Re: [PATCH v4 20/21] refs: add LMDB refs storage backend

From: Duy Nguyen <pclouds@gmail.com>
Date: Feb 14, 2016, 12:04 UTC
Message-ID: <CACsJy8CWS9E0Jb4omm4k0=kZ73w9UoHmofLFCFHUhHu53zfgYw@mail.gmail.com>
In-Reply-To: <1454701462-3817-21-git-send-email-dturner@twopensource.com>

On Sat, Feb 6, 2016 at 2:44 AM, David Turner <dturner@twopensource.com> wrote:

Show 7 quoted lines

> +static char *get_refdb_path(const char *base)
> +{
> +       static struct strbuf path_buf = STRBUF_INIT;
> +       strbuf_reset(&path_buf);
> +       strbuf_addf(&path_buf, "%s/refdb", base);
> +       return path_buf.buf;
> +}

...

Show 9 quoted lines

> +static int lmdb_init_db(struct strbuf *err, int shared)
> +{
> +       /*
> +        * To create a db, all we need to do is make a directory for
> +        * it to live in; lmdb will do the rest.
> +        */
> +
> +       if (!db_path)
> +               db_path = xstrdup(real_path(get_refdb_path(get_git_common_dir())));

This works for multiple worktrees. But scripts may have harder time getting the path. The recommended way is "git rev-parse --git-path refdb" but because "refdb" is not registered in path.c:common_list[], that command becomes git_path("refdb") instead of get_refdb(get_git_... like here. And I will need to know that .git/refdb is _not_ per-worktree when I migrate/convert main worktree (it's very likely I have to go that route to solve .git/config issue in multi worktree).

The solution is register refdb to common_list[] and you can do git_path("refdb") here. But then what happens when another backend is added? Will the new backend use the same path "refdb", or say "refdb.sqlite"? If all backends share the name "refdb", why can't we just reuse "refs" instead because the default filesystem-based backend is technically just another backend?

-- 
Duy