Add a way to add additional collectors

Author: WyriHaximus

etc/di/event-loop.php

@@ -1,24 +1,25 @@
 <?php declare(strict_types=1);
 
+use function EventLoop\getLoop;
+use React\EventLoop\LoopInterface;
 use ReactInspector\EventLoop\LoopCollector;
 use ReactInspector\MemoryUsage\MemoryUsageCollector;
 use ReactInspector\Metrics;
 use ReactInspector\MetricsStreamInterface;
 use ReactInspector\Stream\IOCollector;
-use function EventLoop\getLoop;
-use React\EventLoop\LoopInterface;
 
 return [
     LoopInterface::class => function () {
         return getLoop();
     },
-    MetricsStreamInterface::class => function (LoopInterface $loop) {
+    MetricsStreamInterface::class => function (LoopInterface $loop, AdditionalCollectors $additionalCollectors) {
         return new Metrics(
             $loop,
             1,
             new LoopCollector($loop),
             new MemoryUsageCollector($loop),
-            new IOCollector()
+            new IOCollector(),
+            ...$additionalCollectors->get()
         );
     },
 ];

src/AdditionalCollectors.php

@@ -0,0 +1,19 @@
+<?php
+
+use ReactInspector\CollectorInterface;
+
+final class AdditionalCollectors
+{
+    private $collectors = [];
+
+    public function add(CollectorInterface $collector): void
+    {
+        $this->collectors[] = $collector;
+    }
+
+    public function get(): array
+    {
+        return $this->collectors;
+    }
+}
+