fix memory issue when dealing with large object lists

Author: benwalch

UPGRADE.md

@@ -1,5 +1,7 @@
 # Upgrade Notes
 
+## 3.0.3
+- [IMPROVEMENT] fix memory issue when dealing with large object lists (#41)
 ## 3.0.2
 - [LICENSE] Dual-License with GPL and Dachcom Commercial License (DCL) added
 ## 3.0.1

src/Service/Builder/ObjectListBuilder.php

@@ -32,10 +32,14 @@ public function buildByList(array $options): \Generator
     {
         $list = $this->getList($options);
 
-        foreach ($list->loadIdList() as $id) {
-            if ($object = DataObject::getById($id)) {
+        $idList = $list->loadIdList();
+        for ($i = 0; $i < count($idList); $i++) {
+            if ($object = DataObject::getById($idList[$i])) {
                 yield $object;
             }
+            if ($i % 400 === 0) {
+                \Pimcore::collectGarbage();
+            }
         }
     }