From: David Turner <dturner@twopensource.com>
To: Duy Nguyen <pclouds@gmail.com>
Cc: Git Mailing List <git@vger.kernel.org>,
Michael Haggerty <mhagger@alum.mit.edu>
Subject: Re: [PATCH v4 20/21] refs: add LMDB refs storage backend
Date: Tue, 16 Feb 2016 17:01:21 -0500 [thread overview]
Message-ID: <1455660081.7528.8.camel@twopensource.com> (raw)
In-Reply-To: <CACsJy8AkWpVERj8=ABaQ89xe=6-DRLV5KBz9_sxW8TE4LUzcQw@mail.gmail.com>
On Mon, 2016-02-15 at 16:57 +0700, Duy Nguyen wrote:
> On Sun, Feb 14, 2016 at 7:04 PM, Duy Nguyen <pclouds@gmail.com>
> wrote:
> > 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).
I don't think case-sensitivity is a huge problem here: per-worktree
refs are now HEAD or refs/bisect/*, and refs/bisect is controlled
entirely by the bisection machinery (that is, it won't have user
-defined refs with case conflicts).
> With this split, I think some refs are still
> left behind.. Sorry if this was discussed before, I haven't followed
> this closely.
Previous discussion:
http://comments.gmane.org/gmane.comp.version-control.git/275097
next prev parent reply other threads:[~2016-02-16 22:01 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-05 19:44 [PATCH v4 00/20] refs backend David Turner
2016-02-05 19:44 ` [PATCH v4 01/21] refs: add a backend method structure with transaction functions David Turner
2016-02-05 19:44 ` [PATCH v4 02/21] refs: add methods for misc ref operations David Turner
2016-02-11 7:45 ` Michael Haggerty
2016-02-12 1:09 ` David Turner
2016-02-05 19:44 ` [PATCH v4 03/21] refs: add methods for the ref iterators David Turner
2016-02-11 8:42 ` Michael Haggerty
2016-02-12 1:08 ` David Turner
2016-02-05 19:44 ` [PATCH v4 04/21] refs: add do_for_each_per_worktree_ref David Turner
2016-02-05 19:44 ` [PATCH v4 05/21] refs: add methods for reflog David Turner
2016-02-05 19:44 ` [PATCH v4 06/21] refs: add method for initial ref transaction commit David Turner
2016-02-05 19:44 ` [PATCH v4 07/21] refs: add method for delete_refs David Turner
2016-02-05 19:44 ` [PATCH v4 08/21] refs: add methods to init refs db David Turner
2016-02-11 8:54 ` Michael Haggerty
2016-02-11 21:15 ` David Turner
2016-02-05 19:44 ` [PATCH v4 09/21] refs: add method to rename refs David Turner
2016-02-11 9:00 ` Michael Haggerty
2016-02-11 21:12 ` David Turner
2016-02-05 19:44 ` [PATCH v4 10/21] refs: make lock generic David Turner
2016-02-05 19:44 ` [PATCH v4 11/21] refs: move duplicate check to common code David Turner
2016-02-05 19:44 ` [PATCH v4 12/21] refs: allow log-only updates David Turner
2016-02-11 10:03 ` Michael Haggerty
2016-02-11 21:23 ` David Turner
2016-02-05 19:44 ` [PATCH v4 13/21] refs: resolve symbolic refs first David Turner
2016-02-12 14:09 ` Michael Haggerty
2016-02-18 0:29 ` David Turner
2016-02-18 11:59 ` Michael Haggerty
2016-02-05 19:44 ` [PATCH v4 14/21] refs: always handle non-normal refs in files backend David Turner
2016-02-12 15:07 ` Michael Haggerty
2016-02-18 2:44 ` David Turner
2016-02-18 12:07 ` Michael Haggerty
2016-02-18 18:32 ` David Turner
2016-02-05 19:44 ` [PATCH v4 15/21] init: allow alternate ref strorage to be set for new repos David Turner
2016-02-12 15:26 ` Michael Haggerty
2016-02-17 20:47 ` David Turner
2016-02-18 14:12 ` Michael Haggerty
2016-02-05 19:44 ` [PATCH v4 16/21] refs: check submodules ref storage config David Turner
2016-02-05 19:44 ` [PATCH v4 17/21] clone: allow ref storage backend to be set for clone David Turner
2016-02-05 19:44 ` [PATCH v4 18/21] svn: learn ref-storage argument David Turner
2016-02-05 19:44 ` [PATCH v4 19/21] refs: add register_ref_storage_backends() David Turner
2016-02-12 15:42 ` Michael Haggerty
2016-02-17 20:32 ` David Turner
2016-02-05 19:44 ` [PATCH v4 20/21] refs: add LMDB refs storage backend David Turner
2016-02-11 8:48 ` Michael Haggerty
2016-02-11 21:21 ` David Turner
2016-02-12 17:01 ` Michael Haggerty
2016-02-13 1:23 ` David Turner
2016-02-14 12:04 ` Duy Nguyen
2016-02-15 9:57 ` Duy Nguyen
2016-02-16 22:01 ` David Turner [this message]
2016-02-17 20:32 ` David Turner
2016-02-05 19:44 ` [PATCH v4 21/21] refs: tests for lmdb backend David Turner
2016-02-08 23:37 ` [PATCH v4 00/20] refs backend Junio C Hamano
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