Re: [PATCHv2 5/6] gitweb: last-modified time should be commiter, not author

[Giuseppe Bilotta <giuseppe.bilotta@gmail.com>]

On Thu, Feb 5, 2009 at 12:38 AM, Jakub Narebski <jnareb@gmail.com> wrote:
> On Mon, 26 Jan 2009, Giuseppe Bilotta wrote:
>
>> The last-modified time header added by RSS to increase cache hits from
>> readers should be set to the date the repository was last modified. The
>> author time in this respect is not a good guess because the last commit
>> might come from a oldish patch.
>>
>> Use the committer time for the last-modified header to ensure a more
>> correct guess of the last time the repository was modified.
>
> First, changing %latest_date from author time to committer time affects
> not only Last-Modified HTTP header, but (after this series) also
> various "publication dates" in the feed contents.  But I think that for
> all those committer time is better approximation of publication date
> and last change date than author time.
>
> Second, author time reflects when change (commit) was made, according
> to authors (perhaps skewed) clock.  Committer time reflects when given
> commit (version of a commit) was entered into repository, or to be more
> exact into some clone of given project.  But there is also an issue of
> when changes got into given instance of repository (given clone): that
> I guess might be found by stat-ing HEAD (if it arrived by commit),
> FETCH_HEAD (if it arrived by fetch or pull) and ??? (if it arrived by
> push)... err... it looks like it wouldn't work in most common case,
> sorry, unless we want to stat all refs and packed-refs file. But while
> this date might be better for Last-Modified, I'm not sure if it is good
> at all for publication date.
>
> So committer time is better than author time, and looks like good
> middle ground.

Oops should have finished reading your comments before my previous
reply. The solution would be to introduce a way to determine robustly
when a branch was last _physically_ updated. Checking the
corresponding entry in refs/ would work for non-packed refs, and maybe
one would hope that if the ref got packed, it means it hasn't updated
in a long time ... but I'm not enough of an expert on git's internal
to really know about this. Suggestions?


-- 
Giuseppe "Oblomov" Bilotta