%PDF-
%PDF-
Mini Shell
Mini Shell
<?php
/**
* InterwikiLookup implementing the "classic" interwiki storage (hardcoded up to MW 1.26).
*
* 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
*/
namespace MediaWiki\Interwiki;
use Cdb\Exception as CdbException;
use Cdb\Reader as CdbReader;
use Hooks;
use Interwiki;
use Language;
use MapCacheLRU;
use WANObjectCache;
use Wikimedia\Rdbms\Database;
/**
* InterwikiLookup implementing the "classic" interwiki storage (hardcoded up to MW 1.26).
*
* This implements two levels of caching (in-process array and a WANObjectCache)
* and tree storage backends (SQL, CDB, and plain PHP arrays).
*
* All information is loaded on creation when called by $this->fetch( $prefix ).
* All work is done on replica DB, because this should *never* change (except during
* schema updates etc, which aren't wiki-related)
*
* @since 1.28
*/
class ClassicInterwikiLookup implements InterwikiLookup {
/**
* @var MapCacheLRU
*/
private $localCache;
/**
* @var Language
*/
private $contLang;
/**
* @var WANObjectCache
*/
private $objectCache;
/**
* @var int
*/
private $objectCacheExpiry;
/**
* @var bool|array|string
*/
private $cdbData;
/**
* @var int
*/
private $interwikiScopes;
/**
* @var string
*/
private $fallbackSite;
/**
* @var CdbReader|null
*/
private $cdbReader = null;
/**
* @var string|null
*/
private $thisSite = null;
/**
* @param Language $contLang Language object used to convert prefixes to lower case
* @param WANObjectCache $objectCache Cache for interwiki info retrieved from the database
* @param int $objectCacheExpiry Expiry time for $objectCache, in seconds
* @param bool|array|string $cdbData The path of a CDB file, or
* an array resembling the contents of a CDB file,
* or false to use the database.
* @param int $interwikiScopes Specify number of domains to check for messages:
* - 1: Just local wiki level
* - 2: wiki and global levels
* - 3: site level as well as wiki and global levels
* @param string $fallbackSite The code to assume for the local site,
*/
function __construct(
Language $contLang,
WANObjectCache $objectCache,
$objectCacheExpiry,
$cdbData,
$interwikiScopes,
$fallbackSite
) {
$this->localCache = new MapCacheLRU( 100 );
$this->contLang = $contLang;
$this->objectCache = $objectCache;
$this->objectCacheExpiry = $objectCacheExpiry;
$this->cdbData = $cdbData;
$this->interwikiScopes = $interwikiScopes;
$this->fallbackSite = $fallbackSite;
}
/**
* Check whether an interwiki prefix exists
*
* @param string $prefix Interwiki prefix to use
* @return bool Whether it exists
*/
public function isValidInterwiki( $prefix ) {
$result = $this->fetch( $prefix );
return (bool)$result;
}
/**
* Fetch an Interwiki object
*
* @param string $prefix Interwiki prefix to use
* @return Interwiki|null|bool
*/
public function fetch( $prefix ) {
if ( $prefix == '' ) {
return null;
}
$prefix = $this->contLang->lc( $prefix );
if ( $this->localCache->has( $prefix ) ) {
return $this->localCache->get( $prefix );
}
if ( $this->cdbData ) {
$iw = $this->getInterwikiCached( $prefix );
} else {
$iw = $this->load( $prefix );
if ( !$iw ) {
$iw = false;
}
}
$this->localCache->set( $prefix, $iw );
return $iw;
}
/**
* Resets locally cached Interwiki objects. This is intended for use during testing only.
* This does not invalidate entries in the persistent cache, as invalidateCache() does.
* @since 1.27
*/
public function resetLocalCache() {
$this->localCache->clear();
}
/**
* Purge the in-process and object cache for an interwiki prefix
* @param string $prefix
*/
public function invalidateCache( $prefix ) {
$this->localCache->clear( $prefix );
$key = $this->objectCache->makeKey( 'interwiki', $prefix );
$this->objectCache->delete( $key );
}
/**
* Fetch interwiki prefix data from local cache in constant database.
*
* @note More logic is explained in DefaultSettings.
*
* @param string $prefix Interwiki prefix
* @return Interwiki|false
*/
private function getInterwikiCached( $prefix ) {
$value = $this->getInterwikiCacheEntry( $prefix );
if ( $value ) {
// Split values
list( $local, $url ) = explode( ' ', $value, 2 );
return new Interwiki( $prefix, $url, '', '', (int)$local );
} else {
return false;
}
}
/**
* Get entry from interwiki cache
*
* @note More logic is explained in DefaultSettings.
*
* @param string $prefix Database key
* @return bool|string The interwiki entry or false if not found
*/
private function getInterwikiCacheEntry( $prefix ) {
wfDebug( __METHOD__ . "( $prefix )\n" );
$value = false;
try {
// Resolve site name
if ( $this->interwikiScopes >= 3 && !$this->thisSite ) {
$this->thisSite = $this->getCacheValue( '__sites:' . wfWikiID() );
if ( $this->thisSite == '' ) {
$this->thisSite = $this->fallbackSite;
}
}
$value = $this->getCacheValue( wfWikiID() . ':' . $prefix );
// Site level
if ( $value == '' && $this->interwikiScopes >= 3 ) {
$value = $this->getCacheValue( "_{$this->thisSite}:{$prefix}" );
}
// Global Level
if ( $value == '' && $this->interwikiScopes >= 2 ) {
$value = $this->getCacheValue( "__global:{$prefix}" );
}
if ( $value == 'undef' ) {
$value = '';
}
} catch ( CdbException $e ) {
wfDebug( __METHOD__ . ": CdbException caught, error message was "
. $e->getMessage() );
}
return $value;
}
private function getCacheValue( $key ) {
if ( $this->cdbReader === null ) {
if ( is_string( $this->cdbData ) ) {
$this->cdbReader = \Cdb\Reader::open( $this->cdbData );
} elseif ( is_array( $this->cdbData ) ) {
$this->cdbReader = new \Cdb\Reader\Hash( $this->cdbData );
} else {
$this->cdbReader = false;
}
}
if ( $this->cdbReader ) {
return $this->cdbReader->get( $key );
} else {
return false;
}
}
/**
* Load the interwiki, trying first memcached then the DB
*
* @param string $prefix The interwiki prefix
* @return Interwiki|bool Interwiki if $prefix is valid, otherwise false
*/
private function load( $prefix ) {
$iwData = [];
if ( !Hooks::run( 'InterwikiLoadPrefix', [ $prefix, &$iwData ] ) ) {
return $this->loadFromArray( $iwData );
}
if ( is_array( $iwData ) ) {
$iw = $this->loadFromArray( $iwData );
if ( $iw ) {
return $iw; // handled by hook
}
}
$fname = __METHOD__;
$iwData = $this->objectCache->getWithSetCallback(
$this->objectCache->makeKey( 'interwiki', $prefix ),
$this->objectCacheExpiry,
function ( $oldValue, &$ttl, array &$setOpts ) use ( $prefix, $fname ) {
$dbr = wfGetDB( DB_REPLICA ); // TODO: inject LoadBalancer
$setOpts += Database::getCacheSetOptions( $dbr );
$row = $dbr->selectRow(
'interwiki',
self::selectFields(),
[ 'iw_prefix' => $prefix ],
$fname
);
return $row ? (array)$row : '!NONEXISTENT';
}
);
if ( is_array( $iwData ) ) {
return $this->loadFromArray( $iwData ) ?: false;
}
return false;
}
/**
* Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
*
* @param array $mc Associative array: row from the interwiki table
* @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
*/
private function loadFromArray( $mc ) {
if ( isset( $mc['iw_url'] ) ) {
$url = $mc['iw_url'];
$local = $mc['iw_local'] ?? 0;
$trans = $mc['iw_trans'] ?? 0;
$api = $mc['iw_api'] ?? '';
$wikiId = $mc['iw_wikiid'] ?? '';
return new Interwiki( null, $url, $api, $wikiId, $local, $trans );
}
return false;
}
/**
* Fetch all interwiki prefixes from interwiki cache
*
* @param null|string $local If not null, limits output to local/non-local interwikis
* @return array List of prefixes, where each row is an associative array
*/
private function getAllPrefixesCached( $local ) {
wfDebug( __METHOD__ . "()\n" );
$data = [];
try {
/* Resolve site name */
if ( $this->interwikiScopes >= 3 && !$this->thisSite ) {
$site = $this->getCacheValue( '__sites:' . wfWikiID() );
if ( $site == '' ) {
$this->thisSite = $this->fallbackSite;
} else {
$this->thisSite = $site;
}
}
// List of interwiki sources
$sources = [];
// Global Level
if ( $this->interwikiScopes >= 2 ) {
$sources[] = '__global';
}
// Site level
if ( $this->interwikiScopes >= 3 ) {
$sources[] = '_' . $this->thisSite;
}
$sources[] = wfWikiID();
foreach ( $sources as $source ) {
$list = $this->getCacheValue( '__list:' . $source );
foreach ( explode( ' ', $list ) as $iw_prefix ) {
$row = $this->getCacheValue( "{$source}:{$iw_prefix}" );
if ( !$row ) {
continue;
}
list( $iw_local, $iw_url ) = explode( ' ', $row );
if ( $local !== null && $local != $iw_local ) {
continue;
}
$data[$iw_prefix] = [
'iw_prefix' => $iw_prefix,
'iw_url' => $iw_url,
'iw_local' => $iw_local,
];
}
}
} catch ( CdbException $e ) {
wfDebug( __METHOD__ . ": CdbException caught, error message was "
. $e->getMessage() );
}
return array_values( $data );
}
/**
* Fetch all interwiki prefixes from DB
*
* @param string|null $local If not null, limits output to local/non-local interwikis
* @return array[] Interwiki rows
*/
private function getAllPrefixesDB( $local ) {
$db = wfGetDB( DB_REPLICA ); // TODO: inject DB LoadBalancer
$where = [];
if ( $local !== null ) {
if ( $local == 1 ) {
$where['iw_local'] = 1;
} elseif ( $local == 0 ) {
$where['iw_local'] = 0;
}
}
$res = $db->select( 'interwiki',
self::selectFields(),
$where, __METHOD__, [ 'ORDER BY' => 'iw_prefix' ]
);
$retval = [];
foreach ( $res as $row ) {
$retval[] = (array)$row;
}
return $retval;
}
/**
* Returns all interwiki prefixes
*
* @param string|null $local If set, limits output to local/non-local interwikis
* @return array[] Interwiki rows, where each row is an associative array
*/
public function getAllPrefixes( $local = null ) {
if ( $this->cdbData ) {
return $this->getAllPrefixesCached( $local );
}
return $this->getAllPrefixesDB( $local );
}
/**
* Return the list of interwiki fields that should be selected to create
* a new Interwiki object.
* @return string[]
*/
private static function selectFields() {
return [
'iw_prefix',
'iw_url',
'iw_api',
'iw_wikiid',
'iw_local',
'iw_trans'
];
}
}
Zerion Mini Shell 1.0