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authorPierre Schmitz <pierre@archlinux.de>2013-01-18 16:46:04 +0100
committerPierre Schmitz <pierre@archlinux.de>2013-01-18 16:46:04 +0100
commit63601400e476c6cf43d985f3e7b9864681695ed4 (patch)
treef7846203a952e38aaf66989d0a4702779f549962 /includes/filebackend/lockmanager/LSLockManager.php
parent8ff01378c9e0207f9169b81966a51def645b6a51 (diff)
Update to MediaWiki 1.20.2
this update includes: * adjusted Arch Linux skin * updated FluxBBAuthPlugin * patch for https://bugzilla.wikimedia.org/show_bug.cgi?id=44024
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+<?php
+/**
+ * Version of LockManager based on using lock daemon servers.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup LockManager
+ */
+
+/**
+ * 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 QuorumLockManager {
+ /** @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 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 ) {
+ parent::__construct( $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 = wfRandomString( 32 ); // 128 bits
+ }
+
+ /**
+ * @see QuorumLockManager::getLocksOnServer()
+ * @return Status
+ */
+ protected function getLocksOnServer( $lockSrv, array $paths, $type ) {
+ $status = Status::newGood();
+
+ // Send out the command and get the response...
+ $type = ( $type == self::LOCK_SH ) ? 'SH' : 'EX';
+ $keys = array_unique( array_map( 'LockManager::sha1Base36', $paths ) );
+ $response = $this->sendCommand( $lockSrv, 'ACQUIRE', $type, $keys );
+
+ if ( $response !== 'ACQUIRED' ) {
+ foreach ( $paths as $path ) {
+ $status->fatal( 'lockmanager-fail-acquirelock', $path );
+ }
+ }
+
+ return $status;
+ }
+
+ /**
+ * @see QuorumLockManager::freeLocksOnServer()
+ * @return Status
+ */
+ protected function freeLocksOnServer( $lockSrv, array $paths, $type ) {
+ $status = Status::newGood();
+
+ // Send out the command and get the response...
+ $type = ( $type == self::LOCK_SH ) ? 'SH' : 'EX';
+ $keys = array_unique( array_map( 'LockManager::sha1Base36', $paths ) );
+ $response = $this->sendCommand( $lockSrv, 'RELEASE', $type, $keys );
+
+ if ( $response !== 'RELEASED' ) {
+ foreach ( $paths as $path ) {
+ $status->fatal( 'lockmanager-fail-releaselock', $path );
+ }
+ }
+
+ return $status;
+ }
+
+ /**
+ * @see QuorumLockManager::releaseAllLocks()
+ * @return Status
+ */
+ protected function releaseAllLocks() {
+ $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;
+ }
+
+ /**
+ * @see QuorumLockManager::isServerUp()
+ * @return bool
+ */
+ protected function isServerUp( $lockSrv ) {
+ return (bool)$this->getConnection( $lockSrv );
+ }
+
+ /**
+ * Send a command and get back the response
+ *
+ * @param $lockSrv string
+ * @param $action string
+ * @param $type string
+ * @param $values Array
+ * @return string|bool
+ */
+ 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 );
+ }
+
+ /**
+ * 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];
+ }
+
+ /**
+ * Make sure remaining locks get cleared for sanity
+ */
+ function __destruct() {
+ $this->releaseAllLocks();
+ foreach ( $this->conns as $conn ) {
+ fclose( $conn );
+ }
+ }
+}