[Filesystem] remove dirs atomically if possible

Author: nicolas-grekas

Filesystem.php

@@ -162,6 +162,12 @@ public function remove($files)
         } elseif (!\is_array($files)) {
             $files = [$files];
         }
+
+        self::doRemove($files, false);
+    }
+
+    private static function doRemove(array $files, bool $isRecursive): void
+    {
         $files = array_reverse($files);
         foreach ($files as $file) {
             if (is_link($file)) {
@@ -170,10 +176,35 @@ public function remove($files)
                     throw new IOException(sprintf('Failed to remove symlink "%s": ', $file).self::$lastError);
                 }
             } elseif (is_dir($file)) {
-                $this->remove(new \FilesystemIterator($file, \FilesystemIterator::CURRENT_AS_PATHNAME | \FilesystemIterator::SKIP_DOTS));
+                if (!$isRecursive) {
+                    $tmpName = \dirname(realpath($file)).'/.'.strrev(strtr(base64_encode(random_bytes(2)), '/=', '-.'));
+
+                    if (file_exists($tmpName)) {
+                        try {
+                            self::doRemove([$tmpName], true);
+                        } catch (IOException $e) {
+                        }
+                    }
+
+                    if (!file_exists($tmpName) && self::box('rename', $file, $tmpName)) {
+                        $origFile = $file;
+                        $file = $tmpName;
+                    } else {
+                        $origFile = null;
+                    }
+                }
+
+                $files = new \FilesystemIterator($file, \FilesystemIterator::CURRENT_AS_PATHNAME | \FilesystemIterator::SKIP_DOTS);
+                self::doRemove(iterator_to_array($files, true), true);
+
+                if (!self::box('rmdir', $file) && file_exists($file) && !$isRecursive) {
+                    $lastError = self::$lastError;
+
+                    if (null !== $origFile && self::box('rename', $file, $origFile)) {
+                        $file = $origFile;
+                    }
 
-                if (!self::box('rmdir', $file) && file_exists($file)) {
-                    throw new IOException(sprintf('Failed to remove directory "%s": ', $file).self::$lastError);
+                    throw new IOException(sprintf('Failed to remove directory "%s": ', $file).$lastError);
                 }
             } elseif (!self::box('unlink', $file) && (false !== strpos(self::$lastError, 'Permission denied') || file_exists($file))) {
                 throw new IOException(sprintf('Failed to remove file "%s": ', $file).self::$lastError);