nextcloud / server

lib/private/Preview/Generator.php

Indentation +574 added lines, -574 removed lines

@@ -25,592 +25,592 @@
 use Psr\Log\LoggerInterface;
 
 class Generator {
-	public const SEMAPHORE_ID_ALL = 0x0a11;
-	public const SEMAPHORE_ID_NEW = 0x07ea;
-
-	public function __construct(
-		private IConfig $config,
-		private IPreview $previewManager,
-		private IAppData $appData,
-		private GeneratorHelper $helper,
-		private IEventDispatcher $eventDispatcher,
-		private LoggerInterface $logger,
-	) {
-	}
-
-	/**
-	 * Returns a preview of a file
-	 *
-	 * The cache is searched first and if nothing usable was found then a preview is
-	 * generated by one of the providers
-	 *
-	 * @return ISimpleFile
-	 * @throws NotFoundException
-	 * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid)
-	 */
-	public function getPreview(
-		File $file,
-		int $width = -1,
-		int $height = -1,
-		bool $crop = false,
-		string $mode = IPreview::MODE_FILL,
-		?string $mimeType = null,
-		bool $cacheResult = true,
-	): ISimpleFile {
-		$specification = [
-			'width' => $width,
-			'height' => $height,
-			'crop' => $crop,
-			'mode' => $mode,
-		];
-
-		$this->eventDispatcher->dispatchTyped(new BeforePreviewFetchedEvent(
-			$file,
-			$width,
-			$height,
-			$crop,
-			$mode,
-			$mimeType,
-		));
-
-		$this->logger->debug('Requesting preview for {path} with width={width}, height={height}, crop={crop}, mode={mode}, mimeType={mimeType}', [
-			'path' => $file->getPath(),
-			'width' => $width,
-			'height' => $height,
-			'crop' => $crop,
-			'mode' => $mode,
-			'mimeType' => $mimeType,
-		]);
-
-
-		// since we only ask for one preview, and the generate method return the last one it created, it returns the one we want
-		return $this->generatePreviews($file, [$specification], $mimeType, $cacheResult);
-	}
-
-	/**
-	 * Generates previews of a file
-	 *
-	 * @throws NotFoundException
-	 * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid)
-	 */
-	public function generatePreviews(File $file, array $specifications, ?string $mimeType = null, bool $cacheResult = true): ISimpleFile {
-		//Make sure that we can read the file
-		if (!$file->isReadable()) {
-			$this->logger->warning('Cannot read file: {path}, skipping preview generation.', ['path' => $file->getPath()]);
-			throw new NotFoundException('Cannot read file');
-		}
-
-		if ($mimeType === null) {
-			$mimeType = $file->getMimeType();
-		}
-
-		$previewFolder = $this->getPreviewFolder($file);
-		// List every existing preview first instead of trying to find them one by one
-		$previewFiles = $previewFolder->getDirectoryListing();
-
-		$previewVersion = '';
-		if ($file instanceof IVersionedPreviewFile) {
-			$previewVersion = $file->getPreviewVersion() . '-';
-		}
-
-		// Get the max preview and infer the max preview sizes from that
-		$maxPreview = $this->getMaxPreview($previewFolder, $previewFiles, $file, $mimeType, $previewVersion);
-		$maxPreviewImage = null; // only load the image when we need it
-		if ($maxPreview->getSize() === 0) {
-			$maxPreview->delete();
-			$this->logger->error('Max preview generated for file {path} has size 0, deleting and throwing exception.', ['path' => $file->getPath()]);
-			throw new NotFoundException('Max preview size 0, invalid!');
-		}
-
-		[$maxWidth, $maxHeight] = $this->getPreviewSize($maxPreview, $previewVersion);
-
-		if ($maxWidth <= 0 || $maxHeight <= 0) {
-			throw new NotFoundException('The maximum preview sizes are zero or less pixels');
-		}
-
-		$preview = null;
-
-		foreach ($specifications as $specification) {
-			$width = $specification['width'] ?? -1;
-			$height = $specification['height'] ?? -1;
-			$crop = $specification['crop'] ?? false;
-			$mode = $specification['mode'] ?? IPreview::MODE_FILL;
-
-			// If both width and height are -1 we just want the max preview
-			if ($width === -1 && $height === -1) {
-				$width = $maxWidth;
-				$height = $maxHeight;
-			}
-
-			// Calculate the preview size
-			[$width, $height] = $this->calculateSize($width, $height, $crop, $mode, $maxWidth, $maxHeight);
-
-			// No need to generate a preview that is just the max preview
-			if ($width === $maxWidth && $height === $maxHeight) {
-				// ensure correct return value if this was the last one
-				$preview = $maxPreview;
-				continue;
-			}
-
-			// Try to get a cached preview. Else generate (and store) one
-			try {
-				try {
-					$preview = $this->getCachedPreview($previewFiles, $width, $height, $crop, $maxPreview->getMimeType(), $previewVersion);
-				} catch (NotFoundException $e) {
-					if (!$this->previewManager->isMimeSupported($mimeType)) {
-						throw new NotFoundException();
-					}
-
-					if ($maxPreviewImage === null) {
-						$maxPreviewImage = $this->helper->getImage($maxPreview);
-					}
-
-					$this->logger->debug('Cached preview not found for file {path}, generating a new preview.', ['path' => $file->getPath()]);
-					$preview = $this->generatePreview($previewFolder, $maxPreviewImage, $width, $height, $crop, $maxWidth, $maxHeight, $previewVersion, $cacheResult);
-					// New file, augment our array
-					$previewFiles[] = $preview;
-				}
-			} catch (\InvalidArgumentException $e) {
-				throw new NotFoundException('', 0, $e);
-			}
-
-			if ($preview->getSize() === 0) {
-				$preview->delete();
-				throw new NotFoundException('Cached preview size 0, invalid!');
-			}
-		}
-		assert($preview !== null);
-
-		// Free memory being used by the embedded image resource.  Without this the image is kept in memory indefinitely.
-		// Garbage Collection does NOT free this memory.  We have to do it ourselves.
-		if ($maxPreviewImage instanceof \OCP\Image) {
-			$maxPreviewImage->destroy();
-		}
-
-		return $preview;
-	}
-
-	/**
-	 * Acquire a semaphore of the specified id and concurrency, blocking if necessary.
-	 * Return an identifier of the semaphore on success, which can be used to release it via
-	 * {@see Generator::unguardWithSemaphore()}.
-	 *
-	 * @param int $semId
-	 * @param int $concurrency
-	 * @return false|\SysvSemaphore the semaphore on success or false on failure
-	 */
-	public static function guardWithSemaphore(int $semId, int $concurrency) {
-		if (!extension_loaded('sysvsem')) {
-			return false;
-		}
-		$sem = sem_get($semId, $concurrency);
-		if ($sem === false) {
-			return false;
-		}
-		if (!sem_acquire($sem)) {
-			return false;
-		}
-		return $sem;
-	}
-
-	/**
-	 * Releases the semaphore acquired from {@see Generator::guardWithSemaphore()}.
-	 *
-	 * @param false|\SysvSemaphore $semId the semaphore identifier returned by guardWithSemaphore
-	 * @return bool
-	 */
-	public static function unguardWithSemaphore(false|\SysvSemaphore $semId): bool {
-		if ($semId === false || !($semId instanceof \SysvSemaphore)) {
-			return false;
-		}
-		return sem_release($semId);
-	}
-
-	/**
-	 * Get the number of concurrent threads supported by the host.
-	 *
-	 * @return int number of concurrent threads, or 0 if it cannot be determined
-	 */
-	public static function getHardwareConcurrency(): int {
-		static $width;
-
-		if (!isset($width)) {
-			if (function_exists('ini_get')) {
-				$openBasedir = ini_get('open_basedir');
-				if (empty($openBasedir) || strpos($openBasedir, '/proc/cpuinfo') !== false) {
-					$width = is_readable('/proc/cpuinfo') ? substr_count(file_get_contents('/proc/cpuinfo'), 'processor') : 0;
-				} else {
-					$width = 0;
-				}
-			} else {
-				$width = 0;
-			}
-		}
-		return $width;
-	}
-
-	/**
-	 * Get number of concurrent preview generations from system config
-	 *
-	 * Two config entries, `preview_concurrency_new` and `preview_concurrency_all`,
-	 * are available. If not set, the default values are determined with the hardware concurrency
-	 * of the host. In case the hardware concurrency cannot be determined, or the user sets an
-	 * invalid value, fallback values are:
-	 * For new images whose previews do not exist and need to be generated, 4;
-	 * For all preview generation requests, 8.
-	 * Value of `preview_concurrency_all` should be greater than or equal to that of
-	 * `preview_concurrency_new`, otherwise, the latter is returned.
-	 *
-	 * @param string $type either `preview_concurrency_new` or `preview_concurrency_all`
-	 * @return int number of concurrent preview generations, or -1 if $type is invalid
-	 */
-	public function getNumConcurrentPreviews(string $type): int {
-		static $cached = [];
-		if (array_key_exists($type, $cached)) {
-			return $cached[$type];
-		}
-
-		$hardwareConcurrency = self::getHardwareConcurrency();
-		switch ($type) {
-			case 'preview_concurrency_all':
-				$fallback = $hardwareConcurrency > 0 ? $hardwareConcurrency * 2 : 8;
-				$concurrency_all = $this->config->getSystemValueInt($type, $fallback);
-				$concurrency_new = $this->getNumConcurrentPreviews('preview_concurrency_new');
-				$cached[$type] = max($concurrency_all, $concurrency_new);
-				break;
-			case 'preview_concurrency_new':
-				$fallback = $hardwareConcurrency > 0 ? $hardwareConcurrency : 4;
-				$cached[$type] = $this->config->getSystemValueInt($type, $fallback);
-				break;
-			default:
-				return -1;
-		}
-		return $cached[$type];
-	}
-
-	/**
-	 * @param ISimpleFolder $previewFolder
-	 * @param ISimpleFile[] $previewFiles
-	 * @param File $file
-	 * @param string $mimeType
-	 * @param string $prefix
-	 * @return ISimpleFile
-	 * @throws NotFoundException
-	 */
-	private function getMaxPreview(ISimpleFolder $previewFolder, array $previewFiles, File $file, $mimeType, $prefix) {
-		// We don't know the max preview size, so we can't use getCachedPreview.
-		// It might have been generated with a higher resolution than the current value.
-		foreach ($previewFiles as $node) {
-			$name = $node->getName();
-			if (($prefix === '' || str_starts_with($name, $prefix)) && strpos($name, 'max')) {
-				return $node;
-			}
-		}
-
-		$maxWidth = $this->config->getSystemValueInt('preview_max_x', 4096);
-		$maxHeight = $this->config->getSystemValueInt('preview_max_y', 4096);
-
-		return $this->generateProviderPreview($previewFolder, $file, $maxWidth, $maxHeight, false, true, $mimeType, $prefix);
-	}
-
-	private function generateProviderPreview(ISimpleFolder $previewFolder, File $file, int $width, int $height, bool $crop, bool $max, string $mimeType, string $prefix) {
-		$previewProviders = $this->previewManager->getProviders();
-		foreach ($previewProviders as $supportedMimeType => $providers) {
-			// Filter out providers that does not support this mime
-			if (!preg_match($supportedMimeType, $mimeType)) {
-				continue;
-			}
-
-			foreach ($providers as $providerClosure) {
-				$provider = $this->helper->getProvider($providerClosure);
-				if (!($provider instanceof IProviderV2)) {
-					continue;
-				}
-
-				if (!$provider->isAvailable($file)) {
-					continue;
-				}
-
-				$previewConcurrency = $this->getNumConcurrentPreviews('preview_concurrency_new');
-				$sem = self::guardWithSemaphore(self::SEMAPHORE_ID_NEW, $previewConcurrency);
-				try {
-					$this->logger->debug('Calling preview provider for {mimeType} with width={width}, height={height}', [
-						'mimeType' => $mimeType,
-						'width' => $width,
-						'height' => $height,
-					]);
-					$preview = $this->helper->getThumbnail($provider, $file, $width, $height);
-				} finally {
-					self::unguardWithSemaphore($sem);
-				}
-
-				if (!($preview instanceof IImage)) {
-					continue;
-				}
-
-				$path = $this->generatePath($preview->width(), $preview->height(), $crop, $max, $preview->dataMimeType(), $prefix);
-				try {
-					if ($preview instanceof IStreamImage) {
-						return $previewFolder->newFile($path, $preview->resource());
-					} else {
-						return $previewFolder->newFile($path, $preview->data());
-					}
-				} catch (NotPermittedException $e) {
-					throw new NotFoundException();
-				}
-
-				return $file;
-			}
-		}
-
-		throw new NotFoundException('No provider successfully handled the preview generation');
-	}
-
-	/**
-	 * @param ISimpleFile $file
-	 * @param string $prefix
-	 * @return int[]
-	 */
-	private function getPreviewSize(ISimpleFile $file, string $prefix = '') {
-		$size = explode('-', substr($file->getName(), strlen($prefix)));
-		return [(int)$size[0], (int)$size[1]];
-	}
-
-	/**
-	 * @param int $width
-	 * @param int $height
-	 * @param bool $crop
-	 * @param bool $max
-	 * @param string $mimeType
-	 * @param string $prefix
-	 * @return string
-	 */
-	private function generatePath($width, $height, $crop, $max, $mimeType, $prefix) {
-		$path = $prefix . (string)$width . '-' . (string)$height;
-		if ($crop) {
-			$path .= '-crop';
-		}
-		if ($max) {
-			$path .= '-max';
-		}
-
-		$ext = $this->getExtension($mimeType);
-		$path .= '.' . $ext;
-		return $path;
-	}
-
-
-	/**
-	 * @param int $width
-	 * @param int $height
-	 * @param bool $crop
-	 * @param string $mode
-	 * @param int $maxWidth
-	 * @param int $maxHeight
-	 * @return int[]
-	 */
-	private function calculateSize($width, $height, $crop, $mode, $maxWidth, $maxHeight) {
-		/*
+    public const SEMAPHORE_ID_ALL = 0x0a11;
+    public const SEMAPHORE_ID_NEW = 0x07ea;
+
+    public function __construct(
+        private IConfig $config,
+        private IPreview $previewManager,
+        private IAppData $appData,
+        private GeneratorHelper $helper,
+        private IEventDispatcher $eventDispatcher,
+        private LoggerInterface $logger,
+    ) {
+    }
+
+    /**
+     * Returns a preview of a file
+     *
+     * The cache is searched first and if nothing usable was found then a preview is
+     * generated by one of the providers
+     *
+     * @return ISimpleFile
+     * @throws NotFoundException
+     * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid)
+     */
+    public function getPreview(
+        File $file,
+        int $width = -1,
+        int $height = -1,
+        bool $crop = false,
+        string $mode = IPreview::MODE_FILL,
+        ?string $mimeType = null,
+        bool $cacheResult = true,
+    ): ISimpleFile {
+        $specification = [
+            'width' => $width,
+            'height' => $height,
+            'crop' => $crop,
+            'mode' => $mode,
+        ];
+
+        $this->eventDispatcher->dispatchTyped(new BeforePreviewFetchedEvent(
+            $file,
+            $width,
+            $height,
+            $crop,
+            $mode,
+            $mimeType,
+        ));
+
+        $this->logger->debug('Requesting preview for {path} with width={width}, height={height}, crop={crop}, mode={mode}, mimeType={mimeType}', [
+            'path' => $file->getPath(),
+            'width' => $width,
+            'height' => $height,
+            'crop' => $crop,
+            'mode' => $mode,
+            'mimeType' => $mimeType,
+        ]);
+
+
+        // since we only ask for one preview, and the generate method return the last one it created, it returns the one we want
+        return $this->generatePreviews($file, [$specification], $mimeType, $cacheResult);
+    }
+
+    /**
+     * Generates previews of a file
+     *
+     * @throws NotFoundException
+     * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid)
+     */
+    public function generatePreviews(File $file, array $specifications, ?string $mimeType = null, bool $cacheResult = true): ISimpleFile {
+        //Make sure that we can read the file
+        if (!$file->isReadable()) {
+            $this->logger->warning('Cannot read file: {path}, skipping preview generation.', ['path' => $file->getPath()]);
+            throw new NotFoundException('Cannot read file');
+        }
+
+        if ($mimeType === null) {
+            $mimeType = $file->getMimeType();
+        }
+
+        $previewFolder = $this->getPreviewFolder($file);
+        // List every existing preview first instead of trying to find them one by one
+        $previewFiles = $previewFolder->getDirectoryListing();
+
+        $previewVersion = '';
+        if ($file instanceof IVersionedPreviewFile) {
+            $previewVersion = $file->getPreviewVersion() . '-';
+        }
+
+        // Get the max preview and infer the max preview sizes from that
+        $maxPreview = $this->getMaxPreview($previewFolder, $previewFiles, $file, $mimeType, $previewVersion);
+        $maxPreviewImage = null; // only load the image when we need it
+        if ($maxPreview->getSize() === 0) {
+            $maxPreview->delete();
+            $this->logger->error('Max preview generated for file {path} has size 0, deleting and throwing exception.', ['path' => $file->getPath()]);
+            throw new NotFoundException('Max preview size 0, invalid!');
+        }
+
+        [$maxWidth, $maxHeight] = $this->getPreviewSize($maxPreview, $previewVersion);
+
+        if ($maxWidth <= 0 || $maxHeight <= 0) {
+            throw new NotFoundException('The maximum preview sizes are zero or less pixels');
+        }
+
+        $preview = null;
+
+        foreach ($specifications as $specification) {
+            $width = $specification['width'] ?? -1;
+            $height = $specification['height'] ?? -1;
+            $crop = $specification['crop'] ?? false;
+            $mode = $specification['mode'] ?? IPreview::MODE_FILL;
+
+            // If both width and height are -1 we just want the max preview
+            if ($width === -1 && $height === -1) {
+                $width = $maxWidth;
+                $height = $maxHeight;
+            }
+
+            // Calculate the preview size
+            [$width, $height] = $this->calculateSize($width, $height, $crop, $mode, $maxWidth, $maxHeight);
+
+            // No need to generate a preview that is just the max preview
+            if ($width === $maxWidth && $height === $maxHeight) {
+                // ensure correct return value if this was the last one
+                $preview = $maxPreview;
+                continue;
+            }
+
+            // Try to get a cached preview. Else generate (and store) one
+            try {
+                try {
+                    $preview = $this->getCachedPreview($previewFiles, $width, $height, $crop, $maxPreview->getMimeType(), $previewVersion);
+                } catch (NotFoundException $e) {
+                    if (!$this->previewManager->isMimeSupported($mimeType)) {
+                        throw new NotFoundException();
+                    }
+
+                    if ($maxPreviewImage === null) {
+                        $maxPreviewImage = $this->helper->getImage($maxPreview);
+                    }
+
+                    $this->logger->debug('Cached preview not found for file {path}, generating a new preview.', ['path' => $file->getPath()]);
+                    $preview = $this->generatePreview($previewFolder, $maxPreviewImage, $width, $height, $crop, $maxWidth, $maxHeight, $previewVersion, $cacheResult);
+                    // New file, augment our array
+                    $previewFiles[] = $preview;
+                }
+            } catch (\InvalidArgumentException $e) {
+                throw new NotFoundException('', 0, $e);
+            }
+
+            if ($preview->getSize() === 0) {
+                $preview->delete();
+                throw new NotFoundException('Cached preview size 0, invalid!');
+            }
+        }
+        assert($preview !== null);
+
+        // Free memory being used by the embedded image resource.  Without this the image is kept in memory indefinitely.
+        // Garbage Collection does NOT free this memory.  We have to do it ourselves.
+        if ($maxPreviewImage instanceof \OCP\Image) {
+            $maxPreviewImage->destroy();
+        }
+
+        return $preview;
+    }
+
+    /**
+     * Acquire a semaphore of the specified id and concurrency, blocking if necessary.
+     * Return an identifier of the semaphore on success, which can be used to release it via
+     * {@see Generator::unguardWithSemaphore()}.
+     *
+     * @param int $semId
+     * @param int $concurrency
+     * @return false|\SysvSemaphore the semaphore on success or false on failure
+     */
+    public static function guardWithSemaphore(int $semId, int $concurrency) {
+        if (!extension_loaded('sysvsem')) {
+            return false;
+        }
+        $sem = sem_get($semId, $concurrency);
+        if ($sem === false) {
+            return false;
+        }
+        if (!sem_acquire($sem)) {
+            return false;
+        }
+        return $sem;
+    }
+
+    /**
+     * Releases the semaphore acquired from {@see Generator::guardWithSemaphore()}.
+     *
+     * @param false|\SysvSemaphore $semId the semaphore identifier returned by guardWithSemaphore
+     * @return bool
+     */
+    public static function unguardWithSemaphore(false|\SysvSemaphore $semId): bool {
+        if ($semId === false || !($semId instanceof \SysvSemaphore)) {
+            return false;
+        }
+        return sem_release($semId);
+    }
+
+    /**
+     * Get the number of concurrent threads supported by the host.
+     *
+     * @return int number of concurrent threads, or 0 if it cannot be determined
+     */
+    public static function getHardwareConcurrency(): int {
+        static $width;
+
+        if (!isset($width)) {
+            if (function_exists('ini_get')) {
+                $openBasedir = ini_get('open_basedir');
+                if (empty($openBasedir) || strpos($openBasedir, '/proc/cpuinfo') !== false) {
+                    $width = is_readable('/proc/cpuinfo') ? substr_count(file_get_contents('/proc/cpuinfo'), 'processor') : 0;
+                } else {
+                    $width = 0;
+                }
+            } else {
+                $width = 0;
+            }
+        }
+        return $width;
+    }
+
+    /**
+     * Get number of concurrent preview generations from system config
+     *
+     * Two config entries, `preview_concurrency_new` and `preview_concurrency_all`,
+     * are available. If not set, the default values are determined with the hardware concurrency
+     * of the host. In case the hardware concurrency cannot be determined, or the user sets an
+     * invalid value, fallback values are:
+     * For new images whose previews do not exist and need to be generated, 4;
+     * For all preview generation requests, 8.
+     * Value of `preview_concurrency_all` should be greater than or equal to that of
+     * `preview_concurrency_new`, otherwise, the latter is returned.
+     *
+     * @param string $type either `preview_concurrency_new` or `preview_concurrency_all`
+     * @return int number of concurrent preview generations, or -1 if $type is invalid
+     */
+    public function getNumConcurrentPreviews(string $type): int {
+        static $cached = [];
+        if (array_key_exists($type, $cached)) {
+            return $cached[$type];
+        }
+
+        $hardwareConcurrency = self::getHardwareConcurrency();
+        switch ($type) {
+            case 'preview_concurrency_all':
+                $fallback = $hardwareConcurrency > 0 ? $hardwareConcurrency * 2 : 8;
+                $concurrency_all = $this->config->getSystemValueInt($type, $fallback);
+                $concurrency_new = $this->getNumConcurrentPreviews('preview_concurrency_new');
+                $cached[$type] = max($concurrency_all, $concurrency_new);
+                break;
+            case 'preview_concurrency_new':
+                $fallback = $hardwareConcurrency > 0 ? $hardwareConcurrency : 4;
+                $cached[$type] = $this->config->getSystemValueInt($type, $fallback);
+                break;
+            default:
+                return -1;
+        }
+        return $cached[$type];
+    }
+
+    /**
+     * @param ISimpleFolder $previewFolder
+     * @param ISimpleFile[] $previewFiles
+     * @param File $file
+     * @param string $mimeType
+     * @param string $prefix
+     * @return ISimpleFile
+     * @throws NotFoundException
+     */
+    private function getMaxPreview(ISimpleFolder $previewFolder, array $previewFiles, File $file, $mimeType, $prefix) {
+        // We don't know the max preview size, so we can't use getCachedPreview.
+        // It might have been generated with a higher resolution than the current value.
+        foreach ($previewFiles as $node) {
+            $name = $node->getName();
+            if (($prefix === '' || str_starts_with($name, $prefix)) && strpos($name, 'max')) {
+                return $node;
+            }
+        }
+
+        $maxWidth = $this->config->getSystemValueInt('preview_max_x', 4096);
+        $maxHeight = $this->config->getSystemValueInt('preview_max_y', 4096);
+
+        return $this->generateProviderPreview($previewFolder, $file, $maxWidth, $maxHeight, false, true, $mimeType, $prefix);
+    }
+
+    private function generateProviderPreview(ISimpleFolder $previewFolder, File $file, int $width, int $height, bool $crop, bool $max, string $mimeType, string $prefix) {
+        $previewProviders = $this->previewManager->getProviders();
+        foreach ($previewProviders as $supportedMimeType => $providers) {
+            // Filter out providers that does not support this mime
+            if (!preg_match($supportedMimeType, $mimeType)) {
+                continue;
+            }
+
+            foreach ($providers as $providerClosure) {
+                $provider = $this->helper->getProvider($providerClosure);
+                if (!($provider instanceof IProviderV2)) {
+                    continue;
+                }
+
+                if (!$provider->isAvailable($file)) {
+                    continue;
+                }
+
+                $previewConcurrency = $this->getNumConcurrentPreviews('preview_concurrency_new');
+                $sem = self::guardWithSemaphore(self::SEMAPHORE_ID_NEW, $previewConcurrency);
+                try {
+                    $this->logger->debug('Calling preview provider for {mimeType} with width={width}, height={height}', [
+                        'mimeType' => $mimeType,
+                        'width' => $width,
+                        'height' => $height,
+                    ]);
+                    $preview = $this->helper->getThumbnail($provider, $file, $width, $height);
+                } finally {
+                    self::unguardWithSemaphore($sem);
+                }
+
+                if (!($preview instanceof IImage)) {
+                    continue;
+                }
+
+                $path = $this->generatePath($preview->width(), $preview->height(), $crop, $max, $preview->dataMimeType(), $prefix);
+                try {
+                    if ($preview instanceof IStreamImage) {
+                        return $previewFolder->newFile($path, $preview->resource());
+                    } else {
+                        return $previewFolder->newFile($path, $preview->data());
+                    }
+                } catch (NotPermittedException $e) {
+                    throw new NotFoundException();
+                }
+
+                return $file;
+            }
+        }
+
+        throw new NotFoundException('No provider successfully handled the preview generation');
+    }
+
+    /**
+     * @param ISimpleFile $file
+     * @param string $prefix
+     * @return int[]
+     */
+    private function getPreviewSize(ISimpleFile $file, string $prefix = '') {
+        $size = explode('-', substr($file->getName(), strlen($prefix)));
+        return [(int)$size[0], (int)$size[1]];
+    }
+
+    /**
+     * @param int $width
+     * @param int $height
+     * @param bool $crop
+     * @param bool $max
+     * @param string $mimeType
+     * @param string $prefix
+     * @return string
+     */
+    private function generatePath($width, $height, $crop, $max, $mimeType, $prefix) {
+        $path = $prefix . (string)$width . '-' . (string)$height;
+        if ($crop) {
+            $path .= '-crop';
+        }
+        if ($max) {
+            $path .= '-max';
+        }
+
+        $ext = $this->getExtension($mimeType);
+        $path .= '.' . $ext;
+        return $path;
+    }
+
+
+    /**
+     * @param int $width
+     * @param int $height
+     * @param bool $crop
+     * @param string $mode
+     * @param int $maxWidth
+     * @param int $maxHeight
+     * @return int[]
+     */
+    private function calculateSize($width, $height, $crop, $mode, $maxWidth, $maxHeight) {
+        /*
 		 * If we are not cropping we have to make sure the requested image
 		 * respects the aspect ratio of the original.
 		 */
-		if (!$crop) {
-			$ratio = $maxHeight / $maxWidth;
+        if (!$crop) {
+            $ratio = $maxHeight / $maxWidth;
 
-			if ($width === -1) {
-				$width = $height / $ratio;
-			}
-			if ($height === -1) {
-				$height = $width * $ratio;
-			}
+            if ($width === -1) {
+                $width = $height / $ratio;
+            }
+            if ($height === -1) {
+                $height = $width * $ratio;
+            }
 
-			$ratioH = $height / $maxHeight;
-			$ratioW = $width / $maxWidth;
+            $ratioH = $height / $maxHeight;
+            $ratioW = $width / $maxWidth;
 
-			/*
+            /*
 			 * Fill means that the $height and $width are the max
 			 * Cover means min.
 			 */
-			if ($mode === IPreview::MODE_FILL) {
-				if ($ratioH > $ratioW) {
-					$height = $width * $ratio;
-				} else {
-					$width = $height / $ratio;
-				}
-			} elseif ($mode === IPreview::MODE_COVER) {
-				if ($ratioH > $ratioW) {
-					$width = $height / $ratio;
-				} else {
-					$height = $width * $ratio;
-				}
-			}
-		}
-
-		if ($height !== $maxHeight && $width !== $maxWidth) {
-			/*
+            if ($mode === IPreview::MODE_FILL) {
+                if ($ratioH > $ratioW) {
+                    $height = $width * $ratio;
+                } else {
+                    $width = $height / $ratio;
+                }
+            } elseif ($mode === IPreview::MODE_COVER) {
+                if ($ratioH > $ratioW) {
+                    $width = $height / $ratio;
+                } else {
+                    $height = $width * $ratio;
+                }
+            }
+        }
+
+        if ($height !== $maxHeight && $width !== $maxWidth) {
+            /*
 			 * Scale to the nearest power of four
 			 */
-			$pow4height = 4 ** ceil(log($height) / log(4));
-			$pow4width = 4 ** ceil(log($width) / log(4));
-
-			// Minimum size is 64
-			$pow4height = max($pow4height, 64);
-			$pow4width = max($pow4width, 64);
-
-			$ratioH = $height / $pow4height;
-			$ratioW = $width / $pow4width;
-
-			if ($ratioH < $ratioW) {
-				$width = $pow4width;
-				$height /= $ratioW;
-			} else {
-				$height = $pow4height;
-				$width /= $ratioH;
-			}
-		}
-
-		/*
+            $pow4height = 4 ** ceil(log($height) / log(4));
+            $pow4width = 4 ** ceil(log($width) / log(4));
+
+            // Minimum size is 64
+            $pow4height = max($pow4height, 64);
+            $pow4width = max($pow4width, 64);
+
+            $ratioH = $height / $pow4height;
+            $ratioW = $width / $pow4width;
+
+            if ($ratioH < $ratioW) {
+                $width = $pow4width;
+                $height /= $ratioW;
+            } else {
+                $height = $pow4height;
+                $width /= $ratioH;
+            }
+        }
+
+        /*
 		 * Make sure the requested height and width fall within the max
 		 * of the preview.
 		 */
-		if ($height > $maxHeight) {
-			$ratio = $height / $maxHeight;
-			$height = $maxHeight;
-			$width /= $ratio;
-		}
-		if ($width > $maxWidth) {
-			$ratio = $width / $maxWidth;
-			$width = $maxWidth;
-			$height /= $ratio;
-		}
-
-		return [(int)round($width), (int)round($height)];
-	}
-
-	/**
-	 * @throws NotFoundException
-	 * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid)
-	 */
-	private function generatePreview(
-		ISimpleFolder $previewFolder,
-		IImage $maxPreview,
-		int $width,
-		int $height,
-		bool $crop,
-		int $maxWidth,
-		int $maxHeight,
-		string $prefix,
-		bool $cacheResult,
-	): ISimpleFile {
-		$preview = $maxPreview;
-		if (!$preview->valid()) {
-			throw new \InvalidArgumentException('Failed to generate preview, failed to load image');
-		}
-
-		$previewConcurrency = $this->getNumConcurrentPreviews('preview_concurrency_new');
-		$sem = self::guardWithSemaphore(self::SEMAPHORE_ID_NEW, $previewConcurrency);
-		try {
-			if ($crop) {
-				if ($height !== $preview->height() && $width !== $preview->width()) {
-					//Resize
-					$widthR = $preview->width() / $width;
-					$heightR = $preview->height() / $height;
-
-					if ($widthR > $heightR) {
-						$scaleH = $height;
-						$scaleW = $maxWidth / $heightR;
-					} else {
-						$scaleH = $maxHeight / $widthR;
-						$scaleW = $width;
-					}
-					$preview = $preview->preciseResizeCopy((int)round($scaleW), (int)round($scaleH));
-				}
-				$cropX = (int)floor(abs($width - $preview->width()) * 0.5);
-				$cropY = (int)floor(abs($height - $preview->height()) * 0.5);
-				$preview = $preview->cropCopy($cropX, $cropY, $width, $height);
-			} else {
-				$preview = $maxPreview->resizeCopy(max($width, $height));
-			}
-		} finally {
-			self::unguardWithSemaphore($sem);
-		}
-
-
-		$path = $this->generatePath($width, $height, $crop, false, $preview->dataMimeType(), $prefix);
-		try {
-			if ($cacheResult) {
-				return $previewFolder->newFile($path, $preview->data());
-			} else {
-				return new InMemoryFile($path, $preview->data());
-			}
-		} catch (NotPermittedException $e) {
-			throw new NotFoundException();
-		}
-		return $file;
-	}
-
-	/**
-	 * @param ISimpleFile[] $files Array of FileInfo, as the result of getDirectoryListing()
-	 * @param int $width
-	 * @param int $height
-	 * @param bool $crop
-	 * @param string $mimeType
-	 * @param string $prefix
-	 * @return ISimpleFile
-	 *
-	 * @throws NotFoundException
-	 */
-	private function getCachedPreview($files, $width, $height, $crop, $mimeType, $prefix) {
-		$path = $this->generatePath($width, $height, $crop, false, $mimeType, $prefix);
-		foreach ($files as $file) {
-			if ($file->getName() === $path) {
-				$this->logger->debug('Found cached preview: {path}', ['path' => $path]);
-				return $file;
-			}
-		}
-		throw new NotFoundException();
-	}
-
-	/**
-	 * Get the specific preview folder for this file
-	 *
-	 * @param File $file
-	 * @return ISimpleFolder
-	 *
-	 * @throws InvalidPathException
-	 * @throws NotFoundException
-	 * @throws NotPermittedException
-	 */
-	private function getPreviewFolder(File $file) {
-		// Obtain file id outside of try catch block to prevent the creation of an existing folder
-		$fileId = (string)$file->getId();
-
-		try {
-			$folder = $this->appData->getFolder($fileId);
-		} catch (NotFoundException $e) {
-			$folder = $this->appData->newFolder($fileId);
-		}
-
-		return $folder;
-	}
-
-	/**
-	 * @param string $mimeType
-	 * @return null|string
-	 * @throws \InvalidArgumentException
-	 */
-	private function getExtension($mimeType) {
-		switch ($mimeType) {
-			case 'image/png':
-				return 'png';
-			case 'image/jpeg':
-				return 'jpg';
-			case 'image/webp':
-				return 'webp';
-			case 'image/gif':
-				return 'gif';
-			default:
-				throw new \InvalidArgumentException('Not a valid mimetype: "' . $mimeType . '"');
-		}
-	}
+        if ($height > $maxHeight) {
+            $ratio = $height / $maxHeight;
+            $height = $maxHeight;
+            $width /= $ratio;
+        }
+        if ($width > $maxWidth) {
+            $ratio = $width / $maxWidth;
+            $width = $maxWidth;
+            $height /= $ratio;
+        }
+
+        return [(int)round($width), (int)round($height)];
+    }
+
+    /**
+     * @throws NotFoundException
+     * @throws \InvalidArgumentException if the preview would be invalid (in case the original image is invalid)
+     */
+    private function generatePreview(
+        ISimpleFolder $previewFolder,
+        IImage $maxPreview,
+        int $width,
+        int $height,
+        bool $crop,
+        int $maxWidth,
+        int $maxHeight,
+        string $prefix,
+        bool $cacheResult,
+    ): ISimpleFile {
+        $preview = $maxPreview;
+        if (!$preview->valid()) {
+            throw new \InvalidArgumentException('Failed to generate preview, failed to load image');
+        }
+
+        $previewConcurrency = $this->getNumConcurrentPreviews('preview_concurrency_new');
+        $sem = self::guardWithSemaphore(self::SEMAPHORE_ID_NEW, $previewConcurrency);
+        try {
+            if ($crop) {
+                if ($height !== $preview->height() && $width !== $preview->width()) {
+                    //Resize
+                    $widthR = $preview->width() / $width;
+                    $heightR = $preview->height() / $height;
+
+                    if ($widthR > $heightR) {
+                        $scaleH = $height;
+                        $scaleW = $maxWidth / $heightR;
+                    } else {
+                        $scaleH = $maxHeight / $widthR;
+                        $scaleW = $width;
+                    }
+                    $preview = $preview->preciseResizeCopy((int)round($scaleW), (int)round($scaleH));
+                }
+                $cropX = (int)floor(abs($width - $preview->width()) * 0.5);
+                $cropY = (int)floor(abs($height - $preview->height()) * 0.5);
+                $preview = $preview->cropCopy($cropX, $cropY, $width, $height);
+            } else {
+                $preview = $maxPreview->resizeCopy(max($width, $height));
+            }
+        } finally {
+            self::unguardWithSemaphore($sem);
+        }
+
+
+        $path = $this->generatePath($width, $height, $crop, false, $preview->dataMimeType(), $prefix);
+        try {
+            if ($cacheResult) {
+                return $previewFolder->newFile($path, $preview->data());
+            } else {
+                return new InMemoryFile($path, $preview->data());
+            }
+        } catch (NotPermittedException $e) {
+            throw new NotFoundException();
+        }
+        return $file;
+    }
+
+    /**
+     * @param ISimpleFile[] $files Array of FileInfo, as the result of getDirectoryListing()
+     * @param int $width
+     * @param int $height
+     * @param bool $crop
+     * @param string $mimeType
+     * @param string $prefix
+     * @return ISimpleFile
+     *
+     * @throws NotFoundException
+     */
+    private function getCachedPreview($files, $width, $height, $crop, $mimeType, $prefix) {
+        $path = $this->generatePath($width, $height, $crop, false, $mimeType, $prefix);
+        foreach ($files as $file) {
+            if ($file->getName() === $path) {
+                $this->logger->debug('Found cached preview: {path}', ['path' => $path]);
+                return $file;
+            }
+        }
+        throw new NotFoundException();
+    }
+
+    /**
+     * Get the specific preview folder for this file
+     *
+     * @param File $file
+     * @return ISimpleFolder
+     *
+     * @throws InvalidPathException
+     * @throws NotFoundException
+     * @throws NotPermittedException
+     */
+    private function getPreviewFolder(File $file) {
+        // Obtain file id outside of try catch block to prevent the creation of an existing folder
+        $fileId = (string)$file->getId();
+
+        try {
+            $folder = $this->appData->getFolder($fileId);
+        } catch (NotFoundException $e) {
+            $folder = $this->appData->newFolder($fileId);
+        }
+
+        return $folder;
+    }
+
+    /**
+     * @param string $mimeType
+     * @return null|string
+     * @throws \InvalidArgumentException
+     */
+    private function getExtension($mimeType) {
+        switch ($mimeType) {
+            case 'image/png':
+                return 'png';
+            case 'image/jpeg':
+                return 'jpg';
+            case 'image/webp':
+                return 'webp';
+            case 'image/gif':
+                return 'gif';
+            default:
+                throw new \InvalidArgumentException('Not a valid mimetype: "' . $mimeType . '"');
+        }
+    }
 }