Ref announcements contain the namespace (NID) and the SHA of the new
`rad/sigrefs`. This information can be used by the fetch protocol to
fetch only those `Oid`s for those namespaces.
Add a new stage `SigrefsAnnouncement` that captures this behaviour by
only asking for the advertised `Oid`s and updating the corresponding
`rad/sigrefs` for each namespace. Note that this is a special case of
the `SpecialRefs` stage and so the protocol chooses between these two
by checking if there was announcement passed through. The following
stage, `DataRefs`, stays the same.
Note that this stage can only be activated via a `pull`, and `clone`
stays the same.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Add debugging code for inspecting the in-memory Refdb of the Cache.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Previously, if a delegate's namespace was fetched and its rad/sigrefs
was behind the current state, then it would fail to perform the fetch.
Instead, when the ancestry path is checked the outcome can be used
during the update:
1. If the tip is equal, then the update can be marked as skipped.
2. If the tip is behind, then the update can be rejected, iff the
policy does not allow it.
3. If the tip is ahead, then the update is a fast-forward.
4. If the tip is diverged, then the update results in a failure, iff
the policy does not allow it.
The protocol also prunes any delegates's updates when the `rad/sigrefs`
is behind and returns an error if they are diverged.
For any non-delegates, it will simply prune them.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
The `radicle-fetch` crate introduces a method for fetching from a
server using Git protocol V2, which provides the implementation
control over performing a sequence of fetches and validation over
domain data.
The protocol is built on top of the suite of Gitoxide crates[[0]]. It
builds wrappers on top of Gitoxide's refdb, odb, and transport layers
-- as well as taking the ls-refs and fetch code straight from the code
base to simplify for the needs of this crate.
[0]: https://github.com/Byron/gitoxide
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Fintan Halpenny