When deciding whether or not to fetch a repo based on a refs
announcement, we need to know whether our signed refs are stale or not,
compared to the ones in the announcement. This can be quite expensive as
it requires multiple reads from Git's ODB, which often results in
packfile loading.
To remedy this, we introduce a refs cache in our node database that is
consulted when an announcement is received.
We also remove the logic that generates `info` messages, since they are
rarely needed and introduced more complexity.
Additionally, we revert commit 3ad2b4431f,
which introduced logic to minimze wants and haves with additional logic,
since it potentially also increases the load on the ODB.
This change limits the amount of `wants` and `haves` data that is sent
to the serving side of a fetch.
When a `RefsAt` announcement is sent, the fetching peer can calculate
the difference between the `rad/sigrefs` they're aware of -- if it
exists -- and the newly advertised `rad/sigrefs`. This means they can
efficiently ask for the `wants` and `haves` of references that have
changed -- saving some data sent over to the serving side.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
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
cloudhead
Fintan Halpenny