[RFC/PATCH 3/3] gitweb: Fill project details lazily when caching

From: Jakub Narebski <jnareb@gmail.com>
Date: Mar 17, 2008, 15:09 UTC
Message-ID: <1205766570-13550-4-git-send-email-jnareb@gmail.com>
In-Reply-To: <1205766570-13550-1-git-send-email-jnareb@gmail.com>

If caching is turned on project details can be filled in already from the cache. When refreshing project info details for all project (when cache is stale and has to be refreshed) generate projects info only if modification time (as returned by lstat()) of projects repository gitdir changed.

This way we can avoid hitting repository refs, object database and repository config at the cost of additional lstat.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
This is an idea for further improvement of 'projects list caching'.
Could you please:

 1.) comment if it is a good idea, or why it works, or why it
     couldn't work :),

 2.) check if this change gives any improvements in performance on
     real data; note that testing would require updating repositories
     if test on generated data was done, or gathering statistics over
     larger time period if it was tested on "live" set.

Thanks in advance.

 gitweb/gitweb.perl |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 5527378..1741628 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -3487,8 +3487,14 @@ sub git_patchset_body {
 sub git_get_projects_details {
 	my ($projlist, $check_forks) = @_;
 
+	use File::stat;
 	my @projects;
 	foreach my $pr (@$projlist) {
+		my $mtime;
+		if ($cached && $pr->{'mtime'}) {
+			$mtime = lstat("$projectroot/$pr->{'path'}")->mtime;
+			next if ($mtime <= $pr->{'mtime'});
+		}
 		my (@aa) = git_get_last_activity($pr->{'path'});
 		unless (@aa) {
 			next;
@@ -3513,6 +3519,9 @@ sub git_get_projects_details {
 				$pr->{'forks'} = 0;
 			}
 		}
+		if ($cached) {
+			$pr->{'mtime'} = $mtime;
+		}
 		push @projects, $pr;
 	}
 	return @projects;

-- 
1.5.4.3.453.gc1ad83