree=yes will re-hash all files once, and will update the
content identifier logs with zeroed inodes.
This commit was sponsored by Brett Eisenberg on Patreon.
After the last commit, it was able to throw errors just due to an
unparseable url. This avoids needing to worry about that, as long
as the call site has already checked that it has a parseable url.
Including the non-standard URI form that git-remote-gcrypt uses for rsync.
Eg, "ook://foo:bar" cannot be parsed because "bar" is not a valid port
number. But git could have a remote with that, it would try to run
git-remote-ook to handle it. So, git-annex has to allow for such things,
rather than crashing.
This commit was sponsored by Luke Shumaker on Patreon.
This code I'm reverting works. But it has a problem: The export db and
log and the ContentIdentifier db and log still list the content as being
stored in the remote. So when I ran borg create again and stored the
content in borg again in a new archive, git-annex sync noticed that, but
since it didn't update the tree for the old archives, it then thought
the content that had been removed from them was still in them, and so
git-annex get failed in an ugly way:
Include pattern 'tmp/x/.git/annex/objects/pX/ZJ/SHA256E-s0--e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/SHA256E-s0--e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855' never matched.
[2020-12-28 16:40:44.878952393] process [933616] done ExitFailure 1
user error (borg ["extract","/tmp/b::abs4","tmp/x/.git/annex/objects/pX/ZJ/SHA256E-s0--e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/SHA256E-s0--e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"] exited 1)
It does not seem worth it to update the git tree for the export when dropping
content, that would make drop of many files very expensive in git tree objects
created. So, let's not support this I suppose..
Note that, after changing it with enableremote, syncing won't rescan
known archives in the borg repo using the changed config. Probably not a
problem?
Also used File in some places where filenames that could theoretically
start with - are passed to borg, to avoid it confusing them with
options.
This makes sync a lot faster in the common case where there's no new
backup.
There's still room for it to be faster. Currently the old imported tree
has to be traversed, to generate the ImportableContents. Which then
gets turned around to generate the new imported tree, which is
identical. So, it would be possible to just return a "no new imports",
or an ImportableContents that has a way to graft in a tree. The latter
is probably too far to go to optimise this, unless other things need it.
The former might be worth it, but it's already pretty fast, since git
ls-tree is pretty fast.
It's unusual to use a ContentIdentifier that is not semi-unique
for different contents. Note that in importKeys, it checks if a content
identifier is one that's known before, to avoid downloading the same
content twice. But that's done in a code path not used for borg repos,
because they are thirdpartypopulated.
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.
This is to support, eg a borg repo as a special remote, which is
populated not by running git-annex commands, but by using borg. Then
git-annex sync lists the content of the remote, learns which files are
annex objects, and treats those as present in the remote.
So, most of the import machinery is reused, to a new purpose. While
normally importtree maintains a remote tracking branch, this does not,
because the files stored in the remote are annex object files, not
user-visible filenames. But, internally, a git tree is still generated,
of the files on the remote that are annex objects. This tree is used
by retrieveExportWithContentIdentifier, etc. As with other import/export
remotes, that the tree is recorded in the export log, and gets grafted
into the git-annex branch.
importKey changed to be able to return Nothing, to indicate when an
ImportLocation is not an annex object and so should be skipped from
being included in the tree.
It did not seem to make sense to have git-annex import do this, since
from the user's perspective, it's not like other imports. So only
git-annex sync does it.
Note that, git-annex sync does not yet download objects from such
remotes that are preferred content. importKeys is run with
content downloading disabled, to avoid getting the content of all
objects. Perhaps what's needed is for seekSyncContent to be run with these
remotes, but I don't know if it will just work (in particular, it needs
to avoid trying to transfer objects to them), so I skipped that for now.
(Untested and unused as of yet.)
This commit was sponsored by Jochen Bartl on Patreon.
I think this could cause unnecessary changes to the git-annex branch,
and retrieveExportWithContentIdentifier is now also used for getting
content from importtree=yes remotes, so it would happen more frequently
so let's avoid.
This is better than using the equivilant actions for export remotes,
especially for getting content, since the ContentIdentifier checking
means we can be sure (enough) that the content is valid to not force
verification of content. Which allows getting keys of types that cannot
be verified.
Also, reorganized the internals of adjustExportImport which was becoming
very hard to follow. Now it's clear what each method does in each case.
Ah, it seemed too easy before when I was implementing importrree only,
and it was because all the key-based actions needed to be handled too.
Mostly copied from isexport, and this works. It does seem that
an import remote could use retrieveExportWithContentIdentifier
rather than retrieveExport, and checkPresentExportWithContentIdentifier
rather than checkPresentExport, which would both be more accurate.
