Finishes the start made in 983c9d5a53, by
handling the case where `transfer` fails for some other reason, and so the
ReadContent callback does not get run. I don't know of a case where
`transfer` does fail other than the locking dealt with in that commit, but
it's good to have a guarantee.
StoreContent and StoreContentTo had a similar problem.
Things like `getViaTmp` may decide not to run the transfer action.
And `transfer` could certianly fail, if another transfer of the same
object was in progress. (Or a different object when annex.pidlock is set.)
If the transfer action was not run, the content of the object would
not all get consumed, and so would get interpreted as protocol commands,
which would not go well.
My approach to fixing all of these things is to set a TVar only
once all the data in the transfer is known to have been read/written.
This way the internals of `transfer`, `getViaTmp` etc don't matter.
So in ReadContent, it checks if the transfer completed.
If not, as long as it didn't throw an exception, send empty and Invalid
data to the callback. On an exception the state of the protocol is unknown
so it has to raise ProtoFailureException and close the connection,
same as before.
In StoreContent, if the transfer did not complete
some portion of the DATA has been read, so the protocol is in an unknown
state and it has to close the conection as well.
(The ProtoFailureMessage used here matches the one in Annex.Transfer, which
is the most likely reason. Not ideal to duplicate it..)
StoreContent did not ever close the protocol connection before. So this is
a protocol change, but only in an exceptional circumstance, and it's not
going to break anything, because clients already need to deal with the
connection breaking at any point.
The way this new behavior looks (here origin has annex.pidlock = true so will
only accept one upload to it at a time):
git annex copy --to origin -J2
copy x (to origin...) ok
copy y (to origin...)
Lost connection (fd:25: hGetChar: end of file)
This work is supported by the NIH-funded NICEMAN (ReproNim TR&D3) project.
P2P protocol version 1 adds VALID|INVALID after DATA; INVALID means the
file was detected to change content while it was being sent and so we
may not have received the valid content of the file.
Added new MustVerify constructor for Verification, which forces
verification even when annex.verify=false etc. This is used when INVALID
and in protocol version 0.
As well as changing git-annex-shell p2psdio, this makes git-annex tor
remotes always force verification, since they don't yet use protocol
version 1. Previously, annex.verify=false could skip verification when
using tor remotes, and let bad data into the repository.
This commit was sponsored by Jack Hill on Patreon.
Unfortunately ReceiveMessage didn't handle unknown messages the way it
was documented to; client sending VERSION would cause the server to
return an ERROR and hang up. Fixed that, but old releases of git-annex
use the P2P protocol for tor and will still have that behavior.
So, version is not negotiated for Remote.P2P connections, only for
Remote.Git connections, which will support VERSION from their first
release. There will need to be a later flag day to change Remote.P2P;
left a commented out line that is the only thing that will need to be
changed then.
Version 1 of the P2P protocol is not implemented yet, but updated
the docs for the DATA change that will be allowed by that version.
This commit was sponsored by Jeff Goeke-Smith on Patreon.
Not yet used by git-annex, but this will allow faster transfers etc than
using individual ssh connections and rsync.
Not called git-annex-shell p2p, because git-annex p2p does something
else and I don't want two subcommands with the same name between the two
for sanity reasons.
This commit was sponsored by Øyvind Andersen Holm.
