Merge pull request #1581 from magento-tango/MAGETWO-71554

Bug
- MAGETWO-71554 Visual Merchandiser category edit performance issue - for 2.2

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

@@ -28,6 +28,8 @@
  * @method Category setUrlPath(string $urlPath)
  * @method Category getSkipDeleteChildren()
  * @method Category setSkipDeleteChildren(boolean $value)
+ * @method Category setChangedProductIds(array $categoryIds) Set products ids that inserted or deleted for category
+ * @method array getChangedProductIds() Get products ids that inserted or deleted for category
  *
  * @SuppressWarnings(PHPMD.LongVariable)
  * @SuppressWarnings(PHPMD.ExcessivePublicCount)

app/code/Magento/Catalog/Model/Category/Product/PositionResolver.php

@@ -0,0 +1,59 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Catalog\Model\Category\Product;
+
+/**
+ * Resolver to get product positions by ids assigned to specific category
+ */
+class PositionResolver extends \Magento\Framework\Model\ResourceModel\Db\AbstractDb
+{
+    /**
+     * @param \Magento\Framework\Model\ResourceModel\Db\Context $context
+     * @param string $connectionName
+     */
+    public function __construct(
+        \Magento\Framework\Model\ResourceModel\Db\Context $context,
+        $connectionName = null
+    ) {
+        parent::__construct($context, $connectionName);
+    }
+
+    /**
+     * Initialize resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init('catalog_product_entity', 'entity_id');
+    }
+
+    /**
+     * Get category product positions
+     *
+     * @param int $categoryId
+     * @return array
+     */
+    public function getPositions(int $categoryId)
+    {
+        $connection = $this->getConnection();
+
+        $select = $connection->select()->from(
+            ['cpe' => $this->getTable('catalog_product_entity')],
+            'entity_id'
+        )->joinLeft(
+            ['ccp' => $this->getTable('catalog_category_product')],
+            'ccp.product_id=cpe.entity_id'
+        )->where(
+            'ccp.category_id = ?',
+            $categoryId
+        )->order(
+            'ccp.position ' . \Magento\Framework\DB\Select::SQL_ASC
+        );
+
+        return array_flip($connection->fetchCol($select));
+    }
+}

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

@@ -410,9 +410,18 @@ protected function _saveCategoryProducts($category)
          * Update product positions in category
          */
         if (!empty($update)) {
+            $newPositions = [];
             foreach ($update as $productId => $position) {
-                $where = ['category_id = ?' => (int)$id, 'product_id = ?' => (int)$productId];
-                $bind = ['position' => (int)$position];
+                $delta = $position - $oldProducts[$productId];
+                if (!isset($newPositions[$delta])) {
+                    $newPositions[$delta] = [];
+                }
+                $newPositions[$delta][] = $productId;
+            }
+
+            foreach ($newPositions as $delta => $productIds) {
+                $bind = ['position' => new \Zend_Db_Expr("position + ({$delta})")];
+                $where = ['category_id = ?' => (int)$id, 'product_id IN (?)' => $productIds];
                 $connection->update($this->getCategoryProductTable(), $bind, $where);
             }
         }
@@ -423,6 +432,8 @@ protected function _saveCategoryProducts($category)
                 'catalog_category_change_products',
                 ['category' => $category, 'product_ids' => $productIds]
             );
+
+            $category->setChangedProductIds($productIds);
         }
 
         if (!empty($insert) || !empty($update) || !empty($delete)) {

app/code/Magento/Catalog/Test/Unit/Model/Category/Product/PositionResolverTest.php

@@ -0,0 +1,120 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Catalog\Test\Unit\Model\Category\Product;
+
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Catalog\Model\Category\Product\PositionResolver;
+use Magento\Framework\Model\ResourceModel\Db\Context;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\DB\Select;
+
+class PositionResolverTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var Context|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $context;
+
+    /**
+     * @var ResourceConnection|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $resources;
+
+    /**
+     * @var AdapterInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $connection;
+
+    /**
+     * @var Select|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $select;
+
+    /**
+     * @var PositionResolver
+     */
+    private $model;
+
+    /**
+     * @var array
+     */
+    private $positions = [
+        '3' => 100,
+        '2' => 101,
+        '1' => 102
+    ];
+
+    /**
+     * @var array
+     */
+    private $flippedPositions = [
+        '100' => 3,
+        '101' => 2,
+        '102' => 1
+    ];
+
+    /**
+     * @var int
+     */
+    private $categoryId = 1;
+
+    protected function setUp()
+    {
+        $this->context = $this->getMockBuilder(Context::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $this->resources = $this->getMockBuilder(ResourceConnection::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $this->connection = $this->getMockBuilder(AdapterInterface::class)
+            ->disableOriginalConstructor()
+            ->getMockForAbstractClass();
+
+        $this->select = $this->getMockBuilder(Select::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $this->model = (new ObjectManager($this))->getObject(
+            PositionResolver::class,
+            [
+                'context' => $this->context,
+                null,
+                '_resources' => $this->resources
+            ]
+        );
+    }
+
+    public function testGetPositions()
+    {
+        $this->resources->expects($this->once())
+            ->method('getConnection')
+            ->willReturn($this->connection);
+
+        $this->connection->expects($this->once())
+            ->method('select')
+            ->willReturn($this->select);
+        $this->select->expects($this->once())
+            ->method('from')
+            ->willReturnSelf();
+        $this->select->expects($this->once())
+            ->method('where')
+            ->willReturnSelf();
+        $this->select->expects($this->once())
+            ->method('order')
+            ->willReturnSelf();
+        $this->select->expects($this->once())
+            ->method('joinLeft')
+            ->willReturnSelf();
+        $this->connection->expects($this->once())
+            ->method('fetchCol')
+            ->willReturn($this->positions);
+
+        $this->assertEquals($this->flippedPositions, $this->model->getPositions($this->categoryId));
+    }
+}