Avoid duplicate key generation code in MessageCache

Also explain the use of !NONEXISTANT in the comments a bit more.

Change-Id: Ib087df9bf31023e7acaf2116e74b2dfeda10c9d2

diff --git a/includes/cache/MessageCache.php b/includes/cache/MessageCache.php
index 70e1d9a..8a42a9a 100644 (file)
--- a/includes/cache/MessageCache.php
+++ b/includes/cache/MessageCache.php
@@ -485,7 +485,8 @@ class MessageCache {
                } else {
                        # Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
                        # other than language code.
-                       $conds[] = 'page_title NOT' . $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
+                       $conds[] = 'page_title NOT' .
+                               $dbr->buildLike( $dbr->anyString(), '/', $dbr->anyString() );
                }
 
                # Conditions to fetch oversized pages to ignore them
@@ -551,7 +552,7 @@ class MessageCache {
        /**
         * Updates cache as necessary when message page is changed
         *
-        * @param string $title Message cache key with initial uppercase letter.
+        * @param string $title Message cache key with initial uppercase letter
         * @param string|bool $text New contents of the page (false if deleted)
         */
        public function replace( $title, $text ) {
@@ -596,9 +597,8 @@ class MessageCache {
                                $page->loadPageData( $page::READ_LATEST );
                                $text = $this->getMessageTextFromContent( $page->getContent() );
                                // Check if an individual cache key should exist and update cache accordingly
-                               $titleKey = $this->wanCache->makeKey(
-                                       'messages-big', $this->mCache[$code]['HASH'], $title );
                                if ( is_string( $text ) && strlen( $text ) > $wgMaxMsgCacheEntrySize ) {
+                                       $titleKey = $this->bigMessageCacheKey( $this->mCache[$code]['HASH'], $title );
                                        $this->wanCache->set( $titleKey, ' ' . $text, $this->mExpiry );
                                }
                                // Mark this cache as definitely being "latest" (non-volatile) so
@@ -967,8 +967,8 @@ class MessageCache {
         * some callers require this behavior. LanguageConverter::parseCachedTable()
         * and self::get() are some examples in core.
         *
-        * @param string $title Message cache key with initial uppercase letter.
-        * @param string $code Code denoting the language to try.
+        * @param string $title Message cache key with initial uppercase letter
+        * @param string $code Code denoting the language to try
         * @return string|bool The message, or false if it does not exist or on error
         */
        public function getMsgFromNamespace( $title, $code ) {
@@ -995,8 +995,8 @@ class MessageCache {
                        return false;
                }
 
-               // Try the individual message cache
-               $titleKey = $this->wanCache->makeKey( 'messages-big', $this->mCache[$code]['HASH'], $title );
+               // Individual message cache key
+               $titleKey = $this->bigMessageCacheKey( $this->mCache[$code]['HASH'], $title );
 
                if ( $this->mCacheVolatile[$code] ) {
                        $entry = false;
@@ -1005,6 +1005,7 @@ class MessageCache {
                                __METHOD__ . ': loading volatile key \'{titleKey}\'',
                                [ 'titleKey' => $titleKey, 'code' => $code ] );
                } else {
+                       // Try the individual message cache
                        $entry = $this->wanCache->get( $titleKey );
                }
 
@@ -1057,7 +1058,8 @@ class MessageCache {
                        $message = false; // negative caching
                }
 
-               if ( $message === false ) { // negative caching
+               if ( $message === false ) {
+                       // Negative caching in case a "too big" message is no longer available (deleted)
                        $this->mCache[$code][$title] = '!NONEXISTENT';
                        $this->wanCache->set( $titleKey, '!NONEXISTENT', $this->mExpiry, $cacheOpts );
                }
@@ -1301,4 +1303,13 @@ class MessageCache {
 
                return $msgText;
        }
+
+       /**
+        * @param string $hash Hash for this version of the entire key/value overrides map
+        * @param string $title Message cache key with initial uppercase letter
+        * @return string
+        */
+       private function bigMessageCacheKey( $hash, $title ) {
+               return $this->wanCache->makeKey( 'messages-big', $hash, $title );
+       }
 }