From: Jakub Narebski <jnareb@gmail.com>
Date: Sun, 5 Dec 2010 23:01:09 +0000 (+0100)
Subject: gitweb/lib - Configure running 'generating_info' when generating data
X-Git-Url: https://repo.or.cz/w/git/jnareb-git.git/commitdiff_plain/b7bd7cb929b8f1d4e97d4e9e4fbdb4bdb3c797bb

gitweb/lib - Configure running 'generating_info' when generating data

Add a new 'generating_info_is_safe' cache option; if true, then
process generating data (one that acquired exclusive writer's lock)
would run 'generating_info' if there is no stale data and background
cache generation is enabled.

If function generating (or printing) exits, which leads to cache entry
not being generated (for gitweb this means that there are pages which
are not cached, i.e. error pages), and 'generating_info' also exits,
this could result in bad behavior.  Therefore this new option is false
by default.


Updates t9503 test appropriately.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---

diff --git a/gitweb/lib/GitwebCache/FileCacheWithLocking.pm b/gitweb/lib/GitwebCache/FileCacheWithLocking.pm
index 694c3182e2..0823c5564d 100644
--- a/gitweb/lib/GitwebCache/FileCacheWithLocking.pm
+++ b/gitweb/lib/GitwebCache/FileCacheWithLocking.pm
@@ -80,26 +80,35 @@ use POSIX qw(setsid);
 #    instead), for other process (or bacground process).  It is passed
 #    $cache instance, $key, and opened $lock_fh filehandle to lockfile.
 #    Unset by default (which means no activity indicator).
+#  * 'generating_info_is_safe' (boolean)
+#    If true, run 'generating_info' subroutine also in the project that
+#    is generating data.  This has effect only when 'background_cache'
+#    is true (both 'background_cache' and 'generating_info_is_safe' must
+#    be true for project generating data to run 'generating_info').
+#    Defaults to false for safety.
 sub new {
 	my $class = shift;
 	my %opts = ref $_[0] ? %{ $_[0] } : @_;
 
 	my $self = $class->SUPER::new(\%opts);
 
-	my ($max_lifetime, $background_cache, $generating_info);
+	my ($max_lifetime, $background_cache, $generating_info, $gen_info_is_safe);
 	if (%opts) {
 		$max_lifetime =
 			$opts{'max_lifetime'} ||
 			$opts{'max_cache_lifetime'};
 		$background_cache = $opts{'background_cache'};
 		$generating_info  = $opts{'generating_info'};
+		$gen_info_is_safe = $opts{'generating_info_is_safe'};
 	}
 	$max_lifetime = -1 unless defined($max_lifetime);
 	$background_cache = 1 unless defined($background_cache);
+	$gen_info_is_safe = 0 unless defined($gen_info_is_safe);
 
 	$self->set_max_lifetime($max_lifetime);
 	$self->set_background_cache($background_cache);
 	$self->set_generating_info($generating_info);
+	$self->set_generating_info_is_safe($gen_info_is_safe);
 
 	return $self;
 }
@@ -110,7 +119,8 @@ sub new {
 # http://perldesignpatterns.com/perldesignpatterns.html#AccessorPattern
 
 # creates get_depth() and set_depth($depth) etc. methods
-foreach my $i (qw(max_lifetime background_cache generating_info)) {
+foreach my $i (qw(max_lifetime background_cache
+                  generating_info generating_info_is_safe)) {
 	my $field = $i;
 	no strict 'refs';
 	*{"get_$field"} = sub {
@@ -214,7 +224,8 @@ sub _set_maybe_background {
 		# to regenerate/refresh the cache (generate data),
 		# or if main process would show progress indicator
 		$pid = fork()
-			if (@stale_result || $self->{'generating_info'});
+			if (@stale_result ||
+			    ($self->{'generating_info'} && $self->{'generating_info_is_safe'}));
 	}
 
 	if ($pid) {
diff --git a/t/t9503/test_cache_interface.pl b/t/t9503/test_cache_interface.pl
index 81f0b76527..480cfbc74a 100755
--- a/t/t9503/test_cache_interface.pl
+++ b/t/t9503/test_cache_interface.pl
@@ -333,6 +333,7 @@ subtest 'serving stale data when (re)generating' => sub {
 
 	# with background generation
 	$cache->set_background_cache(1);
+	$cache->set_generating_info_is_safe(1);
 
 	$cache->set($key, $stale_value);
 	$cache->set_expires_in(0);    # set value is now expired