diff options
Diffstat (limited to 'includes/filerepo/backend/lockmanager')
5 files changed, 0 insertions, 1237 deletions
diff --git a/includes/filerepo/backend/lockmanager/DBLockManager.php b/includes/filerepo/backend/lockmanager/DBLockManager.php deleted file mode 100644 index 045056ea..00000000 --- a/includes/filerepo/backend/lockmanager/DBLockManager.php +++ /dev/null @@ -1,469 +0,0 @@ -<?php - -/** - * Version of LockManager based on using DB table locks. - * This is meant for multi-wiki systems that may share files. - * All locks are blocking, so it might be useful to set a small - * lock-wait timeout via server config to curtail deadlocks. - * - * All lock requests for a resource, identified by a hash string, will map - * to one bucket. Each bucket maps to one or several peer DBs, each on their - * own server, all having the filelocks.sql tables (with row-level locking). - * A majority of peer DBs must agree for a lock to be acquired. - * - * Caching is used to avoid hitting servers that are down. - * - * @ingroup LockManager - * @since 1.19 - */ -class DBLockManager extends LockManager { - /** @var Array Map of DB names to server config */ - protected $dbServers; // (DB name => server config array) - /** @var Array Map of bucket indexes to peer DB lists */ - protected $dbsByBucket; // (bucket index => (ldb1, ldb2, ...)) - /** @var BagOStuff */ - protected $statusCache; - - protected $lockExpiry; // integer number of seconds - protected $safeDelay; // integer number of seconds - - protected $session = 0; // random integer - /** @var Array Map Database connections (DB name => Database) */ - protected $conns = array(); - - /** - * Construct a new instance from configuration. - * - * $config paramaters include: - * 'dbServers' : Associative array of DB names to server configuration. - * Configuration is an associative array that includes: - * 'host' - DB server name - * 'dbname' - DB name - * 'type' - DB type (mysql,postgres,...) - * 'user' - DB user - * 'password' - DB user password - * 'tablePrefix' - DB table prefix - * 'flags' - DB flags (see DatabaseBase) - * 'dbsByBucket' : Array of 1-16 consecutive integer keys, starting from 0, - * each having an odd-numbered list of DB names (peers) as values. - * Any DB named 'localDBMaster' will automatically use the DB master - * settings for this wiki (without the need for a dbServers entry). - * 'lockExpiry' : Lock timeout (seconds) for dropped connections. [optional] - * This tells the DB server how long to wait before assuming - * connection failure and releasing all the locks for a session. - * - * @param Array $config - */ - public function __construct( array $config ) { - $this->dbServers = isset( $config['dbServers'] ) - ? $config['dbServers'] - : array(); // likely just using 'localDBMaster' - // Sanitize dbsByBucket config to prevent PHP errors - $this->dbsByBucket = array_filter( $config['dbsByBucket'], 'is_array' ); - $this->dbsByBucket = array_values( $this->dbsByBucket ); // consecutive - - if ( isset( $config['lockExpiry'] ) ) { - $this->lockExpiry = $config['lockExpiry']; - } else { - $met = ini_get( 'max_execution_time' ); - $this->lockExpiry = $met ? $met : 60; // use some sane amount if 0 - } - $this->safeDelay = ( $this->lockExpiry <= 0 ) - ? 60 // pick a safe-ish number to match DB timeout default - : $this->lockExpiry; // cover worst case - - foreach ( $this->dbsByBucket as $bucket ) { - if ( count( $bucket ) > 1 ) { - // Tracks peers that couldn't be queried recently to avoid lengthy - // connection timeouts. This is useless if each bucket has one peer. - $this->statusCache = wfGetMainCache(); - break; - } - } - - $this->session = ''; - for ( $i = 0; $i < 5; $i++ ) { - $this->session .= mt_rand( 0, 2147483647 ); - } - $this->session = wfBaseConvert( sha1( $this->session ), 16, 36, 31 ); - } - - /** - * @see LockManager::doLock() - */ - protected function doLock( array $paths, $type ) { - $status = Status::newGood(); - - $pathsToLock = array(); - // Get locks that need to be acquired (buckets => locks)... - foreach ( $paths as $path ) { - if ( isset( $this->locksHeld[$path][$type] ) ) { - ++$this->locksHeld[$path][$type]; - } elseif ( isset( $this->locksHeld[$path][self::LOCK_EX] ) ) { - $this->locksHeld[$path][$type] = 1; - } else { - $bucket = $this->getBucketFromKey( $path ); - $pathsToLock[$bucket][] = $path; - } - } - - $lockedPaths = array(); // files locked in this attempt - // Attempt to acquire these locks... - foreach ( $pathsToLock as $bucket => $paths ) { - // Try to acquire the locks for this bucket - $res = $this->doLockingQueryAll( $bucket, $paths, $type ); - if ( $res === 'cantacquire' ) { - // Resources already locked by another process. - // Abort and unlock everything we just locked. - foreach ( $paths as $path ) { - $status->fatal( 'lockmanager-fail-acquirelock', $path ); - } - $status->merge( $this->doUnlock( $lockedPaths, $type ) ); - return $status; - } elseif ( $res !== true ) { - // Couldn't contact any DBs for this bucket. - // Abort and unlock everything we just locked. - $status->fatal( 'lockmanager-fail-db-bucket', $bucket ); - $status->merge( $this->doUnlock( $lockedPaths, $type ) ); - return $status; - } - // Record these locks as active - foreach ( $paths as $path ) { - $this->locksHeld[$path][$type] = 1; // locked - } - // Keep track of what locks were made in this attempt - $lockedPaths = array_merge( $lockedPaths, $paths ); - } - - return $status; - } - - /** - * @see LockManager::doUnlock() - */ - protected function doUnlock( array $paths, $type ) { - $status = Status::newGood(); - - foreach ( $paths as $path ) { - if ( !isset( $this->locksHeld[$path] ) ) { - $status->warning( 'lockmanager-notlocked', $path ); - } elseif ( !isset( $this->locksHeld[$path][$type] ) ) { - $status->warning( 'lockmanager-notlocked', $path ); - } else { - --$this->locksHeld[$path][$type]; - if ( $this->locksHeld[$path][$type] <= 0 ) { - unset( $this->locksHeld[$path][$type] ); - } - if ( !count( $this->locksHeld[$path] ) ) { - unset( $this->locksHeld[$path] ); // no SH or EX locks left for key - } - } - } - - // Reference count the locks held and COMMIT when zero - if ( !count( $this->locksHeld ) ) { - $status->merge( $this->finishLockTransactions() ); - } - - return $status; - } - - /** - * Get a connection to a lock DB and acquire locks on $paths. - * This does not use GET_LOCK() per http://bugs.mysql.com/bug.php?id=1118. - * - * @param $lockDb string - * @param $paths Array - * @param $type integer LockManager::LOCK_EX or LockManager::LOCK_SH - * @return bool Resources able to be locked - * @throws DBError - */ - protected function doLockingQuery( $lockDb, array $paths, $type ) { - if ( $type == self::LOCK_EX ) { // writer locks - $db = $this->getConnection( $lockDb ); - if ( !$db ) { - return false; // bad config - } - $keys = array_unique( array_map( 'LockManager::sha1Base36', $paths ) ); - # Build up values for INSERT clause - $data = array(); - foreach ( $keys as $key ) { - $data[] = array( 'fle_key' => $key ); - } - # Wait on any existing writers and block new ones if we get in - $db->insert( 'filelocks_exclusive', $data, __METHOD__ ); - } - return true; - } - - /** - * Attempt to acquire locks with the peers for a bucket. - * This should avoid throwing any exceptions. - * - * @param $bucket integer - * @param $paths Array List of resource keys to lock - * @param $type integer LockManager::LOCK_EX or LockManager::LOCK_SH - * @return bool|string One of (true, 'cantacquire', 'dberrors') - */ - protected function doLockingQueryAll( $bucket, array $paths, $type ) { - $yesVotes = 0; // locks made on trustable DBs - $votesLeft = count( $this->dbsByBucket[$bucket] ); // remaining DBs - $quorum = floor( $votesLeft/2 + 1 ); // simple majority - // Get votes for each DB, in order, until we have enough... - foreach ( $this->dbsByBucket[$bucket] as $lockDb ) { - // Check that DB is not *known* to be down - if ( $this->cacheCheckFailures( $lockDb ) ) { - try { - // Attempt to acquire the lock on this DB - if ( !$this->doLockingQuery( $lockDb, $paths, $type ) ) { - return 'cantacquire'; // vetoed; resource locked - } - ++$yesVotes; // success for this peer - if ( $yesVotes >= $quorum ) { - return true; // lock obtained - } - } catch ( DBConnectionError $e ) { - $this->cacheRecordFailure( $lockDb ); - } catch ( DBError $e ) { - if ( $this->lastErrorIndicatesLocked( $lockDb ) ) { - return 'cantacquire'; // vetoed; resource locked - } - } - } - --$votesLeft; - $votesNeeded = $quorum - $yesVotes; - if ( $votesNeeded > $votesLeft ) { - // In "trust cache" mode we don't have to meet the quorum - break; // short-circuit - } - } - // At this point, we must not have meet the quorum - return 'dberrors'; // not enough votes to ensure correctness - } - - /** - * Get (or reuse) a connection to a lock DB - * - * @param $lockDb string - * @return Database - * @throws DBError - */ - protected function getConnection( $lockDb ) { - if ( !isset( $this->conns[$lockDb] ) ) { - $db = null; - if ( $lockDb === 'localDBMaster' ) { - $lb = wfGetLBFactory()->newMainLB(); - $db = $lb->getConnection( DB_MASTER ); - } elseif ( isset( $this->dbServers[$lockDb] ) ) { - $config = $this->dbServers[$lockDb]; - $db = DatabaseBase::factory( $config['type'], $config ); - } - if ( !$db ) { - return null; // config error? - } - $this->conns[$lockDb] = $db; - $this->conns[$lockDb]->clearFlag( DBO_TRX ); - # If the connection drops, try to avoid letting the DB rollback - # and release the locks before the file operations are finished. - # This won't handle the case of DB server restarts however. - $options = array(); - if ( $this->lockExpiry > 0 ) { - $options['connTimeout'] = $this->lockExpiry; - } - $this->conns[$lockDb]->setSessionOptions( $options ); - $this->initConnection( $lockDb, $this->conns[$lockDb] ); - } - if ( !$this->conns[$lockDb]->trxLevel() ) { - $this->conns[$lockDb]->begin(); // start transaction - } - return $this->conns[$lockDb]; - } - - /** - * Do additional initialization for new lock DB connection - * - * @param $lockDb string - * @param $db DatabaseBase - * @return void - * @throws DBError - */ - protected function initConnection( $lockDb, DatabaseBase $db ) {} - - /** - * Commit all changes to lock-active databases. - * This should avoid throwing any exceptions. - * - * @return Status - */ - protected function finishLockTransactions() { - $status = Status::newGood(); - foreach ( $this->conns as $lockDb => $db ) { - if ( $db->trxLevel() ) { // in transaction - try { - $db->rollback(); // finish transaction and kill any rows - } catch ( DBError $e ) { - $status->fatal( 'lockmanager-fail-db-release', $lockDb ); - } - } - } - return $status; - } - - /** - * Check if the last DB error for $lockDb indicates - * that a requested resource was locked by another process. - * This should avoid throwing any exceptions. - * - * @param $lockDb string - * @return bool - */ - protected function lastErrorIndicatesLocked( $lockDb ) { - if ( isset( $this->conns[$lockDb] ) ) { // sanity - $db = $this->conns[$lockDb]; - return ( $db->wasDeadlock() || $db->wasLockTimeout() ); - } - return false; - } - - /** - * Checks if the DB has not recently had connection/query errors. - * This just avoids wasting time on doomed connection attempts. - * - * @param $lockDb string - * @return bool - */ - protected function cacheCheckFailures( $lockDb ) { - if ( $this->statusCache && $this->safeDelay > 0 ) { - $path = $this->getMissKey( $lockDb ); - $misses = $this->statusCache->get( $path ); - return !$misses; - } - return true; - } - - /** - * Log a lock request failure to the cache - * - * @param $lockDb string - * @return bool Success - */ - protected function cacheRecordFailure( $lockDb ) { - if ( $this->statusCache && $this->safeDelay > 0 ) { - $path = $this->getMissKey( $lockDb ); - $misses = $this->statusCache->get( $path ); - if ( $misses ) { - return $this->statusCache->incr( $path ); - } else { - return $this->statusCache->add( $path, 1, $this->safeDelay ); - } - } - return true; - } - - /** - * Get a cache key for recent query misses for a DB - * - * @param $lockDb string - * @return string - */ - protected function getMissKey( $lockDb ) { - return 'lockmanager:querymisses:' . str_replace( ' ', '_', $lockDb ); - } - - /** - * Get the bucket for resource path. - * This should avoid throwing any exceptions. - * - * @param $path string - * @return integer - */ - protected function getBucketFromKey( $path ) { - $prefix = substr( sha1( $path ), 0, 2 ); // first 2 hex chars (8 bits) - return intval( base_convert( $prefix, 16, 10 ) ) % count( $this->dbsByBucket ); - } - - /** - * Make sure remaining locks get cleared for sanity - */ - function __destruct() { - foreach ( $this->conns as $lockDb => $db ) { - if ( $db->trxLevel() ) { // in transaction - try { - $db->rollback(); // finish transaction and kill any rows - } catch ( DBError $e ) { - // oh well - } - } - $db->close(); - } - } -} - -/** - * MySQL version of DBLockManager that supports shared locks. - * All locks are non-blocking, which avoids deadlocks. - * - * @ingroup LockManager - */ -class MySqlLockManager extends DBLockManager { - /** @var Array Mapping of lock types to the type actually used */ - protected $lockTypeMap = array( - self::LOCK_SH => self::LOCK_SH, - self::LOCK_UW => self::LOCK_SH, - self::LOCK_EX => self::LOCK_EX - ); - - protected function initConnection( $lockDb, DatabaseBase $db ) { - # Let this transaction see lock rows from other transactions - $db->query( "SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;" ); - } - - protected function doLockingQuery( $lockDb, array $paths, $type ) { - $db = $this->getConnection( $lockDb ); - if ( !$db ) { - return false; - } - $keys = array_unique( array_map( 'LockManager::sha1Base36', $paths ) ); - # Build up values for INSERT clause - $data = array(); - foreach ( $keys as $key ) { - $data[] = array( 'fls_key' => $key, 'fls_session' => $this->session ); - } - # Block new writers... - $db->insert( 'filelocks_shared', $data, __METHOD__, array( 'IGNORE' ) ); - # Actually do the locking queries... - if ( $type == self::LOCK_SH ) { // reader locks - # Bail if there are any existing writers... - $blocked = $db->selectField( 'filelocks_exclusive', '1', - array( 'fle_key' => $keys ), - __METHOD__ - ); - # Prospective writers that haven't yet updated filelocks_exclusive - # will recheck filelocks_shared after doing so and bail due to our entry. - } else { // writer locks - $encSession = $db->addQuotes( $this->session ); - # Bail if there are any existing writers... - # The may detect readers, but the safe check for them is below. - # Note: if two writers come at the same time, both bail :) - $blocked = $db->selectField( 'filelocks_shared', '1', - array( 'fls_key' => $keys, "fls_session != $encSession" ), - __METHOD__ - ); - if ( !$blocked ) { - # Build up values for INSERT clause - $data = array(); - foreach ( $keys as $key ) { - $data[] = array( 'fle_key' => $key ); - } - # Block new readers/writers... - $db->insert( 'filelocks_exclusive', $data, __METHOD__ ); - # Bail if there are any existing readers... - $blocked = $db->selectField( 'filelocks_shared', '1', - array( 'fls_key' => $keys, "fls_session != $encSession" ), - __METHOD__ - ); - } - } - return !$blocked; - } -} diff --git a/includes/filerepo/backend/lockmanager/FSLockManager.php b/includes/filerepo/backend/lockmanager/FSLockManager.php deleted file mode 100644 index 42074fd3..00000000 --- a/includes/filerepo/backend/lockmanager/FSLockManager.php +++ /dev/null @@ -1,202 +0,0 @@ -<?php - -/** - * Simple version of LockManager based on using FS lock files. - * All locks are non-blocking, which avoids deadlocks. - * - * This should work fine for small sites running off one server. - * Do not use this with 'lockDirectory' set to an NFS mount unless the - * NFS client is at least version 2.6.12. Otherwise, the BSD flock() - * locks will be ignored; see http://nfs.sourceforge.net/#section_d. - * - * @ingroup LockManager - * @since 1.19 - */ -class FSLockManager extends LockManager { - /** @var Array Mapping of lock types to the type actually used */ - protected $lockTypeMap = array( - self::LOCK_SH => self::LOCK_SH, - self::LOCK_UW => self::LOCK_SH, - self::LOCK_EX => self::LOCK_EX - ); - - protected $lockDir; // global dir for all servers - - /** @var Array Map of (locked key => lock type => lock file handle) */ - protected $handles = array(); - - /** - * Construct a new instance from configuration. - * - * $config includes: - * 'lockDirectory' : Directory containing the lock files - * - * @param array $config - */ - function __construct( array $config ) { - parent::__construct( $config ); - $this->lockDir = $config['lockDirectory']; - } - - protected function doLock( array $paths, $type ) { - $status = Status::newGood(); - - $lockedPaths = array(); // files locked in this attempt - foreach ( $paths as $path ) { - $status->merge( $this->doSingleLock( $path, $type ) ); - if ( $status->isOK() ) { - $lockedPaths[] = $path; - } else { - // Abort and unlock everything - $status->merge( $this->doUnlock( $lockedPaths, $type ) ); - return $status; - } - } - - return $status; - } - - protected function doUnlock( array $paths, $type ) { - $status = Status::newGood(); - - foreach ( $paths as $path ) { - $status->merge( $this->doSingleUnlock( $path, $type ) ); - } - - return $status; - } - - /** - * Lock a single resource key - * - * @param $path string - * @param $type integer - * @return Status - */ - protected function doSingleLock( $path, $type ) { - $status = Status::newGood(); - - if ( isset( $this->locksHeld[$path][$type] ) ) { - ++$this->locksHeld[$path][$type]; - } elseif ( isset( $this->locksHeld[$path][self::LOCK_EX] ) ) { - $this->locksHeld[$path][$type] = 1; - } else { - wfSuppressWarnings(); - $handle = fopen( $this->getLockPath( $path ), 'a+' ); - wfRestoreWarnings(); - if ( !$handle ) { // lock dir missing? - wfMkdirParents( $this->lockDir ); - $handle = fopen( $this->getLockPath( $path ), 'a+' ); // try again - } - if ( $handle ) { - // Either a shared or exclusive lock - $lock = ( $type == self::LOCK_SH ) ? LOCK_SH : LOCK_EX; - if ( flock( $handle, $lock | LOCK_NB ) ) { - // Record this lock as active - $this->locksHeld[$path][$type] = 1; - $this->handles[$path][$type] = $handle; - } else { - fclose( $handle ); - $status->fatal( 'lockmanager-fail-acquirelock', $path ); - } - } else { - $status->fatal( 'lockmanager-fail-openlock', $path ); - } - } - - return $status; - } - - /** - * Unlock a single resource key - * - * @param $path string - * @param $type integer - * @return Status - */ - protected function doSingleUnlock( $path, $type ) { - $status = Status::newGood(); - - if ( !isset( $this->locksHeld[$path] ) ) { - $status->warning( 'lockmanager-notlocked', $path ); - } elseif ( !isset( $this->locksHeld[$path][$type] ) ) { - $status->warning( 'lockmanager-notlocked', $path ); - } else { - $handlesToClose = array(); - --$this->locksHeld[$path][$type]; - if ( $this->locksHeld[$path][$type] <= 0 ) { - unset( $this->locksHeld[$path][$type] ); - // If a LOCK_SH comes in while we have a LOCK_EX, we don't - // actually add a handler, so check for handler existence. - if ( isset( $this->handles[$path][$type] ) ) { - // Mark this handle to be unlocked and closed - $handlesToClose[] = $this->handles[$path][$type]; - unset( $this->handles[$path][$type] ); - } - } - // Unlock handles to release locks and delete - // any lock files that end up with no locks on them... - if ( wfIsWindows() ) { - // Windows: for any process, including this one, - // calling unlink() on a locked file will fail - $status->merge( $this->closeLockHandles( $path, $handlesToClose ) ); - $status->merge( $this->pruneKeyLockFiles( $path ) ); - } else { - // Unix: unlink() can be used on files currently open by this - // process and we must do so in order to avoid race conditions - $status->merge( $this->pruneKeyLockFiles( $path ) ); - $status->merge( $this->closeLockHandles( $path, $handlesToClose ) ); - } - } - - return $status; - } - - private function closeLockHandles( $path, array $handlesToClose ) { - $status = Status::newGood(); - foreach ( $handlesToClose as $handle ) { - wfSuppressWarnings(); - if ( !flock( $handle, LOCK_UN ) ) { - $status->fatal( 'lockmanager-fail-releaselock', $path ); - } - if ( !fclose( $handle ) ) { - $status->warning( 'lockmanager-fail-closelock', $path ); - } - wfRestoreWarnings(); - } - return $status; - } - - private function pruneKeyLockFiles( $path ) { - $status = Status::newGood(); - if ( !count( $this->locksHeld[$path] ) ) { - wfSuppressWarnings(); - # No locks are held for the lock file anymore - if ( !unlink( $this->getLockPath( $path ) ) ) { - $status->warning( 'lockmanager-fail-deletelock', $path ); - } - wfRestoreWarnings(); - unset( $this->locksHeld[$path] ); - unset( $this->handles[$path] ); - } - return $status; - } - - /** - * Get the path to the lock file for a key - * @param $path string - * @return string - */ - protected function getLockPath( $path ) { - $hash = self::sha1Base36( $path ); - return "{$this->lockDir}/{$hash}.lock"; - } - - function __destruct() { - // Make sure remaining locks get cleared for sanity - foreach ( $this->locksHeld as $path => $locks ) { - $this->doSingleUnlock( $path, self::LOCK_EX ); - $this->doSingleUnlock( $path, self::LOCK_SH ); - } - } -} diff --git a/includes/filerepo/backend/lockmanager/LSLockManager.php b/includes/filerepo/backend/lockmanager/LSLockManager.php deleted file mode 100644 index b7ac743c..00000000 --- a/includes/filerepo/backend/lockmanager/LSLockManager.php +++ /dev/null @@ -1,295 +0,0 @@ -<?php - -/** - * Manage locks using a lock daemon server. - * - * Version of LockManager based on using lock daemon servers. - * This is meant for multi-wiki systems that may share files. - * All locks are non-blocking, which avoids deadlocks. - * - * All lock requests for a resource, identified by a hash string, will map - * to one bucket. Each bucket maps to one or several peer servers, each - * running LockServerDaemon.php, listening on a designated TCP port. - * A majority of peers must agree for a lock to be acquired. - * - * @ingroup LockManager - * @since 1.19 - */ -class LSLockManager extends LockManager { - /** @var Array Mapping of lock types to the type actually used */ - protected $lockTypeMap = array( - self::LOCK_SH => self::LOCK_SH, - self::LOCK_UW => self::LOCK_SH, - self::LOCK_EX => self::LOCK_EX - ); - - /** @var Array Map of server names to server config */ - protected $lockServers; // (server name => server config array) - /** @var Array Map of bucket indexes to peer server lists */ - protected $srvsByBucket; // (bucket index => (lsrv1, lsrv2, ...)) - - /** @var Array Map Server connections (server name => resource) */ - protected $conns = array(); - - protected $connTimeout; // float number of seconds - protected $session = ''; // random SHA-1 string - - /** - * Construct a new instance from configuration. - * - * $config paramaters include: - * 'lockServers' : Associative array of server names to configuration. - * Configuration is an associative array that includes: - * 'host' - IP address/hostname - * 'port' - TCP port - * 'authKey' - Secret string the lock server uses - * 'srvsByBucket' : Array of 1-16 consecutive integer keys, starting from 0, - * each having an odd-numbered list of server names (peers) as values. - * 'connTimeout' : Lock server connection attempt timeout. [optional] - * - * @param Array $config - */ - public function __construct( array $config ) { - $this->lockServers = $config['lockServers']; - // Sanitize srvsByBucket config to prevent PHP errors - $this->srvsByBucket = array_filter( $config['srvsByBucket'], 'is_array' ); - $this->srvsByBucket = array_values( $this->srvsByBucket ); // consecutive - - if ( isset( $config['connTimeout'] ) ) { - $this->connTimeout = $config['connTimeout']; - } else { - $this->connTimeout = 3; // use some sane amount - } - - $this->session = ''; - for ( $i = 0; $i < 5; $i++ ) { - $this->session .= mt_rand( 0, 2147483647 ); - } - $this->session = wfBaseConvert( sha1( $this->session ), 16, 36, 31 ); - } - - protected function doLock( array $paths, $type ) { - $status = Status::newGood(); - - $pathsToLock = array(); - // Get locks that need to be acquired (buckets => locks)... - foreach ( $paths as $path ) { - if ( isset( $this->locksHeld[$path][$type] ) ) { - ++$this->locksHeld[$path][$type]; - } elseif ( isset( $this->locksHeld[$path][self::LOCK_EX] ) ) { - $this->locksHeld[$path][$type] = 1; - } else { - $bucket = $this->getBucketFromKey( $path ); - $pathsToLock[$bucket][] = $path; - } - } - - $lockedPaths = array(); // files locked in this attempt - // Attempt to acquire these locks... - foreach ( $pathsToLock as $bucket => $paths ) { - // Try to acquire the locks for this bucket - $res = $this->doLockingRequestAll( $bucket, $paths, $type ); - if ( $res === 'cantacquire' ) { - // Resources already locked by another process. - // Abort and unlock everything we just locked. - foreach ( $paths as $path ) { - $status->fatal( 'lockmanager-fail-acquirelock', $path ); - } - $status->merge( $this->doUnlock( $lockedPaths, $type ) ); - return $status; - } elseif ( $res !== true ) { - // Couldn't contact any servers for this bucket. - // Abort and unlock everything we just locked. - foreach ( $paths as $path ) { - $status->fatal( 'lockmanager-fail-acquirelock', $path ); - } - $status->merge( $this->doUnlock( $lockedPaths, $type ) ); - return $status; - } - // Record these locks as active - foreach ( $paths as $path ) { - $this->locksHeld[$path][$type] = 1; // locked - } - // Keep track of what locks were made in this attempt - $lockedPaths = array_merge( $lockedPaths, $paths ); - } - - return $status; - } - - protected function doUnlock( array $paths, $type ) { - $status = Status::newGood(); - - foreach ( $paths as $path ) { - if ( !isset( $this->locksHeld[$path] ) ) { - $status->warning( 'lockmanager-notlocked', $path ); - } elseif ( !isset( $this->locksHeld[$path][$type] ) ) { - $status->warning( 'lockmanager-notlocked', $path ); - } else { - --$this->locksHeld[$path][$type]; - if ( $this->locksHeld[$path][$type] <= 0 ) { - unset( $this->locksHeld[$path][$type] ); - } - if ( !count( $this->locksHeld[$path] ) ) { - unset( $this->locksHeld[$path] ); // no SH or EX locks left for key - } - } - } - - // Reference count the locks held and release locks when zero - if ( !count( $this->locksHeld ) ) { - $status->merge( $this->releaseLocks() ); - } - - return $status; - } - - /** - * Get a connection to a lock server and acquire locks on $paths - * - * @param $lockSrv string - * @param $paths Array - * @param $type integer LockManager::LOCK_EX or LockManager::LOCK_SH - * @return bool Resources able to be locked - */ - protected function doLockingRequest( $lockSrv, array $paths, $type ) { - if ( $type == self::LOCK_SH ) { // reader locks - $type = 'SH'; - } elseif ( $type == self::LOCK_EX ) { // writer locks - $type = 'EX'; - } else { - return true; // ok... - } - - // Send out the command and get the response... - $keys = array_unique( array_map( 'LockManager::sha1Base36', $paths ) ); - $response = $this->sendCommand( $lockSrv, 'ACQUIRE', $type, $keys ); - - return ( $response === 'ACQUIRED' ); - } - - /** - * Send a command and get back the response - * - * @param $lockSrv string - * @param $action string - * @param $type string - * @param $values Array - * @return string|false - */ - protected function sendCommand( $lockSrv, $action, $type, $values ) { - $conn = $this->getConnection( $lockSrv ); - if ( !$conn ) { - return false; // no connection - } - $authKey = $this->lockServers[$lockSrv]['authKey']; - // Build of the command as a flat string... - $values = implode( '|', $values ); - $key = sha1( $this->session . $action . $type . $values . $authKey ); - // Send out the command... - if ( fwrite( $conn, "{$this->session}:$key:$action:$type:$values\n" ) === false ) { - return false; - } - // Get the response... - $response = fgets( $conn ); - if ( $response === false ) { - return false; - } - return trim( $response ); - } - - /** - * Attempt to acquire locks with the peers for a bucket - * - * @param $bucket integer - * @param $paths Array List of resource keys to lock - * @param $type integer LockManager::LOCK_EX or LockManager::LOCK_SH - * @return bool|string One of (true, 'cantacquire', 'srverrors') - */ - protected function doLockingRequestAll( $bucket, array $paths, $type ) { - $yesVotes = 0; // locks made on trustable servers - $votesLeft = count( $this->srvsByBucket[$bucket] ); // remaining peers - $quorum = floor( $votesLeft/2 + 1 ); // simple majority - // Get votes for each peer, in order, until we have enough... - foreach ( $this->srvsByBucket[$bucket] as $lockSrv ) { - // Attempt to acquire the lock on this peer - if ( !$this->doLockingRequest( $lockSrv, $paths, $type ) ) { - return 'cantacquire'; // vetoed; resource locked - } - ++$yesVotes; // success for this peer - if ( $yesVotes >= $quorum ) { - return true; // lock obtained - } - --$votesLeft; - $votesNeeded = $quorum - $yesVotes; - if ( $votesNeeded > $votesLeft ) { - // In "trust cache" mode we don't have to meet the quorum - break; // short-circuit - } - } - // At this point, we must not have meet the quorum - return 'srverrors'; // not enough votes to ensure correctness - } - - /** - * Get (or reuse) a connection to a lock server - * - * @param $lockSrv string - * @return resource - */ - protected function getConnection( $lockSrv ) { - if ( !isset( $this->conns[$lockSrv] ) ) { - $cfg = $this->lockServers[$lockSrv]; - wfSuppressWarnings(); - $errno = $errstr = ''; - $conn = fsockopen( $cfg['host'], $cfg['port'], $errno, $errstr, $this->connTimeout ); - wfRestoreWarnings(); - if ( $conn === false ) { - return null; - } - $sec = floor( $this->connTimeout ); - $usec = floor( ( $this->connTimeout - floor( $this->connTimeout ) ) * 1e6 ); - stream_set_timeout( $conn, $sec, $usec ); - $this->conns[$lockSrv] = $conn; - } - return $this->conns[$lockSrv]; - } - - /** - * Release all locks that this session is holding - * - * @return Status - */ - protected function releaseLocks() { - $status = Status::newGood(); - foreach ( $this->conns as $lockSrv => $conn ) { - $response = $this->sendCommand( $lockSrv, 'RELEASE_ALL', '', array() ); - if ( $response !== 'RELEASED_ALL' ) { - $status->fatal( 'lockmanager-fail-svr-release', $lockSrv ); - } - } - return $status; - } - - /** - * Get the bucket for resource path. - * This should avoid throwing any exceptions. - * - * @param $path string - * @return integer - */ - protected function getBucketFromKey( $path ) { - $prefix = substr( sha1( $path ), 0, 2 ); // first 2 hex chars (8 bits) - return intval( base_convert( $prefix, 16, 10 ) ) % count( $this->srvsByBucket ); - } - - /** - * Make sure remaining locks get cleared for sanity - */ - function __destruct() { - $this->releaseLocks(); - foreach ( $this->conns as $conn ) { - fclose( $conn ); - } - } -} diff --git a/includes/filerepo/backend/lockmanager/LockManager.php b/includes/filerepo/backend/lockmanager/LockManager.php deleted file mode 100644 index 23603a4f..00000000 --- a/includes/filerepo/backend/lockmanager/LockManager.php +++ /dev/null @@ -1,182 +0,0 @@ -<?php -/** - * @defgroup LockManager Lock management - * @ingroup FileBackend - */ - -/** - * @file - * @ingroup LockManager - * @author Aaron Schulz - */ - -/** - * Class for handling resource locking. - * - * Locks on resource keys can either be shared or exclusive. - * - * Implementations must keep track of what is locked by this proccess - * in-memory and support nested locking calls (using reference counting). - * At least LOCK_UW and LOCK_EX must be implemented. LOCK_SH can be a no-op. - * Locks should either be non-blocking or have low wait timeouts. - * - * Subclasses should avoid throwing exceptions at all costs. - * - * @ingroup LockManager - * @since 1.19 - */ -abstract class LockManager { - /** @var Array Mapping of lock types to the type actually used */ - protected $lockTypeMap = array( - self::LOCK_SH => self::LOCK_SH, - self::LOCK_UW => self::LOCK_EX, // subclasses may use self::LOCK_SH - self::LOCK_EX => self::LOCK_EX - ); - - /** @var Array Map of (resource path => lock type => count) */ - protected $locksHeld = array(); - - /* Lock types; stronger locks have higher values */ - const LOCK_SH = 1; // shared lock (for reads) - const LOCK_UW = 2; // shared lock (for reads used to write elsewhere) - const LOCK_EX = 3; // exclusive lock (for writes) - - /** - * Construct a new instance from configuration - * - * @param $config Array - */ - public function __construct( array $config ) {} - - /** - * Lock the resources at the given abstract paths - * - * @param $paths Array List of resource names - * @param $type integer LockManager::LOCK_* constant - * @return Status - */ - final public function lock( array $paths, $type = self::LOCK_EX ) { - return $this->doLock( array_unique( $paths ), $this->lockTypeMap[$type] ); - } - - /** - * Unlock the resources at the given abstract paths - * - * @param $paths Array List of storage paths - * @param $type integer LockManager::LOCK_* constant - * @return Status - */ - final public function unlock( array $paths, $type = self::LOCK_EX ) { - return $this->doUnlock( array_unique( $paths ), $this->lockTypeMap[$type] ); - } - - /** - * Get the base 36 SHA-1 of a string, padded to 31 digits - * - * @param $path string - * @return string - */ - final protected static function sha1Base36( $path ) { - return wfBaseConvert( sha1( $path ), 16, 36, 31 ); - } - - /** - * Lock resources with the given keys and lock type - * - * @param $paths Array List of storage paths - * @param $type integer LockManager::LOCK_* constant - * @return string - */ - abstract protected function doLock( array $paths, $type ); - - /** - * Unlock resources with the given keys and lock type - * - * @param $paths Array List of storage paths - * @param $type integer LockManager::LOCK_* constant - * @return string - */ - abstract protected function doUnlock( array $paths, $type ); -} - -/** - * Self releasing locks - * - * LockManager helper class to handle scoped locks, which - * release when an object is destroyed or goes out of scope. - * - * @ingroup LockManager - * @since 1.19 - */ -class ScopedLock { - /** @var LockManager */ - protected $manager; - /** @var Status */ - protected $status; - /** @var Array List of resource paths*/ - protected $paths; - - protected $type; // integer lock type - - /** - * @param $manager LockManager - * @param $paths Array List of storage paths - * @param $type integer LockManager::LOCK_* constant - * @param $status Status - */ - protected function __construct( - LockManager $manager, array $paths, $type, Status $status - ) { - $this->manager = $manager; - $this->paths = $paths; - $this->status = $status; - $this->type = $type; - } - - protected function __clone() {} - - /** - * Get a ScopedLock object representing a lock on resource paths. - * Any locks are released once this object goes out of scope. - * The status object is updated with any errors or warnings. - * - * @param $manager LockManager - * @param $paths Array List of storage paths - * @param $type integer LockManager::LOCK_* constant - * @param $status Status - * @return ScopedLock|null Returns null on failure - */ - public static function factory( - LockManager $manager, array $paths, $type, Status $status - ) { - $lockStatus = $manager->lock( $paths, $type ); - $status->merge( $lockStatus ); - if ( $lockStatus->isOK() ) { - return new self( $manager, $paths, $type, $status ); - } - return null; - } - - function __destruct() { - $wasOk = $this->status->isOK(); - $this->status->merge( $this->manager->unlock( $this->paths, $this->type ) ); - if ( $wasOk ) { - // Make sure status is OK, despite any unlockFiles() fatals - $this->status->setResult( true, $this->status->value ); - } - } -} - -/** - * Simple version of LockManager that does nothing - * @since 1.19 - */ -class NullLockManager extends LockManager { - protected function doLock( array $paths, $type ) { - return Status::newGood(); - } - - protected function doUnlock( array $paths, $type ) { - return Status::newGood(); - } -} diff --git a/includes/filerepo/backend/lockmanager/LockManagerGroup.php b/includes/filerepo/backend/lockmanager/LockManagerGroup.php deleted file mode 100644 index 11e77972..00000000 --- a/includes/filerepo/backend/lockmanager/LockManagerGroup.php +++ /dev/null @@ -1,89 +0,0 @@ -<?php -/** - * Class to handle file lock manager registration - * - * @ingroup LockManager - * @author Aaron Schulz - * @since 1.19 - */ -class LockManagerGroup { - - /** - * @var LockManagerGroup - */ - protected static $instance = null; - - /** @var Array of (name => ('class' =>, 'config' =>, 'instance' =>)) */ - protected $managers = array(); - - protected function __construct() {} - protected function __clone() {} - - /** - * @return LockManagerGroup - */ - public static function singleton() { - if ( self::$instance == null ) { - self::$instance = new self(); - self::$instance->initFromGlobals(); - } - return self::$instance; - } - - /** - * Register lock managers from the global variables - * - * @return void - */ - protected function initFromGlobals() { - global $wgLockManagers; - - $this->register( $wgLockManagers ); - } - - /** - * Register an array of file lock manager configurations - * - * @param $configs Array - * @return void - * @throws MWException - */ - protected function register( array $configs ) { - foreach ( $configs as $config ) { - if ( !isset( $config['name'] ) ) { - throw new MWException( "Cannot register a lock manager with no name." ); - } - $name = $config['name']; - if ( !isset( $config['class'] ) ) { - throw new MWException( "Cannot register lock manager `{$name}` with no class." ); - } - $class = $config['class']; - unset( $config['class'] ); // lock manager won't need this - $this->managers[$name] = array( - 'class' => $class, - 'config' => $config, - 'instance' => null - ); - } - } - - /** - * Get the lock manager object with a given name - * - * @param $name string - * @return LockManager - * @throws MWException - */ - public function get( $name ) { - if ( !isset( $this->managers[$name] ) ) { - throw new MWException( "No lock manager defined with the name `$name`." ); - } - // Lazy-load the actual lock manager instance - if ( !isset( $this->managers[$name]['instance'] ) ) { - $class = $this->managers[$name]['class']; - $config = $this->managers[$name]['config']; - $this->managers[$name]['instance'] = new $class( $config ); - } - return $this->managers[$name]['instance']; - } -} |