[FEATURE] Added SignalSlotDispatcher in the getFileForLocalProcessing…

… function. (#38)

That allow processing temporary file before they will be prossed in graphic functions.

Example: we decrease size in the to large files, over 4000 x 4000, before imagemagick processing because him spend a lot of memory for this files.

Classes/Driver/AmazonS3Driver.php

@@ -30,6 +30,7 @@
 use TYPO3\CMS\Core\Resource\ResourceStorage;
 use TYPO3\CMS\Core\Utility\VersionNumberUtility;
 use TYPO3\CMS\Extbase\Object\ObjectManager;
+use TYPO3\CMS\Extbase\SignalSlot\Dispatcher;
 use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
 
 /**
@@ -149,6 +150,11 @@ class AmazonS3Driver extends AbstractHierarchicalFilesystemDriver
      */
     protected $temporaryPaths = [];
 
+    /**
+     * @var Dispatcher
+     */
+    protected $signalSlotDispatcher;
+
     /**
      * AmazonS3Driver constructor.
      *
@@ -499,12 +505,29 @@ public function getFileForLocalProcessing($fileIdentifier, $writable = true)
         if (!is_file($temporaryPath)) {
             throw new \RuntimeException('Copying file ' . $fileIdentifier . ' to temporary path failed.', 1320577649);
         }
+        $this->emitGetFileForLocalProcessingSignal($fileIdentifier, $temporaryPath, $writable);
         if (!isset($this->temporaryPaths[$temporaryPath])) {
             $this->temporaryPaths[$temporaryPath] = $temporaryPath;
         }
         return $temporaryPath;
     }
 
+    /**
+     * @param string $fileIdentifier
+     * @param string $temporaryPath
+     * @param bool $writable
+     * @throws \TYPO3\CMS\Extbase\SignalSlot\Exception\InvalidSlotException
+     * @throws \TYPO3\CMS\Extbase\SignalSlot\Exception\InvalidSlotReturnException
+     */
+    protected function emitGetFileForLocalProcessingSignal(&$fileIdentifier, &$temporaryPath, &$writable)
+    {
+        list($fileIdentifier, $temporaryPath, $writable) = $this->getSignalSlotDispatcher()->dispatch(
+            self::class,
+            'getFileForLocalProcessing',
+            [$fileIdentifier, $temporaryPath, $writable]
+        );
+    }
+
     /**
      * Creates a new (empty) file and returns the identifier.
      *
@@ -1602,4 +1625,17 @@ protected function applyFilterMethodsToDirectoryItem(array $filterMethods, $item
         }
         return true;
     }
+
+    /**
+     * Get the SignalSlot dispatcher
+     *
+     * @return Dispatcher
+     */
+    protected function getSignalSlotDispatcher()
+    {
+        if (!isset($this->signalSlotDispatcher)) {
+            $this->signalSlotDispatcher = GeneralUtility::makeInstance(ObjectManager::class)->get(Dispatcher::class);
+        }
+        return $this->signalSlotDispatcher;
+    }
 }