Improve edit stash hit rate for logged-out users

Check whether they made intervening edits just like logged-in users.

Bug: T134620
Change-Id: Id1e0808caee0e474570c4f2e4b1cf845572e17e0

diff --git a/includes/api/ApiStashEdit.php b/includes/api/ApiStashEdit.php
index 3539eed..93003cc 100644 (file)
--- a/includes/api/ApiStashEdit.php
+++ b/includes/api/ApiStashEdit.php
@@ -294,9 +294,17 @@ class ApiStashEdit extends ApiBase {
                        $logger->debug( "Timestamp-based cache hit for key '$key' (age: $age sec)." );
                        return $editInfo; // assume nothing changed
                } elseif ( isset( $editInfo->edits ) && $editInfo->edits === $user->getEditCount() ) {
+                       // Logged-in user made no local upload/template edits in the meantime
                        $stats->increment( 'editstash.cache_hits.presumed_fresh' );
                        $logger->debug( "Edit count based cache hit for key '$key' (age: $age sec)." );
-                       return $editInfo; // use made no local upload/template edits in the meantime
+                       return $editInfo;
+               } elseif ( $user->isAnon()
+                       && self::lastEditTime( $user ) < $editInfo->output->getCacheTime()
+               ) {
+                       // Logged-out user made no local upload/template edits in the meantime
+                       $stats->increment( 'editstash.cache_hits.presumed_fresh' );
+                       $logger->debug( "Edit check based cache hit for key '$key' (age: $age sec)." );
+                       return $editInfo;
                }
 
                $dbr = wfGetDB( DB_SLAVE );
@@ -359,6 +367,21 @@ class ApiStashEdit extends ApiBase {
                return $editInfo;
        }
 
+       /**
+        * @param User $user
+        * @return string|null TS_MW timestamp or null
+        */
+       private static function lastEditTime( User $user ) {
+               $time = wfGetDB( DB_SLAVE )->selectField(
+                       'recentchanges',
+                       'MAX(rc_timestamp)',
+                       [ 'rc_user_text' => $user->getName() ],
+                       __METHOD__
+               );
+
+               return wfTimestampOrNull( TS_MW, $time );
+       }
+
        /**
         * Get the temporary prepared edit stash key for a user
         *
@@ -371,7 +394,7 @@ class ApiStashEdit extends ApiBase {
         * @param User $user User to get parser options from
         * @return string
         */
-       protected static function getStashKey( Title $title, Content $content, User $user ) {
+       private static function getStashKey( Title $title, Content $content, User $user ) {
                $hash = sha1( implode( ':', [
                        $content->getModel(),
                        $content->getDefaultFormat(),
@@ -394,7 +417,7 @@ class ApiStashEdit extends ApiBase {
         * @param User $user
         * @return array (stash info array, TTL in seconds) or (null, 0)
         */
-       protected static function buildStashValue(
+       private static function buildStashValue(
                Content $pstContent, ParserOutput $parserOutput, $timestamp, User $user
        ) {
                // If an item is renewed, mind the cache TTL determined by config and parser functions.