Make "presumed-fresh" edit stash case cover when users make intervening edits

This still handles users editing inclusions themselves, but is
more relaxed in terms of edits by other users to the inclusions.

Bug: T134620
Change-Id: I6c0d189957481dfb6da0e73581b1d5b69fd3a352

diff --git a/includes/api/ApiStashEdit.php b/includes/api/ApiStashEdit.php
index 5efefbd..3539eed 100644 (file)
--- a/includes/api/ApiStashEdit.php
+++ b/includes/api/ApiStashEdit.php
@@ -147,13 +147,15 @@ class ApiStashEdit extends ApiBase {
                        Hooks::run( 'ParserOutputStashForEdit', [ $page, $content, $editInfo->output ] );
 
                        list( $stashInfo, $ttl ) = self::buildStashValue(
-                               $editInfo->pstContent, $editInfo->output, $editInfo->timestamp
+                               $editInfo->pstContent,
+                               $editInfo->output,
+                               $editInfo->timestamp,
+                               $user
                        );
 
                        if ( $stashInfo ) {
                                $ok = $cache->set( $key, $stashInfo, $ttl );
                                if ( $ok ) {
-
                                        $logger->debug( "Cached parser output for key '$key'." );
                                        return self::ERROR_NONE;
                                } else {
@@ -223,7 +225,7 @@ class ApiStashEdit extends ApiBase {
                $pOut->setCacheTime( wfTimestampNow() );
 
                // Build a value to cache with a proper TTL
-               list( $stashInfo, $ttl ) = self::buildStashValue( $pstContent, $pOut, $timestamp );
+               list( $stashInfo, $ttl ) = self::buildStashValue( $pstContent, $pOut, $timestamp, $user );
                if ( !$stashInfo ) {
                        $logger->info( "Uncacheable parser output for key '$key' (rev/TTL)." );
                        return false;
@@ -291,6 +293,10 @@ class ApiStashEdit extends ApiBase {
                        $stats->increment( 'editstash.cache_hits.presumed_fresh' );
                        $logger->debug( "Timestamp-based cache hit for key '$key' (age: $age sec)." );
                        return $editInfo; // assume nothing changed
+               } elseif ( isset( $editInfo->edits ) && $editInfo->edits === $user->getEditCount() ) {
+                       $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
                }
 
                $dbr = wfGetDB( DB_SLAVE );
@@ -385,12 +391,14 @@ class ApiStashEdit extends ApiBase {
         * @param Content $pstContent
         * @param ParserOutput $parserOutput
         * @param string $timestamp TS_MW
+        * @param User $user
         * @return array (stash info array, TTL in seconds) or (null, 0)
         */
        protected static function buildStashValue(
-               Content $pstContent, ParserOutput $parserOutput, $timestamp
+               Content $pstContent, ParserOutput $parserOutput, $timestamp, User $user
        ) {
-               // If an item is renewed, mind the cache TTL determined by config and parser functions
+               // If an item is renewed, mind the cache TTL determined by config and parser functions.
+               // Put an upper limit on the TTL for sanity to avoid extreme template/file staleness.
                $since = time() - wfTimestamp( TS_UNIX, $parserOutput->getTimestamp() );
                $ttl = min( $parserOutput->getCacheExpiry() - $since, 5 * 60 );
 
@@ -399,7 +407,8 @@ class ApiStashEdit extends ApiBase {
                        $stashInfo = (object)[
                                'pstContent' => $pstContent,
                                'output'     => $parserOutput,
-                               'timestamp'  => $timestamp
+                               'timestamp'  => $timestamp,
+                               'edits'      => $user->getEditCount()
                        ];
                        return [ $stashInfo, $ttl ];
                }