--- /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\DependencyInjection\ParameterBag;
+
+use Symfony\Component\DependencyInjection\Exception\LogicException;
+
+/**
+ * Holds read-only parameters.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class FrozenParameterBag extends ParameterBag
+{
+ /**
+ * For performance reasons, the constructor assumes that
+ * all keys are already lowercased.
+ *
+ * This is always the case when used internally.
+ *
+ * @param array $parameters An array of parameters
+ */
+ public function __construct(array $parameters = array())
+ {
+ $this->parameters = $parameters;
+ $this->resolved = true;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function clear()
+ {
+ throw new LogicException('Impossible to call clear() on a frozen ParameterBag.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function add(array $parameters)
+ {
+ throw new LogicException('Impossible to call add() on a frozen ParameterBag.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function set($name, $value)
+ {
+ throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function remove($name)
+ {
+ throw new LogicException('Impossible to call remove() on a frozen ParameterBag.');
+ }
+}