add WorkerMemoryUsageSubscriber

Author: mlebkowski

src/Messenger/WorkerMemoryUsageSubscriber.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WonderNetwork\SlimKernel\Messenger;
+
+use Psr\Log\LoggerInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\Messenger\Event\WorkerRunningEvent;
+
+final class WorkerMemoryUsageSubscriber implements EventSubscriberInterface {
+    private int $memoryUsage;
+
+    /**
+     * @return iterable<string,string>
+     */
+    public static function getSubscribedEvents(): iterable {
+        return [
+            WorkerRunningEvent::class => 'onWorkerRunning',
+        ];
+    }
+
+    public function __construct(
+        private readonly LoggerInterface $logger,
+        private readonly int $cutoff = 1024,
+    ) {
+        $this->memoryUsage = memory_get_usage();
+    }
+
+    public function onWorkerRunning(): void {
+        $currentUsage = memory_get_usage();
+
+        $difference = abs($this->memoryUsage - $currentUsage);
+        if ($difference < $this->cutoff) {
+            return;
+        }
+
+        $this->logger->debug(
+            "Memory usage changed: {current} ({sign}{difference})",
+            [
+                'current' => $this->formatBytes($currentUsage),
+                'sign' => ($this->memoryUsage > $currentUsage) ? "-" : "+",
+                'difference' => $this->formatBytes($difference),
+            ],
+        );
+
+        $this->memoryUsage = $currentUsage;
+    }
+
+    private function formatBytes(int $bytes): string {
+        $units = ['B', 'KB', 'MB', 'GB', 'TB'];
+
+        $bytes = max($bytes, 0);
+        $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
+        $pow = (int) min($pow, count($units) - 1);
+
+        $bytes /= 1024 ** $pow;
+
+        return sprintf("%s %s", round($bytes, 2), $units[$pow]);
+    }
+}

tests/Messenger/WorkerMemoryUsageSubscriberTest.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WonderNetwork\SlimKernel\Messenger;
+
+use Monolog\Handler\TestHandler;
+use Monolog\Logger;
+use PHPUnit\Framework\TestCase;
+
+final class WorkerMemoryUsageSubscriberTest extends TestCase {
+    public function testReportsAboveCutoff(): void {
+        $buffer = new TestHandler();
+        $logger = new Logger('some');
+        $logger->pushHandler($buffer);
+        $memoryLeak = [];
+
+        $sut = new WorkerMemoryUsageSubscriber($logger, cutoff: 10 * 1024);
+        $sut->onWorkerRunning();
+        self::assertEmpty($buffer->getRecords());
+
+        $memoryLeak[] = str_repeat(' ', 10 * 1024);
+        // triggers the first log
+        $sut->onWorkerRunning();
+        self::assertCount(1, $buffer->getRecords());
+        // the logs themselves take memory, so:
+        $sut->onWorkerRunning();
+        self::assertCount(2, $buffer->getRecords());
+        // no more logs:
+        $sut->onWorkerRunning();
+        $sut->onWorkerRunning();
+        $sut->onWorkerRunning();
+        self::assertCount(2, $buffer->getRecords());
+
+        unset($memoryLeak);
+    }
+}