git upload-pack makes some uncessary writes in sequence, this tries to
gather them together to avoid needing to send multiple DATA packets when
just one will do.
In a small pull, this reduces the average number of DATA packets from
4.5 to 2.5.
Still a couple bugs:
* Closing the connection to the server leaves git upload-pack /
receive-pack running, which could be used to DOS.
* Sometimes the data is transferred, but it fails at the end, sometimes
with:
git-remote-tor-annex: <socket: 10>: commitBuffer: resource vanished (Broken pipe)
Must be a race condition around shutdown.
Almost working, but there's a bug in the relaying.
Also, made tor hidden service setup pick a random port, to make it harder
to port scan.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
This is most of the way to having the p2p protocol working over tor
hidden services, at least enough to do git push/pull.
The free monad was split into two, one for network operations and the
other for local (Annex) operations. This will allow git-remote-tor-annex
to run only an IO action, not needing the Annex monad.
This commit was sponsored by Remy van Elst on Patreon.
A bit tricky since Proto doesn't support threads. Rather than adding
threading support to it, ended up using a callback that waits for both
data on a Handle, and incoming messages at the same time.
This commit was sponsored by Denis Dzyubenko on Patreon.
Is content locking needed in the P2P protocol? Based on re-reading
bugs/concurrent_drop--from_presence_checking_failures.mdwn,
I think so: Peers can form cycles, and multiple peers can all be trying
to drop the same content.
So, added content locking to the protocol, with some difficulty.
The implementation is fine as far as it goes, but note the warning
comment for lockContentWhile -- if the connection to the peer is dropped
unexpectedly, the peer will then unlock the content, and yet the local
side will still think it's locked.
To be honest I'm not sure if Remote.Git's lockKey for ssh remotes
doesn't have the same problem. It checks that the
"ssh remote git-annex-shell lockcontent"
process has not exited, but if the connection closes afer that check,
the lockcontent command will unlock it, and yet the local side will
still think it's locked.
Probably this needs to be fixed by eg, making lockcontent catch any
execptions due to the connection closing, and in that case, wait a
significantly long time before dropping the lock.
This commit was sponsored by Anthony DeRobertis on Patreon.
For use with tor hidden services, and perhaps other transports later.
Based on Utility.SimpleProtocol, it's a line-based protocol,
interspersed with transfers of bytestrings of a specified size.
Implementation of the local and remote sides of the protocol is done
using a free monad. This lets monadic code be included here, without
tying it to any particular way to get bytes peer-to-peer.
This adds a dependency on the haskell package "free", although that
was probably pulled in transitively from other dependencies already.
This commit was sponsored by Jeff Goeke-Smith on Patreon.
