Check if HTTP/2 is supported

composer.json

@@ -25,6 +25,7 @@
     "require": {
         "php": "~8.1.0 || ~8.2.0 || ~8.3.0",
         "ext-ctype": "*",
+        "ext-curl": "*",
         "ext-filter": "*",
         "ext-json": "*",
         "ext-mbstring": "*",

src/Firebase/Messaging/RequestFactory.php

@@ -14,10 +14,13 @@
  */
 final class RequestFactory
 {
+    private bool $environmentSupportsHTTP2;
+
     public function __construct(
         private readonly RequestFactoryInterface $requestFactory,
         private readonly StreamFactoryInterface $streamFactory,
     ) {
+        $this->environmentSupportsHTTP2 = self::environmentSupportsHTTP2();
     }
 
     public function createRequest(Message $message, string $projectId, bool $validateOnly): RequestInterface
@@ -29,6 +32,10 @@ public function createRequest(Message $message, string $projectId, bool $validat
             )
         ;
 
+        if ($this->environmentSupportsHTTP2) {
+            $request = $request->withProtocolVersion('2.0');
+        }
+
         $payload = ['message' => $message];
 
         if ($validateOnly === true) {
@@ -38,10 +45,24 @@ public function createRequest(Message $message, string $projectId, bool $validat
         $body = $this->streamFactory->createStream(Json::encode($payload));
 
         return $request
-            ->withProtocolVersion('2.0')
             ->withBody($body)
             ->withHeader('Content-Type', 'application/json; charset=UTF-8')
             ->withHeader('Content-Length', (string) $body->getSize())
         ;
     }
+
+    /**
+     * @see https://github.com/microsoftgraph/msgraph-sdk-php/issues/854
+     * @see https://github.com/microsoftgraph/msgraph-sdk-php/pull/1120
+     */
+    private static function environmentSupportsHTTP2(): bool
+    {
+        $features = curl_version()["features"] ?? null;
+
+        return
+            extension_loaded('curl')
+            && defined('CURL_VERSION_HTTP2')
+            && ($features & CURL_VERSION_HTTP2) === CURL_VERSION_HTTP2
+        ;
+    }
 }