FOSHttpCacheExtension - Code Metrics - Inspection of "Add query string matching" - FriendsOfSymfony/FOSHttpCacheBundle - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#376)

by Geoffrey

created 2017-08-17 07:37 UTC

FOSHttpCacheExtension D

↳ Parent: Project

Complexity

Total Complexity

Size/Duplication

Total Lines	529
Duplicated Lines	2.27 %

Coupling/Cohesion

Components	1
Dependencies	10

Test Coverage

Coverage

90.37%

Importance

Changes

Metric	Value
wmc	86
c	0
b	0
f	0
lcom	1
cbo	10
dl	12
loc	529
ccs	244
cts	270
cp	0.9037
rs	4.8717

24 Methods

Rating	Name	Duplication	Size	Complexity
A	loadCacheControl()	0	14	3
A	getConfiguration()	0	4	1
F	load()	0	93	21
A	loadCacheable()	0	15	2
A	parseRuleMatcher()	0	20	2
B	loadProxyClient()	0	20	5
B	createHttpDispatcherDefinition()	0	24	4
A	loadVarnish()	0	16	3
A	loadNginx()	0	8	1
A	loadSymfony()	0	5	1
B	loadCacheTagging()	0	27	6
A	loadTest()	0	8	2
A	loadProxyServer()	0	15	3
A	loadVarnishProxyServer()	0	10	2
A	loadNginxProxyServer()	0	10	2
A	loadTagRules()	0	15	2
A	loadInvalidatorRules()	0	9	2
A	validateUrl()	0	8	2
A	prefixSchema()	0	8	2
B	getDefaultProxyClient()	0	24	6
A	createChildDefinition()	0	8	2
B	parseRequestMatcher()	0	27	4
B	parseResponseMatcher()	12	24	5
B	loadUserContext()	0	34	3

How to fix Duplicated Code Complexity

Duplicated Code

Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.

Common duplication problems, and corresponding solutions are:

If you have the same expression in different places: Extract expression to a method
If you have the same method in different sub-classes: Extract method, and pull up field to the parent class
If you have the same code in unrelated classes: Consider extracting the code to a new class, and injecting that class

Complex Class

Tip: Before tackling complexity, make sure that you eliminate any duplication first. This often can reduce the size of classes significantly.

Complex classes like FOSHttpCacheExtension often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

While breaking up the class, it is a good idea to analyze how other classes use FOSHttpCacheExtension, and based on these observations, apply Extract Interface, too.

<?php

/*
 * This file is part of the FOSHttpCacheBundle package.
 *
 * (c) FriendsOfSymfony <http://friendsofsymfony.github.com/>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace FOS\HttpCacheBundle\DependencyInjection;

use FOS\HttpCache\ProxyClient\HttpDispatcher;
use FOS\HttpCacheBundle\DependencyInjection\Compiler\HashGeneratorPass;
use FOS\HttpCacheBundle\Http\ResponseMatcher\ExpressionResponseMatcher;
use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ChildDefinition;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Definition;
use Symfony\Component\DependencyInjection\DefinitionDecorator;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\DependencyInjection\Reference;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\Routing\Generator\UrlGeneratorInterface;

/**
 * {@inheritdoc}
 */
class FOSHttpCacheExtension extends Extension
{
    /**
     * {@inheritdoc}
     */
    public function getConfiguration(array $config, ContainerBuilder $container)
    {
        return new Configuration($container->getParameter('kernel.debug'));
    }

    /**
     * {@inheritdoc}
     */
    public function load(array $configs, ContainerBuilder $container)
    {
        $configuration = $this->getConfiguration($configs, $container);
        $config = $this->processConfiguration($configuration, $configs);
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}

        $loader = new XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
        $loader->load('matcher.xml');

        if ($config['debug']['enabled'] || (!empty($config['cache_control']))) {
            $debugHeader = $config['debug']['enabled'] ? $config['debug']['header'] : false;
            $container->setParameter($this->getAlias().'.debug_header', $debugHeader);
            $loader->load('cache_control_listener.xml');
        }

        $this->loadCacheable($container, $config['cacheable']);

        if (!empty($config['cache_control'])) {
            $this->loadCacheControl($container, $config['cache_control']);
        }

        if (isset($config['proxy_client'])) {
            $this->loadProxyClient($container, $loader, $config['proxy_client']);
        }

        if (isset($config['test'])) {
            $this->loadTest($container, $loader, $config['test']);
        }

        if ($config['cache_manager']['enabled']) {
            if (array_key_exists('custom_proxy_client', $config['cache_manager'])) {
                // overwrite the previously set alias, if a proxy client was also configured
                $container->setAlias(
                    $this->getAlias().'.default_proxy_client',
                    $config['cache_manager']['custom_proxy_client']
                );
            }
            if ('auto' === $config['cache_manager']['generate_url_type']) {
                if (array_key_exists('custom_proxy_client', $config['cache_manager'])) {
                    $generateUrlType = UrlGeneratorInterface::ABSOLUTE_URL;
                } else {
                    $defaultClient = $this->getDefaultProxyClient($config['proxy_client']);
                    if ($defaultClient !== 'noop'
                        && array_key_exists('base_url', $config['proxy_client'][$defaultClient])) {
                        $generateUrlType = UrlGeneratorInterface::ABSOLUTE_PATH;
                    } else {
                        $generateUrlType = UrlGeneratorInterface::ABSOLUTE_URL;
                    }
                }
            } else {
                $generateUrlType = $config['cache_manager']['generate_url_type'];
            }
            $container->setParameter($this->getAlias().'.cache_manager.generate_url_type', $generateUrlType);
            $loader->load('cache_manager.xml');
        }

        if ($config['tags']['enabled']) {
            $this->loadCacheTagging(
                $container,
                $loader,
                $config['tags'],
                array_key_exists('proxy_client', $config)
                    ? $this->getDefaultProxyClient($config['proxy_client'])
                    : 'custom'
            );
        } else {
            $container->setParameter($this->getAlias().'.compiler_pass.tag_annotations', false);
        }

        if ($config['invalidation']['enabled']) {
            $loader->load('invalidation_listener.xml');

            if (!empty($config['invalidation']['expression_language'])) {
                $container->setAlias(
                    $this->getAlias().'.invalidation.expression_language',
                    $config['invalidation']['expression_language']
                );
            }

            if (!empty($config['invalidation']['rules'])) {
                $this->loadInvalidatorRules($container, $config['invalidation']['rules']);
            }
        }

        if ($config['user_context']['enabled']) {
            $this->loadUserContext($container, $loader, $config['user_context']);
        }

        if (!empty($config['flash_message']) && $config['flash_message']['enabled']) {
            $container->setParameter($this->getAlias().'.event_listener.flash_message.options', $config['flash_message']);

            $loader->load('flash_message.xml');
        }
    }

    private function loadCacheable(ContainerBuilder $container, array $config)
    {
        $definition = $container->getDefinition($this->getAlias().'.response_matcher.cacheable');

        // Change CacheableResponseMatcher to ExpressionResponseMatcher
        if ($config['response']['expression']) {
            $definition->setClass(ExpressionResponseMatcher::class)
                ->setArguments([$config['response']['expression']]);
        } else {
            $container->setParameter(
                $this->getAlias().'.cacheable.response.additional_status',
                $config['response']['additional_status']
            );
        }
    }

    /**
     * @param ContainerBuilder $container
     * @param array            $config
     *
     * @throws InvalidConfigurationException
     */
    private function loadCacheControl(ContainerBuilder $container, array $config)
    {
        $controlDefinition = $container->getDefinition($this->getAlias().'.event_listener.cache_control');

        foreach ($config['rules'] as $rule) {
            $ruleMatcher = $this->parseRuleMatcher($container, $rule['match']);

            if ('default' === $rule['headers']['overwrite']) {
                $rule['headers']['overwrite'] = $config['defaults']['overwrite'];
            }

            $controlDefinition->addMethodCall('addRule', [$ruleMatcher, $rule['headers']]);
        }
    }

    /**
     * Parse one cache control rule match configuration.
     *
     * @param ContainerBuilder $container
     * @param array            $match     Request and response match criteria
     *
     * @return Reference pointing to a rule matcher service
     */
    private function parseRuleMatcher(ContainerBuilder $container, array $match)
    {
        $requestMatcher = $this->parseRequestMatcher($container, $match);
        $responseMatcher = $this->parseResponseMatcher($container, $match);

        $signature = serialize([(string) $requestMatcher, (string) $responseMatcher]);
        $id = $this->getAlias().'.cache_control.rule_matcher.'.md5($signature);

        if ($container->hasDefinition($id)) {
            throw new InvalidConfigurationException('Duplicate match criteria. Would be hidden by a previous rule. match: '.json_encode($match));
        }

        $container
            ->setDefinition($id, $this->createChildDefinition($this->getAlias().'.rule_matcher'))
            ->replaceArgument(0, $requestMatcher)
            ->replaceArgument(1, $responseMatcher)
        ;

        return new Reference($id);
    }

    /**
     * Used for cache control, tag and invalidation rules.
     *
     * @param ContainerBuilder $container
     * @param array            $match
     *
     * @return Reference to the request matcher
     */
    private function parseRequestMatcher(ContainerBuilder $container, array $match)
    {
        $match['ips'] = (empty($match['ips'])) ? null : $match['ips'];

        $arguments = [
            $match['path'],
            $match['host'],
            $match['methods'],
            $match['ips'],
            $match['attributes'],
        ];
        $serialized = serialize($arguments);
        $id = $this->getAlias().'.request_matcher.'.md5($serialized).sha1($serialized);

        if (!$container->hasDefinition($id)) {
            $container
                ->setDefinition($id, $this->createChildDefinition($this->getAlias().'.request_matcher'))
                ->setArguments($arguments)
            ;

            if (!empty($match['query_string'])) {
                $container->getDefinition($id)->addMethodCall('setQueryString', [$match['query_string']]);
            }
        }

        return new Reference($id);
    }

    /**
     * Used only for cache control rules.
     *
     * @param ContainerBuilder $container
     * @param array            $config
     *
     * @return Reference to the correct response matcher service
     */
    private function parseResponseMatcher(ContainerBuilder $container, array $config)
    {
        if (!empty($config['additional_response_status'])) {
            $id = $this->getAlias().'cache_control.expression.'.md5(serialize($config['additional_response_status']));
            if (!$container->hasDefinition($id)) {

                $container
                    ->setDefinition($id, $this->createChildDefinition($this->getAlias().'.response_matcher.cache_control.cacheable_response'))
                    ->setArguments([$config['additional_response_status']])
                ;
            }
        } elseif (!empty($config['match_response'])) {
            $id = $this->getAlias().'cache_control.match_response.'.md5($config['match_response']);
            if (!$container->hasDefinition($id)) {

                $container
                    ->setDefinition($id, $this->createChildDefinition($this->getAlias().'.response_matcher.cache_control.expression'))
                    ->replaceArgument(0, $config['match_response'])
                ;
            }
        } else {
            $id = $this->getAlias().'.response_matcher.cacheable';
        }

        return new Reference($id);
    }

    private function loadUserContext(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        $loader->load('user_context.xml');

        $container->getDefinition($this->getAlias().'.user_context.request_matcher')
            ->replaceArgument(0, $config['match']['accept'])
            ->replaceArgument(1, $config['match']['method']);

        $container->setParameter($this->getAlias().'.event_listener.user_context.options', [
            'user_identifier_headers' => $config['user_identifier_headers'],
            'user_hash_header' => $config['user_hash_header'],
            'ttl' => $config['hash_cache_ttl'],
            'add_vary_on_hash' => $config['always_vary_on_context_hash'],
        ]);
        $container->getDefinition($this->getAlias().'.event_listener.user_context')
            ->replaceArgument(0, new Reference($config['match']['matcher_service']));

        $container->getDefinition($this->getAlias().'.user_context.anonymous_request_matcher')
            ->replaceArgument(0, $config['user_identifier_headers']);

        if ($config['logout_handler']['enabled']) {
            $container->getDefinition($this->getAlias().'.user_context.logout_handler')
                ->replaceArgument(1, $config['user_identifier_headers'])
                ->replaceArgument(2, $config['match']['accept']);
        } else {
            $container->removeDefinition($this->getAlias().'.user_context.logout_handler');
        }

        if ($config['role_provider']) {
            $container->getDefinition($this->getAlias().'.user_context.role_provider')
                ->addTag(HashGeneratorPass::TAG_NAME)
                ->setAbstract(false);
        }
    }

    private function loadProxyClient(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        if (isset($config['varnish'])) {
            $this->loadVarnish($container, $loader, $config['varnish']);
        }
        if (isset($config['nginx'])) {
            $this->loadNginx($container, $loader, $config['nginx']);
        }
        if (isset($config['symfony'])) {
            $this->loadSymfony($container, $loader, $config['symfony']);
        }
        if (isset($config['noop'])) {
            $loader->load('noop.xml');
        }

        $container->setAlias(
            $this->getAlias().'.default_proxy_client',
            $this->getAlias().'.proxy_client.'.$this->getDefaultProxyClient($config)
        );
    }

    /**
     * Define the http dispatcher service for the proxy client $name.
     *
     * @param ContainerBuilder $container
     * @param array            $config
     * @param string           $serviceName
     */
    private function createHttpDispatcherDefinition(ContainerBuilder $container, array $config, $serviceName)
    {
        foreach ($config['servers'] as $url) {
            $this->validateUrl($url, 'Not a valid Varnish server address: "%s"');
        }
        if (!empty($config['base_url'])) {
            $baseUrl = $this->prefixSchema($config['base_url']);
            $this->validateUrl($baseUrl, 'Not a valid base path: "%s"');
        } else {
            $baseUrl = null;
        }
        $httpClient = null;
        if ($config['http_client']) {
            $httpClient = new Reference($config['http_client']);
        }

        $definition = new Definition(HttpDispatcher::class, [
            $config['servers'],
            $baseUrl,
            $httpClient,
        ]);

        $container->setDefinition($serviceName, $definition);
    }

    private function loadVarnish(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        $this->createHttpDispatcherDefinition($container, $config['http'], $this->getAlias().'.proxy_client.varnish.http_dispatcher');
        $options = [
            'tags_header' => $config['tags_header'],
        ];
        if (!empty($config['header_length'])) {
            $options['header_length'] = $config['header_length'];
        }
        if (!empty($config['default_ban_headers'])) {
            $options['default_ban_headers'] = $config['default_ban_headers'];
        }
        $container->setParameter($this->getAlias().'.proxy_client.varnish.options', $options);

        $loader->load('varnish.xml');
    }

    private function loadNginx(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        $this->createHttpDispatcherDefinition($container, $config['http'], $this->getAlias().'.proxy_client.nginx.http_dispatcher');
        $container->setParameter($this->getAlias().'.proxy_client.nginx.options', [
            'purge_location' => $config['purge_location'],
        ]);
        $loader->load('nginx.xml');
    }

    private function loadSymfony(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        $this->createHttpDispatcherDefinition($container, $config['http'], $this->getAlias().'.proxy_client.symfony.http_dispatcher');
        $loader->load('symfony.xml');
    }

    /**
     * @param ContainerBuilder $container
     * @param XmlFileLoader    $loader
     * @param array            $config    Configuration section for the tags node
     * @param string           $client    Name of the client used with the cache manager,
     *                                    "custom" when a custom client is used
     */
    private function loadCacheTagging(ContainerBuilder $container, XmlFileLoader $loader, array $config, $client)
    {
        if ('auto' === $config['enabled'] && 'varnish' !== $client) {
            $container->setParameter($this->getAlias().'.compiler_pass.tag_annotations', false);

            return;
        }
        if (!in_array($client, ['varnish', 'custom', 'noop'])) {
            throw new InvalidConfigurationException(sprintf('You can not enable cache tagging with the %s client', $client));
        }

        $container->setParameter($this->getAlias().'.compiler_pass.tag_annotations', true);
        $container->setParameter($this->getAlias().'.tag_handler.response_header', $config['response_header']);
        $container->setParameter($this->getAlias().'.tag_handler.strict', $config['strict']);
        $loader->load('cache_tagging.xml');

        if (!empty($config['expression_language'])) {
            $container->setAlias(
                $this->getAlias().'.tag_handler.expression_language',
                $config['expression_language']
            );
        }

        if (!empty($config['rules'])) {
            $this->loadTagRules($container, $config['rules']);
        }
    }

    private function loadTest(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        $container->setParameter($this->getAlias().'.test.cache_header', $config['cache_header']);

        if ($config['proxy_server']) {
            $this->loadProxyServer($container, $loader, $config['proxy_server']);
        }
    }

    private function loadProxyServer(ContainerBuilder $container, XmlFileLoader $loader, array $config)
    {
        if (isset($config['varnish'])) {
            $this->loadVarnishProxyServer($container, $loader, $config['varnish']);
        }

        if (isset($config['nginx'])) {
            $this->loadNginxProxyServer($container, $loader, $config['varnish']);
        }

        $container->setAlias(
            $this->getAlias().'.test.default_proxy_server',
            $this->getAlias().'.test.proxy_server.'.$this->getDefaultProxyClient($config)
        );
    }

    private function loadVarnishProxyServer(ContainerBuilder $container, XmlFileLoader $loader, $config)
    {
        $loader->load('varnish_proxy.xml');
        foreach ($config as $key => $value) {
            $container->setParameter(
                $this->getAlias().'.test.proxy_server.varnish.'.$key,
                $value
            );
        }
    }

    private function loadNginxProxyServer(ContainerBuilder $container, XmlFileLoader $loader, $config)
    {
        $loader->load('nginx_proxy.xml');
        foreach ($config as $key => $value) {
            $container->setParameter(
                $this->getAlias().'.test.proxy_server.nginx.'.$key,
                $value
            );
        }
    }

    private function loadTagRules(ContainerBuilder $container, array $config)
    {
        $tagDefinition = $container->getDefinition($this->getAlias().'.event_listener.tag');

        foreach ($config as $rule) {
            $ruleMatcher = $this->parseRequestMatcher($container, $rule['match']);

            $tags = [
                'tags' => $rule['tags'],
                'expressions' => $rule['tag_expressions'],
            ];

            $tagDefinition->addMethodCall('addRule', [$ruleMatcher, $tags]);
        }
    }

    private function loadInvalidatorRules(ContainerBuilder $container, array $config)
    {
        $tagDefinition = $container->getDefinition($this->getAlias().'.event_listener.invalidation');

        foreach ($config as $rule) {
            $ruleMatcher = $this->parseRequestMatcher($container, $rule['match']);
            $tagDefinition->addMethodCall('addRule', [$ruleMatcher, $rule['routes']]);
        }
    }

    private function validateUrl($url, $msg)
    {
        $prefixed = $this->prefixSchema($url);

        if (!$parts = parse_url($prefixed)) {
            throw new InvalidConfigurationException(sprintf($msg, $url));
        }
    }

    private function prefixSchema($url)
    {
        if (false === strpos($url, '://')) {
            $url = sprintf('%s://%s', 'http', $url);
        }

        return $url;
    }

    private function getDefaultProxyClient(array $config)
    {
        if (isset($config['default'])) {
            return $config['default'];
        }

        if (isset($config['varnish'])) {
            return 'varnish';
        }

        if (isset($config['nginx'])) {
            return 'nginx';
        }

        if (isset($config['symfony'])) {
            return 'symfony';
        }

        if (isset($config['noop'])) {
            return 'noop';
        }

        throw new InvalidConfigurationException('No proxy client configured');
    }

    /**
     * Build the child definition with fallback for Symfony versions < 3.3.
     *
     * @param string $id Id of the service to extend
     *
     * @return ChildDefinition|DefinitionDecorator
     */
    private function createChildDefinition($id)
    {
        if (class_exists(ChildDefinition::class)) {
            return new ChildDefinition($id);
        }

        return new DefinitionDecorator($id);

    }
}


FriendsOfSymfony / FOSHttpCacheBundle