symfony/src/Symfony/Component/HttpKernel/Kernel.php

<?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\HttpKernel;

use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
use Symfony\Component\DependencyInjection\Loader\IniFileLoader;
use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;
use Symfony\Component\DependencyInjection\Loader\ClosureLoader;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\Bundle\BundleInterface;
use Symfony\Component\HttpKernel\Config\FileLocator;
use Symfony\Component\HttpKernel\DependencyInjection\MergeExtensionConfigurationPass;
use Symfony\Component\Config\Loader\LoaderResolver;
use Symfony\Component\Config\Loader\DelegatingLoader;
use Symfony\Component\Config\ConfigCache;

/**
 * The Kernel is the heart of the Symfony system.
 *
 * It manages an environment made of bundles.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
abstract class Kernel implements KernelInterface
{
    protected $bundles;
    protected $bundleMap;
    protected $container;
    protected $rootDir;
    protected $environment;
    protected $debug;
    protected $booted;
    protected $name;
    protected $startTime;

    const VERSION = '2.0.0-DEV';

    /**
     * Constructor.
     *
     * @param string  $environment The environment
     * @param Boolean $debug       Whether to enable debugging or not
     */
    public function __construct($environment, $debug)
    {
        $this->environment = $environment;
        $this->debug = (Boolean) $debug;
        $this->booted = false;
        $this->rootDir = $this->getRootDir();
        $this->name = preg_replace('/[^a-zA-Z0-9_]+/', '', basename($this->rootDir));

        if ($this->debug) {
            ini_set('display_errors', 1);
            error_reporting(-1);

            $this->startTime = microtime(true);
        } else {
            ini_set('display_errors', 0);
        }
    }

    public function __clone()
    {
        if ($this->debug) {
            $this->startTime = microtime(true);
        }

        $this->booted = false;
        $this->container = null;
    }

    /**
     * Boots the current kernel.
     */
    public function boot()
    {
        if (true === $this->booted) {
            return;
        }

        // init bundles
        $this->initializeBundles();

        // init container
        $this->initializeContainer();

        foreach ($this->getBundles() as $bundle) {
            $bundle->setContainer($this->container);
            $bundle->boot();
        }

        $this->booted = true;
    }

    /**
     * Shutdowns the kernel.
     *
     * This method is mainly useful when doing functional testing.
     */
    public function shutdown()
    {
        $this->booted = false;

        foreach ($this->getBundles() as $bundle) {
            $bundle->shutdown();
            $bundle->setContainer(null);
        }

        $this->container = null;
    }

    /**
     * {@inheritdoc}
     */
    public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
    {
        if (false === $this->booted) {
            $this->boot();
        }

        return $this->getHttpKernel()->handle($request, $type, $catch);
    }

    /**
     * Gets a http kernel from the container
     *
     * @return HttpKernel
     */
    protected function getHttpKernel()
    {
        return $this->container->get('http_kernel');
    }

    /**
     * Gets the registered bundle instances.
     *
     * @return array An array of registered bundle instances
     */
    public function getBundles()
    {
        return $this->bundles;
    }

    /**
     * Checks if a given class name belongs to an active bundle.
     *
     * @param string $class A class name
     *
     * @return Boolean true if the class belongs to an active bundle, false otherwise
     */
    public function isClassInActiveBundle($class)
    {
        foreach ($this->getBundles() as $bundle) {
            if (0 === strpos($class, $bundle->getNamespace())) {
                return true;
            }
        }

        return false;
    }

    /**
     * Returns a bundle and optionally its descendants by its name.
     *
     * @param string  $name  Bundle name
     * @param Boolean $first Whether to return the first bundle only or together with its descendants
     *
     * @return BundleInterface|Array A BundleInterface instance or an array of BundleInterface instances if $first is false
     *
     * @throws \InvalidArgumentException when the bundle is not enabled
     */
    public function getBundle($name, $first = true)
    {
        if (!isset($this->bundleMap[$name])) {
            throw new \InvalidArgumentException(sprintf('Bundle "%s" does not exist or it is not enabled. Maybe you forgot to add it in the registerBundles() function of your %s.php file?', $name, get_class($this)));
        }

        if (true === $first) {
            return $this->bundleMap[$name][0];
        } elseif (false === $first) {
            return $this->bundleMap[$name];
        }
    }

    /**
     * Returns the file path for a given resource.
     *
     * A Resource can be a file or a directory.
     *
     * The resource name must follow the following pattern:
     *
     *     @<BundleName>/path/to/a/file.something
     *
     * where BundleName is the name of the bundle
     * and the remaining part is the relative path in the bundle.
     *
     * If $dir is passed, and the first segment of the path is "Resources",
     * this method will look for a file named:
     *
     *     $dir/<BundleName>/path/without/Resources
     *
     * before looking in the bundle resource folder.
     *
     * @param string  $name  A resource name to locate
     * @param string  $dir   A directory where to look for the resource first
     * @param Boolean $first Whether to return the first path or paths for all matching bundles
     *
     * @return string|array The absolute path of the resource or an array if $first is false
     *
     * @throws \InvalidArgumentException if the file cannot be found or the name is not valid
     * @throws \RuntimeException         if the name contains invalid/unsafe
     * @throws \RuntimeException         if a custom resource is hidden by a resource in a derived bundle
     */
    public function locateResource($name, $dir = null, $first = true)
    {
        if ('@' !== $name[0]) {
            throw new \InvalidArgumentException(sprintf('A resource name must start with @ ("%s" given).', $name));
        }

        if (false !== strpos($name, '..')) {
            throw new \RuntimeException(sprintf('File name "%s" contains invalid characters (..).', $name));
        }

        $name = substr($name, 1);
        list($bundleName, $path) = explode('/', $name, 2);

        $isResource = 0 === strpos($path, 'Resources') && null !== $dir;
        $overridePath = substr($path, 9);
        $resourceBundle = null;
        $bundles = $this->getBundle($bundleName, false);
        
        foreach ($bundles as $bundle) {
            if ($isResource && file_exists($file = $dir.'/'.$bundle->getName().$overridePath)) {
                if (null !== $resourceBundle) {
                    throw new \RuntimeException(sprintf('"%s" resource is hidden by a resource from the "%s" derived bundle. ' .
                        'Create a "%s" file to override the bundle resource.',
                        $file,
                        $resourceBundle,
                        $dir.'/'.$bundles[0]->getName().$overridePath
                    ));
                }

                if ($first) {
                    return $file;
                }
                $files[] = $file;
            }

            if (file_exists($file = $bundle->getPath().'/'.$path)) {
                if ($first && !$isResource) {
                    return $file;
                }
                $files[] = $file;
                $resourceBundle = $bundle->getName();
            }
        }

        if (count($files) > 0) {
            return $first && $isResource ? $files[0] : $files;
        }

        throw new \InvalidArgumentException(sprintf('Unable to find file "@%s".', $name));
    }

    /**
     * Gets the name of the kernel
     *
     * @return string The kernel name
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Gets the environment.
     *
     * @return string The current environment
     */
    public function getEnvironment()
    {
        return $this->environment;
    }

    /**
     * Checks if debug mode is enabled.
     *
     * @return Boolean true if debug mode is enabled, false otherwise
     */
    public function isDebug()
    {
        return $this->debug;
    }

    /**
     * Gets the application root dir.
     *
     * @return string The application root dir
     */
    public function getRootDir()
    {
        if (null === $this->rootDir) {
            $r = new \ReflectionObject($this);
            $this->rootDir = dirname($r->getFileName());
        }

        return $this->rootDir;
    }

    /**
     * Gets the current container.
     *
     * @return ContainerInterface A ContainerInterface instance
     */
    public function getContainer()
    {
        return $this->container;
    }

    /**
     * Gets the request start time (not available if debug is disabled).
     *
     * @return integer The request start timestamp
     */
    public function getStartTime()
    {
        return $this->debug ? $this->startTime : -INF;
    }

    /**
     * Gets the cache directory.
     *
     * @return string The cache directory
     */
    public function getCacheDir()
    {
        return $this->rootDir.'/cache/'.$this->environment;
    }

    /**
     * Gets the log directory.
     *
     * @return string The log directory
     */
    public function getLogDir()
    {
        return $this->rootDir.'/logs';
    }

    /**
     * Initializes the data structures related to the bundle management.
     *
     *  - the bundles property maps a bundle name to the bundle instance,
     *  - the bundleMap property maps a bundle name to the bundle inheritance hierarchy (most derived bundle first).
     *
     * @throws \LogicException if two bundles share a common name
     * @throws \LogicException if a bundle tries to extend a non-registered bundle
     * @throws \LogicException if two bundles extend the same ancestor
     */
    protected function initializeBundles()
    {
        // init bundles
        $this->bundles = array();
        $topMostBundles = array();
        $directChildren = array();

        foreach ($this->registerBundles() as $bundle) {
            $name = $bundle->getName();
            if (isset($this->bundles[$name])) {
                throw new \LogicException(sprintf('Trying to register two bundles with the same name "%s"', $name));
            }
            $this->bundles[$name] = $bundle;

            if ($parentName = $bundle->getParent()) {
                if (isset($directChildren[$parentName])) {
                    throw new \LogicException(sprintf('Bundle "%s" is directly extended by two bundles "%s" and "%s".', $parentName, $name, $directChildren[$parentName]));
                }
                $directChildren[$parentName] = $name;
            } else {
                $topMostBundles[$name] = $bundle;
            }
        }

        // look for orphans
        if (count($diff = array_values(array_diff(array_keys($directChildren), array_keys($this->bundles))))) {
            throw new \LogicException(sprintf('Bundle "%s" extends bundle "%s", which is not registered.', $directChildren[$diff[0]], $diff[0]));
        }

        // inheritance
        $this->bundleMap = array();
        foreach ($topMostBundles as $name => $bundle) {
            $bundleMap = array($bundle);
            $hierarchy = array($name);

            while (isset($directChildren[$name])) {
                $name = $directChildren[$name];
                array_unshift($bundleMap, $this->bundles[$name]);
                $hierarchy[] = $name;
            }

            foreach ($hierarchy as $bundle) {
                $this->bundleMap[$bundle] = $bundleMap;
                array_pop($bundleMap);
            }
        }

    }

    /**
     * Gets the container class.
     *
     * @return string The container class
     */
    protected function getContainerClass()
    {
        return $this->name.ucfirst($this->environment).($this->debug ? 'Debug' : '').'ProjectContainer';
    }

    /**
     * Initializes the service container.
     *
     * The cached version of the service container is used when fresh, otherwise the
     * container is built.
     */
    protected function initializeContainer()
    {
        $class = $this->getContainerClass();
        $cache = new ConfigCache($this->getCacheDir().'/'.$class.'.php', $this->debug);
        $fresh = true;
        if (!$cache->isFresh()) {
            $container = $this->buildContainer();
            $this->dumpContainer($cache, $container, $class);

            $fresh = false;
        }

        require_once $cache;

        $this->container = new $class();
        $this->container->set('kernel', $this);

        if (!$fresh && 'cli' !== php_sapi_name()) {
            $this->container->get('cache_warmer')->warmUp($this->container->getParameter('kernel.cache_dir'));
        }
    }

    /**
     * Returns the kernel parameters.
     *
     * @return array An array of kernel parameters
     */
    protected function getKernelParameters()
    {
        $bundles = array();
        foreach ($this->bundles as $name => $bundle) {
            $bundles[$name] = get_class($bundle);
        }

        return array_merge(
            array(
                'kernel.root_dir'        => $this->rootDir,
                'kernel.environment'     => $this->environment,
                'kernel.debug'           => $this->debug,
                'kernel.name'            => $this->name,
                'kernel.cache_dir'       => $this->getCacheDir(),
                'kernel.logs_dir'        => $this->getLogDir(),
                'kernel.bundles'         => $bundles,
                'kernel.charset'         => 'UTF-8',
                'kernel.container_class' => $this->getContainerClass(),
            ),
            $this->getEnvParameters()
        );
    }

    /**
     * Gets the environment parameters.
     *
     * Only the parameters starting with "SYMFONY__" are considered.
     *
     * @return array An array of parameters
     */
    protected function getEnvParameters()
    {
        $parameters = array();
        foreach ($_SERVER as $key => $value) {
            if ('SYMFONY__' === substr($key, 0, 9)) {
                $parameters[strtolower(str_replace('__', '.', substr($key, 9)))] = $value;
            }
        }

        return $parameters;
    }

    /**
     * Builds the service container.
     *
     * @return ContainerBuilder The compiled service container
     */
    protected function buildContainer()
    {
        $parameterBag = new ParameterBag($this->getKernelParameters());

        $container = new ContainerBuilder($parameterBag);
        $container->getCompilerPassConfig()->setMergePass(new MergeExtensionConfigurationPass());
        foreach ($this->bundles as $bundle) {
            $bundle->build($container);

            if ($this->debug) {
                $container->addObjectResource($bundle);
            }
        }
        $container->addObjectResource($this);

        if (null !== $cont = $this->registerContainerConfiguration($this->getContainerLoader($container))) {
            $container->merge($cont);
        }

        foreach (array('cache', 'logs') as $name) {
            $dir = $container->getParameter(sprintf('kernel.%s_dir', $name));
            if (!is_dir($dir)) {
                if (false === @mkdir($dir, 0777, true)) {
                    exit(sprintf("Unable to create the %s directory (%s)\n", $name, dirname($dir)));
                }
            } elseif (!is_writable($dir)) {
                exit(sprintf("Unable to write in the %s directory (%s)\n", $name, $dir));
            }
        }

        $container->compile();

        return $container;
    }

    /**
     * Dumps the service container to PHP code in the cache.
     *
     * @param ConfigCache       $cache      The config cache
     * @param ContainerBuilder  $container  The service container
     * @param string            $class      The name of the class to generate
     */
    protected function dumpContainer(ConfigCache $cache, ContainerBuilder $container, $class)
    {
        // cache the container
        $dumper = new PhpDumper($container);
        $content = $dumper->dump(array('class' => $class));
        if (!$this->debug) {
            $content = self::stripComments($content);
        }

        $cache->write($content, $container->getResources());
    }

    /**
     * Returns a loader for the container.
     *
     * @param ContainerInterface $container The service container
     *
     * @return DelegatingLoader The loader
     */
    protected function getContainerLoader(ContainerInterface $container)
    {
        $locator = new FileLocator($this);
        $resolver = new LoaderResolver(array(
            new XmlFileLoader($container, $locator),
            new YamlFileLoader($container, $locator),
            new IniFileLoader($container, $locator),
            new PhpFileLoader($container, $locator),
            new ClosureLoader($container, $locator),
        ));

        return new DelegatingLoader($resolver);
    }

    /**
     * Removes comments from a PHP source string.
     *
     * We don't use the PHP php_strip_whitespace() function
     * as we want the content to be readable and well-formatted.
     *
     * @param string $source A PHP string
     *
     * @return string The PHP string with the comments removed
     */
    static public function stripComments($source)
    {
        if (!function_exists('token_get_all')) {
            return $source;
        }

        $output = '';
        foreach (token_get_all($source) as $token) {
            if (is_string($token)) {
                $output .= $token;
            } elseif (!in_array($token[0], array(T_COMMENT, T_DOC_COMMENT))) {
                $output .= $token[1];
            }
        }

        // replace multiple new lines with a single newline
        $output = preg_replace(array('/\s+$/Sm', '/\n+/S'), "\n", $output);

        return $output;
    }

    public function serialize()
    {
        return serialize(array($this->environment, $this->debug));
    }

    public function unserialize($data)
    {
        list($environment, $debug) = unserialize($data);

        $this->__construct($environment, $debug);
    }
}