Elixir storage backend for libgit2.

[redrabbit]

The libgit2 libraries provide a mechanism to plugin our own backend for storing Git data.

A very interesting way to investigate would be to have the libgit2 backend communicate with our application (by exchanging messages) by implementing an Erlang port driver.

I'm not sure at all that this is in any way performant. We will have to do a lot of benchmarks here!

[redrabbit]

We got our first experimental PostgreSQL backend. Switching backends is easy as setting :git_storage config to :postgres and voilà.

Loading the PostgreSQL backend is provided by GitRekt.Git.repository_load/1:

{:ok, repo} = GitRekt.Git.repository_load({:postgres, repo_id, "postgresql://localhost/my_db"})

Git objects and references are stored in Postgres database configured for GitGud.DB. The two tables for storing Git data are called git_objects and git_references.

I could not notice any great performance improvements so far.

A direction I would like to go in future iterations is storing Git objects in separated SQL tables depending on their type (commit, tag, tree, blob, etc.). This way we might be able to optimise slow commands such as counting commits or querying history for a specific pathspec.

[redrabbit]

Closing this because implementing a loopback (Elixir -> NIF -> Elixir) seems not feasible currently.

A while ago, I've stumbled across this presentation: Future Extensions to the Native Interface.
The presentation is from 2011 and nothing so far seems to be available in the Erlang ecosystem.