From 7117e1a798f396f288635f93a66d30bf8a387784 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Deruss=C3=A9?= <jeremy@derusse.com>
Date: Sat, 30 Jan 2021 17:17:32 +0100
Subject: [PATCH] Use a lazyintertor to close files descriptors when no longer
 used

---
 src/Symfony/Component/Finder/Finder.php       |  5 +-
 .../Finder/Iterator/LazyIterator.php          | 30 +++++++++++
 .../Tests/Iterator/LazyIteratorTest.php       | 53 +++++++++++++++++++
 3 files changed, 87 insertions(+), 1 deletion(-)
 create mode 100644 src/Symfony/Component/Finder/Iterator/LazyIterator.php
 create mode 100644 src/Symfony/Component/Finder/Tests/Iterator/LazyIteratorTest.php

diff --git a/src/Symfony/Component/Finder/Finder.php b/src/Symfony/Component/Finder/Finder.php
index 82c2ec78dc..87fc187b2f 100644
--- a/src/Symfony/Component/Finder/Finder.php
+++ b/src/Symfony/Component/Finder/Finder.php
@@ -20,6 +20,7 @@ use Symfony\Component\Finder\Iterator\DepthRangeFilterIterator;
 use Symfony\Component\Finder\Iterator\ExcludeDirectoryFilterIterator;
 use Symfony\Component\Finder\Iterator\FilecontentFilterIterator;
 use Symfony\Component\Finder\Iterator\FilenameFilterIterator;
+use Symfony\Component\Finder\Iterator\LazyIterator;
 use Symfony\Component\Finder\Iterator\SizeRangeFilterIterator;
 use Symfony\Component\Finder\Iterator\SortableIterator;
 
@@ -635,7 +636,9 @@ class Finder implements \IteratorAggregate, \Countable
 
         $iterator = new \AppendIterator();
         foreach ($this->dirs as $dir) {
-            $iterator->append($this->searchInDirectory($dir));
+            $iterator->append(new \IteratorIterator(new LazyIterator(function () use ($dir) {
+                return $this->searchInDirectory($dir);
+            })));
         }
 
         foreach ($this->iterators as $it) {
diff --git a/src/Symfony/Component/Finder/Iterator/LazyIterator.php b/src/Symfony/Component/Finder/Iterator/LazyIterator.php
new file mode 100644
index 0000000000..4388f4f3fd
--- /dev/null
+++ b/src/Symfony/Component/Finder/Iterator/LazyIterator.php
@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Finder\Iterator;
+
+/**
+ * @author Jérémy Derussé <jeremy@derusse.com>
+ */
+class LazyIterator implements \IteratorAggregate
+{
+    private $iteratorFactory;
+
+    public function __construct(callable $iteratorFactory)
+    {
+        $this->iteratorFactory = $iteratorFactory;
+    }
+
+    public function getIterator()
+    {
+        yield from ($this->iteratorFactory)();
+    }
+}
diff --git a/src/Symfony/Component/Finder/Tests/Iterator/LazyIteratorTest.php b/src/Symfony/Component/Finder/Tests/Iterator/LazyIteratorTest.php
new file mode 100644
index 0000000000..1a96c32d0b
--- /dev/null
+++ b/src/Symfony/Component/Finder/Tests/Iterator/LazyIteratorTest.php
@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Finder\Tests\Iterator;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Finder\Iterator\LazyIterator;
+
+class LazyIteratorTest extends TestCase
+{
+    public function testLazy()
+    {
+        new LazyIterator(function () {
+            $this->markTestFailed('lazyIterator should not be called');
+        });
+
+        $this->expectNotToPerformAssertions();
+    }
+
+    public function testDelegate()
+    {
+        $iterator = new LazyIterator(function () {
+            return new Iterator(['foo', 'bar']);
+        });
+
+        $this->assertCount(2, $iterator);
+    }
+
+    public function testInnerDestructedAtTheEnd()
+    {
+        $count = 0;
+        $iterator = new LazyIterator(function () use (&$count) {
+            ++$count;
+
+            return new Iterator(['foo', 'bar']);
+        });
+
+        foreach ($iterator as $x) {
+        }
+        $this->assertSame(1, $count);
+        foreach ($iterator as $x) {
+        }
+        $this->assertSame(2, $count);
+    }
+}