[Pimcore] introduce DataObjectBatchListing

src/CoreShop/Component/Pimcore/BatchProcessing/DataObjectBatchListing.php

@@ -0,0 +1,165 @@
+<?php
+/**
+ * CoreShop.
+ *
+ * This source file is subject to the GNU General Public License version 3 (GPLv3)
+ * For the full copyright and license information, please view the LICENSE.md and gpl-3.0.txt
+ * files that are distributed with this source code.
+ *
+ * @copyright  Copyright (c) 2015-2020 Dominik Pfaffenbauer (https://www.pfaffenbauer.at)
+ * @license    https://www.coreshop.org/license     GNU General Public License version 3 (GPLv3)
+ */
+
+namespace CoreShop\Component\Pimcore\BatchProcessing;
+
+use Countable;
+use Iterator;
+use Pimcore\Model\DataObject;
+
+final class DataObjectBatchListing implements Iterator, Countable
+{
+    /**
+     * @var DataObject\Listing
+     */
+    private $list;
+
+    /**
+     * @var int
+     */
+    private $batchSize;
+
+    /**
+     * @var int
+     */
+    private $index = 0;
+
+    /**
+     * @var int
+     */
+    private $loop = 0;
+
+    /**
+     * @var int
+     */
+    private $currentLoopLoaded = -1;
+
+    /**
+     * @var int
+     */
+    private $total = 0;
+
+    /**
+     * @var array
+     */
+    private $items = [];
+
+    /**
+     * @var array
+     */
+    private $ids = [];
+
+    public function __construct(DataObject\Listing $list, int $batchSize)
+    {
+        $this->list = $list;
+        $this->batchSize = $batchSize;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function current()
+    {
+        return $this->items[$this->index];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function next()
+    {
+        $this->index++;
+
+        if ($this->index >= $this->batchSize) {
+            $this->index = 0;
+            $this->loop++;
+
+            $this->load();
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function key()
+    {
+        return ($this->index + 1) * ($this->loop + 1);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function valid()
+    {
+        return isset($this->items[$this->index]);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function rewind()
+    {
+        $this->index = 0;
+        $this->loop = 0;
+        $this->currentLoopLoaded = -1;
+
+        $this->load();
+    }
+
+    public function count()
+    {
+        if (!$this->total) {
+            $dao = $this->list->getDao();
+
+            if (!method_exists($dao, 'getTotalCount')) {
+                throw new \InvalidArgumentException(sprintf('%s listing class does not support count.',
+                    get_class($this->list)));
+            }
+
+            $this->total = $dao->getTotalCount();
+        }
+
+        return $this->total;
+    }
+
+    /**
+     * Load all items based on current state.
+     */
+    private function load()
+    {
+        if (null === $this->ids) {
+            $dao = $this->list->getDao();
+
+            if (!method_exists($dao, 'loadIdList')) {
+                throw new \InvalidArgumentException(sprintf('%s listing class does not support loadIdList.',
+                    get_class($this->list)));
+            }
+
+            $this->ids = $dao->loadIdList();
+        }
+
+        if ($this->currentLoopLoaded !== $this->loop) {
+            $items = [];
+
+            for ($i = 0; $i < $this->batchSize; $i++) {
+                $idOffset = ($this->loop * $this->batchSize) + $i;
+
+                $itemId = $this->ids[$idOffset];
+
+                $items[$i] = DataObject::getById($itemId);
+            }
+
+            $this->items = $items;
+            $this->currentLoopLoaded = $this->loop;
+        }
+    }
+}