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Diffstat (limited to 'lib/private/Streamer.php')
| -rw-r--r-- | lib/private/Streamer.php | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/lib/private/Streamer.php b/lib/private/Streamer.php new file mode 100644 index 00000000000..e579c42c0d7 --- /dev/null +++ b/lib/private/Streamer.php @@ -0,0 +1,194 @@ +<?php + +/** + * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors + * SPDX-FileCopyrightText: 2016 ownCloud, Inc. + * SPDX-License-Identifier: AGPL-3.0-only + */ +namespace OC; + +use OC\Files\Filesystem; +use OCP\Files\File; +use OCP\Files\Folder; +use OCP\Files\InvalidPathException; +use OCP\Files\IRootFolder; +use OCP\Files\NotFoundException; +use OCP\Files\NotPermittedException; +use OCP\IRequest; +use ownCloud\TarStreamer\TarStreamer; +use Psr\Log\LoggerInterface; +use ZipStreamer\ZipStreamer; + +class Streamer { + // array of regexp. Matching user agents will get tar instead of zip + private const UA_PREFERS_TAR = [ '/macintosh|mac os x/i' ]; + + // streamer instance + private $streamerInstance; + + public static function isUserAgentPreferTar(IRequest $request): bool { + return $request->isUserAgent(self::UA_PREFERS_TAR); + } + + /** + * Streamer constructor. + * + * @param bool|IRequest $preferTar If true a tar stream is used. + * For legacy reasons also a IRequest can be passed to detect this preference by user agent, + * please migrate to `Streamer::isUserAgentPreferTar()` instead. + * @param int|float $size The size of the files in bytes + * @param int $numberOfFiles The number of files (and directories) that will + * be included in the streamed file + */ + public function __construct(IRequest|bool $preferTar, int|float $size, int $numberOfFiles) { + if ($preferTar instanceof IRequest) { + $preferTar = self::isUserAgentPreferTar($preferTar); + } + + /** + * zip32 constraints for a basic (without compression, volumes nor + * encryption) zip file according to the Zip specification: + * - No file size is larger than 4 bytes (file size < 4294967296); see + * 4.4.9 uncompressed size + * - The size of all files plus their local headers is not larger than + * 4 bytes; see 4.4.16 relative offset of local header and 4.4.24 + * offset of start of central directory with respect to the starting + * disk number + * - The total number of entries (files and directories) in the zip file + * is not larger than 2 bytes (number of entries < 65536); see 4.4.22 + * total number of entries in the central dir + * - The size of the central directory is not larger than 4 bytes; see + * 4.4.23 size of the central directory + * + * Due to all that, zip32 is used if the size is below 4GB and there are + * less than 65536 files; the margin between 4*1000^3 and 4*1024^3 + * should give enough room for the extra zip metadata. Technically, it + * would still be possible to create an invalid zip32 file (for example, + * a zip file from files smaller than 4GB with a central directory + * larger than 4GiB), but it should not happen in the real world. + * + * We also have to check for a size above 0. As negative sizes could be + * from not fully scanned external storage. And then things fall apart + * if somebody tries to package to much. + */ + if ($preferTar) { + // If TAR ball is preferred use it + $this->streamerInstance = new TarStreamer(); + } elseif ($size > 0 && $size < 4 * 1000 * 1000 * 1000 && $numberOfFiles < 65536) { + $this->streamerInstance = new ZipStreamer(['zip64' => false]); + } else { + $this->streamerInstance = new ZipStreamer(['zip64' => true]); + } + } + + /** + * Send HTTP headers + * @param string $name + */ + public function sendHeaders($name) { + header('X-Accel-Buffering: no'); + $extension = $this->streamerInstance instanceof ZipStreamer ? '.zip' : '.tar'; + $fullName = $name . $extension; + $this->streamerInstance->sendHeaders($fullName); + } + + /** + * Stream directory recursively + * + * @param string $dir Directory path relative to root of current user + * @throws NotFoundException + * @throws NotPermittedException + * @throws InvalidPathException + */ + public function addDirRecursive(string $dir, string $internalDir = ''): void { + $dirname = basename($dir); + $rootDir = $internalDir . $dirname; + if (!empty($rootDir)) { + $this->streamerInstance->addEmptyDir($rootDir); + } + $internalDir .= $dirname . '/'; + // prevent absolute dirs + $internalDir = ltrim($internalDir, '/'); + + $userFolder = \OC::$server->get(IRootFolder::class)->get(Filesystem::getRoot()); + /** @var Folder $dirNode */ + $dirNode = $userFolder->get($dir); + $files = $dirNode->getDirectoryListing(); + + /** @var LoggerInterface $logger */ + $logger = \OC::$server->query(LoggerInterface::class); + foreach ($files as $file) { + if ($file instanceof File) { + try { + $fh = $file->fopen('r'); + if ($fh === false) { + $logger->error('Unable to open file for stream: ' . print_r($file, true)); + continue; + } + } catch (NotPermittedException $e) { + continue; + } + $this->addFileFromStream( + $fh, + $internalDir . $file->getName(), + $file->getSize(), + $file->getMTime() + ); + fclose($fh); + } elseif ($file instanceof Folder) { + if ($file->isReadable()) { + $this->addDirRecursive($dir . '/' . $file->getName(), $internalDir); + } + } + } + } + + /** + * Add a file to the archive at the specified location and file name. + * + * @param resource $stream Stream to read data from + * @param string $internalName Filepath and name to be used in the archive. + * @param int|float $size Filesize + * @param int|false $time File mtime as int, or false + * @return bool $success + */ + public function addFileFromStream($stream, string $internalName, int|float $size, $time): bool { + $options = []; + if ($time) { + $options = [ + 'timestamp' => $time + ]; + } + + if ($this->streamerInstance instanceof ZipStreamer) { + return $this->streamerInstance->addFileFromStream($stream, $internalName, $options); + } else { + return $this->streamerInstance->addFileFromStream($stream, $internalName, $size, $options); + } + } + + /** + * Add an empty directory entry to the archive. + * + * @param $dirName - Directory Path and name to be added to the archive. + * @param $timestamp - Modification time of the directory (defaults to current time) + */ + public function addEmptyDir(string $dirName, int $timestamp = 0): bool { + $options = null; + if ($timestamp > 0) { + $options = ['timestamp' => $timestamp]; + } + + return $this->streamerInstance->addEmptyDir($dirName, $options); + } + + /** + * Close the archive. + * A closed archive can no longer have new files added to it. After + * closing, the file is completely written to the output stream. + * @return bool $success + */ + public function finalize() { + return $this->streamerInstance->finalize(); + } +} |