CachedPDOIterator: introduce rewindable PDOStatement iterator

models/CachedPDOIterator.php

@@ -0,0 +1,56 @@
+<?php
+/*****************************************************************************
+ * CachedPDOIterator.php
+ * Contains model class CachedPDOIterator.
+ *
+ * Based on https://gist.github.com/hakre/5152090
+ *
+ * Kabuki CMS (C) 2013-2021, Aaron van Geffen
+ *****************************************************************************/
+
+class CachedPDOIterator extends CachingIterator
+{
+    private $index;
+
+    public function __construct(PDOStatement $statement)
+    {
+        parent::__construct(new IteratorIterator($statement), self::FULL_CACHE);
+    }
+
+    public function rewind(): void
+    {
+        if ($this->index === null)
+        {
+            parent::rewind();
+        }
+        $this->index = 0;
+    }
+
+    public function current(): mixed
+    {
+        if ($this->offsetExists($this->index))
+        {
+            return $this->offsetGet($this->index);
+        }
+        return parent::current();
+    }
+
+    public function key(): mixed
+    {
+        return $this->index;
+    }
+
+    public function next(): void
+    {
+        $this->index++;
+        if (!$this->offsetExists($this->index))
+        {
+            parent::next();
+        }
+    }
+
+    public function valid(): bool
+    {
+        return $this->offsetExists($this->index) || parent::valid();
+    }
+}