[FrameworkBundle][HttpClient] Add ThrottlingHttpClient to limit requests within a timeframe

Author: HypeMC

CHANGELOG.md

@@ -7,6 +7,7 @@ CHANGELOG
  * Add `HttpOptions::setHeader()` to add or replace a single header
  * Allow mocking `start_time` info in `MockResponse`
  * Add `MockResponse::fromFile()` and `JsonMockResponse::fromFile()` methods to help using fixtures files
+ * Add `ThrottlingHttpClient` to enable limiting the number request within a certain period
 
 7.0
 ---

Tests/ThrottlingHttpClientTest.php

@@ -0,0 +1,57 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpClient\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpClient\MockHttpClient;
+use Symfony\Component\HttpClient\Response\MockResponse;
+use Symfony\Component\HttpClient\ThrottlingHttpClient;
+use Symfony\Component\RateLimiter\RateLimiterFactory;
+use Symfony\Component\RateLimiter\Storage\InMemoryStorage;
+
+class ThrottlingHttpClientTest extends TestCase
+{
+    public function testThrottling()
+    {
+        $failPauseHandler = static function (float $duration) {
+            self::fail(sprintf('The pause handler should\'t have been called, but it was called with %f.', $duration));
+        };
+
+        $pauseHandler = static fn (float $expectedDuration) => function (float $duration) use ($expectedDuration) {
+            self::assertEqualsWithDelta($expectedDuration, $duration, 1);
+        };
+
+        $rateLimiterFactory = new RateLimiterFactory([
+            'id' => 'token_bucket',
+            'policy' => 'token_bucket',
+            'limit' => 2,
+            'rate' => ['interval' => '5 seconds', 'amount' => 2],
+        ], new InMemoryStorage());
+
+        $client = new ThrottlingHttpClient(
+            new MockHttpClient([
+                new MockResponse('', ['http_code' => 200, 'pause_handler' => $failPauseHandler]),
+                new MockResponse('', ['http_code' => 200, 'pause_handler' => $failPauseHandler]),
+                new MockResponse('', ['http_code' => 200, 'pause_handler' => $pauseHandler(5)]),
+                new MockResponse('', ['http_code' => 200, 'pause_handler' => $pauseHandler(5)]),
+                new MockResponse('', ['http_code' => 200, 'pause_handler' => $pauseHandler(10)]),
+            ]),
+            $rateLimiterFactory->create(),
+        );
+
+        $client->request('GET', 'http://example.com/foo');
+        $client->request('GET', 'http://example.com/bar');
+        $client->request('GET', 'http://example.com/baz');
+        $client->request('GET', 'http://example.com/qux');
+        $client->request('GET', 'http://example.com/corge');
+    }
+}

ThrottlingHttpClient.php

@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpClient;
+
+use Symfony\Component\RateLimiter\LimiterInterface;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+use Symfony\Contracts\Service\ResetInterface;
+
+/**
+ * Limits the number of requests within a certain period.
+ */
+class ThrottlingHttpClient implements HttpClientInterface, ResetInterface
+{
+    use DecoratorTrait {
+        reset as private traitReset;
+    }
+
+    public function __construct(
+        HttpClientInterface $client,
+        private readonly LimiterInterface $rateLimiter,
+    ) {
+        $this->client = $client;
+    }
+
+    public function request(string $method, string $url, array $options = []): ResponseInterface
+    {
+        $response = $this->client->request($method, $url, $options);
+
+        if (0 < $waitDuration = $this->rateLimiter->reserve()->getWaitDuration()) {
+            $response->getInfo('pause_handler')($waitDuration);
+        }
+
+        return $response;
+    }
+
+    public function reset(): void
+    {
+        $this->traitReset();
+        $this->rateLimiter->reset();
+    }
+}

composer.json

@@ -40,6 +40,7 @@
         "symfony/http-kernel": "^6.4|^7.0",
         "symfony/messenger": "^6.4|^7.0",
         "symfony/process": "^6.4|^7.0",
+        "symfony/rate-limiter": "^6.4|^7.0",
         "symfony/stopwatch": "^6.4|^7.0"
     },
     "conflict": {