From 04a9d80e53f64ae97d75e746377f83f8519e416d Mon Sep 17 00:00:00 2001
From: lwelling <lwelling@wikimedia.org>
Date: Thu, 2 May 2013 20:34:25 -0400
Subject: [PATCH] Cache result of Language::isValidCode() to avoid regex
 processing

The function can be called over 2000 times in generating a page. This way
is significantly faster even for random invalid codes.  For real use it
should avoid the regex most of the time with no change in behavior.

Change-Id: I9fcbae1770be0d3f405d3d12254c11943b0d5f46
---
 languages/Language.php | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/languages/Language.php b/languages/Language.php
index b9201d7ed4..84e7f37db8 100644
--- a/languages/Language.php
+++ b/languages/Language.php
@@ -326,13 +326,19 @@ class Language {
 	 * @return bool
 	 */
 	public static function isValidCode( $code ) {
-		return
-			// People think language codes are html safe, so enforce it.
-			// Ideally we should only allow a-zA-Z0-9-
-			// but, .+ and other chars are often used for {{int:}} hacks
-			// see bugs 37564, 37587, 36938
+		static $cache = array();
+		if( isset( $cache[$code] ) ) {
+			return $cache[$code];
+		}
+		// People think language codes are html safe, so enforce it.
+		// Ideally we should only allow a-zA-Z0-9-
+		// but, .+ and other chars are often used for {{int:}} hacks
+		// see bugs 37564, 37587, 36938
+		$return =
 			strcspn( $code, ":/\\\000&<>'\"" ) === strlen( $code )
 			&& !preg_match( Title::getTitleInvalidRegex(), $code );
+		$cache[ $code ] = $return;
+		return $return;
 	}
 
 	/**
-- 
2.20.1