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<?php |
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/* |
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* This file is part of the circuit-breaker package |
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* |
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* Copyright (c) 2016 Guillaume Cavana |
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* |
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* For the full copyright and license information, please view the LICENSE |
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* file that was distributed with this source code. |
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* |
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* Feel free to edit as you please, and have fun. |
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* |
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* @author Guillaume Cavana <[email protected]> |
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*/ |
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namespace Eljam\CircuitBreaker; |
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use Doctrine\Common\Cache\ArrayCache; |
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use Doctrine\Common\Cache\Cache; |
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use Eljam\CircuitBreaker\Event\CircuitEvent; |
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use Eljam\CircuitBreaker\Event\CircuitEvents; |
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use Eljam\CircuitBreaker\Exception\CircuitOpenException; |
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use Eljam\CircuitBreaker\Handler\Handler; |
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use Eljam\CircuitBreaker\Handler\HandlerInterface; |
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use Eljam\CircuitBreaker\Util\Utils; |
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use Symfony\Component\EventDispatcher\EventDispatcher; |
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use Symfony\Component\EventDispatcher\EventDispatcherInterface; |
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use Symfony\Component\OptionsResolver\OptionsResolver; |
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/** |
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* Class Breaker. |
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*/ |
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class Breaker |
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{ |
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/** |
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* $cache. |
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* |
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* @var Cache |
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*/ |
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protected $store; |
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/** |
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* $config. |
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* |
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* @var array |
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*/ |
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protected $config; |
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/** |
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* $handler. |
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* |
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* @var HandlerInterface |
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*/ |
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protected $handler; |
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/** |
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* $dispatcher. |
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* |
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* @var EventDispatcherInterface |
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*/ |
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protected $dispatcher; |
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/** |
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* Constructor. |
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* |
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* @param string $name |
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* @param array $config |
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* @param Cache $store |
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* @param Handler $handler |
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* @param EventDispatcherInterface $dispatcher |
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*/ |
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public function __construct( |
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$name, |
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array $config = [], |
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Cache $store = null, |
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HandlerInterface $handler = null, |
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EventDispatcherInterface $dispatcher = null |
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) { |
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$resolver = new OptionsResolver(); |
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$resolver->setDefaults([ |
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'max_failure' => 5, |
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'reset_timeout' => 5, |
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'exclude_exceptions' => [], |
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'ignore_exceptions' => false, |
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]); |
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$resolver->setAllowedTypes('exclude_exceptions', 'array'); |
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$resolver->setAllowedTypes('max_failure', 'int'); |
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$resolver->setAllowedTypes('reset_timeout', 'int'); |
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$this->config = $resolver->resolve($config); |
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$this->store = null !== $store ? $store : (new ArrayCache()); |
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$this->handler = null !== $handler ? $handler($this->config) : new Handler($this->config); |
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$this->dispatcher = null !== $dispatcher ? $dispatcher : new EventDispatcher(); |
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$name = Utils::snakeCase($name); |
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$this->circuit = $this->loadCircuit($name); |
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} |
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/** |
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* protect. |
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* |
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* @param \Closure $closure |
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* @throw \Exception |
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* |
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* @return mixed |
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*/ |
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public function protect(\Closure $closure) |
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{ |
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try { |
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$result = null; |
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$circuitOpenException = null; |
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if ($this->isClosed($this->circuit) || $this->isHalfOpen($this->circuit)) { |
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$result = $closure(); |
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$this->success($this->circuit); |
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} elseif ($this->isOpen($this->circuit)) { |
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$circuitOpenException = new CircuitOpenException(); |
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} |
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} catch (\Exception $e) { |
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$this->failure($this->circuit); |
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if (!$this->config['ignore_exceptions']) { |
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if (!in_array(get_class($e), $this->config['exclude_exceptions'])) { |
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$result = $e; |
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} |
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} |
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} |
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// Throw circuit exception when it is opened |
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if (null !== $circuitOpenException) { |
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throw $circuitOpenException; |
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} |
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//Throw closure exception |
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if ($result instanceof \Exception) { |
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throw $result; |
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} |
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return $result; |
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} |
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/** |
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* addListener. |
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* |
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* @param string $eventName |
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* @param \Closure|array $listener |
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*/ |
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public function addListener($eventName, $listener) |
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{ |
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$this->dispatcher->addListener($eventName, $listener); |
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} |
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/** |
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* isClosed. |
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* |
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* @param Circuit $circuit |
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* |
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* @return bool |
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*/ |
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View Code Duplication |
protected function isClosed($circuit) |
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{ |
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if ($this->handler->isClosed($circuit)) { |
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$this->dispatcher->dispatch(CircuitEvents::CLOSED, (new CircuitEvent($circuit))); |
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return true; |
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} |
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return; |
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} |
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/** |
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* isOpen. |
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* |
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* @param Circuit $circuit |
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* |
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* @return bool |
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*/ |
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View Code Duplication |
protected function isOpen($circuit) |
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{ |
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if ($this->handler->isOpen($circuit)) { |
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$this->dispatcher->dispatch(CircuitEvents::OPEN, (new CircuitEvent($circuit))); |
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return true; |
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} |
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return; |
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} |
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/** |
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* isHalfOpen. |
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* |
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* @param Circuit $circuit |
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* |
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* @return bool |
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*/ |
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View Code Duplication |
protected function isHalfOpen($circuit) |
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{ |
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if ($this->handler->isHalfOpen($circuit)) { |
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$this->dispatcher->dispatch(CircuitEvents::HALF_OPEN, (new CircuitEvent($circuit))); |
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return true; |
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} |
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return; |
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} |
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/** |
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* success. |
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* |
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* @param Circuit $circuit |
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*/ |
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protected function success($circuit) |
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{ |
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$circuit->resetFailture(); |
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$this->dispatcher->dispatch(CircuitEvents::SUCCESS, (new CircuitEvent($circuit))); |
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$this->writeToStore($circuit); |
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} |
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/** |
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* failure. |
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* |
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* @param Circuit $circuit |
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*/ |
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protected function failure(Circuit $circuit) |
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{ |
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$circuit->incrementFailure(); |
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$circuit->setLastFailure(time()); |
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$this->dispatcher->dispatch(CircuitEvents::FAILURE, (new CircuitEvent($circuit))); |
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$this->writeToStore($circuit); |
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} |
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/** |
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* loadCircuit. |
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* |
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* @param string $name |
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* |
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* @return Circuit |
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*/ |
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protected function loadCircuit($name) |
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{ |
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if ($this->store->contains($name)) { |
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$circuit = $this->store->fetch($name); |
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} else { |
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$circuit = new Circuit($name); |
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} |
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$this->writeToStore($circuit); |
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return $circuit; |
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} |
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protected function writeToStore(Circuit $circuit) |
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{ |
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$this->store->save($circuit->getName(), $circuit); |
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} |
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} |
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In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: