Reduce the rate of calls to Category::refreshCounts

Bug: T199762
Change-Id: I23e2e1ebf187d21ea4bd22304aa622199a8b9c5b

diff --git a/includes/Category.php b/includes/Category.php
index f8ac8ae..3352c2c 100644 (file)
--- a/includes/Category.php
+++ b/includes/Category.php
@@ -420,4 +420,45 @@ class Category {
 
                return true;
        }
+
+       /**
+        * Call refreshCounts() if there are no entries in the categorylinks table
+        * or if the category table has a row that states that there are no entries
+        *
+        * Due to lock errors or other failures, the precomputed counts can get out of sync,
+        * making it hard to know when to delete the category row without checking the
+        * categorylinks table.
+        *
+        * @return bool Whether links were refreshed
+        * @since 1.32
+        */
+       public function refreshCountsIfEmpty() {
+               $dbw = wfGetDB( DB_MASTER );
+
+               $hasLink = $dbw->selectField(
+                       'categorylinks',
+                       '1',
+                       [ 'cl_to' => $this->getName() ],
+                       __METHOD__
+               );
+               if ( !$hasLink ) {
+                       $this->refreshCounts(); // delete any category table entry
+
+                       return true;
+               }
+
+               $hasBadRow = $dbw->selectField(
+                       'category',
+                       '1',
+                       [ 'cat_title' => $this->getName(), 'cat_pages <= 0' ],
+                       __METHOD__
+               );
+               if ( $hasBadRow ) {
+                       $this->refreshCounts(); // clean up this row
+
+                       return true;
+               }
+
+               return false;
+       }
 }

diff --git a/includes/deferred/LinksDeletionUpdate.php b/includes/deferred/LinksDeletionUpdate.php
index 9f6257c..f370e43 100644 (file)
--- a/includes/deferred/LinksDeletionUpdate.php
+++ b/includes/deferred/LinksDeletionUpdate.php
@@ -101,7 +101,8 @@ class LinksDeletionUpdate extends DataUpdate implements EnqueueableDataUpdate {
                if ( $title->getNamespace() === NS_CATEGORY ) {
                        // T166757: do the update after the main job DB commit
                        DeferredUpdates::addCallableUpdate( function () use ( $title ) {
-                               $this->refreshCategoryIfEmpty( $title );
+                               $cat = Category::newFromName( $title->getDBkey() );
+                               $cat->refreshCountsIfEmpty();
                        } );
                }
 
@@ -187,35 +188,6 @@ class LinksDeletionUpdate extends DataUpdate implements EnqueueableDataUpdate {
                ScopedCallback::consume( $scopedLock );
        }
 
-       /**
-        * @param Title $title
-        */
-       private function refreshCategoryIfEmpty( Title $title ) {
-               $dbw = $this->getDB();
-
-               $row = $dbw->selectRow(
-                       'category',
-                       [ 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ],
-                       [ 'cat_title' => $title->getDBkey(), 'cat_pages <= 100' ],
-                       __METHOD__
-               );
-
-               if ( !$row ) {
-                       return; // nothing to delete
-               }
-
-               $cat = Category::newFromRow( $row, $title );
-               $hasLink = $dbw->selectField(
-                       'categorylinks',
-                       '1',
-                       [ 'cl_to' => $title->getDBkey() ],
-                       __METHOD__
-               );
-               if ( !$hasLink ) {
-                       $cat->refreshCounts(); // delete the category table entry
-               }
-       }
-
        private function batchDeleteByPK( $table, array $conds, array $pk, $bSize ) {
                $services = MediaWikiServices::getInstance();
                $lbFactory = $services->getDBLoadBalancerFactory();

diff --git a/includes/page/WikiPage.php b/includes/page/WikiPage.php
index 7cc25bd..0a80892 100644 (file)
--- a/includes/page/WikiPage.php
+++ b/includes/page/WikiPage.php
@@ -3343,23 +3343,10 @@ class WikiPage implements Page, IDBAccessObject {
                foreach ( $deleted as $catName ) {
                        $cat = Category::newFromName( $catName );
                        Hooks::run( 'CategoryAfterPageRemoved', [ $cat, $this, $id ] );
-               }
-
-               // Refresh counts on categories that should be empty now
-               if ( count( $deleted ) ) {
-                       $rows = $dbw->select(
-                               'category',
-                               [ 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ],
-                               [ 'cat_title' => $deleted, 'cat_pages <= 100' ],
-                               __METHOD__
-                       );
-                       foreach ( $rows as $row ) {
-                               $cat = Category::newFromRow( $row );
-                               // T166757: do the update after this DB commit
-                               DeferredUpdates::addCallableUpdate( function () use ( $cat ) {
-                                       $cat->refreshCounts();
-                               } );
-                       }
+                       // Refresh counts on categories that should be empty now (after commit, T166757)
+                       DeferredUpdates::addCallableUpdate( function () use ( $cat ) {
+                               $cat->refreshCountsIfEmpty();
+                       } );
                }
        }