From 1c60cfa55d4bd805f20a6ce0baf8331d8525e506 Mon Sep 17 00:00:00 2001
From: Ivan Pepelko <ivan.pepelko@gmail.com>
Date: Thu, 14 Mar 2024 11:04:11 +0100
Subject: [PATCH] Implement Generator-based response streaming

---
 src/Http/StreamedResponse.php                 | 59 +++++++++++++++++++
 src/RoadRunnerBridge/HttpFoundationWorker.php | 13 ++--
 2 files changed, 67 insertions(+), 5 deletions(-)
 create mode 100644 src/Http/StreamedResponse.php

diff --git a/src/Http/StreamedResponse.php b/src/Http/StreamedResponse.php
new file mode 100644
index 0000000..e14756c
--- /dev/null
+++ b/src/Http/StreamedResponse.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Baldinof\RoadRunnerBundle\Http;
+
+use Symfony\Component\HttpFoundation\StreamedResponse as SymfonyStreamedResponse;
+
+class StreamedResponse extends SymfonyStreamedResponse
+{
+    private \Closure $obControl;
+
+    /**
+     * @param callable|null $obControl Sets the output buffering control. Called only when sending response trough sendResponse().
+     */
+    public function __construct(?callable $callback = null, int $status = 200, array $headers = [], ?callable $obControl = null)
+    {
+        parent::__construct($callback, $status, $headers);
+
+        $this->obControl = $obControl ?? function () {
+            if (\ob_get_status()) {
+                \ob_flush();
+            }
+            \flush();
+        };
+    }
+
+    public function getGenerator(): \Generator
+    {
+        if (!isset($this->callback)) {
+            throw new \LogicException('The Response callback must be set.');
+        }
+
+        $generator = ($this->callback)();
+        if (!$generator instanceof \Generator) {
+            throw new \LogicException('The Response callback is not a valid generator.');
+        }
+
+        return $generator;
+    }
+
+    public function sendContent(): static
+    {
+        if ($this->streamed) {
+            return $this;
+        }
+
+        $this->streamed = true;
+
+        if (!isset($this->callback)) {
+            throw new \LogicException('The Response callback must be set.');
+        }
+
+        foreach ($this->getGenerator() as $chunk) {
+            echo $chunk;
+            ($this->obControl)();
+        }
+
+        return $this;
+    }
+}
diff --git a/src/RoadRunnerBridge/HttpFoundationWorker.php b/src/RoadRunnerBridge/HttpFoundationWorker.php
index 148493e..229997a 100644
--- a/src/RoadRunnerBridge/HttpFoundationWorker.php
+++ b/src/RoadRunnerBridge/HttpFoundationWorker.php
@@ -4,6 +4,7 @@
 
 namespace Baldinof\RoadRunnerBundle\RoadRunnerBridge;
 
+use Baldinof\RoadRunnerBundle\Http\StreamedResponse;
 use Spiral\RoadRunner\Http\HttpWorkerInterface;
 use Spiral\RoadRunner\Http\Request as RoadRunnerRequest;
 use Spiral\RoadRunner\WorkerInterface;
@@ -11,7 +12,7 @@
 use Symfony\Component\HttpFoundation\File\UploadedFile;
 use Symfony\Component\HttpFoundation\Request as SymfonyRequest;
 use Symfony\Component\HttpFoundation\Response as SymfonyResponse;
-use Symfony\Component\HttpFoundation\StreamedResponse;
+use Symfony\Component\HttpFoundation\StreamedResponse as SymfonyStreamedResponse;
 
 final class HttpFoundationWorker implements HttpFoundationWorkerInterface
 {
@@ -42,8 +43,10 @@ public function respond(SymfonyResponse $symfonyResponse): void
             if ($content === false) {
                 throw new \RuntimeException(sprintf("Cannot read file '%s'", $symfonyResponse->getFile()->getPathname())); // TODO: custom error
             }
-        } else {
-            if ($symfonyResponse instanceof StreamedResponse || $symfonyResponse instanceof BinaryFileResponse) {
+        } elseif ($symfonyResponse instanceof SymfonyStreamedResponse || $symfonyResponse instanceof BinaryFileResponse) {
+            if ($symfonyResponse instanceof StreamedResponse) {
+                $content = $symfonyResponse->getGenerator();
+            } else {
                 $content = '';
                 ob_start(function ($buffer) use (&$content) {
                     $content .= $buffer;
@@ -53,9 +56,9 @@ public function respond(SymfonyResponse $symfonyResponse): void
 
                 $symfonyResponse->sendContent();
                 ob_end_clean();
-            } else {
-                $content = (string) $symfonyResponse->getContent();
             }
+        } else {
+            $content = (string) $symfonyResponse->getContent();
         }
 
         $headers = $this->stringifyHeaders($symfonyResponse->headers->all());