Merge "Reinstate small category refresh logic in LinksDeletionUpdate"

[lhc/web/wiklou.git] / includes / Category.php

diff --git a/includes/Category.php b/includes/Category.php
index f8ac8ae..34ac0e1 100644 (file)
--- a/includes/Category.php
+++ b/includes/Category.php
@@ -25,8 +25,6 @@
  * Category objects are immutable, strictly speaking. If you call methods that change the database,
  * like to refresh link counts, the objects will be appropriately reinitialized.
  * Member variables are lazy-initialized.
- *
- * @todo Move some stuff from CategoryPage.php to here, and use that.
  */
 class Category {
        /** Name of the category, normalized to DB-key form */
@@ -43,6 +41,8 @@ class Category {
        const LOAD_ONLY = 0;
        const LAZY_INIT_ROW = 1;
 
+       const ROW_COUNT_SMALL = 100;
+
        private function __construct() {
        }
 
@@ -299,10 +299,10 @@ class Category {
        /**
         * Generic accessor
         * @param string $key
-        * @return bool
+        * @return mixed
         */
        private function getX( $key ) {
-               if ( !$this->initialize( self::LAZY_INIT_ROW ) ) {
+               if ( $this->{$key} === null && !$this->initialize( self::LAZY_INIT_ROW ) ) {
                        return false;
                }
                return $this->{$key};
@@ -420,4 +420,74 @@ 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() {
+               return $this->refreshCountsIfSmall( 0 );
+       }
+
+       /**
+        * Call refreshCounts() if there are few entries in the categorylinks table
+        *
+        * 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.
+        *
+        * This method will do a non-locking select first to reduce contention.
+        *
+        * @param int $maxSize Only refresh if there are this or less many backlinks
+        * @return bool Whether links were refreshed
+        * @since 1.34
+        */
+       public function refreshCountsIfSmall( $maxSize = self::ROW_COUNT_SMALL ) {
+               $dbw = wfGetDB( DB_MASTER );
+               $dbw->startAtomic( __METHOD__ );
+
+               $typeOccurances = $dbw->selectFieldValues(
+                       'categorylinks',
+                       'cl_type',
+                       [ 'cl_to' => $this->getName() ],
+                       __METHOD__,
+                       [ 'LIMIT' => $maxSize + 1 ]
+               );
+
+               if ( !$typeOccurances ) {
+                       $doRefresh = true; // delete any category table entry
+               } elseif ( count( $typeOccurances ) <= $maxSize ) {
+                       $countByType = array_count_values( $typeOccurances );
+                       $doRefresh = !$dbw->selectField(
+                               'category',
+                               '1',
+                               [
+                                       'cat_title' => $this->getName(),
+                                       'cat_pages' => $countByType['page'] ?? 0,
+                                       'cat_subcats' => $countByType['subcat'] ?? 0,
+                                       'cat_files' => $countByType['file'] ?? 0
+                               ],
+                               __METHOD__
+                       );
+               } else {
+                       $doRefresh = false; // category is too big
+               }
+
+               $dbw->endAtomic( __METHOD__ );
+
+               if ( $doRefresh ) {
+                       $this->refreshCounts(); // update the row
+
+                       return true;
+               }
+
+               return false;
+       }
 }