[RFC PATCH 05/10] gitweb: Use Cache::Cache compatibile (get, set) output caching (WIP)

From

Jakub Narebski <jnareb@gmail.com>

Date

Jan 23, 2010, 00:27 UTC

Message-ID

<553a364cdfdbb1d5c6dfc75f0545e46143a1be8a.1264198194.git.jnareb@gmail.com>

In-Reply-To

<1263432185-21334-10-git-send-email-warthog9@eaglescrag.net>

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
This patch, as you can see, lack proper commit message: it is work in
progress.

As you can see cache_fetch() subroutine is much, much simpler that the
one in original patch by J.H.:
  [PATCH 9/9] gitweb: File based caching layer (from git.kernel.org)
  Message-ID: <1263432185-21334-10-git-send-email-warthog9@eaglescrag.net>
  http://permalink.gmane.org/gmane.comp.version-control.git/136917

  Cache Last Updated: ". gmtime( time )

I have forgot about adding this feature...

 gitweb/cache.pm                        |   36 ++++++++++++++++++++++++++++
 gitweb/gitweb.perl                     |   40 +++++++++++++++++++++++++++++--
 t/gitweb-lib.sh                        |    2 +
 t/t9500-gitweb-standalone-no-errors.sh |   13 ++++++++++
 4 files changed, 88 insertions(+), 3 deletions(-)

diff --git a/gitweb/cache.pm b/gitweb/cache.pm
index 12a7a78..3a33158 100644
--- a/gitweb/cache.pm
+++ b/gitweb/cache.pm
@@ -359,4 +359,41 @@ sub compute {
 1;
 } # end of package GitwebCache::SimpleFileCache;
 
+# human readable key identifying gitweb output
+sub gitweb_output_key {
+	return href(-replay => 1, -full => 1, -path_info => 0);
+}
+
+sub cache_fetch {
+	my ($cache, $action) = @_;
+
+	my $key = gitweb_output_key();
+	my $data = $cache->get($key);
+
+	if (defined $data) {
+		# print cached data
+		binmode STDOUT, ':raw';
+		print STDOUT $data;
+
+	} else {
+		# calculate data and regenerate data
+		open my $data_fh, '>', \$data
+			or die "Can't open memory file: $!";
+		# matches "binmode STDOUT, ':uft8'" at beginning
+		binmode $data_fh, ':utf8';
+
+		$out = $data_fh || \*STDOUT;
+		$actions{$action}->();
+
+		if (defined $data) {
+			$cache->set($key, $data);
+			binmode STDOUT, ':raw';
+			local $/ = undef;
+			print STDOUT $data;
+		}
+
+		close $data_fh;
+	}
+}
+
 1;
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index cd5073c..0394dc8 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -234,6 +234,22 @@ our $gitlinkurl_base = ("++GITWEB_BASE_URL++" =~ m!^(git://.*)$!) ? $1 : '';
 # Leave it undefined (or set to 'undef') to turn off load checking.
 our $maxload = 300;
 
+# This enables/disables the caching layer in gitweb.  Currently supported
+# is only output (response) caching, similar to the one used on git.kernel.org.
+our $caching_enabled = 0;
+# Set to _initialized_ instance of cache interface implementing (at least)
+# get($key) and set($key, $data) methods (Cache::Cache and CHI interfaces).
+# If unset, GitwebCache::SimpleFileCache would be used, which is 'dumb'
+# (but fast) file based caching layer, currently without any support for
+# cache size limiting.  It is therefore recommended that the cache directory
+# be periodically completely deleted; this operation is safe to perform.
+# Suggested mechanism:
+# mv $cachedir $cachedir.flush && mkdir $cachedir && rm -rf $cachedir.flush
+our $cache;
+# Locations of 'cache.pm' file; if it is relative path, it is relative to
+# the directory gitweb is run from
+our $cache_pm = 'cache.pm';
+
 # You define site-wide feature defaults here; override them with
 # $GITWEB_CONFIG as necessary.
 our %feature = (
@@ -998,7 +1014,21 @@ if ($action !~ m/^(?:opml|project_list|project_index)$/ &&
     !$project) {
 	die_error(400, "Project needed");
 }
-$actions{$action}->();
+
+if ($caching_enabled) {
+	do $cache_pm;
+	die $@ if $@;
+
+	$cache ||= GitwebCache::SimpleFileCache->new({
+		'cache_root'  => '/tmp/cache',
+		'cache_depth' => 2,
+		'expires_in'  => 20, # in seconds
+	});
+	cache_fetch($cache, $action);
+} else {
+	$actions{$action}->();
+}
+
 exit;
 
 ## ======================================================================
@@ -3207,7 +3237,9 @@ sub git_header_html {
 	# 'application/xhtml+xml', otherwise send it as plain old 'text/html'.
 	# we have to do this because MSIE sometimes globs '*/*', pretending to
 	# support xhtml+xml but choking when it gets what it asked for.
-	if (defined $cgi->http('HTTP_ACCEPT') &&
+	# Disable content-type negotiation when caching (use mimetype good for all).
+	if (!$caching_enabled &&
+	    defined $cgi->http('HTTP_ACCEPT') &&
 	    $cgi->http('HTTP_ACCEPT') =~ m/(,|;|\s|^)application\/xhtml\+xml(,|;|\s|$)/ &&
 	    $cgi->Accept('application/xhtml+xml') != 0) {
 		$content_type = 'application/xhtml+xml';
@@ -3380,7 +3412,9 @@ sub git_footer_html {
 	}
 	print {$out} "</div>\n"; # class="page_footer"
 
-	if (defined $t0 && gitweb_check_feature('timed')) {
+	# timing info doesn't make much sense with output (response) caching
+	if (!$caching_enabled &&
+	    defined $t0 && gitweb_check_feature('timed')) {
 		print {$out} "<div id=\"generating_info\">\n";
 		print {$out} 'This page took '.
 		             '<span id="generating_time" class="time_span">'.
diff --git a/t/gitweb-lib.sh b/t/gitweb-lib.sh
index d9ffc90..d041083 100755
--- a/t/gitweb-lib.sh
+++ b/t/gitweb-lib.sh
@@ -27,6 +27,8 @@ our \$export_ok = '';
 our \$strict_export = '';
 our \$git_versions_must_match = 0;
 
+our \$cache_pm = '$TEST_DIRECTORY/../gitweb/cache.pm';
+
 EOF
 
 	cat >.git/description <<EOF
diff --git a/t/t9500-gitweb-standalone-no-errors.sh b/t/t9500-gitweb-standalone-no-errors.sh
index 2fc7fdb..0f93962 100755
--- a/t/t9500-gitweb-standalone-no-errors.sh
+++ b/t/t9500-gitweb-standalone-no-errors.sh
@@ -639,4 +639,17 @@ test_expect_success \
 	 gitweb_run "p=.git;a=summary"'
 test_debug 'cat gitweb.log'
 
+# ----------------------------------------------------------------------
+# caching
+
+cat >>gitweb_config.perl <<\EOF
+
+$caching_enabled = 1;
+EOF
+test_expect_success \
+	'caching enabled' \
+	'gitweb_run "p=.git;a=summary"'
+test_debug 'cat gitweb.log'
+
+
 test_done

-- 
1.6.6.1