Merge pull request #1741 from nextcloud/new_preview

Improve previews

7 files changed, 669 insertions, 4 deletions

diff --git a/lib/private/Preview.php b/lib/private/Preview.php
index ccaec738caf..caa1e89bacc 100644
--- a/lib/private/Preview.php
+++ b/lib/private/Preview.php
@@ -125,7 +125,7 @@ class Preview {
 		$sysConfig = \OC::$server->getConfig();
 		$this->configMaxWidth = $sysConfig->getSystemValue('preview_max_x', 2048);
 		$this->configMaxHeight = $sysConfig->getSystemValue('preview_max_y', 2048);
-		$this->maxScaleFactor = $sysConfig->getSystemValue('preview_max_scale_factor', 2);
+		$this->maxScaleFactor = $sysConfig->getSystemValue('preview_max_scale_factor', 1);
 
 		//save parameters
 		$this->setFile($file);
diff --git a/lib/private/Preview/Generator.php b/lib/private/Preview/Generator.php
new file mode 100644
index 00000000000..3d4e9bf3677
--- /dev/null
+++ b/lib/private/Preview/Generator.php
@@ -0,0 +1,338 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Preview;
+
+use OCP\Files\File;
+use OCP\Files\IAppData;
+use OCP\Files\NotFoundException;
+use OCP\Files\SimpleFS\ISimpleFile;
+use OCP\Files\SimpleFS\ISimpleFolder;
+use OCP\IConfig;
+use OCP\IImage;
+use OCP\IPreview;
+use OCP\Preview\IProvider;
+
+class Generator {
+
+	/** @var IPreview */
+	private $previewManager;
+	/** @var IConfig */
+	private $config;
+	/** @var IAppData */
+	private $appData;
+	/** @var GeneratorHelper */
+	private $helper;
+
+	/**
+	 * @param IConfig $config
+	 * @param IPreview $previewManager
+	 * @param IAppData $appData
+	 * @param GeneratorHelper $helper
+	 */
+	public function __construct(
+		IConfig $config,
+		IPreview $previewManager,
+		IAppData $appData,
+		GeneratorHelper $helper
+	) {
+		$this->config = $config;
+		$this->previewManager = $previewManager;
+		$this->appData = $appData;
+		$this->helper = $helper;
+	}
+
+	/**
+	 * 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
+	 *
+	 * @param File $file
+	 * @param int $width
+	 * @param int $height
+	 * @param bool $crop
+	 * @param string $mode
+	 * @param string $mimeType
+	 * @return ISimpleFile
+	 * @throws NotFoundException
+	 */
+	public function getPreview(File $file, $width = -1, $height = -1, $crop = false, $mode = IPreview::MODE_FILL, $mimeType = null) {
+		if ($mimeType === null) {
+			$mimeType = $file->getMimeType();
+		}
+		if (!$this->previewManager->isMimeSupported($mimeType)) {
+			throw new NotFoundException();
+		}
+
+		$previewFolder = $this->getPreviewFolder($file);
+
+		// Get the max preview and infer the max preview sizes from that
+		$maxPreview = $this->getMaxPreview($previewFolder, $file, $mimeType);
+		list($maxWidth, $maxHeight) = $this->getPreviewSize($maxPreview);
+
+		// Calculate the preview size
+		list($width, $height) = $this->calculateSize($width, $height, $crop, $mode, $maxWidth, $maxHeight);
+
+		// Try to get a cached preview. Else generate (and store) one
+		try {
+			$file = $this->getCachedPreview($previewFolder, $width, $height, $crop);
+		} catch (NotFoundException $e) {
+			$file = $this->generatePreview($previewFolder, $maxPreview, $width, $height, $crop, $maxWidth, $maxHeight);
+		}
+
+		return $file;
+	}
+
+	/**
+	 * @param ISimpleFolder $previewFolder
+	 * @param File $file
+	 * @param string $mimeType
+	 * @return ISimpleFile
+	 * @throws NotFoundException
+	 */
+	private function getMaxPreview(ISimpleFolder $previewFolder, File $file, $mimeType) {
+		$nodes = $previewFolder->getDirectoryListing();
+
+		foreach ($nodes as $node) {
+			if (strpos($node->getName(), 'max')) {
+				return $node;
+			}
+		}
+
+		$previewProviders = $this->previewManager->getProviders();
+		foreach ($previewProviders as $supportedMimeType => $providers) {
+			if (!preg_match($supportedMimeType, $mimeType)) {
+				continue;
+			}
+
+			foreach ($providers as $provider) {
+				$provider = $this->helper->getProvider($provider);
+				if (!($provider instanceof IProvider)) {
+					continue;
+				}
+
+				$maxWidth = (int)$this->config->getSystemValue('preview_max_x', 2048);
+				$maxHeight = (int)$this->config->getSystemValue('preview_max_y', 2048);
+
+				$preview = $this->helper->getThumbnail($provider, $file, $maxWidth, $maxHeight);
+
+				if (!($preview instanceof IImage)) {
+					continue;
+				}
+
+				$path = strval($preview->width()) . '-' . strval($preview->height()) . '-max.png';
+				$file = $previewFolder->newFile($path);
+				$file->putContent($preview->data());
+
+				return $file;
+			}
+		}
+
+		throw new NotFoundException();
+	}
+
+	/**
+	 * @param ISimpleFile $file
+	 * @return int[]
+	 */
+	private function getPreviewSize(ISimpleFile $file) {
+		$size = explode('-', $file->getName());
+		return [(int)$size[0], (int)$size[1]];
+	}
+
+	/**
+	 * @param int $width
+	 * @param int $height
+	 * @param bool $crop
+	 * @return string
+	 */
+	private function generatePath($width, $height, $crop) {
+		$path = strval($width) . '-' . strval($height);
+		if ($crop) {
+			$path .= '-crop';
+		}
+		$path .= '.png';
+		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 / $maxWidth;
+
+			if ($width === -1) {
+				$width = $height / $ratio;
+			}
+			if ($height === -1) {
+				$height = $width * $ratio;
+			}
+
+			$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 / $ratio;
+				}
+			} else if ($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 two
+			 */
+			$pow2height = pow(2, ceil(log($height) / log(2)));
+			$pow2width = pow(2, ceil(log($width) / log(2)));
+
+			$ratioH = $height / $pow2height;
+			$ratioW = $width / $pow2width;
+
+			if ($ratioH < $ratioW) {
+				$width = $pow2width;
+				$height = $height / $ratioW;
+			} else {
+				$height = $pow2height;
+				$width = $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 = $width / $ratio;
+		}
+		if ($width > $maxWidth) {
+			$ratio = $width / $maxWidth;
+			$width = $maxWidth;
+			$height = $height / $ratio;
+		}
+
+		return [(int)round($width), (int)round($height)];
+	}
+
+	/**
+	 * @param ISimpleFolder $previewFolder
+	 * @param ISimpleFile $maxPreview
+	 * @param int $width
+	 * @param int $height
+	 * @param bool $crop
+	 * @param int $maxWidth
+	 * @param int $maxHeight
+	 * @return ISimpleFile
+	 * @throws NotFoundException
+	 */
+	private function generatePreview(ISimpleFolder $previewFolder, ISimpleFile $maxPreview, $width, $height, $crop, $maxWidth, $maxHeight) {
+		$preview = $this->helper->getImage($maxPreview);
+
+		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;
+				}
+				$preview->preciseResize(round($scaleW), round($scaleH));
+			}
+			$cropX = floor(abs($width - $preview->width()) * 0.5);
+			$cropY = 0;
+			$preview->crop($cropX, $cropY, $width, $height);
+		} else {
+			$preview->resize(max($width, $height));
+		}
+
+		$path = $this->generatePath($width, $height, $crop);
+		$file = $previewFolder->newFile($path);
+		$file->putContent($preview->data());
+
+		return $file;
+	}
+
+	/**
+	 * @param ISimpleFolder $previewFolder
+	 * @param int $width
+	 * @param int $height
+	 * @param bool $crop
+	 * @return ISimpleFile
+	 *
+	 * @throws NotFoundException
+	 */
+	private function getCachedPreview(ISimpleFolder $previewFolder, $width, $height, $crop) {
+		$path = $this->generatePath($width, $height, $crop);
+
+		return $previewFolder->getFile($path);
+	}
+
+	/**
+	 * Get the specific preview folder for this file
+	 *
+	 * @param File $file
+	 * @return ISimpleFolder
+	 */
+	private function getPreviewFolder(File $file) {
+		try {
+			$folder = $this->appData->getFolder($file->getId());
+		} catch (NotFoundException $e) {
+			$folder = $this->appData->newFolder($file->getId());
+		}
+
+		return $folder;
+	}
+}
diff --git a/lib/private/Preview/GeneratorHelper.php b/lib/private/Preview/GeneratorHelper.php
new file mode 100644
index 00000000000..282c46a2a5d
--- /dev/null
+++ b/lib/private/Preview/GeneratorHelper.php
@@ -0,0 +1,91 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OC\Preview;
+
+use OC\Files\View;
+use OCP\Files\File;
+use OCP\Files\IRootFolder;
+use OCP\Files\SimpleFS\ISimpleFile;
+use OCP\IImage;
+use OCP\Image as img;
+use OCP\Preview\IProvider;
+
+/**
+ * Very small wrapper class to make the generator fully unit testable
+ */
+class GeneratorHelper {
+
+	/** @var IRootFolder */
+	private $rootFolder;
+
+	public function __construct(IRootFolder $rootFolder) {
+		$this->rootFolder = $rootFolder;
+	}
+
+	/**
+	 * @param IProvider $provider
+	 * @param File $file
+	 * @param int $maxWidth
+	 * @param int $maxHeight
+	 * @return bool|IImage
+	 */
+	public function getThumbnail(IProvider $provider, File $file, $maxWidth, $maxHeight) {
+		list($view, $path) = $this->getViewAndPath($file);
+		return $provider->getThumbnail($path, $maxWidth, $maxHeight, false, $view);
+	}
+
+	/**
+	 * @param File $file
+	 * @return array
+	 * This is required to create the old view and path
+	 */
+	private function getViewAndPath(File $file) {
+		$owner = $file->getOwner()->getUID();
+
+		$userFolder = $this->rootFolder->getUserFolder($owner)->getParent();
+
+		$nodes = $userFolder->getById($file->getId());
+		$file = $nodes[0];
+
+		$view = new View($userFolder->getPath());
+		$path = $userFolder->getRelativePath($file->getPath());
+
+		return [$view, $path];
+	}
+
+	/**
+	 * @param ISimpleFile $maxPreview
+	 * @return IImage
+	 */
+	public function getImage(ISimpleFile $maxPreview) {
+		return new img($maxPreview->getContent());
+	}
+
+	/**
+	 * @param $provider
+	 * @return IProvider
+	 */
+	public function getProvider($provider) {
+		return $provider();
+	}
+}
diff --git a/lib/private/Preview/Watcher.php b/lib/private/Preview/Watcher.php
new file mode 100644
index 00000000000..0b87bcda86e
--- /dev/null
+++ b/lib/private/Preview/Watcher.php
@@ -0,0 +1,98 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OC\Preview;
+
+use OCP\Files\File;
+use OCP\Files\Node;
+use OCP\Files\Folder;
+use OCP\Files\IAppData;
+use OCP\Files\NotFoundException;
+
+/**
+ * Class Watcher
+ *
+ * @package OC\Preview
+ *
+ * Class that will watch filesystem activity and remove previews as needed.
+ */
+class Watcher {
+	/** @var IAppData */
+	private $appData;
+
+	/** @var int[] */
+	private $toDelete = [];
+
+	/**
+	 * Watcher constructor.
+	 *
+	 * @param IAppData $appData
+	 */
+	public function __construct(IAppData $appData) {
+		$this->appData = $appData;
+	}
+
+	public function postWrite(Node $node) {
+		// We only handle files
+		if ($node instanceof Folder) {
+			return;
+		}
+
+		try {
+			$folder = $this->appData->getFolder($node->getId());
+			$folder->delete();
+		} catch (NotFoundException $e) {
+			//Nothing to do
+		}
+	}
+
+	public function preDelete(Node $node) {
+		// To avoid cycles
+		if ($this->toDelete !== []) {
+			return;
+		}
+
+		if ($node instanceof File) {
+			$this->toDelete[] = $node->getId();
+			return;
+		}
+
+		/** @var Folder $node */
+		$nodes = $node->search('');
+		foreach ($nodes as $node) {
+			if ($node instanceof File) {
+				$this->toDelete[] = $node->getId();
+			}
+		}
+	}
+
+	public function postDelete(Node $node) {
+		foreach ($this->toDelete as $fid) {
+			try {
+				$folder = $this->appData->getFolder($fid);
+				$folder->delete();
+			} catch (NotFoundException $e) {
+				// continue
+			}
+		}
+	}
+}
diff --git a/lib/private/Preview/WatcherConnector.php b/lib/private/Preview/WatcherConnector.php
new file mode 100644
index 00000000000..4e6e786cec7
--- /dev/null
+++ b/lib/private/Preview/WatcherConnector.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OC\Preview;
+
+use OC\SystemConfig;
+use OCP\Files\Node;
+use OCP\Files\IRootFolder;
+
+class WatcherConnector {
+
+	/** @var IRootFolder */
+	private $root;
+
+	/** @var SystemConfig */
+	private $config;
+
+	/**
+	 * WatcherConnector constructor.
+	 *
+	 * @param IRootFolder $root
+	 * @param SystemConfig $config
+	 */
+	public function __construct(IRootFolder $root,
+								SystemConfig $config) {
+		$this->root = $root;
+		$this->config = $config;
+	}
+
+	/**
+	 * @return Watcher
+	 */
+	private function getWatcher() {
+		return \OC::$server->query(Watcher::class);
+	}
+
+	public function connectWatcher() {
+		// Do not connect if we are not setup yet!
+		if ($this->config->getValue('instanceid', null) !== null) {
+			$this->root->listen('\OC\Files', 'postWrite', function (Node $node) {
+				$this->getWatcher()->postWrite($node);
+			});
+
+			$this->root->listen('\OC\Files', 'preDelete', function (Node $node) {
+				$this->getWatcher()->preDelete($node);
+			});
+
+			$this->root->listen('\OC\Files', 'postDelete', function (Node $node) {
+				$this->getWatcher()->postDelete($node);
+			});
+		}
+	}
+}
diff --git a/lib/private/PreviewManager.php b/lib/private/PreviewManager.php
index 109feb45864..a2ef9659b3b 100644
--- a/lib/private/PreviewManager.php
+++ b/lib/private/PreviewManager.php
@@ -25,13 +25,30 @@
  */
 namespace OC;
 
+use OC\Preview\Generator;
+use OC\Preview\GeneratorHelper;
+use OCP\Files\File;
+use OCP\Files\IAppData;
+use OCP\Files\IRootFolder;
+use OCP\Files\NotFoundException;
+use OCP\Files\SimpleFS\ISimpleFile;
+use OCP\IConfig;
 use OCP\IPreview;
 use OCP\Preview\IProvider;
 
 class PreviewManager implements IPreview {
-	/** @var \OCP\IConfig */
+	/** @var IConfig */
 	protected $config;
 
+	/** @var IRootFolder */
+	protected $rootFolder;
+
+	/** @var IAppData */
+	protected $appData;
+
+	/** @var Generator */
+	private $generator;
+
 	/** @var bool */
 	protected $providerListDirty = false;
 
@@ -52,8 +69,12 @@ class PreviewManager implements IPreview {
 	 *
 	 * @param \OCP\IConfig $config
 	 */
-	public function __construct(\OCP\IConfig $config) {
+	public function __construct(IConfig $config,
+								IRootFolder $rootFolder,
+								IAppData $appData) {
 		$this->config = $config;
+		$this->rootFolder = $rootFolder;
+		$this->appData = $appData;
 	}
 
 	/**
@@ -121,6 +142,37 @@ class PreviewManager implements IPreview {
 	}
 
 	/**
+	 * 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
+	 *
+	 * @param File $file
+	 * @param int $width
+	 * @param int $height
+	 * @param bool $crop
+	 * @param string $mode
+	 * @param string $mimeType
+	 * @return ISimpleFile
+	 * @throws NotFoundException
+	 * @since 9.2.0
+	 */
+	public function getPreview(File $file, $width = -1, $height = -1, $crop = false, $mode = IPreview::MODE_FILL, $mimeType = null) {
+		if ($this->generator === null) {
+			$this->generator = new Generator(
+				$this->config,
+				$this,
+				$this->appData,
+				new GeneratorHelper(
+					$this->rootFolder
+				)
+			);
+		}
+
+		return $this->generator->getPreview($file, $width, $height, $crop, $mode, $mimeType);
+	}
+
+	/**
 	 * returns true if the passed mime type is supported
 	 *
 	 * @param string $mimeType
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 9f993ade7fe..8f4e7d9ca2d 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -117,7 +117,17 @@ class Server extends ServerContainer implements IServerContainer {
 		});
 
 		$this->registerService('PreviewManager', function (Server $c) {
-			return new PreviewManager($c->getConfig());
+			return new PreviewManager(
+				$c->getConfig(),
+				$c->getRootFolder(),
+				$c->getAppDataDir('preview')
+			);
+		});
+
+		$this->registerService(\OC\Preview\Watcher::class, function (Server $c) {
+			return new \OC\Preview\Watcher(
+				$c->getAppDataDir('preview')
+			);
 		});
 
 		$this->registerService('EncryptionManager', function (Server $c) {
@@ -192,6 +202,10 @@ class Server extends ServerContainer implements IServerContainer {
 			);
 			$connector = new HookConnector($root, $view);
 			$connector->viewToNode();
+
+			$previewConnector = new \OC\Preview\WatcherConnector($root, $c->getSystemConfig());
+			$previewConnector->connectWatcher();
+
 			return $root;
 		});
 		$this->registerService('LazyRootFolder', function(Server $c) {