From d6445e55a86a7ac96720c94830c9f06d39a85c09 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Tue, 5 Sep 2006 14:44:50 +0000
Subject: [PATCH] added getRelatedCache()

---
 includes/Title.php | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/includes/Title.php b/includes/Title.php
index 7eae801723..cf79780f2c 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -2244,6 +2244,46 @@ class Title {
 		}
 	}
 
+	/**
+	 * Get the last touched timestamp
+	 */
+	function getTouched() {
+		$dbr =& wfGetDB( DB_SLAVE );
+		$touched = $dbr->selectField( 'page', 'page_touched',
+			array( 
+				'page_namespace' => $this->getNamespace(),
+				'page_title' => $this->getDBkey()
+			), __METHOD__
+		);
+		return $touched;
+	}
+
+	/**
+	 * Get a cached value from a global cache that is invalidated when this page changes
+	 * @param string $key the key
+	 * @param callback $callback A callback function which generates the value on cache miss
+	 */
+	function getRelatedCache( $memc, $key, $expiry, $callback, $params = array() ) {
+		$touched = $this->getTouched();
+		$cacheEntry = $memc->get( $key );
+		if ( $cacheEntry ) {
+			if ( $cacheEntry['touched'] >= $touched ) {
+				return $cacheEntry['value'];
+			} else {
+				wfDebug( __METHOD__.": $key expired\n" );
+			}
+		} else {
+			wfDebug( __METHOD__.": $key not found\n" );
+		}
+		$value = call_user_func_array( $callback, $params );
+		$cacheEntry = array(
+			'value' => $value,
+			'touched' => $touched
+		);
+		$memc->set( $key, $cacheEntry, $expiry );
+		return $value;
+	}
+
 	function trackbackURL() {
 		global $wgTitle, $wgScriptPath, $wgServer;
 
-- 
2.20.1