MessageCache: Fix isMainCacheable() logic for non-content languages

The way isMainCacheable() was used, it always returned false in
non-content languages, because it would try to find strings like
'hidetoc/fr' in the array of message keys (which contains strings like
'hidetoc').

The consequence of this was that MessageCache would check the database
for a MediaWiki:hidetoc/fr page even if it already knew that that page
didn't exist. This is a substantial performance hit when requesting lots
of messages, like when building version hashes for ResourceLoader's
startup module.

Follows-up 4fc5ba8bf83102b02.

Bug: T228555
Change-Id: I20433175ca919acc1c995f4a9cd50ca53afcdd02

diff --git a/includes/cache/MessageCache.php b/includes/cache/MessageCache.php
index b0716b1..a8bcfc6 100644 (file)
--- a/includes/cache/MessageCache.php
+++ b/includes/cache/MessageCache.php
@@ -525,9 +525,8 @@ class MessageCache {
                        __METHOD__ . "($code)-big"
                );
                foreach ( $res as $row ) {
-                       $name = $this->contLang->lcfirst( $row->page_title );
                        // Include entries/stubs for all keys in $mostused in adaptive mode
-                       if ( $wgAdaptiveMessageCache || $this->isMainCacheable( $name, $overridable ) ) {
+                       if ( $wgAdaptiveMessageCache || $this->isMainCacheable( $row->page_title, $overridable ) ) {
                                $cache[$row->page_title] = '!TOO BIG';
                        }
                        // At least include revision ID so page changes are reflected in the hash
@@ -549,9 +548,8 @@ class MessageCache {
                        $revQuery['joins']
                );
                foreach ( $res as $row ) {
-                       $name = $this->contLang->lcfirst( $row->page_title );
                        // Include entries/stubs for all keys in $mostused in adaptive mode
-                       if ( $wgAdaptiveMessageCache || $this->isMainCacheable( $name, $overridable ) ) {
+                       if ( $wgAdaptiveMessageCache || $this->isMainCacheable( $row->page_title, $overridable ) ) {
                                try {
                                        $rev = $revisionStore->newRevisionFromRow( $row );
                                        $content = $rev->getContent( MediaWiki\Revision\SlotRecord::MAIN );
@@ -592,14 +590,17 @@ class MessageCache {
        }
 
        /**
-        * @param string $name Message name with lowercase first letter
+        * @param string $name Message name (possibly with /code suffix)
         * @param array $overridable Map of (key => unused) for software-defined messages
         * @return bool
         */
        private function isMainCacheable( $name, array $overridable ) {
+               // Convert first letter to lowercase, and strip /code suffix
+               $name = $this->contLang->lcfirst( $name );
+               $msg = preg_replace( '/\/[a-z0-9-]{2,}$/', '', $name );
                // Include common conversion table pages. This also avoids problems with
                // Installer::parse() bailing out due to disallowed DB queries (T207979).
-               return ( isset( $overridable[$name] ) || strpos( $name, 'conversiontable/' ) === 0 );
+               return ( isset( $overridable[$msg] ) || strpos( $name, 'conversiontable/' ) === 0 );
        }
 
        /**
@@ -1069,8 +1070,7 @@ class MessageCache {
                        );
                } else {
                        // Message page either does not exist or does not override a software message
-                       $name = $this->contLang->lcfirst( $title );
-                       if ( !$this->isMainCacheable( $name, $this->overridable ) ) {
+                       if ( !$this->isMainCacheable( $title, $this->overridable ) ) {
                                // Message page does not override any software-defined message. A custom
                                // message might be defined to have content or settings specific to the wiki.
                                // Load the message page, utilizing the individual message cache as needed.

diff --git a/tests/phpunit/includes/cache/MessageCacheTest.php b/tests/phpunit/includes/cache/MessageCacheTest.php
index 2fa662b..35dacac 100644 (file)
--- a/tests/phpunit/includes/cache/MessageCacheTest.php
+++ b/tests/phpunit/includes/cache/MessageCacheTest.php
@@ -204,7 +204,7 @@ class MessageCacheTest extends MediaWikiLangTestCase {
                ];
        }
 
-       public function testNoDBAccess() {
+       public function testNoDBAccessContentLanguage() {
                global $wgContLanguageCode;
 
                $dbr = wfGetDB( DB_REPLICA );
@@ -218,7 +218,22 @@ class MessageCacheTest extends MediaWikiLangTestCase {
 
                $dbr->restoreFlags();
 
-               $this->assertEquals( 0, $dbr->trxLevel(), "No DB read queries" );
+               $this->assertEquals( 0, $dbr->trxLevel(), "No DB read queries (content language)" );
+       }
+
+       public function testNoDBAccessNonContentLanguage() {
+               $dbr = wfGetDB( DB_REPLICA );
+
+               MessageCache::singleton()->getMsgFromNamespace( 'allpages/nl', 'nl' );
+
+               $this->assertEquals( 0, $dbr->trxLevel() );
+               $dbr->setFlag( DBO_TRX, $dbr::REMEMBER_PRIOR ); // make queries trigger TRX
+
+               MessageCache::singleton()->getMsgFromNamespace( 'go/nl', 'nl' );
+
+               $dbr->restoreFlags();
+
+               $this->assertEquals( 0, $dbr->trxLevel(), "No DB read queries (non-content language)" );
        }
 
        /**