Added Delete class

Signed-off-by: charleypaulus <[email protected]>

core/Command/Preview/Delete.php

@@ -0,0 +1,174 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2021, Charley Paulus <[email protected]>
+ *
+ * @author Charley Paulus <[email protected]>
+ *
+ * @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\Core\Command\Preview;
+
+use OC\Preview\Storage\Root;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\Files\IMimeTypeLoader;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+use OCP\IDBConnection;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class Delete extends Command {
+	protected IDBConnection $connection;
+	private Root $previewFolder;
+	private IMimeTypeLoader $mimeTypeLoader;
+
+	public function __construct(IDBConnection $connection,
+								Root $previewFolder,
+								IMimeTypeLoader $mimeTypeLoader) {
+		parent::__construct();
+
+		$this->connection = $connection;
+		$this->previewFolder = $previewFolder;
+		$this->mimeTypeLoader = $mimeTypeLoader;
+	}
+
+	protected function configure() {
+		$this
+			->setName('preview:delete')
+			->setDescription('Deletes all previews')
+			->addOption('old-only', 'o', InputOption::VALUE_NONE, 'Limit deletion to old previews (no longer having their original file)')
+			->addOption('mimetype', 'm', InputArgument::OPTIONAL, 'Limit deletion to this mimetype, eg. --mimetype="image/jpeg"')
+			->addOption('dry', 'd', InputOption::VALUE_NONE, 'Dry mode (will not delete any files). In combination with the verbose mode one could check the operations');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$oldOnly = $input->getOption('old-only');
+
+        $selectedMimetype = $input->getOption('mimetype');
+        if ($selectedMimetype) {
+            if ($oldOnly) {
+                $output->writeln('Mimetype of absent original files cannot be determined. Aborting...');
+                return 0;
+            } else {
+                if (! $this->mimeTypeLoader->exists($selectedMimetype)) {
+                    $output->writeln('Mimetype ' . $selectedMimetype . ' does not exist in database. Aborting...');
+                    return 0;
+                }
+            }
+        }
+
+		$dryMode = $input->getOption('dry');
+		if ($dryMode) {
+			$output->writeln('INFO: The command is run in dry mode and will not modify anything.');
+			$output->writeln('');
+		}
+
+		$this->deletePreviews($output, $oldOnly, $selectedMimetype, $dryMode);
+
+		return 0;
+	}
+
+	private function deletePreviews(OutputInterface $output, bool $oldOnly, string $selectedMimetype = null, bool $dryMode): void {
+		$previewFoldersToDeleteCount = 0;
+
+		foreach ($this->getPreviewsToDelete($output, $oldOnly, $selectedMimetype) as ['name' => $previewFileId, 'path' => $filePath]) {
+            if ($oldOnly || $filePath === null) {
+                $output->writeln('Deleting previews of absent original file (fileid:' . $previewFileId . ')', OutputInterface::VERBOSITY_VERBOSE);
+            } else {
+			    $output->writeln('Deleting previews of original file ' . substr($filePath, 7) . ' (fileid:' . $previewFileId . ')', OutputInterface::VERBOSITY_VERBOSE);
+            }
+
+			$previewFoldersToDeleteCount++;
+
+			if ($dryMode) {
+				continue;
+			}
+
+			try {
+				$preview = $this->previewFolder->getFolder((string)$previewFileId);
+				$preview->delete();
+			} catch (NotFoundException $e) {
+				// continue
+			} catch (NotPermittedException $e) {
+				// continue
+			}
+		}
+
+		$output->writeln('Deleted previews of ' . $previewFoldersToDeleteCount . ' original files');
+	}
+
+	// Copy pasted and adjusted from
+	// "lib/private/Preview/BackgroundCleanupJob.php".
+	private function getPreviewsToDelete(OutputInterface $output, bool $oldOnly, string $selectedMimetype = null): \Iterator {
+    	// Get preview folder
+    	$qb = $this->connection->getQueryBuilder();
+    	$qb->select('path', 'mimetype')
+    		->from('filecache')
+    		->where($qb->expr()->eq('fileid', $qb->createNamedParameter($this->previewFolder->getId())));
+    	$cursor = $qb->execute();
+    	$data = $cursor->fetch();
+    	$cursor->closeCursor();
+
+        $output->writeln('Preview folder: ' . $data['path'], OutputInterface::VERBOSITY_VERBOSE);
+
+    	if ($data === null) {
+    		return [];
+    	}
+
+        // Get previews to delete
+        // Initialize Query Builder
+        $qb = $this->connection->getQueryBuilder();
+
+		/* This lovely like is the result of the way the new previews are stored
+		 * We take the md5 of the name (fileid) and split the first 7 chars. That way
+		 * there are not a gazillion files in the root of the preview appdata.*/
+		$like = $this->connection->escapeLikeParameter($data['path']) . '/_/_/_/_/_/_/_/%';
+
+        // Specify conditions based on options
+        $and = $qb->expr()->andX();
+        $and->add($qb->expr()->like('a.path', $qb->createNamedParameter($like)));
+        $and->add($qb->expr()->eq('a.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('httpd/unix-directory'))));
+        if ($oldOnly) {
+            $and->add($qb->expr()->isNull('b.fileid'));
+        }
+        if ($selectedMimetype) {
+            $and->add($qb->expr()->eq('b.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('image/jpeg'))));
+        }
+
+        // Build query
+		$qb->select('a.name', 'b.path')
+			->from('filecache', 'a')
+			->leftJoin('a', 'filecache', 'b', $qb->expr()->eq(
+				$qb->expr()->castColumn('a.name', IQueryBuilder::PARAM_INT), 'b.fileid'
+			))
+			->where($and);
+
+		$cursor = $qb->execute();
+
+		while ($row = $cursor->fetch()) {
+			yield $row;
+		}
+
+		$cursor->closeCursor();
+	}
+}