Merge pull request #124 from akrabat/cached-stream

Add support for caching the underlying stream

.travis.yml

@@ -5,9 +5,9 @@ dist: trusty
 matrix:
   include:
     - php: 7.1
-      env: ANALYSIS='true'
     - php: 7.2
     - php: 7.3
+      env: ANALYSIS='true'
     - php: nightly
   allow_failures:
     - php: nightly

src/Factory/ServerRequestFactory.php

@@ -18,6 +18,7 @@
 use Slim\Psr7\Cookies;
 use Slim\Psr7\Headers;
 use Slim\Psr7\Request;
+use Slim\Psr7\Stream;
 use Slim\Psr7\UploadedFile;
 
 class ServerRequestFactory implements ServerRequestFactoryInterface
@@ -90,7 +91,11 @@ public static function createFromGlobals(): Request
         $headers = Headers::createFromGlobals();
         $cookies = Cookies::parseHeader($headers->getHeader('Cookie', []));
 
-        $body = (new StreamFactory())->createStreamFromFile('php://input');
+        // Cache the php://input stream as it cannot be re-read
+        $cacheResource = fopen('php://temp', 'wb+');
+        $cache = $cacheResource ? new Stream($cacheResource) : null;
+
+        $body = (new StreamFactory())->createStreamFromFile('php://input', 'r', $cache);
         $uploadedFiles = UploadedFile::createFromGlobals($_SERVER);
 
         $request = new Request($method, $uri, $headers, $cookies, $_SERVER, $body, $uploadedFiles);

src/Factory/StreamFactory.php

@@ -39,8 +39,11 @@ public function createStream(string $content = ''): StreamInterface
     /**
      * {@inheritdoc}
      */
-    public function createStreamFromFile(string $filename, string $mode = 'r'): StreamInterface
-    {
+    public function createStreamFromFile(
+        string $filename,
+        string $mode = 'r',
+        StreamInterface $cache = null
+    ): StreamInterface {
         $resource = fopen($filename, $mode);
 
         if (!is_resource($resource)) {
@@ -49,20 +52,20 @@ public function createStreamFromFile(string $filename, string $mode = 'r'): Stre
             );
         }
 
-        return new Stream($resource);
+        return new Stream($resource, $cache);
     }
 
     /**
      * {@inheritdoc}
      */
-    public function createStreamFromResource($resource): StreamInterface
+    public function createStreamFromResource($resource, StreamInterface $cache = null): StreamInterface
     {
         if (!is_resource($resource)) {
             throw new InvalidArgumentException(
                 'Parameter 1 of StreamFactory::createStreamFromResource() must be a resource.'
             );
         }
 
-        return new Stream($resource);
+        return new Stream($resource, $cache);
     }
 }

src/Stream.php

@@ -60,13 +60,29 @@ class Stream implements StreamInterface
     protected $isPipe;
 
     /**
-     * @param  resource $stream A PHP resource handle.
+     * @var bool
+     */
+    protected $finished;
+
+    /**
+     * @var StreamInterface | null
+     */
+    protected $cache;
+
+    /**
+     * @param  resource $stream  A PHP resource handle.
+     * @param  StreamInterface $cache A stream to cache $stream (useful for non-seekable streams)
      *
      * @throws InvalidArgumentException If argument is not a resource.
      */
-    public function __construct($stream)
+    public function __construct($stream, StreamInterface $cache = null)
     {
         $this->attach($stream);
+
+        if ($cache && (!$cache->isSeekable() || !$cache->isWritable())) {
+            throw new RuntimeException('Cache stream must be seekable and writable');
+        }
+        $this->cache = $cache;
     }
 
     /**
@@ -137,6 +153,11 @@ public function __toString(): string
             return '';
         }
 
+        if ($this->cache && $this->finished) {
+            $this->cache->rewind();
+            return $this->cache->getContents();
+        }
+
         try {
             $this->rewind();
             return $this->getContents();
@@ -292,6 +313,12 @@ public function read($length): string
         }
 
         if (is_string($data)) {
+            if ($this->cache) {
+                $this->cache->write($data);
+            }
+            if ($this->eof()) {
+                $this->finished = true;
+            }
             return $data;
         }
 
@@ -322,13 +349,24 @@ public function write($string)
      */
     public function getContents(): string
     {
+        if ($this->cache && $this->finished) {
+            $this->cache->rewind();
+            return $this->cache->getContents();
+        }
+
         $contents = false;
 
         if ($this->stream) {
             $contents = stream_get_contents($this->stream);
         }
 
         if (is_string($contents)) {
+            if ($this->cache) {
+                $this->cache->write($contents);
+            }
+            if ($this->eof()) {
+                $this->finished = true;
+            }
             return $contents;
         }
 

tests/Factory/ServerRequestFactoryTest.php

@@ -12,6 +12,7 @@
 use Interop\Http\Factory\ServerRequestFactoryTestCase;
 use InvalidArgumentException;
 use Psr\Http\Message\UriInterface;
+use ReflectionClass;
 use Slim\Psr7\Environment;
 use Slim\Psr7\Factory\ServerRequestFactory;
 use Slim\Psr7\Factory\UriFactory;
@@ -117,6 +118,19 @@ public function testCreateFromGlobalsBodyPointsToPhpInput()
         $this->assertEquals('php://input', $request->getBody()->getMetadata('uri'));
     }
 
+    public function testCreateFromGlobalsSetsACache()
+    {
+        $request = ServerRequestFactory::createFromGlobals();
+
+        // ensure that the Stream's $cache property has been set for this php://input stream
+        $stream = $request->getBody();
+        $class = new ReflectionClass($stream);
+        $property = $class->getProperty('cache');
+        $property->setAccessible(true);
+        $cacheStreamValue = $property->getValue($stream);
+        $this->assertNotNull($cacheStreamValue);
+    }
+
     public function testCreateFromGlobalsWithUploadedFiles()
     {
         $_SERVER = Environment::mock([

tests/StreamTest.php

@@ -201,4 +201,43 @@ private function openPipeStream()
         $this->pipeFh = popen('echo 12', 'r');
         $this->pipeStream = new Stream($this->pipeFh);
     }
+
+    public function testReadOnlyCachedStreamsAreDisallowed()
+    {
+        $resource = fopen('php://temp', 'w+');
+        $cache =  new Stream(fopen('php://temp', 'r'));
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cache stream must be seekable and writable');
+        new Stream($resource, $cache);
+    }
+
+    public function testNonSeekableCachedStreamsAreDisallowed()
+    {
+        $resource = fopen('php://temp', 'w+');
+        $cache =  new Stream(fopen('php://output', 'w'));
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cache stream must be seekable and writable');
+
+        new Stream($resource, $cache);
+    }
+
+    public function testCachedStreamsGetsContentFromTheCache()
+    {
+        $resource = popen('echo HelloWorld', 'r');
+        $stream = new Stream($resource, new Stream(fopen('php://temp', 'w+')));
+
+        $this->assertEquals("HelloWorld\n", $stream->getContents());
+        $this->assertEquals("HelloWorld\n", $stream->getContents());
+    }
+
+    public function testCachedStreamsFillsCacheOnRead()
+    {
+        $resource = fopen('data://,0', 'r');
+        $stream = new Stream($resource, new Stream(fopen('php://temp', 'w+')));
+
+        $this->assertEquals("0", $stream->read(100));
+        $this->assertEquals("0", $stream->__toString());
+    }
 }