To improve the reliability and flexibility of the protocol, we introduce
multiplexing over peer connections. This involves a new `Frame` type
that carries a stream-id and payload.
Three stream types are made available:
1. Control
2. Gossip
3. Git
This change brings the following improvements:
* Removed need to queue fetch requests
* Removed need to queue gossip messages
* Removed need for `Fetch` and `FetchOk` messages
* Service doesn't need to know about inbound fetches
* Removed one round-trip for fetch negotiation
* Removed special `done` git packet
* Removed session logic and state around Git/Fetch protocols
* Removed code around upgrading/downgrading transport
* Worker in responder mode is able to process any number of fetches
* Connections support any number of concurrent fetches
We had to introduce a few extra things however to make it all work:
* A `VarInt` type for variable-length integers, since we want the frames
to be lightweight.
* A custom "tunnel" implementation, since we couldn't use the existing
one anymore.
Overall the change removes more complexity than it adds, while improving
the protocol along the way.
A fetch is a client-server interaction and so there are two sides to
this interaction. These sides are generally referred to as receive --
the client side -- and upload -- the server side.
The `Fetch` type indicated whether it was doing a receive or upload by
using a field `initiated: bool`. However, this can be confusing when
you pair it with the `namespaces: Namespaces` field, since only the
receive side should be sending what refspecs it wants and the upload
side responds with those matching refspecs.
A better way to represent this is using an enum for which direction
the fetch is being considered, where the receive side contains the
Namespaces. To borrow from Noise, the variant names are 'Initiator'
for the client and 'Responder' for the server.
The resulting code then makes decisions based on what variant of the
enum was passed.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
It is possible for a pair of nodes to concurrently ask each other
to fetch some repo. These "crossing" requests are problematic,
because the nodes end up waiting for each other to reply, and
the reply never comes.
With this change, the node pair agrees on proceeding with one of
the fetches, while canceling the other.
We weren't updating the sessions map when a persistent peer
was re-attempted. It would then panic when `connected` was called,
because the state would be `Disconnected`.
There are few unrelated changes in this commit that I wasn't able to
split out, mostly due to laziness, so I'll list them here:
* The node startup logic is moved out of the main function, and into a
dedicated functionin `client.rs`.
* There is a tentative worker implementation that is untested, and
handles git replication both ways. It's likely lacking in various ways
but I wanted to get it in there anyway.
* `Address` was moved from `radicle-node` to `radicle`, because it's
needed to send `Connect` commands from the node handle.
* The `netservices` dependency was updated.
* Finally, there is a first end-to-end node test, which currently
doesn't use NoiseXK, but uses the new reactor in `netservices`.
Signed-off-by: Alexis Sellier <self@cloudhead.io>
This is a large change that introduces transport encryption via
a Noise_XK handshake. The inner `Service` now works directly
with `NodeId` and doesn't need to interact with socket addresses.
The transport logic takes place in `wire::transport`, and the
established sessions are passed down to `Service`.
Note that the i/o implementation in the `poll-reactor` crate still
needs testing, and there is still work to be done to integrate the
Git transport as part of this architecture.
Signed-off-by: Alexis Sellier <alexis@radicle.xyz>
Rename the module to session from peer to be consistent with recent
renaming of the type from Peer to Session. Remove stutter by renaming
session::SessionState to session::State, and session::SessionError to
session::Error.
Signed-off-by: Slack Coder <slackcoder@server.ky>
This type that was wrapping `Message` isn't very useful here.
If we decide that we do need something like that, it's best handled one
layer below.
Signed-off-by: Alexis Sellier <alexis@radicle.xyz>
Alexis Sellier
xphoniex
Fintan Halpenny
Alexis Sellier
Dr. Maxim Orlovsky
Dr Maxim Orlovsky
Slack Coder