Merge pull request #291 from clue-labs/happy-empty

Improve performance by skipping buffering empty request body

Author: WyriHaximus

src/Middleware/RequestBodyBufferMiddleware.php

@@ -32,11 +32,12 @@ public function __construct($sizeLimit = null)
     public function __invoke(ServerRequestInterface $request, $stack)
     {
         $body = $request->getBody();
+        $size = $body->getSize();
 
-        // skip if body is already buffered
-        if (!$body instanceof ReadableStreamInterface) {
-            // replace with empty buffer if size limit is exceeded
-            if ($body->getSize() > $this->sizeLimit) {
+        // happy path: skip if body is known to be empty (or is already buffered)
+        if ($size === 0 || !$body instanceof ReadableStreamInterface) {
+            // replace with empty body if body is streaming (or buffered size exceeds limit)
+            if ($body instanceof ReadableStreamInterface || $size > $this->sizeLimit) {
                 $request = $request->withBody(new BufferStream(0));
             }
 
@@ -45,7 +46,7 @@ public function __invoke(ServerRequestInterface $request, $stack)
 
         // request body of known size exceeding limit
         $sizeLimit = $this->sizeLimit;
-        if ($body->getSize() > $this->sizeLimit) {
+        if ($size > $this->sizeLimit) {
             $sizeLimit = 0;
         }
 

tests/Middleware/RequestBodyBufferMiddlewareTest.php

@@ -68,6 +68,54 @@ function (ServerRequestInterface $request) use (&$exposedRequest) {
         $this->assertSame($body, $exposedRequest->getBody()->getContents());
     }
 
+    public function testEmptyStreamingResolvesImmediatelyWithEmptyBufferedBody()
+    {
+        $stream = new ThroughStream();
+        $serverRequest = new ServerRequest(
+            'GET',
+            'https://example.com/',
+            array(),
+            $body = new HttpBodyStream($stream, 0)
+        );
+
+        $exposedRequest = null;
+        $buffer = new RequestBodyBufferMiddleware();
+        $buffer(
+            $serverRequest,
+            function (ServerRequestInterface $request) use (&$exposedRequest) {
+                $exposedRequest = $request;
+            }
+        );
+
+        $this->assertSame(0, $exposedRequest->getBody()->getSize());
+        $this->assertSame('', $exposedRequest->getBody()->getContents());
+        $this->assertNotSame($body, $exposedRequest->getBody());
+    }
+
+    public function testEmptyBufferedResolvesImmediatelyWithSameBody()
+    {
+        $serverRequest = new ServerRequest(
+            'GET',
+            'https://example.com/',
+            array(),
+            ''
+        );
+        $body = $serverRequest->getBody();
+
+        $exposedRequest = null;
+        $buffer = new RequestBodyBufferMiddleware();
+        $buffer(
+            $serverRequest,
+            function (ServerRequestInterface $request) use (&$exposedRequest) {
+                $exposedRequest = $request;
+            }
+        );
+
+        $this->assertSame(0, $exposedRequest->getBody()->getSize());
+        $this->assertSame('', $exposedRequest->getBody()->getContents());
+        $this->assertSame($body, $exposedRequest->getBody());
+    }
+
     public function testKnownExcessiveSizedBodyIsDisgardedTheRequestIsPassedDownToTheNextMiddleware()
     {
         $loop = Factory::create();