From: Jakub Narebski <jnareb@gmail•com>
To: Peter Vereshagin <peter@vereshagin•org>
Cc: Petr Baudis <pasky@suse•cz>, Eric Wong <normalperson@yhbt•net>,
git@vger•kernel.org, Sam Vilain <sam.vilain@catalyst•net.nz>,
Juan Jose Comellas <juanjo@comellas•org>,
John Goerzen <jgoerzen@complete•org>
Subject: Re: [PATCH 0/2] gitweb: Add support for running gitweb as FastCGI script
Date: Mon, 10 May 2010 17:29:03 +0200 [thread overview]
Message-ID: <201005101729.07334.jnareb@gmail.com> (raw)
In-Reply-To: <20100510071340.GA3382@screwed.box>
On Mon, 10 May 2010, Peter Vereshagin wrote:
> 2010/05/09 20:18:52 +0200 Jakub Narebski <jnareb@gmail•com> => To Peter Vereshagin :
>
> Great! I was just about to ask on caching, etc. What a complex history on all
> of that, will be on those tracks after some of my whiles. ;-)
You can find current state of my take on gitweb output caching (based
on / inspired by work by John 'Warthog9' Hawley) in my repository on
repo.or.cz, in the 'gitweb/cache-kernel-pu' branch:
http://repo.or.cz/w/git/jnareb-git.git gitweb/cache-kernel-pu
You can find progress reports (and what current show-stoppers are) in
git mailing list archives.
Note that http://repo.or.cz does its own gitweb caching, IIRC by
caching Perl data, and only for 'projects_list' page (the most costly
one).
There was also "Gitweb caching" projects in GSoC 2008 by Lea Wiemann,
which IIUC cached output of git commands. This project was, I think,
completed but didn't get merged into git.
> JN> What are required changes to gitweb to use FCGI::Spawn to run gitweb as
> JN> a FastCGI script? Alternatively, how the wrapper script for gitweb
> JN> (gitweb.fcgi) to be run as FastCGI should look like to use FCGI::Spawn?
>
> By far it's only an exit() of the what I use (1.6.0.6):
Why so old git? Current version is git version 1.7.1
>
> --- /usr/local/share/examples/git/gitweb/gitweb.cgi 2010-02-25 13:49:30.068287112 +0300
> +++ www/gitweb.cgi 2010-03-13 14:28:45.326244103 +0300
Hrmph. Why not use "git diff --no-index <file1> <file2>" here?
The Perl-aware equivalent of '-p' option of GNU diff, i.e. showing in
which function we are in hunk headers, would help here.
> @@ -933,7 +933,7 @@
> die_error(400, "Project needed");
> }
> $actions{$action}->();
> -exit;
> +# exit;
This 'exit' was here just in case there were some forgotten code below
this line outside subroutines (that should not be run). It can be
safely removed.
>
> ## ======================================================================
> ## action links
> @@ -3371,7 +3371,7 @@ sub die_error {
I have added my guess of in which subroutine this code is above.
> </div>
> EOF
> git_footer_html();
> - exit;
> +# exit;
> }
Err... and gitweb works correctly with this change? This 'exit' was
required for die_error to function like 'die' in that it finishes
serving request, and should not continue subroutine it was called
from.
I have changed this 'exit' to non-local goto to toplevel. It could be
done instead by redefining 'exit' subroutine, like shown below, but I
feel that would be hacky if you can change gitweb code (it is not
black box you should not touch).
>
> ## ----------------------------------------------------------------------
>
> but it's probably even not necessary with -e parameter:
> http://search.cpan.org/~veresc/FCGI-Spawn-0.16.1/fcgi_spawn#Command_line_options
> which is definitely required for bugzilla, the worst boy in that sandbox. The
> parameter does just this:
> ===
> my $cref = sub {
> if ('FCGI::ProcManager' eq scalar caller) {
> CORE::exit @_;
> } else {
> no warnings;
> last CALLED_OUT;
> }
> };
> *CORE::GLOBAL::exit = $cref;
> *CORE::GLOBAL::exit;
> ===
This is quite nice idea to replace 'exit' by subroutine that does
non-local jump to outside of application, at the end of request loop.
Such "monkey patching" is the only solution if you can't or shouldn't
modify application code (like FCGI::Spawn being generic solution).
> so this requires configuration
> ( $PREFIX/etc/fcgi_spawn/preload_nonprepared_01.pl, in my case ) for fcgi_spawn
> daemon like this:
> ===
> $spawn->{ callout } = sub{ do shift;
> CALLED_OUT:
> };
> ===
Here
$spawn->{'callout'} = sub {
my $cgi_app = shift;
do $cgi_app;
# this is needed for sane error handling
die "Couldn't parse $cgi_app: $@" if $@;
CALLED_OUT:
};
could be simply replaced by
use CGI::Compile;
# ...
$spawn->{'callout'} = \&{CGI::Compile->compile}
or something like that. See CGI::Compile manpage and CGI::Compile source:
http://cpansearch.perl.org/src/MIYAGAWA/CGI-Compile-0.11/lib/CGI/Compile.pm
>
> All of that is not needed without exit() in gitweb, now.
BTW I wonder what are the consequences for performance on replacing
'exit' by non-local jump. It can degrade performance a bit for gitweb
run as pure CGI (mod_cgi / mod_cgid), but should improve performance
for mod_perl, at least if there are more connections... unless
ModPerl::Registry does similar trick with exit().
>
> I didn't mean FCGI::PM is a problem by itself. The standalone gitweb daemon is
> great thing for those who need such a choice. FCGI::Spawn is just for some
> different task: to put several ( wish to say: any CGI app ) applications inside
> the same fork()ed processes. It should be just obviously documented for a user
> as a dependency for implementation of a gitweb fastcgi daemon. Although I'm not
> sure if the FCGI::PM package should be a dependency for git package for any OS:
> for those modules use()d in eval() my guess is: particular user's choice to be
> offered.
>
> So FCGI::PM usage I think makes a flavor taste for any daemon and thus should
> be explicit. YMMV for those uninvolved in daemonizing, of course. ;-)
Hmmm... is FCGI::Spawn really needed, or can it be replaced by simple
PSGI wrapper using either Plack::App::CGIBin,
use Plack::App::CGIBin;
use Plack::Builder;
my $app = Plack::App::CGIBin->new(root => "/path/to/cgi-bin")->to_app;
builder {
mount "/cgi-bin" => $app;
};
or Plack::App::WrapCGI plus Plack::App::URLMap, the last indirectly
via Plack::Builder DSL:
use Plack::Builder;
use Plack::App::WrapCGI;
builder {
mount "/foo" =>
Plack::App::WrapCGI->new(script => "foo.cgi")->to_app;
mount "/bar" =>
Plack::App::WrapCGI->new(script => "bar.cgi")->to_app;
};
>
> Is it probable that gitweb doesn't take any POSTs requests? The main trick
> around FCGI::Spawn is the need to patch the CGI.pm but if that is the case...
> I'd try to redefine the STDIN to /dev/null or zero so FCGI.Spawn.CGI.pm.patch
> should be unnecessary for one who only wants to run the gitweb in FCGI::Spawn.
> If switch to FCGI.pm will be way complicated to me.
Errr... excuse me, what you wanted to say in the paragraph above?
Gitweb doesn't use no POST requests: it is read-only web repository
browser... well, except for the 'show_ctags' action.
--
Jakub Narebski
Poland
next prev parent reply other threads:[~2010-05-10 15:29 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-07 12:54 [PATCH 0/2] gitweb: Add support for running gitweb as FastCGI script Jakub Narebski
2010-05-07 12:54 ` [PATCH/RFC 1/2] gitweb: Put all per-connection code in run() subroutine Jakub Narebski
2010-05-07 12:54 ` [RFC/PATCH 2/2] gitweb: Add support for FastCGI, using CGI::Fast Jakub Narebski
2010-05-08 7:59 ` [RFC/PATCHv2 " Jakub Narebski
2010-05-08 22:41 ` [PATCH 0/2] gitweb: Add support for running gitweb as FastCGI script Jakub Narebski
2010-05-09 9:31 ` Eric Wong
2010-05-09 11:48 ` Ævar Arnfjörð Bjarmason
2010-05-09 12:39 ` Jakub Narebski
2010-05-09 16:47 ` Peter Vereshagin
2010-05-09 18:18 ` Jakub Narebski
2010-05-10 7:13 ` Peter Vereshagin
2010-05-10 15:29 ` Jakub Narebski [this message]
2010-05-11 6:24 ` Peter Vereshagin
2010-05-11 8:35 ` Petr Baudis
2010-05-11 10:58 ` Jakub Narebski
2010-05-11 12:09 ` Peter Vereshagin
2010-05-11 13:51 ` Jakub Narebski
2010-05-13 13:10 ` Peter Vereshagin
2010-05-13 17:13 ` Ævar Arnfjörð Bjarmason
2010-05-14 15:58 ` Peter Vereshagin
2010-05-14 10:53 ` Jakub Narebski
2010-05-14 15:36 ` Peter Vereshagin
2010-05-14 17:58 ` Jakub Narebski
2010-05-14 18:43 ` Jakub Narebski
2010-05-15 10:06 ` Peter Vereshagin
2010-05-15 13:58 ` Jakub Narebski
2010-05-16 10:15 ` Peter Vereshagin
2010-05-18 1:06 ` Jakub Narebski
2010-05-16 10:26 ` Petr Baudis
2010-05-15 11:51 ` Petr Baudis
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