MC-32792: Get Categories server side API operation to improve in 2.4

Author: Leonid Poluianov

app/code/Magento/Catalog/Model/ResourceModel/Category/Collection.php

@@ -5,8 +5,11 @@
  */
 namespace Magento\Catalog\Model\ResourceModel\Category;
 
+use Magento\Catalog\Model\Category;
+use Magento\Catalog\Model\Product\Visibility;
 use Magento\CatalogUrlRewrite\Model\CategoryUrlRewriteGenerator;
 use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\DB\Select;
 use Magento\Store\Model\ScopeInterface;
 
 /**
@@ -68,6 +71,11 @@ class Collection extends \Magento\Catalog\Model\ResourceModel\Collection\Abstrac
      */
     private $scopeConfig;
 
+    /**
+     * @var Visibility
+     */
+    private $catalogProductVisibility;
+
     /**
      * Constructor
      * @param \Magento\Framework\Data\Collection\EntityFactory $entityFactory
@@ -96,7 +104,8 @@ public function __construct(
         \Magento\Framework\Validator\UniversalFactory $universalFactory,
         \Magento\Store\Model\StoreManagerInterface $storeManager,
         \Magento\Framework\DB\Adapter\AdapterInterface $connection = null,
-        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig = null
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig = null,
+        Visibility $catalogProductVisibility = null
     ) {
         parent::__construct(
             $entityFactory,
@@ -113,6 +122,8 @@ public function __construct(
         );
         $this->scopeConfig = $scopeConfig ?:
             \Magento\Framework\App\ObjectManager::getInstance()->get(ScopeConfigInterface::class);
+        $this->catalogProductVisibility = $catalogProductVisibility ?:
+            \Magento\Framework\App\ObjectManager::getInstance()->get(Visibility::class);
     }
 
     /**
@@ -122,7 +133,7 @@ public function __construct(
      */
     protected function _construct()
     {
-        $this->_init(\Magento\Catalog\Model\Category::class, \Magento\Catalog\Model\ResourceModel\Category::class);
+        $this->_init(Category::class, \Magento\Catalog\Model\ResourceModel\Category::class);
     }
 
     /**
@@ -259,6 +270,7 @@ protected function _loadProductCount()
      * @return $this
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      * @SuppressWarnings(PHPMD.UnusedLocalVariable)
+     * @throws \Magento\Framework\Exception\NoSuchEntityException
      */
     public function loadProductCount($items, $countRegular = true, $countAnchor = true)
     {
@@ -310,34 +322,14 @@ public function loadProductCount($items, $countRegular = true, $countAnchor = tr
 
         if ($countAnchor) {
             // Retrieve Anchor categories product counts
+            $categoryIds = array_keys($anchor);
+            $countSelect = $this->getProductsCountQuery($categoryIds, (bool)$websiteId);
+            $categoryProductsCount = $this->_conn->fetchPairs($countSelect);
             foreach ($anchor as $item) {
-                if ($allChildren = $item->getAllChildren()) {
-                    $bind = ['entity_id' => $item->getId(), 'c_path' => $item->getPath() . '/%'];
-                    $select = $this->_conn->select();
-                    $select->from(
-                        ['main_table' => $this->getProductTable()],
-                        new \Zend_Db_Expr('COUNT(DISTINCT main_table.product_id)')
-                    )->joinInner(
-                        ['e' => $this->getTable('catalog_category_entity')],
-                        'main_table.category_id=e.entity_id',
-                        []
-                    )->where(
-                        '(e.entity_id = :entity_id OR e.path LIKE :c_path)'
-                    );
-                    if ($websiteId) {
-                        $select->join(
-                            ['w' => $this->getProductWebsiteTable()],
-                            'main_table.product_id = w.product_id',
-                            []
-                        )->where(
-                            'w.website_id = ?',
-                            $websiteId
-                        );
-                    }
-                    $item->setProductCount((int)$this->_conn->fetchOne($select, $bind));
-                } else {
-                    $item->setProductCount(0);
-                }
+                $productsCount = isset($categoriesProductsCount[$item->getId()])
+                    ? (int)$categoryProductsCount[$item->getId()]
+                    : $this->getProductsCountFromCategoryTable($item, $websiteId);
+                $item->setProductCount($productsCount);
             }
         }
         return $this;
@@ -513,4 +505,66 @@ public function getProductTable()
         }
         return $this->_productTable;
     }
+
+    /**
+     * @param Category $item
+     * @param string $websiteId
+     * @return int
+     */
+    private function getProductsCountFromCategoryTable(Category $item, string $websiteId): int
+    {
+        $productCount = 0;
+
+        if ($item->getAllChildren()) {
+            $bind = ['entity_id' => $item->getId(), 'c_path' => $item->getPath() . '/%'];
+            $select = $this->_conn->select();
+            $select->from(
+                ['main_table' => $this->getProductTable()],
+                new \Zend_Db_Expr('COUNT(DISTINCT main_table.product_id)')
+            )->joinInner(
+                ['e' => $this->getTable('catalog_category_entity')],
+                'main_table.category_id=e.entity_id',
+                []
+            )->where(
+                '(e.entity_id = :entity_id OR e.path LIKE :c_path)'
+            );
+            if ($websiteId) {
+                $select->join(
+                    ['w' => $this->getProductWebsiteTable()],
+                    'main_table.product_id = w.product_id',
+                    []
+                )->where(
+                    'w.website_id = ?',
+                    $websiteId
+                );
+            }
+            $productCount = (int)$this->_conn->fetchOne($select, $bind);
+        }
+        return $productCount;
+    }
+
+    /**
+     * Get query for retrieve count of products per category
+     *
+     * @param array $categoryIds
+     * @return Select
+     */
+    private function getProductsCountQuery(array $categoryIds, $addVisibilityFilter = true): Select
+    {
+        $categoryTable = $this->getTable('catalog_category_product_index');
+        $select = $this->_conn->select()
+            ->from(
+                ['cat_index' => $categoryTable],
+                ['category_id' => 'cat_index.category_id', 'count' => 'count(cat_index.product_id)']
+            )
+            ->where('cat_index.category_id in (?)', \array_map('\intval', $categoryIds));
+        if (true === $addVisibilityFilter) {
+            $select->where('cat_index.visibility in (?)', $this->catalogProductVisibility->getVisibleInSiteIds());
+        }
+        if (count($categoryIds) > 1) {
+            $select->group('cat_index.category_id');
+        }
+
+        return $select;
+    }
 }