Add events to delegate the WebP/thumbnail generation

wcfsetup/install/files/lib/event/file/GenerateThumbnail.class.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace wcf\event\file;
+
+use wcf\data\file\File;
+use wcf\event\IPsr14Event;
+use wcf\system\file\processor\ThumbnailFormat;
+
+/**
+ * Requests the generation of a thumbnail.
+ *
+ * @author      Alexander Ebert
+ * @copyright   2001-2024 WoltLab GmbH
+ * @license     GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @since       6.1
+ */
+final class GenerateThumbnail implements IPsr14Event
+{
+    private string $pathname;
+
+    public function __construct(
+        public readonly File $file,
+        public readonly ThumbnailFormat $thumbnailFormat,
+    ) {}
+
+    /**
+     * Returns true if a file has already been set and no further files are
+     * being accepted.
+     */
+    public function hasFile(): bool
+    {
+        return isset($this->pathname);
+    }
+
+    /**
+     * Sets the pathname of the generated image unless it has already been set
+     * in which case the call will throw an exception. You must check the result
+     * of `hasFile()` first.
+     */
+    public function setGeneratedFile(string $pathname): void
+    {
+        if (isset($this->pathname)) {
+            throw new \BadMethodCallException("Cannot set the generated file, a value has already been set.");
+        }
+
+        $this->pathname = $pathname;
+    }
+
+    public function getPathname(): ?string
+    {
+        return $this->pathname ?? null;
+    }
+}

wcfsetup/install/files/lib/event/file/GenerateWebpVariant.class.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace wcf\event\file;
+
+use BadMethodCallException;
+use wcf\data\file\File;
+use wcf\event\IPsr14Event;
+
+/**
+ * Requests the generation of a WebP variant for the provided image.
+ *
+ * @author      Alexander Ebert
+ * @copyright   2001-2024 WoltLab GmbH
+ * @license     GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @since       6.1
+ */
+final class GenerateWebpVariant implements IPsr14Event
+{
+    private string $pathname;
+
+    public function __construct(
+        public readonly File $file
+    ) {}
+
+    /**
+     * Returns true if a file has already been set and no further files are
+     * being accepted.
+     */
+    public function hasFile(): bool
+    {
+        return isset($this->pathname);
+    }
+
+    /**
+     * Sets the pathname of the generated image unless it has already been set
+     * in which case the call will throw an exception. You must check the result
+     * of `hasFile()` first.
+     */
+    public function setGeneratedFile(string $pathname): void
+    {
+        if (isset($this->pathname)) {
+            throw new \BadMethodCallException("Cannot set the generated file, a value has already been set.");
+        }
+
+        $this->pathname = $pathname;
+    }
+
+    public function getPathname(): ?string
+    {
+        return $this->pathname ?? null;
+    }
+}

wcfsetup/install/files/lib/system/file/processor/FileProcessor.class.php

@@ -9,7 +9,10 @@
 use wcf\data\file\thumbnail\FileThumbnailList;
 use wcf\data\object\type\ObjectType;
 use wcf\data\object\type\ObjectTypeCache;
+use wcf\event\file\GenerateThumbnail;
+use wcf\event\file\GenerateWebpVariant;
 use wcf\system\database\util\PreparedStatementConditionBuilder;
+use wcf\system\event\EventHandler;
 use wcf\system\exception\SystemException;
 use wcf\system\file\processor\exception\DamagedImage;
 use wcf\system\image\adapter\exception\ImageNotProcessable;
@@ -159,32 +162,38 @@ public function generateWebpVariant(File $file): void
             }
         }
 
-        $imageAdapter = ImageHandler::getInstance()->getAdapter();
-        if (!$imageAdapter->checkMemoryLimit($file->width, $file->height, $file->mimeType)) {
-            return;
-        }
+        $event = new GenerateWebpVariant($file);
+        EventHandler::getInstance()->fire($event);
 
-        try {
-            $imageAdapter->loadSingleFrameFromFile($file->getPathname());
-        } catch (SystemException | ImageNotReadable) {
-            throw new DamagedImage($file->fileID);
-        } catch (ImageNotProcessable $e) {
-            logThrowable($e);
-
-            return;
-        }
+        $filename = $event->getPathname();
+        if ($filename === null) {
+            $imageAdapter = ImageHandler::getInstance()->getAdapter();
+            if (!$imageAdapter->checkMemoryLimit($file->width, $file->height, $file->mimeType)) {
+                return;
+            }
 
-        $filename = FileUtil::getTemporaryFilename(extension: 'webp');
+            try {
+                $imageAdapter->loadSingleFrameFromFile($file->getPathname());
+            } catch (SystemException | ImageNotReadable) {
+                throw new DamagedImage($file->fileID);
+            } catch (ImageNotProcessable $e) {
+                logThrowable($e);
 
-        try {
-            $imageAdapter->saveImageAs($imageAdapter->getImage(), $filename, 'webp', 80);
-        } catch (\Throwable $e) {
-            // Ignore any errors trying to save the file unless in debug mode.
-            if (\ENABLE_DEBUG_MODE) {
-                throw $e;
+                return;
             }
 
-            return;
+            $filename = FileUtil::getTemporaryFilename(extension: 'webp');
+
+            try {
+                $imageAdapter->saveImageAs($imageAdapter->getImage(), $filename, 'webp', 80);
+            } catch (\Throwable $e) {
+                // Ignore any errors trying to save the file unless in debug mode.
+                if (\ENABLE_DEBUG_MODE) {
+                    throw $e;
+                }
+
+                return;
+            }
         }
 
         (new FileEditor($file))->update([
@@ -251,36 +260,42 @@ public function generateThumbnails(File $file): void
                 }
             }
 
-            if ($imageAdapter === null) {
-                $imageAdapter = ImageHandler::getInstance()->getAdapter();
-                if (!$imageAdapter->checkMemoryLimit($file->width, $file->height, $file->mimeType)) {
-                    return;
+            $event = new GenerateThumbnail($file, $format);
+            EventHandler::getInstance()->fire($event);
+
+            $filename = $event->getPathname();
+            if ($filename === null) {
+                if ($imageAdapter === null) {
+                    $imageAdapter = ImageHandler::getInstance()->getAdapter();
+                    if (!$imageAdapter->checkMemoryLimit($file->width, $file->height, $file->mimeType)) {
+                        return;
+                    }
+
+                    try {
+                        $imageAdapter->loadSingleFrameFromFile($file->getPathname());
+                    } catch (SystemException | ImageNotReadable $e) {
+                        throw new DamagedImage($file->fileID, $e);
+                    } catch (ImageNotProcessable $e) {
+                        logThrowable($e);
+
+                        return;
+                    }
                 }
 
+                \assert($imageAdapter instanceof ImageAdapter);
+
                 try {
-                    $imageAdapter->loadSingleFrameFromFile($file->getPathname());
-                } catch (SystemException | ImageNotReadable $e) {
-                    throw new DamagedImage($file->fileID, $e);
-                } catch (ImageNotProcessable $e) {
+                    $image = $imageAdapter->createThumbnail($format->width, $format->height, $format->retainDimensions);
+                } catch (\Throwable $e) {
                     logThrowable($e);
 
-                    return;
+                    continue;
                 }
-            }
-
-            \assert($imageAdapter instanceof ImageAdapter);
 
-            try {
-                $image = $imageAdapter->createThumbnail($format->width, $format->height, $format->retainDimensions);
-            } catch (\Throwable $e) {
-                logThrowable($e);
-
-                continue;
+                $filename = FileUtil::getTemporaryFilename(extension: 'webp');
+                $imageAdapter->saveImageAs($image, $filename, 'webp', 80);
             }
 
-            $filename = FileUtil::getTemporaryFilename(extension: 'webp');
-            $imageAdapter->saveImageAs($image, $filename, 'webp', 80);
-
             $fileThumbnail = FileThumbnailEditor::createFromTemporaryFile($file, $format, $filename);
             $processor->adoptThumbnail($fileThumbnail);
         }