--- /dev/null
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\Common\Persistence\Mapping\Driver;
+
+use Doctrine\Common\Persistence\Mapping\ClassMetadata;
+use Doctrine\Common\Persistence\Mapping\MappingException;
+
+/**
+ * The DriverChain allows you to add multiple other mapping drivers for
+ * certain namespaces.
+ *
+ * @since 2.2
+ * @author Benjamin Eberlei <kontakt@beberlei.de>
+ * @author Guilherme Blanco <guilhermeblanco@hotmail.com>
+ * @author Jonathan H. Wage <jonwage@gmail.com>
+ * @author Roman Borschel <roman@code-factory.org>
+ */
+class MappingDriverChain implements MappingDriver
+{
+ /**
+ * The default driver.
+ *
+ * @var MappingDriver|null
+ */
+ private $defaultDriver;
+
+ /**
+ * @var array
+ */
+ private $drivers = [];
+
+ /**
+ * Gets the default driver.
+ *
+ * @return MappingDriver|null
+ */
+ public function getDefaultDriver()
+ {
+ return $this->defaultDriver;
+ }
+
+ /**
+ * Set the default driver.
+ *
+ * @param MappingDriver $driver
+ *
+ * @return void
+ */
+ public function setDefaultDriver(MappingDriver $driver)
+ {
+ $this->defaultDriver = $driver;
+ }
+
+ /**
+ * Adds a nested driver.
+ *
+ * @param MappingDriver $nestedDriver
+ * @param string $namespace
+ *
+ * @return void
+ */
+ public function addDriver(MappingDriver $nestedDriver, $namespace)
+ {
+ $this->drivers[$namespace] = $nestedDriver;
+ }
+
+ /**
+ * Gets the array of nested drivers.
+ *
+ * @return array $drivers
+ */
+ public function getDrivers()
+ {
+ return $this->drivers;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public function loadMetadataForClass($className, ClassMetadata $metadata)
+ {
+ /* @var $driver MappingDriver */
+ foreach ($this->drivers as $namespace => $driver) {
+ if (strpos($className, $namespace) === 0) {
+ $driver->loadMetadataForClass($className, $metadata);
+ return;
+ }
+ }
+
+ if (null !== $this->defaultDriver) {
+ $this->defaultDriver->loadMetadataForClass($className, $metadata);
+ return;
+ }
+
+ throw MappingException::classNotFoundInNamespaces($className, array_keys($this->drivers));
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public function getAllClassNames()
+ {
+ $classNames = [];
+ $driverClasses = [];
+
+ /* @var $driver MappingDriver */
+ foreach ($this->drivers AS $namespace => $driver) {
+ $oid = spl_object_hash($driver);
+
+ if (!isset($driverClasses[$oid])) {
+ $driverClasses[$oid] = $driver->getAllClassNames();
+ }
+
+ foreach ($driverClasses[$oid] AS $className) {
+ if (strpos($className, $namespace) === 0) {
+ $classNames[$className] = true;
+ }
+ }
+ }
+
+ if (null !== $this->defaultDriver) {
+ foreach ($this->defaultDriver->getAllClassNames() as $className) {
+ $classNames[$className] = true;
+ }
+ }
+
+ return array_keys($classNames);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public function isTransient($className)
+ {
+ /* @var $driver MappingDriver */
+ foreach ($this->drivers AS $namespace => $driver) {
+ if (strpos($className, $namespace) === 0) {
+ return $driver->isTransient($className);
+ }
+ }
+
+ if ($this->defaultDriver !== null) {
+ return $this->defaultDriver->isTransient($className);
+ }
+
+ return true;
+ }
+}