[PATCH 17/18] gitweb: Prepare for cached error pages & better error page handling

From: John 'Warthog9' Hawley <warthog9@eaglescrag.net>
Date: Dec 9, 2010, 21:57 UTC
Message-ID: <1291931844-28454-18-git-send-email-warthog9@eaglescrag.net>
In-Reply-To: <1291931844-28454-1-git-send-email-warthog9@eaglescrag.net>

To quote myself from an e-mail of mine:

	I've got a hammer, it clearly solves all problems!

This is the prepatory work to set up a mechanism inside the caching engine to cache the error pages instead of throwing them straight out to the client.

This adds two functions:

die_error_cache() - this gets back called from die_error() so that the error message generated can be cached.

cacheDisplayErr() - this is a simplified version of cacheDisplay() that does an initial check, if the error page exists - display it and exit. If not, return.

Signed-off-by: John 'Warthog9' Hawley <warthog9@eaglescrag.net>
---
 gitweb/lib/cache.pl |   52 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/gitweb/lib/cache.pl b/gitweb/lib/cache.pl
index a8c902d..6cb82c8 100644
--- a/gitweb/lib/cache.pl
+++ b/gitweb/lib/cache.pl
@@ -302,6 +302,36 @@ sub cacheUpdate {
 	}
 }
 
+sub die_error_cache {
+	my ($output) = @_;
+
+	open(my $cacheFileErr, '>:utf8', "$fullhashpath.err");
+	my $lockStatus = flock($cacheFileErr,LOCK_EX|LOCK_NB);
+
+	if (! $lockStatus ){
+		if ( $areForked ){
+			exit(0);
+		}else{
+			return;
+		}
+	}
+
+	# Actually dump the output to the proper file handler
+	local $/ = undef;
+	$|++;
+	print $cacheFileErr "$output";
+	$|--;
+
+	flock($cacheFileErr,LOCK_UN);
+	close($cacheFileErr);
+
+	if ( $areForked ){
+		exit(0);
+	}else{
+		return;
+	}
+}
+
 
 sub cacheWaitForUpdate {
 	my ($action) = @_;
@@ -380,6 +410,28 @@ EOF
 	return;
 }
 
+sub cacheDisplayErr {
+
+	return if ( ! -e "$fullhashpath.err" );
+
+	open($cacheFileErr, '<:utf8', "$fullhashpath.err");
+	$lockStatus = flock($cacheFileErr,LOCK_SH|LOCK_NB);
+
+	if (! $lockStatus ){
+		show_warning(
+				"<p>".
+				"<strong>*** Warning ***:</strong> Locking error when trying to lock error cache page, file $fullhashpath.err<br/>/\n".
+				"This is about as screwed up as it gets folks - see your systems administrator for more help with this.".
+				"<p>"
+				);
+	}
+
+	while( <$cacheFileErr> ){
+		print $_;
+	}
+	exit(0);
+}
+
 sub cacheDisplay {
 	local $/ = undef;
 	$|++;

-- 
1.7.2.3