Add callable type support to the fallback property of CircuitBreaker Attribute (#6363)

Co-authored-by: Deeka Wong <8337659+huangdijia@users.noreply.github.com>

CHANGELOG-3.1.md

@@ -11,6 +11,7 @@
 
 - [#6342](https://github.com/hyperf/hyperf/pull/6342) Added `Coroutine::fork()` method and `Coroutine::pid()` method.
 - [#6360](https://github.com/hyperf/hyperf/pull/6360/files) Added response `content-type` header for swagger server.
+- [#6363](https://github.com/hyperf/hyperf/pull/6363) Add callable type support to the fallback property of CircuitBreaker Attribute.
 
 # v3.1.0 - 2023-12-01
 

docs/en/circuit-breaker.md

@@ -36,7 +36,7 @@ class UserService
     #[Inject]
     private UserServiceClient $client;
 
-    #[CircuitBreaker(timeout: 0.05, failCounter: 1, successCounter: 1, fallback: "App\UserService::searchFallback")]
+    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: [UserService::class, 'searchFallback'])]
     public function search($offset, $limit)
     {
         return $this->client->users($offset, $limit);

docs/zh-cn/circuit-breaker.md

@@ -30,7 +30,7 @@ class UserService
     #[Inject]
     private UserServiceClient $client;
 
-    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: "App\Service\UserService::searchFallback")]
+    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: [UserService::class, 'searchFallback'])]
     public function search($offset, $limit)
     {
         return $this->client->users($offset, $limit);

docs/zh-hk/circuit-breaker.md

@@ -30,7 +30,7 @@ class UserService
     #[Inject]
     private UserServiceClient $client;
 
-    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: "App\Service\UserService::searchFallback")]
+    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: [UserService::class, 'searchFallback'])]
     public function search($offset, $limit)
     {
         return $this->client->users($offset, $limit);

docs/zh-tw/circuit-breaker.md

@@ -30,7 +30,7 @@ class UserService
     #[Inject]
     private UserServiceClient $client;
 
-    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: "App\Service\UserService::searchFallback")]
+    #[CircuitBreaker(options: ['timeout' => 0.05], failCounter: 1, successCounter: 1, fallback: [UserService::class, 'searchFallback'])]
     public function search($offset, $limit)
     {
         return $this->client->users($offset, $limit);

src/circuit-breaker/src/Annotation/CircuitBreaker.php

@@ -29,7 +29,7 @@ class CircuitBreaker extends AbstractAnnotation
      */
     public function __construct(
         public string $handler = TimeoutHandler::class,
-        public ?string $fallback = null,
+        public string|array $fallback = [],
         public float $duration = 10.0,
         public int $successCounter = 10,
         public int $failCounter = 10,

src/circuit-breaker/src/Exception/BadFallbackException.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * This file is part of Hyperf.
+ *
+ * @link     https://www.hyperf.io
+ * @document https://hyperf.wiki
+ * @contact  group@hyperf.io
+ * @license  https://github.com/hyperf/hyperf/blob/master/LICENSE
+ */
+namespace Hyperf\CircuitBreaker\Exception;
+
+use RuntimeException;
+
+class BadFallbackException extends RuntimeException
+{
+}

src/circuit-breaker/src/Handler/AbstractHandler.php

@@ -15,6 +15,7 @@ use Hyperf\CircuitBreaker\Annotation\CircuitBreaker as Annotation;
 use Hyperf\CircuitBreaker\CircuitBreaker;
 use Hyperf\CircuitBreaker\CircuitBreakerFactory;
 use Hyperf\CircuitBreaker\CircuitBreakerInterface;
+use Hyperf\CircuitBreaker\Exception\BadFallbackException;
 use Hyperf\CircuitBreaker\Exception\CircuitBreakerException;
 use Hyperf\CircuitBreaker\FallbackInterface;
 use Hyperf\Contract\StdoutLoggerInterface;
@@ -169,27 +170,34 @@ abstract class AbstractHandler implements HandlerInterface
 
     protected function fallback(ProceedingJoinPoint $proceedingJoinPoint, CircuitBreakerInterface $breaker, Annotation $annotation)
     {
-        [$className, $methodName] = $this->prepareHandler($annotation->fallback);
+        [$class, $method] = $this->prepareHandler($annotation->fallback, $proceedingJoinPoint);
 
-        $class = $this->container->get($className);
-        if ($class instanceof FallbackInterface) {
-            return $class->fallback($proceedingJoinPoint);
+        $instance = $this->container->get($class);
+        if ($instance instanceof FallbackInterface) {
+            return $instance->fallback($proceedingJoinPoint);
         }
 
-        $argument = $proceedingJoinPoint->getArguments();
+        $arguments = $proceedingJoinPoint->getArguments();
 
-        return $class->{$methodName}(...$argument);
+        return $instance->{$method}(...$arguments);
     }
 
     abstract protected function process(ProceedingJoinPoint $proceedingJoinPoint, CircuitBreakerInterface $breaker, Annotation $annotation);
 
-    protected function prepareHandler(string $fallback): array
+    protected function prepareHandler(string|array $fallback, ProceedingJoinPoint $proceedingJoinPoint): array
     {
-        $result = explode('::', $fallback);
+        if (is_string($fallback)) {
+            $fallback = explode('::', $fallback);
+            if (! isset($fallback[1]) && is_callable([$proceedingJoinPoint->className, $fallback[0]])) {
+                return [$proceedingJoinPoint->className, $fallback[0]];
+            }
+            $fallback[1] ??= 'fallback';
+        }
 
-        return [
-            $result[0],
-            $result[1] ?? 'fallback',
-        ];
+        if (is_array($fallback) && is_callable($fallback)) {
+            return $fallback;
+        }
+
+        throw new BadFallbackException('The fallback is invalid.');
     }
 }