From: ringmaster Date: Wed, 28 May 2014 13:04:05 +0000 (-0400) Subject: Move Lock to private namespace, add interface. Update PHPDoc. X-Git-Tag: v7.0.0alpha2~127^2~11 X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=54865815f5c6044b3b4ea4793f6677d48c16604d;p=nextcloud-server.git Move Lock to private namespace, add interface. Update PHPDoc. --- diff --git a/lib/private/files/lock.php b/lib/private/files/lock.php new file mode 100644 index 00000000000..b752b16f023 --- /dev/null +++ b/lib/private/files/lock.php @@ -0,0 +1,308 @@ +. + * + */ + +namespace OC\Files; + +use OCP\Config; +use OC\Files\Filesystem; + +/** + * Class Lock + * @package OC\Files + */ +class Lock implements \OCP\Files\Lock { + + /** @var int $retries Number of lock retries to attempt */ + public static $retries = 40; + + /** @var int $retryInterval Milliseconds between retries */ + public static $retryInterval = 50; + + /** @var string $path Filename of the file as represented in storage */ + protected $path; + + /** @var array $stack A stack of lock data */ + protected $stack = array(); + + /** @var resource $handle A file handle used to maintain a lock */ + protected $handle; + + /** @var string $lockFile Filename of the lock file */ + protected $lockFile; + + /** @var resource $lockFileHandle The file handle used to maintain a lock on the lock file */ + protected $lockFileHandle; + + /** + * Constructor for the lock instance + * @param string $path Absolute pathname for a local file on which to obtain a lock + */ + public function __construct($path) { + $this->path = Filesystem::normalizePath($path); + } + + protected function obtainReadLock($existingHandle = null) { + \OC_Log::write('lock', sprintf('INFO: Read lock requested for %s', $this->path), \OC_Log::DEBUG); + $timeout = Lock::$retries; + + // Re-use an existing handle or get a new one + if(empty($existingHandle)) { + $handle = fopen($this->path, 'r'); + } + else { + $handle = $existingHandle; + } + + do { + if($this->isLockFileLocked($this->getLockFile($this->path))) { + \OC_Log::write('lock', sprintf('INFO: Read lock has locked lock file %s for %s', $this->getLockFile($this->path), $this->path), \OC_Log::DEBUG); + do { + usleep(Lock::$retryInterval); + $timeout--; + } while($this->isLockFileLocked($this->getLockFile($this->path)) && $timeout > 0); + \OC_Log::write('lock', sprintf('INFO: Lock file %s has become unlocked for %s', $this->getLockFile($this->path), $this->path), \OC_Log::DEBUG); + } + } while ((!$lockReturn = flock($handle, LOCK_SH | LOCK_NB, $wouldBlock)) && $timeout > 0); + if ($wouldBlock == true || $lockReturn == false || $timeout <= 0) { + \OC_Log::write('lock', sprintf('FAIL: Failed to acquire read lock for %s', $this->path), \OC_Log::DEBUG); + return false; + } + $this->handle = $handle; + \OC_Log::write('lock', sprintf('PASS: Acquired read lock for %s', $this->path), \OC_Log::DEBUG); + return true; + } + + protected function obtainWriteLock($existingHandle = null) { + \OC_Log::write('lock', sprintf('INFO: Write lock requested for %s', $this->path), \OC_Log::DEBUG); + + // Re-use an existing handle or get a new one + if (empty($existingHandle)) { + $handle = fopen($this->path, 'c'); + } + else { + $handle = $existingHandle; + } + + // If the file doesn't exist, but we can create a lock for it + if (!file_exists($this->path) && $this->lockLockFile($this->path)) { + $lockReturn = flock($handle, LOCK_EX | LOCK_NB, $wouldBlock); + if ($lockReturn == false || $wouldBlock == true) { + \OC_Log::write('lock', sprintf('FAIL: Write lock failed, unable to exclusively lock new file %s', $this->path), \OC_Log::DEBUG); + return false; + } + $this->handle = $handle; + return true; + } + + + // Since this file does exist, wait for locks to release to get an exclusive lock + $timeout = Lock::$retries; + $haveBlock = false; + while ((!$lockReturn = flock($handle, LOCK_EX | LOCK_NB, $wouldBlock)) && $timeout > 0) { + // We don't have a lock on the original file, try to get a lock on its lock file + if ($haveBlock || $haveBlock = $this->lockLockFile($this->lockFile)) { + usleep(Lock::$retryInterval); + } + else { + \OC_Log::write('lock', sprintf('FAIL: Write lock failed, unable to lock original %s or lock file', $this->path), \OC_Log::DEBUG); + return false; + } + $timeout--; + } + if ($wouldBlock == true || $lockReturn == false) { + \OC_Log::write('lock', sprintf('FAIL: Write lock failed due to timeout on %s', $this->path), \OC_Log::DEBUG); + return false; + } + \OC_Log::write('lock', sprintf('PASS: Write lock succeeded on %s', $this->path), \OC_Log::DEBUG); + + return true; + } + + /** + * Create a lock file and lock it + * Sets $this->lockFile to the specified lock file, indicating that the lock file is IN USE for this lock instance + * Also sets $this->lockFileHandle to a file handle of the lock file + * @param string $filename The name of the file to lock + * @return bool False if lock can't be acquired, true if it can. + */ + protected function lockLockFile ( $filename ) { + $lockFile = $this->getLockFile($filename); + \OC_Log::write('lock', sprintf('INFO: Locking lock file %s for %s', $lockFile, $filename), \OC_Log::DEBUG); + + // If we already manage the lockfile, success + if(!empty($this->lockFile)) { + \OC_Log::write('lock', sprintf('PASS: Lock file %s was locked by this request for %s', $lockFile, $filename), \OC_Log::DEBUG); + return true; + } + + // Check if the lockfile exists, and if not, try to create it + \OC_Log::write('lock', sprintf('INFO: Does lock file %s already exist? %s', $lockFile, file_exists($lockFile) ? 'yes' : 'no'), \OC_Log::DEBUG); + $handle = fopen($lockFile, 'c'); + if(!$handle) { + \OC_Log::write('lock', sprintf('FAIL: Could not create lock file %s', $lockFile), \OC_Log::DEBUG); + return false; + } + + // Attempt to acquire lock on lock file + $wouldBlock = false; + $timeout = self::$retries; + // Wait for lock over timeout + while((!$lockReturn = flock($handle, LOCK_EX | LOCK_NB, $wouldBlock)) && $timeout > 0) { + \OC_Log::write('lock', sprintf('FAIL: Could not acquire lock on lock file %s, %s timeout increments remain.', $lockFile, $timeout), \OC_Log::DEBUG); + usleep(self::$retryInterval); + $timeout--; + } + if ($wouldBlock == true || $lockReturn == false) { + \OC_Log::write('lock', sprintf('FAIL: Could not acquire lock on lock file %s', $lockFile), \OC_Log::DEBUG); + return false; + } + fwrite($handle, $filename); + \OC_Log::write('lock', sprintf('PASS: Wrote filename to lock lock file %s', $lockFile), \OC_Log::DEBUG); + + $this->lockFile = $lockFile; + $this->lockFileHandle = $handle; + + return true; + } + + /** + * Add a lock of a specific type to the stack + * @param integer $lockType A constant representing the type of lock to queue + * @param null|resource $existingHandle An existing file handle from an fopen() + * @throws LockNotAcquiredException + */ + public function addLock($lockType, $existingHandle = null) { + if(!isset($this->stack[$lockType])) { + switch($lockType) { + case Lock::READ: + $result = $this->obtainReadLock($existingHandle); + break; + case Lock::WRITE: + $result = $this->obtainWriteLock($existingHandle); + break; + default: + $result = false; + break; + } + if($result) { + $this->stack[$lockType] = 0; + } + else { + throw new LockNotAcquiredException($this->path, $lockType); + } + } + + \OC_Log::write('lock', sprintf('INFO: Incrementing lock type %d count for %s', $lockType, $this->path), \OC_Log::DEBUG); + $this->stack[$lockType]++; + + } + + /** + * Release locks on handles and files + */ + public function release($lockType) { + if(isset($this->stack[$lockType])) { + $this->stack[$lockType]--; + if($this->stack[$lockType] <= 0) { + unset($this->stack[$lockType]); + } + } + + if(count($this->stack) == 0) { + // No more locks needed on this file, release the handle and/or lockfile + $this->releaseAll(); + } + + return true; + } + + + /** + * Get the lock file associated to a file + * @param string $filename The filename of the file to create a lock file for + * @return string The filename of the lock file + */ + public static function getLockFile($filename) { + static $locksDir = false; + if(!$locksDir) { + $dataDir = Config::getSystemValue('datadirectory'); + $locksDir = $dataDir . '/.locks'; + if(!file_exists($locksDir)) { + mkdir($locksDir); + } + } + $filename = Filesystem::normalizePath($filename); + return $locksDir . '/' . sha1($filename) . '.lock'; + } + + /** + * Determine if a file has an associated and flocked lock file + * @param string $lockFile The filename of the lock file to check + * @return bool True if the lock file is flocked + */ + protected function isLockFileLocked($lockFile) { + if(file_exists($lockFile)) { + if($handle = fopen($lockFile, 'c')) { + if($lock = flock($handle, LOCK_EX | LOCK_NB)) { + // Got lock, not blocking, release and unlink + unlink($lockFile); + fclose($handle); + flock($lock, LOCK_UN); + return false; + } + else { + return true; + } + } + else { + return true; + } + } + return false; + } + + /** + * Release all queued locks on the file + * @return bool + */ + public function releaseAll() { + $this->stack = array(); + \OC_Log::write('lock', sprintf('INFO: Releasing locks on %s', $this->path), \OC_Log::DEBUG); + if (!empty($this->handle) && is_resource($this->handle)) { + flock($this->handle, LOCK_UN); + \OC_Log::write('lock', sprintf('INFO: Released lock handle %s on %s', $this->handle, $this->path), \OC_Log::DEBUG); + $this->handle = null; + } + if (!empty($this->lockFile) && file_exists($this->lockFile)) { + unlink($this->lockFile); + \OC_Log::write('lock', sprintf('INFO: Released lock file %s on %s', $this->lockFile, $this->path), \OC_Log::DEBUG); + $this->lockFile = null; + } + \OC_Log::write('lock', sprintf('FREE: Released locks on %s', $this->path), \OC_Log::DEBUG); + return true; + } + + public function __destruct() { + // Only releaseAll if we have locks to release + if(!empty($this->handle) || !empty($this->lockFile)) { + \OC_Log::write('lock', sprintf('INFO: Destroying locks on %s', $this->path), \OC_Log::DEBUG); + $this->releaseAll(); + } + } + +} \ No newline at end of file diff --git a/lib/private/files/storage/wrapper/lockingwrapper.php b/lib/private/files/storage/wrapper/lockingwrapper.php index 4f41c528253..428c2c516a4 100644 --- a/lib/private/files/storage/wrapper/lockingwrapper.php +++ b/lib/private/files/storage/wrapper/lockingwrapper.php @@ -10,7 +10,7 @@ namespace OC\Files\Storage\Wrapper; use OC\Files\Filesystem; -use OCP\Files\Lock; +use OC\Files\Lock; /** * Class LockingWrapper @@ -23,7 +23,7 @@ use OCP\Files\Lock; */ class LockingWrapper extends Wrapper { - /** @var array $locks Holds an array of lock instances indexed by path for this storage */ + /** @var \OCP\Files\Lock[] $locks Holds an array of lock instances indexed by path for this storage */ protected $locks = array(); /** diff --git a/lib/public/files/lock.php b/lib/public/files/lock.php index 196134724d3..34d307e8939 100644 --- a/lib/public/files/lock.php +++ b/lib/public/files/lock.php @@ -18,169 +18,20 @@ namespace OCP\Files; -use OCP\Config; -use OC\Files\Filesystem; - /** * Class Lock * @package OC\Files */ -class Lock { +interface Lock { const READ = 1; const WRITE = 2; - /** @var int $retries Number of lock retries to attempt */ - public static $retries = 40; - - /** @var int $retryInterval Milliseconds between retries */ - public static $retryInterval = 50; - - /** @var string $path Filename of the file as represented in storage */ - protected $path; - - /** @var array $stack A stack of lock data */ - protected $stack = array(); - - /** @var resource $handle A file handle used to maintain a lock */ - protected $handle; - - /** @var string $lockFile Filename of the lock file */ - protected $lockFile; - - /** @var resource $lockFileHandle The file handle used to maintain a lock on the lock file */ - protected $lockFileHandle; - /** * Constructor for the lock instance * @param string $path Absolute pathname for a local file on which to obtain a lock */ - public function __construct($path) { - $this->path = Filesystem::normalizePath($path); - } - - protected function obtainReadLock($existingHandle = null) { - \OC_Log::write('lock', sprintf('INFO: Read lock requested for %s', $this->path), \OC_Log::DEBUG); - $timeout = Lock::$retries; - - // Re-use an existing handle or get a new one - if(empty($existingHandle)) { - $handle = fopen($this->path, 'r'); - } - else { - $handle = $existingHandle; - } - - do { - if($this->isLockFileLocked($this->getLockFile($this->path))) { - \OC_Log::write('lock', sprintf('INFO: Read lock has locked lock file %s for %s', $this->getLockFile($this->path), $this->path), \OC_Log::DEBUG); - do { - usleep(Lock::$retryInterval); - $timeout--; - } while($this->isLockFileLocked($this->getLockFile($this->path)) && $timeout > 0); - \OC_Log::write('lock', sprintf('INFO: Lock file %s has become unlocked for %s', $this->getLockFile($this->path), $this->path), \OC_Log::DEBUG); - } - } while ((!$lockReturn = flock($handle, LOCK_SH | LOCK_NB, $wouldBlock)) && $timeout > 0); - if ($wouldBlock == true || $lockReturn == false || $timeout <= 0) { - \OC_Log::write('lock', sprintf('FAIL: Failed to acquire read lock for %s', $this->path), \OC_Log::DEBUG); - return false; - } - $this->handle = $handle; - \OC_Log::write('lock', sprintf('PASS: Acquired read lock for %s', $this->path), \OC_Log::DEBUG); - return true; - } - - protected function obtainWriteLock($existingHandle = null) { - \OC_Log::write('lock', sprintf('INFO: Write lock requested for %s', $this->path), \OC_Log::DEBUG); - - // Re-use an existing handle or get a new one - if (empty($existingHandle)) { - $handle = fopen($this->path, 'c'); - } - else { - $handle = $existingHandle; - } - - // If the file doesn't exist, but we can create a lock for it - if (!file_exists($this->path) && $this->lockLockFile($this->path)) { - $lockReturn = flock($handle, LOCK_EX | LOCK_NB, $wouldBlock); - if ($lockReturn == false || $wouldBlock == true) { - \OC_Log::write('lock', sprintf('FAIL: Write lock failed, unable to exclusively lock new file %s', $this->path), \OC_Log::DEBUG); - return false; - } - $this->handle = $handle; - return true; - } - - - // Since this file does exist, wait for locks to release to get an exclusive lock - $timeout = Lock::$retries; - $haveBlock = false; - while ((!$lockReturn = flock($handle, LOCK_EX | LOCK_NB, $wouldBlock)) && $timeout > 0) { - // We don't have a lock on the original file, try to get a lock on its lock file - if ($haveBlock || $haveBlock = $this->lockLockFile($this->lockFile)) { - usleep(Lock::$retryInterval); - } - else { - \OC_Log::write('lock', sprintf('FAIL: Write lock failed, unable to lock original %s or lock file', $this->path), \OC_Log::DEBUG); - return false; - } - $timeout--; - } - if ($wouldBlock == true || $lockReturn == false) { - \OC_Log::write('lock', sprintf('FAIL: Write lock failed due to timeout on %s', $this->path), \OC_Log::DEBUG); - return false; - } - \OC_Log::write('lock', sprintf('PASS: Write lock succeeded on %s', $this->path), \OC_Log::DEBUG); - - return true; - } - - /** - * Create a lock file and lock it - * Sets $this->lockFile to the specified lock file, indicating that the lock file is IN USE for this lock instance - * Also sets $this->lockFileHandle to a file handle of the lock file - * @param string $filename The name of the file to lock - * @return bool False if lock can't be acquired, true if it can. - */ - protected function lockLockFile ( $filename ) { - $lockFile = $this->getLockFile($filename); - \OC_Log::write('lock', sprintf('INFO: Locking lock file %s for %s', $lockFile, $filename), \OC_Log::DEBUG); - - // If we already manage the lockfile, success - if(!empty($this->lockFile)) { - \OC_Log::write('lock', sprintf('PASS: Lock file %s was locked by this request for %s', $lockFile, $filename), \OC_Log::DEBUG); - return true; - } - - // Check if the lockfile exists, and if not, try to create it - \OC_Log::write('lock', sprintf('INFO: Does lock file %s already exist? %s', $lockFile, file_exists($lockFile) ? 'yes' : 'no'), \OC_Log::DEBUG); - $handle = fopen($lockFile, 'c'); - if(!$handle) { - \OC_Log::write('lock', sprintf('FAIL: Could not create lock file %s', $lockFile), \OC_Log::DEBUG); - return false; - } - - // Attempt to acquire lock on lock file - $wouldBlock = false; - $timeout = self::$retries; - // Wait for lock over timeout - while((!$lockReturn = flock($handle, LOCK_EX | LOCK_NB, $wouldBlock)) && $timeout > 0) { - \OC_Log::write('lock', sprintf('FAIL: Could not acquire lock on lock file %s, %s timeout increments remain.', $lockFile, $timeout), \OC_Log::DEBUG); - usleep(self::$retryInterval); - $timeout--; - } - if ($wouldBlock == true || $lockReturn == false) { - \OC_Log::write('lock', sprintf('FAIL: Could not acquire lock on lock file %s', $lockFile), \OC_Log::DEBUG); - return false; - } - fwrite($handle, $filename); - \OC_Log::write('lock', sprintf('PASS: Wrote filename to lock lock file %s', $lockFile), \OC_Log::DEBUG); - - $this->lockFile = $lockFile; - $this->lockFileHandle = $handle; + public function __construct($path); - return true; - } /** * Add a lock of a specific type to the stack @@ -188,50 +39,12 @@ class Lock { * @param null|resource $existingHandle An existing file handle from an fopen() * @throws LockNotAcquiredException */ - public function addLock($lockType, $existingHandle = null) { - if(!isset($this->stack[$lockType])) { - switch($lockType) { - case Lock::READ: - $result = $this->obtainReadLock($existingHandle); - break; - case Lock::WRITE: - $result = $this->obtainWriteLock($existingHandle); - break; - default: - $result = false; - break; - } - if($result) { - $this->stack[$lockType] = 0; - } - else { - throw new LockNotAcquiredException($this->path, $lockType); - } - } - - \OC_Log::write('lock', sprintf('INFO: Incrementing lock type %d count for %s', $lockType, $this->path), \OC_Log::DEBUG); - $this->stack[$lockType]++; - - } + public function addLock($lockType, $existingHandle = null); /** * Release locks on handles and files */ - public function release($lockType) { - if(isset($this->stack[$lockType])) { - $this->stack[$lockType]--; - if($this->stack[$lockType] <= 0) { - unset($this->stack[$lockType]); - } - } - - if(count($this->stack) == 0) { - // No more locks needed on this file, release the handle and/or lockfile - $this->releaseAll(); - } - - return true; - } + public function release($lockType); /** @@ -239,72 +52,12 @@ class Lock { * @param string $filename The filename of the file to create a lock file for * @return string The filename of the lock file */ - public static function getLockFile($filename) { - static $locksDir = false; - if(!$locksDir) { - $dataDir = Config::getSystemValue('datadirectory'); - $locksDir = $dataDir . '/.locks'; - if(!file_exists($locksDir)) { - mkdir($locksDir); - } - } - $filename = Filesystem::normalizePath($filename); - return $locksDir . '/' . sha1($filename) . '.lock'; - } - - /** - * Determine if a file has an associated and flocked lock file - * @param string $lockFile The filename of the lock file to check - * @return bool True if the lock file is flocked - */ - protected function isLockFileLocked($lockFile) { - if(file_exists($lockFile)) { - if($handle = fopen($lockFile, 'c')) { - if($lock = flock($handle, LOCK_EX | LOCK_NB)) { - // Got lock, not blocking, release and unlink - unlink($lockFile); - fclose($handle); - flock($lock, LOCK_UN); - return false; - } - else { - return true; - } - } - else { - return true; - } - } - return false; - } + public static function getLockFile($filename); /** * Release all queued locks on the file * @return bool */ - public function releaseAll() { - $this->stack = array(); - \OC_Log::write('lock', sprintf('INFO: Releasing locks on %s', $this->path), \OC_Log::DEBUG); - if (!empty($this->handle) && is_resource($this->handle)) { - flock($this->handle, LOCK_UN); - \OC_Log::write('lock', sprintf('INFO: Released lock handle %s on %s', $this->handle, $this->path), \OC_Log::DEBUG); - $this->handle = null; - } - if (!empty($this->lockFile) && file_exists($this->lockFile)) { - unlink($this->lockFile); - \OC_Log::write('lock', sprintf('INFO: Released lock file %s on %s', $this->lockFile, $this->path), \OC_Log::DEBUG); - $this->lockFile = null; - } - \OC_Log::write('lock', sprintf('FREE: Released locks on %s', $this->path), \OC_Log::DEBUG); - return true; - } - - public function __destruct() { - // Only releaseAll if we have locks to release - if(!empty($this->handle) || !empty($this->lockFile)) { - \OC_Log::write('lock', sprintf('INFO: Destroying locks on %s', $this->path), \OC_Log::DEBUG); - $this->releaseAll(); - } - } + public function releaseAll(); } \ No newline at end of file