From 5ddebb1b8512d1f2faf4e30a8faf1cfb5552fbb4 Mon Sep 17 00:00:00 2001
From: Chad Horohoe <demon@users.mediawiki.org>
Date: Thu, 3 Jul 2008 07:49:35 +0000
Subject: [PATCH] Cache foreign image descriptions in the transcache, saves an
 Http::get() on cache hit.

---
 RELEASE-NOTES                  |  2 ++
 includes/filerepo/File.php     | 42 +++++++++++++++++++++++++++++++++-
 includes/filerepo/FileRepo.php |  2 +-
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 5cec8db2c9..bc60b96218 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -179,6 +179,8 @@ it from source control: http://www.mediawiki.org/wiki/Download_from_SVN
 * Added blank special page Special:BlankPage for benchmarking, etc.
 * (bug 13862) Specialpages now has a horizontal TOC if there's three or more
   groups.
+* Foreign repo file descriptions via fetchDescription are now cached in the
+  transcache.
  
 === Bug fixes in 1.13 ===
 
diff --git a/includes/filerepo/File.php b/includes/filerepo/File.php
index 7a1c68e3dc..af5519c1e9 100644
--- a/includes/filerepo/File.php
+++ b/includes/filerepo/File.php
@@ -1067,13 +1067,53 @@ abstract class File {
 		}
 		$renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName() );
 		if ( $renderUrl ) {
+			if ( $this->repo->useTransCache ) {
+				wfDebug("Attempting to get the description from the transwiki cache...");
+				$this->purgeTransCacheEntries();
+				$dbr = wfGetDB(DB_SLAVE);
+				$obj = $dbr->selectRow('transcache', array('tc_contents'),
+											array('tc_url' => $renderUrl));
+				if ($obj) {
+					wfDebug("success!\n");
+					return $obj->tc_contents;
+				}
+				wfDebug("miss\n");
+			}
 			wfDebug( "Fetching shared description from $renderUrl\n" );
-			return Http::get( $renderUrl );
+			$res = Http::get( $renderUrl );
+			if ( $res && $this->repo->useTransCache ) $this->addToTransCache( $res, $renderUrl );
+			return $res;
 		} else {
 			return false;
 		}
 	}
 
+	/**
+	 * Purge expired transcache entries
+	 */
+	function purgeTranscacheEntries() {
+		global $wgTranscludeCacheExpiry;
+		$dbw = wfGetDB( DB_MASTER );
+		$table = $dbw->tableName('transcache');
+		$expiry = $dbw->addQuotes(time() - $wgTranscludeCacheExpiry);
+		$res = $dbw->delete( $table, array("tc_time < $expiry"), __METHOD__ );
+		if ($res) wfDebug("purging old transcache entries...");		
+	}
+	
+	/**
+	 * Add new transcache entry
+	 * 
+	 * @param string $text Text to add to the cache
+	 * @param string $url Url we're caching
+	 */
+	function addToTransCache( $text, $url ) {
+		$dbw = wfGetDB( DB_MASTER );
+				$dbw->replace('transcache', array('tc_url'), array(
+			'tc_url' => $url,
+			'tc_time' => time(),
+			'tc_contents' => $text));
+	}
+
 	/**
 	 * Get discription of file revision
 	 * STUB
diff --git a/includes/filerepo/FileRepo.php b/includes/filerepo/FileRepo.php
index 3606292f5e..93089a8553 100644
--- a/includes/filerepo/FileRepo.php
+++ b/includes/filerepo/FileRepo.php
@@ -30,7 +30,7 @@ abstract class FileRepo {
 		// Optional settings
 		$this->initialCapital = true; // by default
 		foreach ( array( 'descBaseUrl', 'scriptDirUrl', 'articleUrl', 'fetchDescription',
-			'thumbScriptUrl', 'initialCapital', 'pathDisclosureProtection' ) as $var )
+			'thumbScriptUrl', 'initialCapital', 'pathDisclosureProtection', 'useTransCache' ) as $var )
 		{
 			if ( isset( $info[$var] ) ) {
 				$this->$var = $info[$var];
-- 
2.20.1