abstract protected function doUnlock( array $paths, $type );
}
-/**
- * Version of LockManager that uses a quorum from peer servers for locks.
- * The resource space can also be sharded into separate peer groups.
- *
- * @ingroup LockManager
- * @since 1.20
- */
-abstract class QuorumLockManager extends LockManager {
- /** @var Array Map of bucket indexes to peer server lists */
- protected $srvsByBucket = array(); // (bucket index => (lsrv1, lsrv2, ...))
-
- /**
- * @see LockManager::doLock()
- * @param $paths array
- * @param $type int
- * @return Status
- */
- final protected function doLock( array $paths, $type ) {
- $status = Status::newGood();
-
- $pathsToLock = array(); // (bucket => paths)
- // 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
- $status->merge( $this->doLockingRequestBucket( $bucket, $paths, $type ) );
- if ( !$status->isOK() ) {
- $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()
- * @param $paths array
- * @param $type int
- * @return Status
- */
- final protected function doUnlock( array $paths, $type ) {
- $status = Status::newGood();
-
- $pathsToUnlock = array();
- foreach ( $paths as $path ) {
- if ( !isset( $this->locksHeld[$path][$type] ) ) {
- $status->warning( 'lockmanager-notlocked', $path );
- } else {
- --$this->locksHeld[$path][$type];
- // Reference count the locks held and release locks when zero
- if ( $this->locksHeld[$path][$type] <= 0 ) {
- unset( $this->locksHeld[$path][$type] );
- $bucket = $this->getBucketFromKey( $path );
- $pathsToUnlock[$bucket][] = $path;
- }
- if ( !count( $this->locksHeld[$path] ) ) {
- unset( $this->locksHeld[$path] ); // no SH or EX locks left for key
- }
- }
- }
-
- // Remove these specific locks if possible, or at least release
- // all locks once this process is currently not holding any locks.
- foreach ( $pathsToUnlock as $bucket => $paths ) {
- $status->merge( $this->doUnlockingRequestBucket( $bucket, $paths, $type ) );
- }
- if ( !count( $this->locksHeld ) ) {
- $status->merge( $this->releaseAllLocks() );
- }
-
- return $status;
- }
-
- /**
- * Attempt to acquire locks with the peers for a bucket.
- * This is all or nothing; if any key is locked then this totally fails.
- *
- * @param $bucket integer
- * @param $paths Array List of resource keys to lock
- * @param $type integer LockManager::LOCK_EX or LockManager::LOCK_SH
- * @return Status
- */
- final protected function doLockingRequestBucket( $bucket, array $paths, $type ) {
- $status = Status::newGood();
-
- $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 $lockSrv ) {
- if ( !$this->isServerUp( $lockSrv ) ) {
- --$votesLeft;
- $status->warning( 'lockmanager-fail-svr-acquire', $lockSrv );
- continue; // server down?
- }
- // Attempt to acquire the lock on this peer
- $status->merge( $this->getLocksOnServer( $lockSrv, $paths, $type ) );
- if ( !$status->isOK() ) {
- return $status; // vetoed; resource locked
- }
- ++$yesVotes; // success for this peer
- if ( $yesVotes >= $quorum ) {
- return $status; // lock obtained
- }
- --$votesLeft;
- $votesNeeded = $quorum - $yesVotes;
- if ( $votesNeeded > $votesLeft ) {
- break; // short-circuit
- }
- }
- // At this point, we must not have met the quorum
- $status->setResult( false );
-
- return $status;
- }
-
- /**
- * Attempt to release 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 Status
- */
- final protected function doUnlockingRequestBucket( $bucket, array $paths, $type ) {
- $status = Status::newGood();
-
- foreach ( $this->srvsByBucket[$bucket] as $lockSrv ) {
- if ( !$this->isServerUp( $lockSrv ) ) {
- $status->fatal( 'lockmanager-fail-svr-release', $lockSrv );
- // Attempt to release the lock on this peer
- } else {
- $status->merge( $this->freeLocksOnServer( $lockSrv, $paths, $type ) );
- }
- }
-
- 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 (int)base_convert( $prefix, 16, 10 ) % count( $this->srvsByBucket );
- }
-
- /**
- * Check if a lock server is up
- *
- * @param $lockSrv string
- * @return bool
- */
- abstract protected function isServerUp( $lockSrv );
-
- /**
- * Get a connection to a lock server and acquire locks on $paths
- *
- * @param $lockSrv string
- * @param $paths array
- * @param $type integer
- * @return Status
- */
- abstract protected function getLocksOnServer( $lockSrv, array $paths, $type );
-
- /**
- * Get a connection to a lock server and release locks on $paths.
- *
- * Subclasses must effectively implement this or releaseAllLocks().
- *
- * @param $lockSrv string
- * @param $paths array
- * @param $type integer
- * @return Status
- */
- abstract protected function freeLocksOnServer( $lockSrv, array $paths, $type );
-
- /**
- * Release all locks that this session is holding.
- *
- * Subclasses must effectively implement this or freeLocksOnServer().
- *
- * @return Status
- */
- abstract protected function releaseAllLocks();
-}
-
/**
* Simple version of LockManager that does nothing
* @since 1.19
--- /dev/null
+<?php
+/**
+ * Version of LockManager that uses a quorum from peer servers for locks.
+ *
+ * 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
+ */
+
+/**
+ * Version of LockManager that uses a quorum from peer servers for locks.
+ * The resource space can also be sharded into separate peer groups.
+ *
+ * @ingroup LockManager
+ * @since 1.20
+ */
+abstract class QuorumLockManager extends LockManager {
+ /** @var Array Map of bucket indexes to peer server lists */
+ protected $srvsByBucket = array(); // (bucket index => (lsrv1, lsrv2, ...))
+
+ /**
+ * @see LockManager::doLock()
+ * @param $paths array
+ * @param $type int
+ * @return Status
+ */
+ final protected function doLock( array $paths, $type ) {
+ $status = Status::newGood();
+
+ $pathsToLock = array(); // (bucket => paths)
+ // 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
+ $status->merge( $this->doLockingRequestBucket( $bucket, $paths, $type ) );
+ if ( !$status->isOK() ) {
+ $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()
+ * @param $paths array
+ * @param $type int
+ * @return Status
+ */
+ final protected function doUnlock( array $paths, $type ) {
+ $status = Status::newGood();
+
+ $pathsToUnlock = array();
+ foreach ( $paths as $path ) {
+ if ( !isset( $this->locksHeld[$path][$type] ) ) {
+ $status->warning( 'lockmanager-notlocked', $path );
+ } else {
+ --$this->locksHeld[$path][$type];
+ // Reference count the locks held and release locks when zero
+ if ( $this->locksHeld[$path][$type] <= 0 ) {
+ unset( $this->locksHeld[$path][$type] );
+ $bucket = $this->getBucketFromKey( $path );
+ $pathsToUnlock[$bucket][] = $path;
+ }
+ if ( !count( $this->locksHeld[$path] ) ) {
+ unset( $this->locksHeld[$path] ); // no SH or EX locks left for key
+ }
+ }
+ }
+
+ // Remove these specific locks if possible, or at least release
+ // all locks once this process is currently not holding any locks.
+ foreach ( $pathsToUnlock as $bucket => $paths ) {
+ $status->merge( $this->doUnlockingRequestBucket( $bucket, $paths, $type ) );
+ }
+ if ( !count( $this->locksHeld ) ) {
+ $status->merge( $this->releaseAllLocks() );
+ }
+
+ return $status;
+ }
+
+ /**
+ * Attempt to acquire locks with the peers for a bucket.
+ * This is all or nothing; if any key is locked then this totally fails.
+ *
+ * @param $bucket integer
+ * @param $paths Array List of resource keys to lock
+ * @param $type integer LockManager::LOCK_EX or LockManager::LOCK_SH
+ * @return Status
+ */
+ final protected function doLockingRequestBucket( $bucket, array $paths, $type ) {
+ $status = Status::newGood();
+
+ $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 $lockSrv ) {
+ if ( !$this->isServerUp( $lockSrv ) ) {
+ --$votesLeft;
+ $status->warning( 'lockmanager-fail-svr-acquire', $lockSrv );
+ continue; // server down?
+ }
+ // Attempt to acquire the lock on this peer
+ $status->merge( $this->getLocksOnServer( $lockSrv, $paths, $type ) );
+ if ( !$status->isOK() ) {
+ return $status; // vetoed; resource locked
+ }
+ ++$yesVotes; // success for this peer
+ if ( $yesVotes >= $quorum ) {
+ return $status; // lock obtained
+ }
+ --$votesLeft;
+ $votesNeeded = $quorum - $yesVotes;
+ if ( $votesNeeded > $votesLeft ) {
+ break; // short-circuit
+ }
+ }
+ // At this point, we must not have met the quorum
+ $status->setResult( false );
+
+ return $status;
+ }
+
+ /**
+ * Attempt to release 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 Status
+ */
+ final protected function doUnlockingRequestBucket( $bucket, array $paths, $type ) {
+ $status = Status::newGood();
+
+ foreach ( $this->srvsByBucket[$bucket] as $lockSrv ) {
+ if ( !$this->isServerUp( $lockSrv ) ) {
+ $status->fatal( 'lockmanager-fail-svr-release', $lockSrv );
+ // Attempt to release the lock on this peer
+ } else {
+ $status->merge( $this->freeLocksOnServer( $lockSrv, $paths, $type ) );
+ }
+ }
+
+ 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 (int)base_convert( $prefix, 16, 10 ) % count( $this->srvsByBucket );
+ }
+
+ /**
+ * Check if a lock server is up
+ *
+ * @param $lockSrv string
+ * @return bool
+ */
+ abstract protected function isServerUp( $lockSrv );
+
+ /**
+ * Get a connection to a lock server and acquire locks on $paths
+ *
+ * @param $lockSrv string
+ * @param $paths array
+ * @param $type integer
+ * @return Status
+ */
+ abstract protected function getLocksOnServer( $lockSrv, array $paths, $type );
+
+ /**
+ * Get a connection to a lock server and release locks on $paths.
+ *
+ * Subclasses must effectively implement this or releaseAllLocks().
+ *
+ * @param $lockSrv string
+ * @param $paths array
+ * @param $type integer
+ * @return Status
+ */
+ abstract protected function freeLocksOnServer( $lockSrv, array $paths, $type );
+
+ /**
+ * Release all locks that this session is holding.
+ *
+ * Subclasses must effectively implement this or freeLocksOnServer().
+ *
+ * @return Status
+ */
+ abstract protected function releaseAllLocks();
+}
dépôts / lhc / web / wiklou.git / commitdiff