Simply feed each chunk in turn to the incremental verifier.
When resuming an interrupted retrieve, it does not do incremental
verification. That would need to read the file, up to the resume point,
and feed it to the incremental verifier. That seems easy to get wrong.
Also it would mean extra work done before the transfer can start. Which
would complicate displaying progress, and would perhaps not appear to the
user as if it was resuming from where it left off. Instead, in that
situation, return UnVerified, and let the verification be done in a
separate pass.
Granted, Annex.CopyFile does manage all that, but it's not complicated
by dealing with chunks too.
Sponsored-by: Dartmouth College's DANDI project
Several special remotes verify content while it is being retrieved,
avoiding a separate checksum pass. They are: S3, bup, ddar, and
gcrypt (with a local repository).
Not done when using chunking, yet.
Complicated by Retriever needing to change to be polymorphic. Which in turn
meant RankNTypes is needed, and also needed some code changes. The
change in Remote.External does not change behavior at all but avoids
the type checking failing because of a "rigid, skolem type" which
"would escape its scope". So I refactored slightly to make the type
checker's job easier there.
Unfortunately, directory uses fileRetriever (except when chunked),
so it is not amoung the improved ones. Fixing that would need a way for
FileRetriever to return a Verification. But, since the file retrieved
may be encrypted or chunked, it would be extra work to always
incrementally checksum the file while retrieving it. Hm.
Some other special remotes use fileRetriever, and so don't get incremental
verification, but could be converted to byteRetriever later. One is
GitLFS, which uses downloadConduit, which writes to the file, so could
verify as it goes. Other special remotes like web could too, but don't
use Remote.Helper.Special and so will need to be addressed separately.
Sponsored-by: Dartmouth College's DANDI project
This eliminates the distinction between decodeBS and decodeBS', encodeBS
and encodeBS', etc. The old implementation truncated at NUL, and the
primed versions had to do extra work to avoid that problem. The new
implementation does not truncate at NUL, and is also a lot faster.
(Benchmarked at 2x faster for decodeBS and 3x for encodeBS; more for the
primed versions.)
Note that filepath-bytestring 1.4.2.1.8 contains the same optimisation,
and upgrading to it will speed up to/fromRawFilePath.
AFAIK, nothing relied on the old behavior of truncating at NUL. Some
code used the faster versions in places where I was sure there would not
be a NUL. So this change is unlikely to break anything.
Also, moved s2w8 and w82s out of the module, as they do not involve
filesystem encoding really.
Sponsored-by: Shae Erisson on Patreon
The goal is that Database.Keys be able to use it; it can't use
Annex.Content.Presence due to an import loop.
Several other things also needed to be moved to Annex.Verify as a
conseqence.
Which could happen occasionally before when concurrency is enabled.
While not much of a problem when it did happen, better to avoid it. Also,
since it seems likely the gpg-agent sometimes fails in such a situation,
this makes it not happen when running a single git-annex command with
concurrency enabled.
This commit was sponsored by Jake Vosloo on Patreon.
This fixes fsck of a remote that uses chunking displaying
(checking remotename) (checking remotename)" for every chunk.
Also, some remotes displayed the message, and others did not, with no
consistency. It was originally displayed only when accessing remotes
that were expensive or might involve a password prompt, I think, but
nothing in the API said when to do it so it became an inconsistent mess.
Originally I thought fsck should always display it. But it only displays
in fsck --from remote, so the user knows the remote is being accessed,
so there is no reason to tell them it's accessing it over and over.
It was also possible for git-annex move to sometimes display it twice,
due to checking if content is present twice. But, the user of move
specifies --from/--to, so it does not need to display when it's
accessing the remote, as the user expects it to access the remote.
git-annex get might display it, but only if the remote also supports
hasKeyCheap, which is really only local git remotes, which didn't
display it always; and in any case nothing displayed it before hasKeyCheap,
which is checked first, so I don't think this needs to display it ever.
mirror is like move. And that's all the main places it would have been
displayed.
This commit was sponsored by Jochen Bartl on Patreon.
If it's passed a ConfigKey such as annex.version, avoid returning
an empty remote name and return Nothing instead. Also, foo.bar.baz is
not treated as a remote named "bar".
Had to add to AnnexRead an indication of whether debugging is enabled.
Could have just made setupConsole not install a debug output action that
outputs, and have enableDebug be what installs that, but then in the
common case where there is no debug selector, and so all debug output is
selected, it would run the debug output action every time, which entails
an IORef access. Which would make fastDebug too slow..
This uses a DebugSelector, rather than debug levels, which will allow
for a later option like --debug-from=Process to only
see debuging about running processes.
The module name that contains the thing being debugged is used as the
DebugSelector (in most cases; does not need to be a hard and fast rule).
Debug calls were changed to add that. hslogger did not display
that first parameter to debugM, but the DebugSelector does get
displayed.
Also fastDebug will allow doing debugging in places that are used in
tight loops, with the DebugSelector coming from the Annex Reader
essentially for free. Not done yet.
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.
When autoenabling special remotes of type S3, weddav, or glacier, do not
take login credentials from environment variables, as the user may not be
expecting the autoenable to happen, and may have those set for other
purposes.
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.
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.)
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..
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.
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.
I do think this was a reversion, but I have not tracked back to what
version. While involving the remote config, it's not the same class of
problems that I kept having to chase down for a while after the remote
config parser reworking.
Done on unix, could not implement it on windows quite.
The signal library gets part of the way needed for windows.
But I had to open https://github.com/pmlodawski/signal/issues/1 because
it lacks raiseSignal.
Also, I don't know what the equivilant of getProcessGroupIDOf is on
windows. And System.Process does not provide a way to send any signal to
a process group except for SIGINT.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
There was no particular reason not to support this, other than maybe a lack
of a use case. One use case would of course be a remote that you want to
avoid overwriting content on. A new use case is the idea of importing from
backups, eg borg, where exporting is not necessarily supported at all.
This commit was sponsored by Brock Spratlen on Patreon.
It's not concurrent-output safe, and doesn't support
--json-error-messages.
Using Annex.makeRunner is a bit scary, because what if it's run in a
different thread from an active annex action? Normally the same Annex
state is not used concurrently in several threads, and it's not designed
to be fully concurrency safe. (Annex.Concurrent exists to deal with
that.) I think it will be ok in these simple cases though. Eg,
when buffering a warning message to json, Annex.changeState is used,
and it modifies the MVar in a concurrency safe way.
The only warningIO remaining is not a problem.
9cb250f7be got the ones in RawFilePath,
but there were others that used the one from unix-compat, which fails at
runtime on windows. To avoid this,
import System.PosixCompat.Files hiding removeLink
This commit was sponsored by Ethan Aubin.
It looks to me like the old code would have already dealt with the case
of ssh starting a ssh daemon that inherits stderr and keeps it open.
The ender thread closed the handle, which would unblock the other thread
and let it exit. Using hGetLineUntilExitOrEOF makes this more explicit
that it's dealt with and simplifies the code.
Lots of nice wins from this in avoiding unncessary work, and I think
nothing got slower.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
nukeFile replaced with removeWhenExistsWith removeLink, which allows
using RawFilePath. Utility.Directory cannot use RawFilePath since setup
does not depend on posix.
This commit was sponsored by Graham Spencer on Patreon.
Only done in checkPresentChunks, although retrieveChunks could also do
it. Does not seem necessary though, because git-annex never retrives
content without first checking if it's present AFAICR. And really this will
only be needed when using fsck. Puttting it here, rather than in fsck
avoids breaking an abstraction boundary, and is nice and inexpensive.
When a special remote has chunking enabled, but no chunk sizes are
recorded (or the recorded ones are not found), speculatively try chunks
using the configured chunk size.
This makes eg, git-annex fsck --from remote be able to fix up the
location log of a file that the git-annex branch does not indicate is
stored on the remote.
Note that fsck does *not* fix up the chunk log to indicate the chunk
size. So, changing the chunk config of the remote after that will still
prevent accessing the chunks stored on it. Maybe fsck should, but I
wanted to start with this and see if it's needed.
Only supported by some special remotes: directory
I need to check the rest and they're currently missing methods until I do.
git-annex sync --no-content does not yet use this to do imports
Fix bug that made creds not be stored in git when a special remote was
initialized with gpg encryption, but without an explicit embedcreds=yes.
(Yet nother regression introduced in version 7.20200202.7. 5th so far.)
Some recent changes to use mask missed that async exceptions can still
be thrown inside it. The goal is to make sure a block of cleanup code
runs entirely, w/o being interrupted by an async exception, so use
uninterruptibleMask.
Also, converted a few to bracket, which is nicer.
Except for the assistant, which I think may use them between threads?
Most of the uses of SomeException were already catching only async exceptions.
But I did find a few places that were accidentially catching them.
Masking ensures that EndStderrHandler gets written, so the helper
threads shut down.
However, nothing currently guarantees that calls to closeP2PSshConnection
are async exception safe, so made a note about it.
At this point, I've audited all calls to async, and made them all async
exception safe, except for ones in the assistant, and a few in leaf
commands (remotedaemon, enable-tor, multicast, p2p) which don't need to
be.
Fix bug that made enableremote of S3 and webdav remotes, that have
embedcreds=yes, fail to set up the embedded creds, so accessing the remotes
failed.
(Regression introduced in version 7.20200202.7 in when reworking all the
remote configs to be parsed.)
Root problem is that parseEncryptionConfig excludes all other config keys
except encryption ones, so it is then unable to find the
credPairRemoteField. And since that field is not required to be
present, it proceeds as if it's not, rather than failing in any visible
way.
This causes it to not find any creds, and so it does not cache
them. When when the S3 remote tries to make a S3 connection, it finds no
creds, so assumes it's being used in no-creds mode, and tries to find a
public url. With no public url available, it fails, but the failure doesn't
say a lack of creds is the problem.
Fix is to provide setRemoteCredPair with a ParsedRemoteConfig, so the full
set of configs of the remote can be parsed. A bit annoying to need to
parse the remote config before the full config (as returned by
setRemoteCredPair) is available, but this avoids the problem.
I assume webdav also had the problem by inspection, but didn't try to
reproduce it with it.
Also, getRemoteCredPair used getRemoteConfigValue to get a ProposedAccepted
String, but that does not seem right. Now that it runs that code, it
crashed saying it had just a String.
Remotes that have already been enableremoted, and so lack the cached creds
file will work after this fix, because getRemoteCredPair will extract
the creds from the remote config, writing the missing file.
This commit was sponsored by Ilya Shlyakhter on Patreon.
Finishes the transition to make remote methods throw exceptions, rather
than silently hide them.
A bit on the fence about this one, because when renameExport fails,
it falls back to deleting instead, and so does the user care why it failed?
However, it did let me clean up several places in the code.
This commit was sponsored by Ethan Aubin.
Part of ongoing transition to make remote methods
throw exceptions, rather than silently hide them.
This commit was sponsored by Ilya Shlyakhter on Patreon.
Part of ongoing transition to make remote methods
throw exceptions, rather than silently hide them.
This commit was sponsored by Graham Spencer on Patreon.
retrieveExport is part of ongoing transition to make remote methods
throw exceptions, rather than silently hide them.
getKey very rarely fails, and when it does it's always for the same reason
(user configured annex.backend to url for some reason). So, this will
avoid dealing with Nothing everywhere it's used.
This commit was sponsored by Ilya Shlyakhter on Patreon.
When storing content on remote fails, always display a reason why.
Since the Storer used by special remotes already did, this mostly affects
git remotes, but not entirely. For example, if git-lfs failed to connect to
the endpoint, it used to silently return False.
That had almost no benefit at all, and complicated things quite a lot.
What I proably wanted this to be was something like ResourceT, but it
was not. The few remotes that actually need some preparation done only
once and reused used a MVar and not Preparer.
Fix serious regression in gcrypt and encrypted git-lfs remotes.
Since version 7.20200202.7, git-annex incorrectly stored content
on those remotes without encrypting it.
Problem was, Remote.Git enumerates all git remotes, including git-lfs
and gcrypt. It then dispatches to those. So, Remote.List used the
RemoteConfigParser from Remote.Git, instead of from git-lfs or gcrypt,
and that parser does not know about encryption fields, so did not
include them in the ParsedRemoteConfig. (Also didn't include other
fields specific to those remotes, perhaps chunking etc also didn't
get through.)
To fix, had to move RemoteConfig parsing down into the generate methods
of each remote, rather than doing it in Remote.List.
And a consequence of that was that ParsedRemoteConfig had to change to
include the RemoteConfig that got parsed, so that testremote can
generate a new remote based on an existing remote.
(I would have rather fixed this just inside Remote.Git, but that was not
practical, at least not w/o re-doing work that Remote.List already did.
Big ugly mostly mechanical patch seemed preferable to making git-annex
slower.)
remoteAnnexConfig will avoid bugs like
a3a674d15b
Use now more generic remoteConfig in a couple places that built
non-annex config settings manually before.
Special remote programs that use GETCONFIG/SETCONFIG are recommended
to implement it.
The description is not yet used, but will be useful later when adding a way
to make initremote list all accepted configs.
configParser now takes a RemoteConfig parameter. Normally, that's not
needed, because configParser returns a parter, it does not parse it
itself. But, it's needed to look at externaltype and work out what
external remote program to run for LISTCONFIGS.
Note that, while externalUUID is changed to a Maybe UUID, checkExportSupported
used to use NoUUID. The code that now checks for Nothing used to behave
in some undefined way if the external program made requests that
triggered it.
Also, note that in externalSetup, once it generates external,
it parses the RemoteConfig strictly. That generates a
ParsedRemoteConfig, which is thrown away. The reason it's ok to throw
that away, is that, if the strict parse succeeded, the result must be
the same as the earlier, lenient parse.
initremote of an external special remote now runs the program three
times. First for LISTCONFIGS, then EXPORTSUPPORTED, and again
LISTCONFIGS+INITREMOTE. It would not be hard to eliminate at least
one of those, and it should be possible to only run the program once.
Avoids parse error when the fields are added to RemoteConfig at setup
time and it then gets parsed, also at setup time. After setup time, such
internally added fields are not a problem, because they're Accepted. So
it may not be necessary in all cases to list such internally added
fields, but I think it's a good idea to always do so.
Needed so Remote.External can query the external program for its
configs. When the external program does not support the query,
the passthrough option will make all input fields be available.
Use of Typeable means the type checker can't catch this kind of mistake,
the error is deferred to runtime.
testremote now passes on a directory special remote
Remote now contains a ParsedRemoteConfig. The parsing happens when the
Remote is constructed, rather than when individual configs are used.
This is more efficient, and it lets initremote/enableremote
reject configs that have unknown fields or unparsable values.
It also allows for improved type safety, as shown in
Remote.Helper.Encryptable where things that used to match on string
configs now match on data types.
This is a work in progress, it does not build yet.
The main risk in this conversion is forgetting to add a field to
RemoteConfigParser. That will prevent using that field with
initremote/enableremote, and will prevent remotes that already are set
up from seeing that configuration. So will need to check carefully that
every field that getRemoteConfigValue is called on has been added to
RemoteConfigParser.
(One such case I need to remember is that credPairRemoteField needs to be
included in the RemoteConfigParser.)
This is a first step toward that goal, using the ProposedAccepted type
in RemoteConfig lets initremote/enableremote reject bad parameters that
were passed in a remote's configuration, while avoiding enableremote
rejecting bad parameters that have already been stored in remote.log
This does not eliminate every place where a remote config is parsed and a
default value is used if the parse false. But, I did fix several
things that expected foo=yes/no and so confusingly accepted foo=true but
treated it like foo=no. There are still some fields that are parsed with
yesNo but not not checked when initializing a remote, and there are other
fields that are parsed in other ways and not checked when initializing a
remote.
This also lays groundwork for rejecting unknown/typoed config keys.
Remove dup definitions and just use the RawFilePath one. </> etc are
enough faster that it's probably faster than building a String directly,
although I have not benchmarked.
Adds a dependency on filepath-bytestring, an as yet unreleased fork of
filepath that operates on RawFilePath.
Git.Repo also changed to use RawFilePath for the path to the repo.
This does eliminate some RawFilePath -> FilePath -> RawFilePath
conversions. And filepath-bytestring's </> is probably faster.
But I don't expect a major performance improvement from this.
This is mostly groundwork for making Annex.Location use RawFilePath,
which will allow for a conversion-free pipleline.
The parser and looking up config keys in the map should both be faster
due to using ByteString.
I had hoped this would speed up startup time, but any improvement to
that was too small to measure. Seems worth keeping though.
Note that the parser breaks up the ByteString, but a config map ends up
pointing to the config as read, which is retained in memory until every
value from it is no longer used. This can change memory usage
patterns marginally, but won't affect git-annex.
Finally builds (oh the agoncy of making it build), but still very
unmergable, only Command.Find is included and lots of stuff is badly
hacked to make it compile.
Benchmarking vs master, this git-annex find is significantly faster!
Specifically:
num files old new speedup
48500 4.77 3.73 28%
12500 1.36 1.02 66%
20 0.075 0.074 0% (so startup time is unchanged)
That's without really finishing the optimization. Things still to do:
* Eliminate all the fromRawFilePath, toRawFilePath, encodeBS,
decodeBS conversions.
* Use versions of IO actions like getFileStatus that take a RawFilePath.
* Eliminate some Data.ByteString.Lazy.toStrict, which is a slow copy.
* Use ByteString for parsing git config to speed up startup.
It's likely several of those will speed up git-annex find further.
And other commands will certianly benefit even more.
This will speed up the common case where a Key is deserialized from
disk, but is then serialized to build eg, the path to the annex object.
Previously attempted in 4536c93bb2
and reverted in 96aba8eff7.
The problems mentioned in the latter commit are addressed now:
Read/Show of KeyData is backwards-compatible with Read/Show of Key from before
this change, so Types.Distribution will keep working.
The Eq instance is fixed.
Also, Key has smart constructors, avoiding needing to remember to update
the cached serialization.
Used git-annex benchmark:
find is 7% faster
whereis is 3% faster
get when all files are already present is 5% faster
Generally, the benchmarks are running 0.1 seconds faster per 2000 files,
on a ram disk in my laptop.
warningIO is not concurrent output safe, and it doesn't go to
--json-error-messages
There are a few more that would be too hard to remove, and there are also
several dozen direct prints to stderr still.
This solves the problem of sameas remotes trampling over per-remote
state. Used for:
* per-remote state, of course
* per-remote metadata, also of course
* per-remote content identifiers, because two remote implementations
could in theory generate the same content identifier for two different
peices of content
While chunk logs are per-remote data, they don't use this, because the
number and size of chunks stored is a common property across sameas
remotes.
External special remote had a complication, where it was theoretically
possible for a remote to send SETSTATE or GETSTATE during INITREMOTE or
EXPORTSUPPORTED. Since the uuid of the remote is typically generate in
Remote.setup, it would only be possible to pass a Maybe
RemoteStateHandle into it, and it would otherwise have to construct its
own. Rather than go that route, I decided to send an ERROR in this case.
It seems unlikely that any existing external special remote will be
affected. They would have to make up a git-annex key, and set state for
some reason during INITREMOTE. I can imagine such a hack, but it doesn't
seem worth complicating the code in such an ugly way to support it.
Unfortunately, both TestRemote and Annex.Import needed the Remote
to have a new field added that holds its RemoteStateHandle.
I found a way to avoid inheritance complicating anything outside of
Logs.Remote. It seems fine to require all inherited values to be
inherited and not set in the sameas remote's config. Since inherited
values will be used for stuff like encryption and perhaps chunking, which
control the actual content stored on the remote, it seems likely that
there will not be any reason to need them to vary between two remotes
that access the same underlying data store.
The newer version of containers is free; the minimum ghc version is
bundled with a newer version than that.