Re: [PATCH v4 20/21] refs: add LMDB refs storage backend
- From
Duy Nguyen <pclouds@gmail.com>
- Date
- Feb 15, 2016, 09:57 UTC
- Message-ID
- <CACsJy8AkWpVERj8=ABaQ89xe=6-DRLV5KBz9_sxW8TE4LUzcQw@mail.gmail.com>
- In-Reply-To
- <CACsJy8CWS9E0Jb4omm4k0=kZ73w9UoHmofLFCFHUhHu53zfgYw@mail.gmail.com>
On Sun, Feb 14, 2016 at 7:04 PM, Duy Nguyen <pclouds@gmail.com> wrote:
Show 34 quoted lines
> On Sat, Feb 6, 2016 at 2:44 AM, David Turner <dturner@twopensource.com> wrote:
>> +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;
>> +}
> ...
>> +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?To answer myself: I forgot that there were per-worktree refs (e.g. refs/bisect). It makes me wonder if we should put per-worktree refs to lmdb as well (maybe one per worktree if we don't want to put all in one db). One of the advantages of moving away from fs-based backend is the ability to deal with case sensitivity, "nested" refs (e.g. a/b and a/b/c are both refs). With this split, I think some refs are still left behind.. Sorry if this was discussed before, I haven't followed this closely.
-- Duy