From d9022f63880ce039446fba8364f68e656b7bf4cb Mon Sep 17 00:00:00 2001
From: Pierre Schmitz <pierre@archlinux.de>
Date: Thu, 3 May 2012 13:01:35 +0200
Subject: Update to MediaWiki 1.19.0

---
 .../filerepo/backend/lockmanager/LockManager.php   | 182 +++++++++++++++++++++
 1 file changed, 182 insertions(+)
 create mode 100644 includes/filerepo/backend/lockmanager/LockManager.php

(limited to 'includes/filerepo/backend/lockmanager/LockManager.php')

diff --git a/includes/filerepo/backend/lockmanager/LockManager.php b/includes/filerepo/backend/lockmanager/LockManager.php
new file mode 100644
index 00000000..23603a4f
--- /dev/null
+++ b/includes/filerepo/backend/lockmanager/LockManager.php
@@ -0,0 +1,182 @@
+<?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();
+	}
+}
-- 
cgit v1.2.3-54-g00ecf