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authorPierre Schmitz <pierre@archlinux.de>2015-06-04 07:31:04 +0200
committerPierre Schmitz <pierre@archlinux.de>2015-06-04 07:58:39 +0200
commitf6d65e533c62f6deb21342d4901ece24497b433e (patch)
treef28adf0362d14bcd448f7b65a7aaf38650f923aa /includes/cache/bloom/BloomCache.php
parentc27b2e832fe25651ef2410fae85b41072aae7519 (diff)
Update to MediaWiki 1.25.1
Diffstat (limited to 'includes/cache/bloom/BloomCache.php')
-rw-r--r--includes/cache/bloom/BloomCache.php323
1 files changed, 0 insertions, 323 deletions
diff --git a/includes/cache/bloom/BloomCache.php b/includes/cache/bloom/BloomCache.php
deleted file mode 100644
index 236db954..00000000
--- a/includes/cache/bloom/BloomCache.php
+++ /dev/null
@@ -1,323 +0,0 @@
-<?php
-/**
- * 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
- * @author Aaron Schulz
- */
-
-/**
- * Persistent bloom filter used to avoid expensive lookups
- *
- * @since 1.24
- */
-abstract class BloomCache {
- /** @var string Unique ID for key namespacing */
- protected $cacheID;
-
- /** @var array Map of (id => BloomCache) */
- protected static $instances = array();
-
- /**
- * @param string $id
- * @return BloomCache
- */
- final public static function get( $id ) {
- global $wgBloomFilterStores;
-
- if ( !isset( self::$instances[$id] ) ) {
- if ( isset( $wgBloomFilterStores[$id] ) ) {
- $class = $wgBloomFilterStores[$id]['class'];
- self::$instances[$id] = new $class( $wgBloomFilterStores[$id] );
- } else {
- wfDebug( "No bloom filter store '$id'; using EmptyBloomCache." );
- return new EmptyBloomCache( array() );
- }
- }
-
- return self::$instances[$id];
- }
-
- /**
- * Create a new bloom cache instance from configuration.
- * This should only be called from within BloomCache.
- *
- * @param array $config Parameters include:
- * - cacheID : Prefix to all bloom filter names that is unique to this cache.
- * It should only consist of alphanumberic, '-', and '_' characters.
- * This ID is what avoids collisions if multiple logical caches
- * use the same storage system, so this should be set carefully.
- */
- public function __construct( array $config ) {
- $this->cacheID = $config['cacheId'];
- if ( !preg_match( '!^[a-zA-Z0-9-_]{1,32}$!', $this->cacheID ) ) {
- throw new MWException( "Cache ID '{$this->cacheID}' is invalid." );
- }
- }
-
- /**
- * Check if a member is set in the bloom filter
- *
- * A member being set means that it *might* have been added.
- * A member not being set means it *could not* have been added.
- *
- * This abstracts over isHit() to deal with filter updates and readiness.
- * A class must exist with the name BloomFilter<type> and a static public
- * mergeAndCheck() method. The later takes the following arguments:
- * (BloomCache $bcache, $domain, $virtualKey, array $status)
- * The method should return a bool indicating whether to use the filter.
- *
- * The 'shared' bloom key must be used for any updates and will be used
- * for the membership check if the method returns true. Since the key is shared,
- * the method should never use delete(). The filter cannot be used in cases where
- * membership in the filter needs to be taken away. In such cases, code *cannot*
- * use this method - instead, it can directly use the other BloomCache methods
- * to manage custom filters with their own keys (e.g. not 'shared').
- *
- * @param string $domain
- * @param string $type
- * @param string $member
- * @return bool True if set, false if not (also returns true on error)
- */
- final public function check( $domain, $type, $member ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- if ( method_exists( "BloomFilter{$type}", 'mergeAndCheck' ) ) {
- try {
- $virtualKey = "$domain:$type";
-
- $status = $this->getStatus( $virtualKey );
- if ( $status == false ) {
- wfDebug( "Could not query virtual bloom filter '$virtualKey'." );
- return null;
- }
-
- $useFilter = call_user_func_array(
- array( "BloomFilter{$type}", 'mergeAndCheck' ),
- array( $this, $domain, $virtualKey, $status )
- );
-
- if ( $useFilter ) {
- return ( $this->isHit( 'shared', "$virtualKey:$member" ) !== false );
- }
- } catch ( MWException $e ) {
- MWExceptionHandler::logException( $e );
- return true;
- }
- }
-
- return true;
- }
-
- /**
- * Inform the bloom filter of a new member in order to keep it up to date
- *
- * @param string $domain
- * @param string $type
- * @param string|array $members
- * @return bool Success
- */
- final public function insert( $domain, $type, $members ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- if ( method_exists( "BloomFilter{$type}", 'mergeAndCheck' ) ) {
- try {
- $virtualKey = "$domain:$type";
- $prefixedMembers = array();
- foreach ( (array)$members as $member ) {
- $prefixedMembers[] = "$virtualKey:$member";
- }
-
- return $this->add( 'shared', $prefixedMembers );
- } catch ( MWException $e ) {
- MWExceptionHandler::logException( $e );
- return false;
- }
- }
-
- return true;
- }
-
- /**
- * Create a new bloom filter at $key (if one does not exist yet)
- *
- * @param string $key
- * @param integer $size Bit length [default: 1000000]
- * @param float $precision [default: .001]
- * @return bool Success
- */
- final public function init( $key, $size = 1000000, $precision = .001 ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- return $this->doInit( "{$this->cacheID}:$key", $size, min( .1, $precision ) );
- }
-
- /**
- * Add a member to the bloom filter at $key
- *
- * @param string $key
- * @param string|array $members
- * @return bool Success
- */
- final public function add( $key, $members ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- return $this->doAdd( "{$this->cacheID}:$key", (array)$members );
- }
-
- /**
- * Check if a member is set in the bloom filter.
- *
- * A member being set means that it *might* have been added.
- * A member not being set means it *could not* have been added.
- *
- * If this returns true, then the caller usually should do the
- * expensive check (whatever that may be). It can be avoided otherwise.
- *
- * @param string $key
- * @param string $member
- * @return bool|null True if set, false if not, null on error
- */
- final public function isHit( $key, $member ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- return $this->doIsHit( "{$this->cacheID}:$key", $member );
- }
-
- /**
- * Destroy a bloom filter at $key
- *
- * @param string $key
- * @return bool Success
- */
- final public function delete( $key ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- return $this->doDelete( "{$this->cacheID}:$key" );
- }
-
- /**
- * Set the status map of the virtual bloom filter at $key
- *
- * @param string $virtualKey
- * @param array $values Map including some of (lastID, asOfTime, epoch)
- * @return bool Success
- */
- final public function setStatus( $virtualKey, array $values ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- return $this->doSetStatus( "{$this->cacheID}:$virtualKey", $values );
- }
-
- /**
- * Get the status map of the virtual bloom filter at $key
- *
- * The map includes:
- * - lastID : the highest ID of the items merged in
- * - asOfTime : UNIX timestamp that the filter is up-to-date as of
- * - epoch : UNIX timestamp that filter started being populated
- * Unset fields will have a null value.
- *
- * @param string $virtualKey
- * @return array|bool False on failure
- */
- final public function getStatus( $virtualKey ) {
- $section = new ProfileSection( get_class( $this ) . '::' . __FUNCTION__ );
-
- return $this->doGetStatus( "{$this->cacheID}:$virtualKey" );
- }
-
- /**
- * Get an exclusive lock on a filter for updates
- *
- * @param string $virtualKey
- * @return ScopedCallback|ScopedLock|null Returns null if acquisition failed
- */
- public function getScopedLock( $virtualKey ) {
- return null;
- }
-
- /**
- * @param string $key
- * @param integer $size Bit length
- * @param float $precision
- * @return bool Success
- */
- abstract protected function doInit( $key, $size, $precision );
-
- /**
- * @param string $key
- * @param array $members
- * @return bool Success
- */
- abstract protected function doAdd( $key, array $members );
-
- /**
- * @param string $key
- * @param string $member
- * @return bool|null
- */
- abstract protected function doIsHit( $key, $member );
-
- /**
- * @param string $key
- * @return bool Success
- */
- abstract protected function doDelete( $key );
-
- /**
- * @param string $virtualKey
- * @param array $values
- * @return bool Success
- */
- abstract protected function doSetStatus( $virtualKey, array $values );
-
- /**
- * @param string $key
- * @return array|bool
- */
- abstract protected function doGetStatus( $key );
-}
-
-class EmptyBloomCache extends BloomCache {
- public function __construct( array $config ) {
- parent::__construct( array( 'cacheId' => 'none' ) );
- }
-
- protected function doInit( $key, $size, $precision ) {
- return true;
- }
-
- protected function doAdd( $key, array $members ) {
- return true;
- }
-
- protected function doIsHit( $key, $member ) {
- return true;
- }
-
- protected function doDelete( $key ) {
- return true;
- }
-
- protected function doSetStatus( $virtualKey, array $values ) {
- return true;
- }
-
- protected function doGetStatus( $virtualKey ) {
- return array( 'lastID' => null, 'asOfTime' => null, 'epoch' => null ) ;
- }
-}