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.
The previous fetching logic had some pitfalls regarding its logic:
* Fetched 'rad' references could end up not being verifiable and leaving
the storage in a corrupt state
* Forced pushes would be prohibited, since they would be rejected by
the client side due to the refspecs being used.
The new approach is to stage a fetch in 2 steps. The first step is to
fetch the relevant `rad/id` and `rad/sigrefs` for verification. For
all remotes that are verified, fetch all references listed in their
respective `rad/sigrefs`, using the `+` marker in the refspec,
allowing to update for any force pushes -- note that this becomes a
safe operation since the `sigrefs` are signed by the remote that
created them.
To prevent unverifiable 'rad' references from polluting storage, all
fetch negotiations are done in a staging repository set up in a
temporary directory. All successful fetches are then transferred,
using the 'file://' protocol, from the temporary directory into the
radicle storage.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
This avoids race conditions, especially in tests, where we try to
connect to the node right after spawning it, but since the
`Runtime::run` function is often called in a different thread, the
socket is not created in time.
The fetch implementation will potentially fetch the local operator's
remote, which is unnecessary and could result in deleted data.
Fix this by threading the local operator's public key and add an
ignore refspec to the fetch arguments, i.e.
^refs/namespaces/<local>/*
The implementation also strictly fetches all or one namespace. This is
improved upon by introducing a new variant for specifying a set of
namespaces.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
The tracking configuration has no way of consulting for a configured
scope.
This change allows the storing of this scope inside the tracking
`Config` -- currently unused.
The default Scope is chosen as Trusted, so that nodes do not
implicitly track any other node. If this behaviour is desired -- for
example, for seed nodes -- then All should be chosen.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
When a specific tracking policy isn't found, we allow setting a default.
To preserve existing behavior, the default is `Block`, ie. if a node
isn't tracked explicitly, it is blocked.
However, this change allows for using `Track` as the default, which
is a way to track everything without having to know the entities in
advance.
Alexis Sellier
Fintan Halpenny
Alexis Sellier
xphoniex