public inbox for git@vger.kernel.org 
 help / color / mirror / Atom feed
From: Shawn Pearce <spearce@spearce•org>
To: Daniel Barkalow <barkalow@iabervon•org>
Cc: Junio C Hamano <junkio@cox•net>, git@vger•kernel.org
Subject: Re: Current Issues #3
Date: Mon, 22 May 2006 19:12:57 -0400	[thread overview]
Message-ID: <20060522231257.GA21124@spearce.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0605221738090.6713@iabervon.org>

Daniel Barkalow <barkalow@iabervon•org> wrote:
> On Mon, 22 May 2006, Junio C Hamano wrote:
> 
> > * reflog
> > 
> >   I still haven't merged this series to "next" -- I do not have
> >   much against what the code does, but I am unconvinced if it is
> >   useful.  Also objections raised on the list that this can be
> >   replaced by making sure that a repository that has hundreds of
> >   tags usable certainly have a point.
> 
> I think it would make gitweb's summary view clearer, and Linus seemed 
> interested in being able to look up what happened in the fast forward 
> which was the first of several merges in a day.
> 
> It could be replaced by a repository with hundreds of machine-readable 
> tags with code to parse dates into queries for suitable tags. But I don't 
> think there's an advantage to using the tag mechanism here, because you 
> never want to look the history up by exactly which history it is (the 
> thing that a tag ref is good for); you'll be looking for whatever reflog 
> item is the newest not after a specified time, where the specified time is 
> almost never a time that a reflog item was created.

The thing is this might also be easily represented as a structure
of tags; for example:

	refs/logs/heads/<ref>/<year>/<month>/<day> <hour>:<min>:<sec>:<seq>

where the tag is a tag of the commit which was valid in that ref
at that time.  Searching for an entry "around a particular time"
isn't that much more difficult than parsing a file, you just have
to walk backwards through the sorted directory listings then read
the tag object which matches; that tag object will point at the
tree/commit/tag which is was in that ref..

What's ugly about this is simply the disk storage: a ref file is an
expensive thing (relatively speaking) on most UNIX file systems due
to the inode overhead.  If this was stored in a more compact format
(such as a GIT tree) then this would cost very little.

So the alternative that I have been mentaly kicking around for
the past two days is storing the GIT_DIR/refs directory within a
standard GIT tree.  This of course would need to be an option that
gets enabled by the user as currently most tools expect the refs
directory to actually be a directory, not a tree.  The advantage here
is that unlike proposed reflog it is a compact ref representation
which could be used by other features, such as tagging a GIT
commit with the unique name of the same change from another SCM.
Or tagging your repository on every automated build, which runs
once every 5 minutes.

-- 
Shawn.

      parent reply	other threads:[~2006-05-22 23:13 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-05-22  8:44 Current Issues #3 Junio C Hamano
2006-05-22 10:18 ` Linus Torvalds
     [not found]   ` <20060522071929.0be8d026.seanlkml@sympatico.ca>
2006-05-22 11:19     ` Sean
2006-05-23 21:58   ` Jakub Narebski
2006-05-22 10:20 ` Martin Waitz
2006-05-22 21:54 ` Daniel Barkalow
2006-05-22 22:02   ` Carl Worth
2006-05-22 23:12   ` Shawn Pearce [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20060522231257.GA21124@spearce.org \
    --to=spearce@spearce$(echo .)org \
    --cc=barkalow@iabervon$(echo .)org \
    --cc=git@vger$(echo .)kernel.org \
    --cc=junkio@cox$(echo .)net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox