Extracted business logic into Circuit breaker places

composer.json

@@ -51,7 +51,7 @@
         "psalm": "@php ./vendor/bin/psalm --threads=8 --diff --diff-methods",
         "cs-fix": "@php ./vendor/bin/php-cs-fixer fix",
         "test": "@php ./vendor/bin/phpunit",
-        "phpqa": "@php ./vendor/bin/phpqa --report --tools phpcs:0,phpmd:0,phpcpd:0,phpmetrics,phploc,pdepend,security-checker:0,parallel-lint:0 --ignoredDirs vendor"
+        "phpqa": "@php ./vendor/bin/phpqa --report --tools phpcs:0,phpmd:0,phpcpd:0,phpmetrics,phploc,pdepend,security-checker:0,parallel-lint:0 --ignoredDirs tests,vendor"
     },
     "scripts-descriptions": {
         "phpstan": "Execute PHPStan analysis",

psalm.xml.dist

@@ -43,6 +43,9 @@
             </errorLevel>
         </MixedAssignment>
 
+        <!-- Injection using setter (while not recommended) is perfectly valid! -->
+        <PropertyNotSetInConstructor errorLevel="suppress" />
+
         <!-- level 3 issues - slightly lazy code writing, but provably low false-negatives -->
 
         <DeprecatedMethod errorLevel="info" />
@@ -61,7 +64,6 @@
         <InvalidDocblock errorLevel="info" />
         <MisplacedRequiredParam errorLevel="info" />
 
-        <PropertyNotSetInConstructor errorLevel="info" />
         <MissingConstructor errorLevel="info" />
         <MissingClosureParamType errorLevel="info" />
         <MissingParamType errorLevel="info" />

src/Clients/GuzzleClient.php

@@ -2,10 +2,12 @@
 
 namespace Resiliency\Clients;
 
-use Exception;
 use GuzzleHttp\Client as OriginalGuzzleClient;
-use Resiliency\Contracts\Client;
 use Resiliency\Exceptions\UnavailableService;
+use Resiliency\Contracts\Service;
+use Resiliency\Contracts\Client;
+use Resiliency\Contracts\Place;
+use Exception;
 
 /**
  * Guzzle implementation of client.
@@ -26,14 +28,19 @@ public function __construct(array $mainOptions = [])
     /**
      * {@inheritdoc}
      */
-    public function request($resource, array $options): string
+    public function request(Service $service, Place $place): string
     {
+        $options = [];
         try {
             $client = new OriginalGuzzleClient($this->mainOptions);
-            $method = $this->defineMethod($options);
+            $method = $this->defineMethod($service->getParameters());
             $options['http_errors'] = true;
+            $options['connect_timeout'] = $place->getTimeout();
+            $options['timeout'] = $place->getTimeout();
+
+            $clientParameters = array_merge($service->getParameters(), $options);
 
-            return (string) $client->request($method, $resource, $options)->getBody();
+            return (string) $client->request($method, $service->getURI(), $clientParameters)->getBody();
         } catch (Exception $exception) {
             throw new UnavailableService($exception->getMessage());
         }

src/Contracts/CircuitBreaker.php

@@ -10,57 +10,59 @@
 interface CircuitBreaker
 {
     /**
-     * @return string the circuit breaker state
+     * @return Place the circuit breaker state
      */
-    public function getState(): string;
+    public function getState(): Place;
 
     /**
-     * The function that execute the service.
-     *
-     * @param string $service the service to call
-     * @param array $serviceParameters the service parameters
-     * @param callable $fallback if the service is unavailable, rely on the fallback
-     *
-     * @return string
+     * @return Storage the circuit breaker storage
      */
-    public function call(string $service, callable $fallback, array $serviceParameters = []): string;
+    public function getStorage(): Storage;
 
     /**
-     * @return bool checks if the circuit breaker is open
+     * @return TransitionDispatcher the circuit breaker dispatcher
      */
-    public function isOpened(): bool;
+    public function getDispatcher(): TransitionDispatcher;
 
     /**
-     * @return bool checks if the circuit breaker is half open
-     */
-    public function isHalfOpened(): bool;
-
-    /**
-     * @return bool checks if the circuit breaker is closed
-     */
-    public function isClosed(): bool;
-
-    /**
-     * @return bool checks if the circuit breaker is isolated
+     * The function that try to reach the uri.
+     *
+     * @param string $uri the uri to call
+     * @param array $uriParameters the uri parameters
+     * @param callable $fallback if the service is unavailable, rely on the fallback
+     *
+     * @throws Exception in case of failure, throws an exception
+     *
+     * @return string
      */
-    public function isIsolated(): bool;
+    public function call(string $uri, callable $fallback, array $uriParameters = []): string;
 
     /**
      * Manually open (and hold open) the Circuit Breaker
      * This can be used for example to take it offline for maintenance.
      *
-     * @param string $service the service to call
+     * @param string $serviceUri the service to call
      *
      * @return self
      */
-    public function isolate(string $service): self;
+    public function isolate(string $serviceUri): self;
 
     /**
      * Reset the breaker to closed state to start accepting actions again.
      *
-     * @param string $service the service to call
+     * @param string $serviceUri the service to call
+     *
+     * @return self
+     */
+    public function reset(string $serviceUri): self;
+
+    /**
+     * Update the circuit breaker state
+     *
+     * @param string $state the Place state
+     * @param Service $service the service
      *
      * @return self
      */
-    public function reset(string $service): self;
+    public function moveStateTo($state, Service $service): self;
 }

src/Contracts/Client.php

@@ -2,6 +2,8 @@
 
 namespace Resiliency\Contracts;
 
+use Resiliency\Exceptions\UnavailableService;
+
 /**
  * In charge of calling the resource and return a response.
  * Must throw UnavailableService exception if not reachable.
@@ -14,10 +16,12 @@ interface Client
     const DEFAULT_METHOD = 'GET';
 
     /**
-     * @param string $resource the URI of the service to be reached
-     * @param array $options the options if needed
+     * @param Service $service the Service
+     * @param Place $place the place
+     *
+     * @throws UnavailableService
      *
      * @return string
      */
-    public function request($resource, array $options): string;
+    public function request(Service $service, Place $place): string;
 }

src/Contracts/Exception.php

@@ -2,9 +2,11 @@
 
 namespace Resiliency\Contracts;
 
+use Throwable;
+
 /**
  * Define any Resiliency exception.
  */
-interface Exception
+interface Exception extends Throwable
 {
 }

src/Contracts/Place.php

@@ -3,14 +3,13 @@
 namespace Resiliency\Contracts;
 
 /**
- * A circuit breaker can be in 3 places:
- * closed, half open or open. Each place have its
- * own properties and behaviors.
+ * A circuit breaker can be in 4 places: closed, half open, open or isolated.
+ * Each place have its own properties and behaviors.
  */
 interface Place
 {
     /**
-     * Return the current state of the Circuit Breaker.
+     * Return the state.
      *
      * @return string
      */
@@ -30,4 +29,25 @@ public function getThreshold(): float;
      * @return float the allowed timeout
      */
     public function getTimeout(): float;
+
+    /**
+     * The function that execute the service.
+     *
+     * @param Transaction $transaction the service transaction
+     * @param callable $fallback if the service is unavailable, rely on the fallback
+     *
+     * @throws Exception in case of failure, throws an exception
+     *
+     * @return string
+     */
+    public function call(Transaction $transaction, callable $fallback): string;
+
+    /**
+     * Set the Circuit Breaker to the place.
+     *
+     * @param CircuitBreaker $circuitBreaker the circuit breaker
+     *
+     * @return self
+     */
+    public function setCircuitBreaker(CircuitBreaker $circuitBreaker): self;
 }

src/Contracts/Service.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Resiliency\Contracts;
+
+/**
+ * Describe what is a service for the Resiliency library.
+ */
+interface Service
+{
+    /**
+     * @return string the URI we try to reach
+     */
+    public function getURI(): string;
+
+    /**
+     * @return array the URI parameters
+     */
+    public function getParameters(): array;
+}

src/Contracts/Transaction.php

@@ -11,9 +11,9 @@
 interface Transaction
 {
     /**
-     * @return string the service name
+     * @return Service the service
      */
-    public function getService(): string;
+    public function getService(): Service;
 
     /**
      * @return int the number of failures to call the service
@@ -37,4 +37,11 @@ public function getThresholdDateTime(): DateTime;
      * @return bool
      */
     public function incrementFailures(): bool;
+
+    /**
+     * If the service is up again, reset the number of failures to 0.
+     *
+     * @return bool
+     */
+    public function clearFailures(): bool;
 }

src/Contracts/TransitionDispatcher.php

@@ -12,9 +12,8 @@ interface TransitionDispatcher
      * Dispatch a Circuit Breaker transition.
      *
      * @param CircuitBreaker $circuitBreaker the Circuit Breaker
+     * @param Service $service the service called
      * @param string $transition the Circuit Breaker transition name
-     * @param string $service the URI service called
-     * @param array $parameters the service parameters
      */
-    public function dispatch(CircuitBreaker $circuitBreaker, $transition, $service, array $parameters): void;
+    public function dispatch(CircuitBreaker $circuitBreaker, Service $service, string $transition): void;
 }

src/Events/TransitionEvent.php

@@ -2,6 +2,7 @@
 
 namespace Resiliency\Events;
 
+use Resiliency\Contracts\Service;
 use Resiliency\Contracts\CircuitBreaker;
 use Symfony\Component\EventDispatcher\Event;
 
@@ -18,26 +19,20 @@ class TransitionEvent extends Event
     private $eventName;
 
     /**
-     * @var string the Service URI
+     * @var Service the Service URI
      */
     private $service;
 
     /**
-     * @var array the Service parameters
-     */
-    private $parameters;
-
-    /**
+     * @param CircuitBreaker $circuitBreaker the circuit breaker
      * @param string $eventName the transition name
-     * @param string $service the Service URI
-     * @param array $parameters the Service parameters
+     * @param Service $service the Service
      */
-    public function __construct(CircuitBreaker $circuitBreaker, $eventName, $service, array $parameters)
+    public function __construct(CircuitBreaker $circuitBreaker, string $eventName, Service $service)
     {
         $this->circuitBreaker = $circuitBreaker;
         $this->eventName = $eventName;
         $this->service = $service;
-        $this->parameters = $parameters;
     }
 
     /**
@@ -57,18 +52,10 @@ public function getEvent(): string
     }
 
     /**
-     * @return string the Service URI
+     * @return Service the Service
      */
-    public function getService(): string
+    public function getService(): Service
     {
         return $this->service;
     }
-
-    /**
-     * @return array the Service parameters
-     */
-    public function getParameters(): array
-    {
-        return $this->parameters;
-    }
 }

src/Exceptions/InvalidTransaction.php

@@ -19,7 +19,7 @@ final class InvalidTransaction extends Exception implements ResiliencyException
     public static function invalidParameters($service, $failures, $state, $threshold): self
     {
         $exceptionMessage = 'Invalid parameters for Transaction' . PHP_EOL .
-            ErrorFormatter::format('service', $service, 'isURI', 'an URI') .
+            ErrorFormatter::format('service', $service, 'isAService', 'an instance of Service') .
             ErrorFormatter::format('failures', $failures, 'isPositiveInteger', 'a positive integer') .
             ErrorFormatter::format('state', $state, 'isString', 'a string') .
             ErrorFormatter::format('threshold', $threshold, 'isPositiveInteger', 'a positive integer');