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<?php
/**
* @file
* Contains \Drupal\image\Controller\ImageStyleDownloadController.
*/
namespace Drupal\image\Controller;
use Drupal\Component\Utility\Crypt;
use Drupal\Core\Image\ImageFactory;
use Drupal\Core\Lock\LockBackendInterface;
use Drupal\image\ImageStyleInterface;
use Drupal\system\FileDownloadController;
use Psr\Log\LoggerInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\BinaryFileResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
/**
* Defines a controller to serve image styles.
*/
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class ImageStyleDownloadController extends FileDownloadController {
/**
* The lock backend.
*
* @var \Drupal\Core\Lock\LockBackendInterface
*/
protected $lock;
/**
* The image factory.
*
* @var \Drupal\Core\Image\ImageFactory
*/
protected $imageFactory;
/**
* A logger instance.
*
* @var \Psr\Log\LoggerInterface
*/
protected $logger;
/**
* Constructs a ImageStyleDownloadController object.
*
* @param \Drupal\Core\Lock\LockBackendInterface $lock
* The lock backend.
* @param \Drupal\Core\Image\ImageFactory $image_factory
* The image factory.
* @param \Psr\Log\LoggerInterface $logger
* A logger instance.
*/
public function __construct(LockBackendInterface $lock, ImageFactory $image_factory, LoggerInterface $logger) {
$this->lock = $lock;
$this->imageFactory = $image_factory;
$this->logger = $logger;
}
/**
* {@inheritdoc}
*/
public static function create(ContainerInterface $container) {
return new static(
$container->get('lock'),
$container->get('image.factory'),
$container->get('logger.factory')->get('image')
);
}
/**
* Generates a derivative, given a style and image path.
*
* After generating an image, transfer it to the requesting agent.
*
* @param \Symfony\Component\HttpFoundation\Request $request
* The request object.
* @param string $scheme
* The file scheme, defaults to 'private'.
* @param \Drupal\image\ImageStyleInterface $image_style
* The image style to deliver.
*
* @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
* Thrown when the user does not have access to the file.
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* @throws \Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException
* Thrown when the file is still being generated.
*
* @return \Symfony\Component\HttpFoundation\BinaryFileResponse|\Symfony\Component\HttpFoundation\Response
* The transferred file as response or some error response.
*/
public function deliver(Request $request, $scheme, ImageStyleInterface $image_style) {
$target = $request->query->get('file');
$image_uri = $scheme . '://' . $target;
// Check that the style is defined, the scheme is valid, and the image
// derivative token is valid. Sites which require image derivatives to be
// generated without a token can set the
// 'image.settings:allow_insecure_derivatives' configuration to TRUE to
// bypass the latter check, but this will increase the site's vulnerability
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// to denial-of-service attacks. To prevent this variable from leaving the
// site vulnerable to the most serious attacks, a token is always required
// when a derivative of a style is requested.
// The $target variable for a derivative of a style has
// styles/<style_name>/... as structure, so we check if the $target variable
// starts with styles/.
$valid = !empty($image_style) && file_stream_wrapper_valid_scheme($scheme);
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if (!$this->config('image.settings')->get('allow_insecure_derivatives') || strpos(ltrim($target, '\/'), 'styles/') === 0) {
$valid &= $request->query->get(IMAGE_DERIVATIVE_TOKEN) === $image_style->getPathToken($image_uri);
}
if (!$valid) {
throw new AccessDeniedHttpException();
}
$derivative_uri = $image_style->buildUri($image_uri);
$headers = array();
// If using the private scheme, let other modules provide headers and
// control access to the file.
if ($scheme == 'private') {
if (file_exists($derivative_uri)) {
return parent::download($request, $scheme);
}
else {
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$headers = $this->moduleHandler()->invokeAll('file_download', array($image_uri));
if (in_array(-1, $headers) || empty($headers)) {
throw new AccessDeniedHttpException();
}
}
}
// Don't try to generate file if source is missing.
if (!file_exists($image_uri)) {
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// If the image style converted the extension, it has been added to the
// original file, resulting in filenames like image.png.jpeg. So to find
// the actual source image, we remove the extension and check if that
// image exists.
$path_info = pathinfo($image_uri);
$converted_image_uri = $path_info['dirname'] . DIRECTORY_SEPARATOR . $path_info['filename'];
if (!file_exists($converted_image_uri)) {
$this->logger->notice('Source image at %source_image_path not found while trying to generate derivative image at %derivative_path.', array('%source_image_path' => $image_uri, '%derivative_path' => $derivative_uri));
return new Response($this->t('Error generating image, missing source file.'), 404);
}
else {
// The converted file does exist, use it as the source.
$image_uri = $converted_image_uri;
}
}
// Don't start generating the image if the derivative already exists or if
// generation is in progress in another thread.
$lock_name = 'image_style_deliver:' . $image_style->id() . ':' . Crypt::hashBase64($image_uri);
if (!file_exists($derivative_uri)) {
$lock_acquired = $this->lock->acquire($lock_name);
if (!$lock_acquired) {
// Tell client to retry again in 3 seconds. Currently no browsers are
// known to support Retry-After.
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throw new ServiceUnavailableHttpException(3, $this->t('Image generation in progress. Try again shortly.'));
}
}
// Try to generate the image, unless another thread just did it while we
// were acquiring the lock.
$success = file_exists($derivative_uri) || $image_style->createDerivative($image_uri, $derivative_uri);
if (!empty($lock_acquired)) {
$this->lock->release($lock_name);
}
if ($success) {
$image = $this->imageFactory->get($derivative_uri);
$uri = $image->getSource();
$headers += array(
'Content-Type' => $image->getMimeType(),
'Content-Length' => $image->getFileSize(),
);
return new BinaryFileResponse($uri, 200, $headers);
}
else {
$this->logger->notice('Unable to generate the derived image located at %path.', array('%path' => $derivative_uri));
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return new Response($this->t('Error generating image.'), 500);