Checksum calculating storage wrapper: Initial draft owncloud#26655

lib/private/Files/Storage/Wrapper/Checksum.php

@@ -0,0 +1,82 @@
+<?php
+/**
+ * @author Ilja Neumann <[email protected]>
+ *
+ * @copyright Copyright (c) 2017, ownCloud GmbH.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OC\Files\Storage\Wrapper;
+
+
+class Checksum extends Wrapper {
+
+	const FILTER_NAME = 'sha1_checksum';
+
+	private $fileHashes = [];
+
+	/**
+	 * @param array $parameters
+	 */
+	public function __construct($parameters) {
+		parent::__construct($parameters);
+		stream_filter_register(self::FILTER_NAME, '\OC\Files\Stream\Filter\Sha1');
+	}
+
+	/**
+	 * @param string $path
+	 * @param string $mode
+	 * @return false|resource
+	 */
+	public function fopen($path, $mode) {
+		$stream = $this->getWrapperStorage()->fopen($path, $mode);
+
+		if (!self::requiresChecksum($path, $mode)) {
+			return $stream;
+		}
+
+		stream_filter_append(
+			$stream,
+			self::FILTER_NAME,
+			STREAM_FILTER_WRITE,
+			['path' => $path, 'callback' => [$this, 'addFileHash']]
+		);
+
+		return $stream;
+	}
+
+	/**
+	 * Checksum is only required for everything under files/
+	 * @param $path
+	 * @param $mode
+	 * @return bool
+	 */
+	private static function requiresChecksum($path, $mode) {
+		return substr($path, 0, 6) == 'files/' && $mode != 'r';
+	}
+
+	public function rename($path1, $path2) {
+		if (array_key_exists($path1, $this->fileHashes)) {
+			$checksum = $this->fileHashes[$path1];
+			// Update checksum in oc_filecache here?
+		}
+
+		return $this->getWrapperStorage()->rename($path1, $path2);
+	}
+
+	public function addFileHash($path, $hash) {
+		$this->fileHashes[$path] = $hash;
+	}
+}

lib/private/Files/Stream/Filter/Sha1.php

@@ -0,0 +1,71 @@
+<?php
+/**
+ * @author Ilja Neumann <[email protected]>
+ *
+ * @copyright Copyright (c) 2017, ownCloud GmbH.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OC\Files\Stream\Filter;
+
+class Sha1 extends \php_user_filter {
+
+	/** @var  resource */
+	private $ctx;
+
+	/**
+	 * @return bool
+	 */
+	function onCreate () {
+		$this->ctx = hash_init('sha1');
+		return true;
+	}
+
+	/**
+	 * @return bool
+	 */
+	function onClose () {
+		$hash = hash_final($this->ctx);
+		// Debug
+		file_put_contents(
+			'/tmp/hashtest.txt', $this->params['path'] . ' --> ' . $hash . PHP_EOL,
+			FILE_APPEND
+		);
+
+		call_user_func_array(
+			$this->params['callback'],
+			[$this->params['path'], $hash]
+		);
+
+		return true;
+	}
+
+	/**
+	 * @param resource $in
+	 * @param resource $out
+	 * @param int $consumed
+	 * @param bool $closing
+	 * @return int
+	 */
+	function filter ($in, $out, &$consumed, $closing) {
+		while ($bucket = stream_bucket_make_writeable($in)) {
+			hash_update($this->ctx, $bucket->data);
+			$consumed += $bucket->datalen;
+			stream_bucket_append($out, $bucket);
+		}
+
+		return PSFS_PASS_ON;
+	}
+}

lib/private/legacy/util.php

@@ -175,6 +175,11 @@ public static function setupFS($user = '') {
 			return $storage;
 		});
 
+		// install storage checksum wrapper
+		\OC\Files\Filesystem::addStorageWrapper('oc_checksum', function ($mountPoint, $storage) {
+			return new \OC\Files\Storage\Wrapper\Checksum(['storage' => $storage]);
+		});
+
 		\OC\Files\Filesystem::addStorageWrapper('oc_encoding', function ($mountPoint, \OCP\Files\Storage $storage, \OCP\Files\Mount\IMountPoint $mount) {
 			if ($mount->getOption('encoding_compatibility', false) && !$storage->instanceOfStorage('\OCA\Files_Sharing\SharedStorage') && !$storage->isLocal()) {
 				return new \OC\Files\Storage\Wrapper\Encoding(['storage' => $storage]);