Symfony stream json factory improvement (accept iterable insted of Iterator)

Author: Triplkrypl

.github/README.md

@@ -125,6 +125,7 @@ $response = \SimpleAsFuck\ApiToolkit\Factory\Server\ResponseFactory::makeJson($y
 // response with some array or collection (avoiding out of memory problem recommended some lazy loading iterator)
 $response = \SimpleAsFuck\ApiToolkit\Factory\Server\ResponseFactory::makeJsonStream(new \ArrayIterator([$yourModelForResponseBody]), $transformer);
 //$response = \SimpleAsFuck\ApiToolkit\Factory\Symfony\ResponseFactory::makeJsonStream(new \ArrayIterator([$yourModelForResponseBody]), $transformer);
+//$response = \SimpleAsFuck\ApiToolkit\Factory\Symfony\ResponseFactory::makeJsonStream([$yourModelForResponseBody], $transformer);
 
 ```
 

src/Factory/Server/ResponseFactory.php

@@ -10,6 +10,7 @@
 use Kayex\HttpCodes;
 use Psr\Http\Message\ResponseFactoryInterface;
 use Psr\Http\Message\ResponseInterface;
+use SimpleAsFuck\ApiToolkit\Service\Server\SpeedLimitService;
 use SimpleAsFuck\ApiToolkit\Service\Transformation\Transformer;
 
 final class ResponseFactory
@@ -72,13 +73,7 @@ public static function makeJsonStream(\Iterator $body, ?Transformer $transformer
             $body->next();
             if ($body->valid()) {
                 $item .= ',';
-                if ($speedLimit > 0) {
-                    $timeLimit = (strlen($item) / 1024) / $speedLimit;
-                    $timeOverHead = $timeLimit - (\microtime(true) - $previousItemTime);
-                    if ($timeOverHead > 0) {
-                        \usleep((int) ($timeOverHead * 1000000));
-                    }
-                }
+                SpeedLimitService::slowdownDataSending($speedLimit, strlen($item), $previousItemTime);
             } else {
                 $item .= ']';
             }

src/Factory/Symfony/ResponseFactory.php

@@ -4,9 +4,12 @@
 
 namespace SimpleAsFuck\ApiToolkit\Factory\Symfony;
 
+use GuzzleHttp\Utils;
 use Kayex\HttpCodes;
+use SimpleAsFuck\ApiToolkit\Service\Server\SpeedLimitService;
 use SimpleAsFuck\ApiToolkit\Service\Transformation\Transformer;
 use Symfony\Bridge\PsrHttpMessage\Factory\HttpFoundationFactory;
+use Symfony\Component\HttpFoundation\StreamedResponse;
 
 final class ResponseFactory
 {
@@ -25,15 +28,40 @@ public static function makeJson($body, ?Transformer $transformer = null, int $co
 
     /**
      * @template TBody
-     * @param \Iterator<TBody> $body
+     * @param iterable<TBody> $body
      * @param Transformer<TBody>|null $transformer
      * @param int<100,505> $code
      * @param array<non-empty-string, string|array<string>> $headers
      * @param float $speedLimit speed limit in KB/s for sending response slow down, zero means no slow down (this is not precise but is something)
      */
-    public static function makeJsonStream(\Iterator $body, ?Transformer $transformer = null, int $code = HttpCodes::HTTP_OK, array $headers = [], float $speedLimit = 0): \Symfony\Component\HttpFoundation\Response
+    public static function makeJsonStream(iterable $body, ?Transformer $transformer = null, int $code = HttpCodes::HTTP_OK, array $headers = [], float $speedLimit = 0): StreamedResponse
     {
-        $factory = new HttpFoundationFactory();
-        return $factory->createResponse(\SimpleAsFuck\ApiToolkit\Factory\Server\ResponseFactory::makeJsonStream($body, $transformer, $code, $headers, $speedLimit), true);
+        return new StreamedResponse(
+            static function () use ($body, $transformer, $speedLimit) {
+                $dataSeparator = '';
+
+                echo '[';
+
+                foreach ($body as $responseData) {
+                    $batchSendingStartAt = \microtime(true);
+                    echo $dataSeparator;
+
+                    if ($transformer !== null) {
+                        $responseData = $transformer->toApi($responseData);
+                    }
+
+                    /** @var non-empty-string $responseData */
+                    $responseData = Utils::jsonEncode($responseData);
+                    echo $responseData;
+
+                    SpeedLimitService::slowdownDataSending($speedLimit, strlen($dataSeparator) + strlen($responseData), $batchSendingStartAt);
+                    $dataSeparator = ',';
+                }
+
+                echo ']';
+            },
+            $code,
+            $headers
+        );
     }
 }

src/Service/Server/SpeedLimitService.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleAsFuck\ApiToolkit\Service\Server;
+
+final class SpeedLimitService
+{
+    /**
+     * @param float $speedLimit speed limit in KB/s for sending response slow down, zero means no slow down (this is not precise but is something)
+     * @param positive-int $batchSize size of sended batch in bytes
+     * @param float $batchSendingStartAt microtime when sending the batch started
+     */
+    public static function slowdownDataSending(float $speedLimit, int $batchSize, float $batchSendingStartAt): void
+    {
+        if ($speedLimit > 0) {
+            $timeLimit = ($batchSize / 1024) / $speedLimit;
+            $timeOverHead = $timeLimit - (\microtime(true) - $batchSendingStartAt);
+            if ($timeOverHead > 0) {
+                \usleep((int) ($timeOverHead * 1000000));
+            }
+        }
+    }
+}

test/Factory/Server/ResponseFactoryTest.php

@@ -7,10 +7,26 @@
 
 final class ResponseFactoryTest extends TestCase
 {
-    public function testMakeJsonStream(): void
+    /**
+     * @dataProvider dataProviderMakeJsonStream
+     *
+     * @param array<mixed> $streamedData
+     */
+    public function testMakeJsonStream(string $expectedBody, array $streamedData): void
     {
-        $response = ResponseFactory::makeJsonStream(new \ArrayIterator([548846, 'sadasjkfghjsg']));
+        $response = ResponseFactory::makeJsonStream(new \ArrayIterator($streamedData));
 
-        self::assertSame('[548846,"sadasjkfghjsg"]', $response->getBody()->getContents());
+        self::assertSame($expectedBody, $response->getBody()->getContents());
+    }
+
+    /**
+     * @return array<array<mixed>>
+     */
+    public function dataProviderMakeJsonStream(): array
+    {
+        return [
+            ['[548846,"sadasjkfghjsg"]', [548846, 'sadasjkfghjsg']],
+            ['[]', []],
+        ];
     }
 }

test/Factory/Symfony/ResponseFactoryTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Factory\Symfony;
+
+use PHPUnit\Framework\TestCase;
+use SimpleAsFuck\ApiToolkit\Factory\Symfony\ResponseFactory;
+
+final class ResponseFactoryTest extends TestCase
+{
+    /**
+     * @dataProvider dataProviderMakeJsonStream
+     *
+     * @param iterable<mixed> $streamedData
+     */
+    public function testMakeJsonStream(string $expectedBody, iterable $streamedData): void
+    {
+        $response = ResponseFactory::makeJsonStream($streamedData);
+
+        ob_start();
+        $response->sendContent();
+        $responseContent = ob_get_clean();
+
+        self::assertSame($expectedBody, $responseContent);
+    }
+
+    /**
+     * @return array<array<mixed>>
+     */
+    public function dataProviderMakeJsonStream(): array
+    {
+        return [
+            ['[548846,"sadasjkfghjsg"]', [548846, 'sadasjkfghjsg']],
+            ['[]', new \ArrayIterator([])],
+        ];
+    }
+}