Dispatcher - Code Metrics - Inspection of "Added helper method for removing complexity in Dis..." - tomaj/hermes - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 1f2f1a...d37772 )

by Tomas

created 2021-01-12 08:53 UTC

Dispatcher A

↳ Parent: Project

Complexity

Total Complexity

Size/Duplication

Total Lines	278
Duplicated Lines	7.91 %

Coupling/Cohesion

Components	1
Dependencies	8

Test Coverage

Coverage

95.83%

Importance

Changes

Metric	Value
wmc	34
lcom	1
cbo	8
dl	22
loc	278
ccs	69
cts	72
cp	0.9583
rs	9.68
c	0
b	0
f	0

12 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	13	3
A	emit()	11	11	1
B	handle()	0	26	6
A	dispatch()	0	20	5
A	handleMessage()	0	31	5
A	retryMessage()	0	10	4
A	nextRetry()	0	4	1
A	hasHandlers()	0	4	2
A	registerHandler()	0	9	2
A	registerHandlers()	0	7	2
A	messageLoggerContext()	11	11	1
A	log()	0	6	2

How to fix Duplicated Code

<?php
declare(strict_types=1);

namespace Tomaj\Hermes;

use DateTime;
use Exception;
use Psr\Log\LogLevel;
use Psr\Log\LoggerInterface;
use Tomaj\Hermes\Driver\DriverInterface;
use Tomaj\Hermes\Driver\RestartTrait;
use Tomaj\Hermes\Handler\HandlerInterface;
use Tomaj\Hermes\Restart\RestartException;
use Tomaj\Hermes\Restart\RestartInterface;
use Tracy\Debugger;

class Dispatcher implements DispatcherInterface
{
    /**
     * Dispatcher driver
     *
     * @var DriverInterface
     */
    private $driver;

    /**
     * Logger
     *
     * @var LoggerInterface
     */
    private $logger;

    /**
     * Restart
     *
     * @var RestartInterface
     */
    private $restart;

    /**
     * All registered handlers
     *
     * @var HandlerInterface[][]
     */
    private $handlers = [];

    /**
     * @var DateTime
     */
    private $startTime;

    /**
     * Create new Dispatcher
     *
     * @param DriverInterface $driver
     * @param LoggerInterface|null $logger
     * @param RestartInterface|null $restart
     */
    public function __construct(DriverInterface $driver, LoggerInterface $logger = null, RestartInterface $restart = null)
    {
        $this->driver = $driver;
        $this->logger = $logger;
        $this->restart = $restart;
        $this->startTime = new DateTime();


        // check if driver use RestartTrait
        if ($restart && method_exists($this->driver, 'setRestart')) {
            $this->driver->setRestart($restart);
interface User
{
    /** @return string */
    public function getPassword();
}

class MyUser implements User
{
    public function getPassword()
    {
        // return something
    }

    public function getDisplayName()
    {
        // return some name.
    }
}

class AuthSystem
{
    public function authenticate(User $user)
    {
        $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName()));
        // do something.
    }
}
        }
    }

    /**
     * @param MessageInterface $message
     * @return DispatcherInterface
     * @deprecated - use Emitter::emit method instead
     */
    public function emit(MessageInterface $message): DispatcherInterface

    {
        $this->driver->send($message);

        $this->log(
            LogLevel::INFO,
            "Dispatcher send message #{$message->getId()} to driver " . get_class($this->driver),
            $this->messageLoggerContext($message)
        );
        return $this;
    }

    /**
     * Basic method for background job to star listening.
     *
     * This method hook to driver wait() method and start listening events.
     * Method is blocking, so when you call it all processing will stop.
     * WARNING! Don't use it on web server calls. Run it only with cli.
     *
     * @return void
     */
    public function handle(): void
    {
        try {
            $this->driver->wait(function (MessageInterface $message) {
                $this->log(
                    LogLevel::INFO,
                    "Start handle message #{$message->getId()} ({$message->getType()})",
                    $this->messageLoggerContext($message)
                );

                $result = $this->dispatch($message);

                if ($this->restart !== null && $this->restart->shouldRestart($this->startTime)) {
                    throw new RestartException('Restart');
                }

                return $result;
            });
        } catch (RestartException $e) {
            $this->log(LogLevel::NOTICE, 'Exiting hermes dispatcher - restart');
        } catch (Exception $exception) {
            if (Debugger::isEnabled()) {
                Debugger::log($exception, Debugger::EXCEPTION);
            }
        }
    }

    /**
     * Dispatch message
     *
     * @param MessageInterface $message
     *
     * @return bool
     */
    private function dispatch(MessageInterface $message): bool
    {
        $type = $message->getType();

        if (!$this->hasHandlers($type)) {
            return true;
        }

        $result = true;

        foreach ($this->handlers[$type] as $handler) {
            $handlerResult = $this->handleMessage($handler, $message);

            if ($result && !$handlerResult) {
                $result = false;
            }
        }

        return $result;
    }

    /**
     * Handle given message with given handler
     *
     * @param HandlerInterface $handler
     * @param MessageInterface $message
     *
     * @return bool
     */
    private function handleMessage(HandlerInterface $handler, MessageInterface $message): bool
    {
        // check if handler implements Psr\Log\LoggerAwareInterface (you can use \Psr\Log\LoggerAwareTrait)
        if ($this->logger !== null && method_exists($handler, 'setLogger')) {
            $handler->setLogger($this->logger);

        }

        try {
            $result = $handler->handle($message);

            $this->log(
                LogLevel::INFO,
                "End handle message #{$message->getId()} ({$message->getType()})",
                $this->messageLoggerContext($message)
            );
        } catch (Exception $e) {
            $this->log(
                LogLevel::ERROR,
                "Handler " . get_class($handler) . " throws exception - {$e->getMessage()}",
                ['error' => $e, 'message' => $this->messageLoggerContext($message), 'exception' => $e]
            );
            if (Debugger::isEnabled()) {
                Debugger::log($e, Debugger::EXCEPTION);
            }

            $this->retryMessage($message, $handler);

            $result = false;
        }
        return $result;
    }

    /**
     * Helper function for sending retrying message back to driver
     *
     * @param MessageInterface $message
     * @param HandlerInterface $handler
     */
    private function retryMessage(MessageInterface $message, HandlerInterface $handler): void
    {
        if (method_exists($handler, 'canRetry') && method_exists($handler, 'maxRetry')) {
            if ($message->getRetries() < $handler->maxRetry()) {
                $executeAt = $this->nextRetry($message);
                $newMessage = new Message($message->getType(), $message->getPayload(), $message->getId(), $message->getCreated(), $executeAt, $message->getRetries() + 1);
                $this->driver->send($newMessage);
            }
        }
    }

    /**
     * Calculate next retry
     *
     * Inspired by ruby sidekiq (https://github.com/mperham/sidekiq/wiki/Error-Handling#automatic-job-retry)
     *
     * @param MessageInterface $message
     * @return float
     */
    private function nextRetry(MessageInterface $message): float
    {
        return microtime(true) + pow($message->getRetries(), 4) + 15 + (rand(1, 30) * ($message->getRetries() + 1));
    }

    /**
     * Check if actual dispatcher has handler for given type
     *
     * @param string $type
     *
     * @return bool
     */
    private function hasHandlers(string $type): bool
    {
        return isset($this->handlers[$type]) && count($this->handlers[$type]) > 0;
    }

    /**
     * {@inheritdoc}
     */
    public function registerHandler(string $type, HandlerInterface $handler): DispatcherInterface
    {
        if (!isset($this->handlers[$type])) {
            $this->handlers[$type] = [];
        }

        $this->handlers[$type][] = $handler;
        return $this;
    }

    /**
     * {@inheritdoc}
     */
    public function registerHandlers(string $type, array $handlers): DispatcherInterface
    {
        foreach ($handlers as $handler) {
            $this->registerHandler($type, $handler);
        }
        return $this;
    }

    /**
     * Serialize message to logger context
     *
     * @param MessageInterface $message
     *
     * @return array
     */
    private function messageLoggerContext(MessageInterface $message): array

    {
        return [
            'id' => $message->getId(),
            'created' => $message->getCreated(),
            'type' => $message->getType(),
            'payload' => $message->getPayload(),
            'retries' => $message->getRetries(),
            'execute_at' => $message->getExecuteAt(),
        ];
    }

    /**
     * Interal log method wrapper
     *
     * @param mixed $level
     * @param string $message
     * @param array $context
     *
     * @return void
     */
    private function log($level, string $message, array $context = array()): void
    {
        if ($this->logger !== null) {
            $this->logger->log($level, $message, $context);
        }
    }
}


1			<?php
2			declare(strict_types=1);
3
4			namespace Tomaj\Hermes;
5
6			use DateTime;
7			use Exception;
8			use Psr\Log\LogLevel;
9			use Psr\Log\LoggerInterface;
10			use Tomaj\Hermes\Driver\DriverInterface;
11			use Tomaj\Hermes\Driver\RestartTrait;
12			use Tomaj\Hermes\Handler\HandlerInterface;
13			use Tomaj\Hermes\Restart\RestartException;
14			use Tomaj\Hermes\Restart\RestartInterface;
15			use Tracy\Debugger;
16
17			class Dispatcher implements DispatcherInterface
18			{
19			/**
20			* Dispatcher driver
21			*
22			* @var DriverInterface
23			*/
24			private $driver;
25
26			/**
27			* Logger
28			*
29			* @var LoggerInterface
30			*/
31			private $logger;
32
33			/**
34			* Restart
35			*
36			* @var RestartInterface
37			*/
38			private $restart;
39
40			/**
41			* All registered handlers
42			*
43			* @var HandlerInterface[][]
44			*/
45			private $handlers = [];
46
47			/**
48			* @var DateTime
49			*/
50			private $startTime;
51
52			/**
53			* Create new Dispatcher
54			*
55			* @param DriverInterface $driver
56			* @param LoggerInterface\|null $logger
57	18		* @param RestartInterface\|null $restart
58			*/
59	18		public function __construct(DriverInterface $driver, LoggerInterface $logger = null, RestartInterface $restart = null)
60	18		{
61	18		$this->driver = $driver;
62	18		$this->logger = $logger;
63	18		$this->restart = $restart;
64			$this->startTime = new DateTime();
65
66
67			// check if driver use RestartTrait
68			if ($restart && method_exists($this->driver, 'setRestart')) {
69			$this->driver->setRestart($restart);
			0 ignored issues – show Bug introduced 2020-10-20 20:32 UTC by Report Bug Copy Issue Report It seems like you code against a concrete implementation and not the interface `Tomaj\Hermes\Driver\DriverInterface` as the method `setRestart()` does only exist in the following implementations of said interface: `Tomaj\Hermes\Driver\AmazonSqsDriver`, `Tomaj\Hermes\Driver\LazyRabbitMqDriver`, `Tomaj\Hermes\Driver\RedisSetDriver`. Let’s take a look at an example: interface User { /** @return string / public function getPassword(); } class MyUser implements User { public function getPassword() { // return something } public function getDisplayName() { // return some name. } } class AuthSystem { public function authenticate(User $user) { $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName())); // do something. } } In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break. Available Fixes Change the type-hint for the parameter: class AuthSystem { public function authenticate(MyUser $user) { / ... / } } Add an additional type-check: class AuthSystem { public function authenticate(User $user) { if ($user instanceof MyUser) { $this->logger->info(/* ... /); } // or alternatively if ( ! $user instanceof MyUser) { throw new \LogicException( '$user must be an instance of MyUser, ' .'other instances are not supported.' ); } } } Note:* PHP Analyzer uses reverse abstract interpretation to narrow down the types inside the if block in such a case. Add the method to the interface: interface User { /** @return string / public function getPassword(); /* @return string */ public function getDisplayName(); } Loading history...
70			}
71			}
72
73			/**
74			* @param MessageInterface $message
75			* @return DispatcherInterface
76			* @deprecated - use Emitter::emit method instead
77			*/
78		View Code Duplication	public function emit(MessageInterface $message): DispatcherInterface
			0 ignored issues – show Duplication introduced 2018-11-30 13:41 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
79			{
80			$this->driver->send($message);
81
82			$this->log(
83			LogLevel::INFO,
84			"Dispatcher send message #{$message->getId()} to driver " . get_class($this->driver),
85			$this->messageLoggerContext($message)
86			);
87			return $this;
88			}
89
90			/**
91			* Basic method for background job to star listening.
92	18		*
93	18		* This method hook to driver wait() method and start listening events.
94	18		* Method is blocking, so when you call it all processing will stop.
95	18		* WARNING! Don't use it on web server calls. Run it only with cli.
96	18		*
97	12		* @return void
98			*/
99	18		public function handle(): void
100			{
101	18		try {
102	3		$this->driver->wait(function (MessageInterface $message) {
103			$this->log(
104			LogLevel::INFO,
105	15		"Start handle message #{$message->getId()} ({$message->getType()})",
106	18		$this->messageLoggerContext($message)
107	13		);
108	3
109	2		$result = $this->dispatch($message);
110
111			if ($this->restart !== null && $this->restart->shouldRestart($this->startTime)) {
112	18		throw new RestartException('Restart');
113			}
114
115			return $result;
116			});
117			} catch (RestartException $e) {
118			$this->log(LogLevel::NOTICE, 'Exiting hermes dispatcher - restart');
119			} catch (Exception $exception) {
120			if (Debugger::isEnabled()) {
121	18		Debugger::log($exception, Debugger::EXCEPTION);
122			}
123	18		}
124			}
125	18
126	6		/**
127			* Dispatch message
128			*
129	15		* @param MessageInterface $message
130			*
131	15		* @return bool
132	15		*/
133			private function dispatch(MessageInterface $message): bool
134	15		{
135	6		$type = $message->getType();
136	4
137	10		if (!$this->hasHandlers($type)) {
138			return true;
139	15		}
140
141			$result = true;
142
143			foreach ($this->handlers[$type] as $handler) {
144			$handlerResult = $this->handleMessage($handler, $message);
145
146			if ($result && !$handlerResult) {
147			$result = false;
148			}
149			}
150	15
151			return $result;
152			}
153	15
154			/**
155			* Handle given message with given handler
156			*
157			* @param HandlerInterface $handler
158	15		* @param MessageInterface $message
159			*
160	12		* @return bool
161	12		*/
162	12		private function handleMessage(HandlerInterface $handler, MessageInterface $message): bool
163	12		{
164	8		// check if handler implements Psr\Log\LoggerAwareInterface (you can use \Psr\Log\LoggerAwareTrait)
165	11		if ($this->logger !== null && method_exists($handler, 'setLogger')) {
166	3		$handler->setLogger($this->logger);
			0 ignored issues – show Bug introduced 2016-03-23 14:13 UTC by Report Bug Copy Issue Report The method `setLogger()` does not seem to exist on `object<Tomaj\Hermes\Handler\HandlerInterface>`. This check looks for calls to methods that do not seem to exist on a given type. It looks for the method on the type itself as well as in inherited classes or implemented interfaces. This is most likely a typographical error or the method has been renamed. Loading history...
167	3		}
168	3
169	3		try {
170	2		$result = $handler->handle($message);
171	3
172	3		$this->log(
173			LogLevel::INFO,
174	15		"End handle message #{$message->getId()} ({$message->getType()})",
175			$this->messageLoggerContext($message)
176			);
177			} catch (Exception $e) {
178			$this->log(
179			LogLevel::ERROR,
180			"Handler " . get_class($handler) . " throws exception - {$e->getMessage()}",
181			['error' => $e, 'message' => $this->messageLoggerContext($message), 'exception' => $e]
182			);
183			if (Debugger::isEnabled()) {
184	18		Debugger::log($e, Debugger::EXCEPTION);
185			}
186	18
187			$this->retryMessage($message, $handler);
188
189			$result = false;
190			}
191			return $result;
192	18		}
193
194	18		/**
195	18		* Helper function for sending retrying message back to driver
196	12		*
197			* @param MessageInterface $message
198	18		* @param HandlerInterface $handler
199	18		*/
200			private function retryMessage(MessageInterface $message, HandlerInterface $handler): void
201			{
202			if (method_exists($handler, 'canRetry') && method_exists($handler, 'maxRetry')) {
203			if ($message->getRetries() < $handler->maxRetry()) {
204			$executeAt = $this->nextRetry($message);
205			$newMessage = new Message($message->getType(), $message->getPayload(), $message->getId(), $message->getCreated(), $executeAt, $message->getRetries() + 1);
206			$this->driver->send($newMessage);
207			}
208	18		}
209			}
210
211	18		/**
212	18		* Calculate next retry
213	18		*
214	18		* Inspired by ruby sidekiq (https://github.com/mperham/sidekiq/wiki/Error-Handling#automatic-job-retry)
215	12		*
216			* @param MessageInterface $message
217			* @return float
218			*/
219			private function nextRetry(MessageInterface $message): float
220			{
221			return microtime(true) + pow($message->getRetries(), 4) + 15 + (rand(1, 30) * ($message->getRetries() + 1));
222			}
223
224			/**
225			* Check if actual dispatcher has handler for given type
226			*
227	18		* @param string $type
228			*
229	18		* @return bool
230	3		*/
231	2		private function hasHandlers(string $type): bool
232	18		{
233			return isset($this->handlers[$type]) && count($this->handlers[$type]) > 0;
234			}
235
236			/**
237			* {@inheritdoc}
238			*/
239			public function registerHandler(string $type, HandlerInterface $handler): DispatcherInterface
240			{
241			if (!isset($this->handlers[$type])) {
242			$this->handlers[$type] = [];
243			}
244
245			$this->handlers[$type][] = $handler;
246			return $this;
247			}
248
249			/**
250			* {@inheritdoc}
251			*/
252			public function registerHandlers(string $type, array $handlers): DispatcherInterface
253			{
254			foreach ($handlers as $handler) {
255			$this->registerHandler($type, $handler);
256			}
257			return $this;
258			}
259
260			/**
261			* Serialize message to logger context
262			*
263			* @param MessageInterface $message
264			*
265			* @return array
266			*/
267		View Code Duplication	private function messageLoggerContext(MessageInterface $message): array
			0 ignored issues – show Duplication introduced 2018-11-30 13:41 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
268			{
269			return [
270			'id' => $message->getId(),
271			'created' => $message->getCreated(),
272			'type' => $message->getType(),
273			'payload' => $message->getPayload(),
274			'retries' => $message->getRetries(),
275			'execute_at' => $message->getExecuteAt(),
276			];
277			}
278
279			/**
280			* Interal log method wrapper
281			*
282			* @param mixed $level
283			* @param string $message
284			* @param array $context
285			*
286			* @return void
287			*/
288			private function log($level, string $message, array $context = array()): void
289			{
290			if ($this->logger !== null) {
291			$this->logger->log($level, $message, $context);
292			}
293			}
294			}
295

tomaj / hermes

Push — master ( 1f2f1a...d37772 )

Dispatcher A

Complexity

Size/Duplication

Coupling/Cohesion

Test Coverage

Importance

12 Methods

How to fix Duplicated Code

Duplicated Code

Available Fixes

Duplication Side-by-Side

Filter issues like