Move \OC\Lock to PSR-4

4 files changed, 578 insertions, 0 deletions

diff --git a/lib/private/Lock/AbstractLockingProvider.php b/lib/private/Lock/AbstractLockingProvider.php
new file mode 100644
index 00000000000..f96358778c1
--- /dev/null
+++ b/lib/private/Lock/AbstractLockingProvider.php
@@ -0,0 +1,119 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Lock;
+
+use OCP\Lock\ILockingProvider;
+
+/**
+ * Base locking provider that keeps track of locks acquired during the current request
+ * to release any left over locks at the end of the request
+ */
+abstract class AbstractLockingProvider implements ILockingProvider {
+	protected $ttl; // how long until we clear stray locks in seconds
+
+	protected $acquiredLocks = [
+		'shared' => [],
+		'exclusive' => []
+	];
+
+	/**
+	 * Check if we've locally acquired a lock
+	 *
+	 * @param string $path
+	 * @param int $type
+	 * @return bool
+	 */
+	protected function hasAcquiredLock($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			return isset($this->acquiredLocks['shared'][$path]) && $this->acquiredLocks['shared'][$path] > 0;
+		} else {
+			return isset($this->acquiredLocks['exclusive'][$path]) && $this->acquiredLocks['exclusive'][$path] === true;
+		}
+	}
+
+	/**
+	 * Mark a locally acquired lock
+	 *
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markAcquire($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			if (!isset($this->acquiredLocks['shared'][$path])) {
+				$this->acquiredLocks['shared'][$path] = 0;
+			}
+			$this->acquiredLocks['shared'][$path]++;
+		} else {
+			$this->acquiredLocks['exclusive'][$path] = true;
+		}
+	}
+
+	/**
+	 * Mark a release of a locally acquired lock
+	 *
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markRelease($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			if (isset($this->acquiredLocks['shared'][$path]) and $this->acquiredLocks['shared'][$path] > 0) {
+				$this->acquiredLocks['shared'][$path]--;
+			}
+		} else if ($type === self::LOCK_EXCLUSIVE) {
+			unset($this->acquiredLocks['exclusive'][$path]);
+		}
+	}
+
+	/**
+	 * Change the type of an existing tracked lock
+	 *
+	 * @param string $path
+	 * @param int $targetType self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markChange($path, $targetType) {
+		if ($targetType === self::LOCK_SHARED) {
+			unset($this->acquiredLocks['exclusive'][$path]);
+			if (!isset($this->acquiredLocks['shared'][$path])) {
+				$this->acquiredLocks['shared'][$path] = 0;
+			}
+			$this->acquiredLocks['shared'][$path]++;
+		} else if ($targetType === self::LOCK_EXCLUSIVE) {
+			$this->acquiredLocks['exclusive'][$path] = true;
+			$this->acquiredLocks['shared'][$path]--;
+		}
+	}
+
+	/**
+	 * release all lock acquired by this instance which were marked using the mark* methods
+	 */
+	public function releaseAll() {
+		foreach ($this->acquiredLocks['shared'] as $path => $count) {
+			for ($i = 0; $i < $count; $i++) {
+				$this->releaseLock($path, self::LOCK_SHARED);
+			}
+		}
+
+		foreach ($this->acquiredLocks['exclusive'] as $path => $hasLock) {
+			$this->releaseLock($path, self::LOCK_EXCLUSIVE);
+		}
+	}
+}
diff --git a/lib/private/Lock/DBLockingProvider.php b/lib/private/Lock/DBLockingProvider.php
new file mode 100644
index 00000000000..9e97df44d3f
--- /dev/null
+++ b/lib/private/Lock/DBLockingProvider.php
@@ -0,0 +1,269 @@
+<?php
+/**
+ * @author Björn Schießle <schiessle@owncloud.com>
+ * @author Individual IT Services <info@individual-it.net>
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Lock;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IDBConnection;
+use OCP\ILogger;
+use OCP\Lock\ILockingProvider;
+use OCP\Lock\LockedException;
+
+/**
+ * Locking provider that stores the locks in the database
+ */
+class DBLockingProvider extends AbstractLockingProvider {
+	/**
+	 * @var \OCP\IDBConnection
+	 */
+	private $connection;
+
+	/**
+	 * @var \OCP\ILogger
+	 */
+	private $logger;
+
+	/**
+	 * @var \OCP\AppFramework\Utility\ITimeFactory
+	 */
+	private $timeFactory;
+
+	private $sharedLocks = [];
+
+	/**
+	 * Check if we have an open shared lock for a path
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	protected function isLocallyLocked($path) {
+		return isset($this->sharedLocks[$path]) && $this->sharedLocks[$path];
+	}
+
+	/**
+	 * Mark a locally acquired lock
+	 *
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markAcquire($path, $type) {
+		parent::markAcquire($path, $type);
+		if ($type === self::LOCK_SHARED) {
+			$this->sharedLocks[$path] = true;
+		}
+	}
+
+	/**
+	 * Change the type of an existing tracked lock
+	 *
+	 * @param string $path
+	 * @param int $targetType self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markChange($path, $targetType) {
+		parent::markChange($path, $targetType);
+		if ($targetType === self::LOCK_SHARED) {
+			$this->sharedLocks[$path] = true;
+		} else if ($targetType === self::LOCK_EXCLUSIVE) {
+			$this->sharedLocks[$path] = false;
+		}
+	}
+
+	/**
+	 * @param \OCP\IDBConnection $connection
+	 * @param \OCP\ILogger $logger
+	 * @param \OCP\AppFramework\Utility\ITimeFactory $timeFactory
+	 * @param int $ttl
+	 */
+	public function __construct(IDBConnection $connection, ILogger $logger, ITimeFactory $timeFactory, $ttl = 3600) {
+		$this->connection = $connection;
+		$this->logger = $logger;
+		$this->timeFactory = $timeFactory;
+		$this->ttl = $ttl;
+	}
+
+	/**
+	 * Insert a file locking row if it does not exists.
+	 *
+	 * @param string $path
+	 * @param int $lock
+	 * @return int number of inserted rows
+	 */
+
+	protected function initLockField($path, $lock = 0) {
+		$expire = $this->getExpireTime();
+		return $this->connection->insertIfNotExist('*PREFIX*file_locks', ['key' => $path, 'lock' => $lock, 'ttl' => $expire], ['key']);
+	}
+
+	/**
+	 * @return int
+	 */
+	protected function getExpireTime() {
+		return $this->timeFactory->getTime() + $this->ttl;
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 * @return bool
+	 */
+	public function isLocked($path, $type) {
+		if ($this->hasAcquiredLock($path, $type)) {
+			return true;
+		}
+		$query = $this->connection->prepare('SELECT `lock` from `*PREFIX*file_locks` WHERE `key` = ?');
+		$query->execute([$path]);
+		$lockValue = (int)$query->fetchColumn();
+		if ($type === self::LOCK_SHARED) {
+			if ($this->isLocallyLocked($path)) {
+				// if we have a shared lock we kept open locally but it's released we always have at least 1 shared lock in the db
+				return $lockValue > 1;
+			} else {
+				return $lockValue > 0;
+			}
+		} else if ($type === self::LOCK_EXCLUSIVE) {
+			return $lockValue === -1;
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 * @throws \OCP\Lock\LockedException
+	 */
+	public function acquireLock($path, $type) {
+		$expire = $this->getExpireTime();
+		if ($type === self::LOCK_SHARED) {
+			if (!$this->isLocallyLocked($path)) {
+				$result = $this->initLockField($path, 1);
+				if ($result <= 0) {
+					$result = $this->connection->executeUpdate(
+						'UPDATE `*PREFIX*file_locks` SET `lock` = `lock` + 1, `ttl` = ? WHERE `key` = ? AND `lock` >= 0',
+						[$expire, $path]
+					);
+				}
+			} else {
+				$result = 1;
+			}
+		} else {
+			$existing = 0;
+			if ($this->hasAcquiredLock($path, ILockingProvider::LOCK_SHARED) === false && $this->isLocallyLocked($path)) {
+				$existing = 1;
+			}
+			$result = $this->initLockField($path, -1);
+			if ($result <= 0) {
+				$result = $this->connection->executeUpdate(
+					'UPDATE `*PREFIX*file_locks` SET `lock` = -1, `ttl` = ? WHERE `key` = ? AND `lock` = ?',
+					[$expire, $path, $existing]
+				);
+			}
+		}
+		if ($result !== 1) {
+			throw new LockedException($path);
+		}
+		$this->markAcquire($path, $type);
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	public function releaseLock($path, $type) {
+		$this->markRelease($path, $type);
+
+		// we keep shared locks till the end of the request so we can re-use them
+		if ($type === self::LOCK_EXCLUSIVE) {
+			$this->connection->executeUpdate(
+				'UPDATE `*PREFIX*file_locks` SET `lock` = 0 WHERE `key` = ? AND `lock` = -1',
+				[$path]
+			);
+		}
+	}
+
+	/**
+	 * Change the type of an existing lock
+	 *
+	 * @param string $path
+	 * @param int $targetType self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 * @throws \OCP\Lock\LockedException
+	 */
+	public function changeLock($path, $targetType) {
+		$expire = $this->getExpireTime();
+		if ($targetType === self::LOCK_SHARED) {
+			$result = $this->connection->executeUpdate(
+				'UPDATE `*PREFIX*file_locks` SET `lock` = 1, `ttl` = ? WHERE `key` = ? AND `lock` = -1',
+				[$expire, $path]
+			);
+		} else {
+			// since we only keep one shared lock in the db we need to check if we have more then one shared lock locally manually
+			if (isset($this->acquiredLocks['shared'][$path]) && $this->acquiredLocks['shared'][$path] > 1) {
+				throw new LockedException($path);
+			}
+			$result = $this->connection->executeUpdate(
+				'UPDATE `*PREFIX*file_locks` SET `lock` = -1, `ttl` = ? WHERE `key` = ? AND `lock` = 1',
+				[$expire, $path]
+			);
+		}
+		if ($result !== 1) {
+			throw new LockedException($path);
+		}
+		$this->markChange($path, $targetType);
+	}
+
+	/**
+	 * cleanup empty locks
+	 */
+	public function cleanExpiredLocks() {
+		$expire = $this->timeFactory->getTime();
+		try {
+			$this->connection->executeUpdate(
+				'DELETE FROM `*PREFIX*file_locks` WHERE `ttl` < ?',
+				[$expire]
+			);
+		} catch (\Exception $e) {
+			// If the table is missing, the clean up was successful
+			if ($this->connection->tableExists('file_locks')) {
+				throw $e;
+			}
+		}
+	}
+
+	/**
+	 * release all lock acquired by this instance which were marked using the mark* methods
+	 */
+	public function releaseAll() {
+		parent::releaseAll();
+
+		// since we keep shared locks we need to manually clean those
+		foreach ($this->sharedLocks as $path => $lock) {
+			if ($lock) {
+				$this->connection->executeUpdate(
+					'UPDATE `*PREFIX*file_locks` SET `lock` = `lock` - 1 WHERE `key` = ? AND `lock` > 0',
+					[$path]
+				);
+			}
+		}
+	}
+}
diff --git a/lib/private/Lock/MemcacheLockingProvider.php b/lib/private/Lock/MemcacheLockingProvider.php
new file mode 100644
index 00000000000..536b29e2c28
--- /dev/null
+++ b/lib/private/Lock/MemcacheLockingProvider.php
@@ -0,0 +1,122 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Lock;
+
+use OCP\IMemcacheTTL;
+use OCP\Lock\LockedException;
+use OCP\IMemcache;
+
+class MemcacheLockingProvider extends AbstractLockingProvider {
+	/**
+	 * @var \OCP\IMemcache
+	 */
+	private $memcache;
+
+	/**
+	 * @param \OCP\IMemcache $memcache
+	 * @param int $ttl
+	 */
+	public function __construct(IMemcache $memcache, $ttl = 3600) {
+		$this->memcache = $memcache;
+		$this->ttl = $ttl;
+	}
+
+	private function setTTL($path) {
+		if ($this->memcache instanceof IMemcacheTTL) {
+			$this->memcache->setTTL($path, $this->ttl);
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 * @return bool
+	 */
+	public function isLocked($path, $type) {
+		$lockValue = $this->memcache->get($path);
+		if ($type === self::LOCK_SHARED) {
+			return $lockValue > 0;
+		} else if ($type === self::LOCK_EXCLUSIVE) {
+			return $lockValue === 'exclusive';
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 * @throws \OCP\Lock\LockedException
+	 */
+	public function acquireLock($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			if (!$this->memcache->inc($path)) {
+				throw new LockedException($path);
+			}
+		} else {
+			$this->memcache->add($path, 0);
+			if (!$this->memcache->cas($path, 0, 'exclusive')) {
+				throw new LockedException($path);
+			}
+		}
+		$this->setTTL($path);
+		$this->markAcquire($path, $type);
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	public function releaseLock($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			if (isset($this->acquiredLocks['shared'][$path]) and $this->acquiredLocks['shared'][$path] > 0) {
+				$this->memcache->dec($path);
+				$this->memcache->cad($path, 0);
+			}
+		} else if ($type === self::LOCK_EXCLUSIVE) {
+			$this->memcache->cad($path, 'exclusive');
+		}
+		$this->markRelease($path, $type);
+	}
+
+	/**
+	 * Change the type of an existing lock
+	 *
+	 * @param string $path
+	 * @param int $targetType self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 * @throws \OCP\Lock\LockedException
+	 */
+	public function changeLock($path, $targetType) {
+		if ($targetType === self::LOCK_SHARED) {
+			if (!$this->memcache->cas($path, 'exclusive', 1)) {
+				throw new LockedException($path);
+			}
+		} else if ($targetType === self::LOCK_EXCLUSIVE) {
+			// we can only change a shared lock to an exclusive if there's only a single owner of the shared lock
+			if (!$this->memcache->cas($path, 1, 'exclusive')) {
+				throw new LockedException($path);
+			}
+		}
+		$this->setTTL($path);
+		$this->markChange($path, $targetType);
+	}
+}
diff --git a/lib/private/Lock/NoopLockingProvider.php b/lib/private/Lock/NoopLockingProvider.php
new file mode 100644
index 00000000000..dc58230f77e
--- /dev/null
+++ b/lib/private/Lock/NoopLockingProvider.php
@@ -0,0 +1,68 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Lock;
+
+use OCP\Lock\ILockingProvider;
+
+/**
+ * Locking provider that does nothing.
+ *
+ * To be used when locking is disabled.
+ */
+class NoopLockingProvider implements ILockingProvider {
+
+    /**
+     * {@inheritdoc}
+     */
+	public function isLocked($path, $type) {
+		return false;
+	}
+
+    /**
+     * {@inheritdoc}
+     */
+	public function acquireLock($path, $type) {
+		// do nothing
+	}
+
+	/**
+     * {@inheritdoc}
+	 */
+	public function releaseLock($path, $type) {
+		// do nothing
+	}
+
+	/**1
+	 * {@inheritdoc}
+	 */
+	public function releaseAll() {
+		// do nothing
+	}
+
+	/**
+	 * {@inheritdoc}
+	 */
+	public function changeLock($path, $targetType) {
+		// do nothing
+	}
+}