--- /dev/null
+<?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\Config\Resource;
+
+/**
+ * ComposerResource tracks the PHP version and Composer dependencies.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class ComposerResource implements SelfCheckingResourceInterface, \Serializable
+{
+ private $vendors;
+
+ private static $runtimeVendors;
+
+ public function __construct()
+ {
+ self::refresh();
+ $this->vendors = self::$runtimeVendors;
+ }
+
+ public function getVendors()
+ {
+ return array_keys($this->vendors);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __toString()
+ {
+ return __CLASS__;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function isFresh($timestamp)
+ {
+ self::refresh();
+
+ return self::$runtimeVendors === $this->vendors;
+ }
+
+ public function serialize()
+ {
+ return serialize($this->vendors);
+ }
+
+ public function unserialize($serialized)
+ {
+ $this->vendors = unserialize($serialized);
+ }
+
+ private static function refresh()
+ {
+ self::$runtimeVendors = array();
+
+ foreach (get_declared_classes() as $class) {
+ if ('C' === $class[0] && 0 === strpos($class, 'ComposerAutoloaderInit')) {
+ $r = new \ReflectionClass($class);
+ $v = dirname(dirname($r->getFileName()));
+ if (file_exists($v.'/composer/installed.json')) {
+ self::$runtimeVendors[$v] = @filemtime($v.'/composer/installed.json');
+ }
+ }
+ }
+ }
+}