[9.x] Add unique locking to broadcast events

src/Illuminate/Broadcasting/BroadcastManager.php

@@ -11,6 +11,7 @@
 use Illuminate\Broadcasting\Broadcasters\PusherBroadcaster;
 use Illuminate\Broadcasting\Broadcasters\RedisBroadcaster;
 use Illuminate\Contracts\Broadcasting\Factory as FactoryContract;
+use Illuminate\Contracts\Broadcasting\ShouldBeUnique;
 use Illuminate\Contracts\Broadcasting\ShouldBroadcastNow;
 use Illuminate\Contracts\Bus\Dispatcher as BusDispatcherContract;
 use Illuminate\Contracts\Foundation\CachesRoutes;
@@ -166,7 +167,10 @@ public function queue($event)
         }
 
         $this->app->make('queue')->connection($event->connection ?? null)->pushOn(
-            $queue, new BroadcastEvent(clone $event)
+            $queue,
+            $event instanceof ShouldBeUnique
+                    ? new UniqueBroadcastEvent(clone $event)
+                    : new BroadcastEvent(clone $event)
         );
     }
 

src/Illuminate/Broadcasting/UniqueBroadcastEvent.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Illuminate\Broadcasting;
+
+use Illuminate\Contracts\Queue\ShouldBeUnique;
+
+class UniqueBroadcastEvent extends BroadcastEvent implements ShouldBeUnique
+{
+    /**
+     * The unique lock identifier.
+     *
+     * @var mixed
+     */
+    public $uniqueId;
+
+    /**
+     * The number of seconds the unique lock should be maintained.
+     *
+     * @var int
+     */
+    public $uniqueFor;
+
+    /**
+     * The cache repository implementation that should be used to obtain unique locks.
+     *
+     * @var \Illuminate\Contracts\Cache\Repository
+     */
+    public $uniqueVia;
+
+    /**
+     * Create a new job handler instance.
+     *
+     * @param  mixed  $event
+     * @return void
+     */
+    public function __construct($event)
+    {
+        $this->uniqueId = get_class($event);
+
+        if (method_exists($event, 'uniqueId')) {
+            $this->uniqueId = $event->uniqueId();
+        } elseif (property_exists($event, 'uniqueId')) {
+            $this->uniqueId = $event->uniqueId;
+        }
+
+        if (method_exists($event, 'uniqueFor')) {
+            $this->uniqueFor = $event->uniqueFor();
+        } elseif (property_exists($event, 'uniqueFor')) {
+            $this->uniqueFor = $event->uniqueFor;
+        }
+
+        if (method_exists($event, 'uniqueVia')) {
+            $this->uniqueVia = $event->uniqueVia();
+        } elseif (property_exists($event, 'uniqueVia')) {
+            $this->uniqueVia = $event->uniqueVia;
+        }
+
+        parent::__construct($event);
+    }
+}

src/Illuminate/Contracts/Broadcasting/ShouldBeUnique.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Illuminate\Contracts\Broadcasting;
+
+interface ShouldBeUnique
+{
+    //
+}

tests/Integration/Broadcasting/BroadcastManagerTest.php

@@ -3,8 +3,11 @@
 namespace Illuminate\Tests\Integration\Broadcasting;
 
 use Illuminate\Broadcasting\BroadcastEvent;
+use Illuminate\Broadcasting\UniqueBroadcastEvent;
+use Illuminate\Contracts\Broadcasting\ShouldBeUnique;
 use Illuminate\Contracts\Broadcasting\ShouldBroadcast;
 use Illuminate\Contracts\Broadcasting\ShouldBroadcastNow;
+use Illuminate\Contracts\Cache\Repository as Cache;
 use Illuminate\Support\Facades\Broadcast;
 use Illuminate\Support\Facades\Bus;
 use Illuminate\Support\Facades\Queue;
@@ -33,6 +36,20 @@ public function testEventsCanBeBroadcast()
         Bus::assertNotDispatched(BroadcastEvent::class);
         Queue::assertPushed(BroadcastEvent::class);
     }
+
+    public function testUniqueEventsCanBeBroadcast()
+    {
+        Bus::fake();
+        Queue::fake();
+
+        Broadcast::queue(new TestEventUnique);
+
+        Bus::assertNotDispatched(UniqueBroadcastEvent::class);
+        Queue::assertPushed(UniqueBroadcastEvent::class);
+
+        $lockKey = 'laravel_unique_job:'.UniqueBroadcastEvent::class.TestEventUnique::class;
+        $this->assertTrue($this->app->get(Cache::class)->lock($lockKey, 10)->get());
+    }
 }
 
 class TestEvent implements ShouldBroadcast
@@ -60,3 +77,16 @@ public function broadcastOn()
         //
     }
 }
+
+class TestEventUnique implements ShouldBroadcast, ShouldBeUnique
+{
+    /**
+     * Get the channels the event should broadcast on.
+     *
+     * @return \Illuminate\Broadcasting\Channel|\Illuminate\Broadcasting\Channel[]
+     */
+    public function broadcastOn()
+    {
+        //
+    }
+}