includes/interwiki/Interwiki.php

   1 <?php
   2 /**
   3  * Interwiki table entry.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22 use \Cdb\Exception as CdbException;
  23 use \Cdb\Reader as CdbReader;
  24
  25 /**
  26  * The interwiki class
  27  * All information is loaded on creation when called by Interwiki::fetch( $prefix ).
  28  * All work is done on slave, because this should *never* change (except during
  29  * schema updates etc, which aren't wiki-related)
  30  */
  31 class Interwiki {
  32         // Cache - removes oldest entry when it hits limit
  33         protected static $smCache = [];
  34         const CACHE_LIMIT = 100; // 0 means unlimited, any other value is max number of entries.
  35
  36         /** @var string The interwiki prefix, (e.g. "Meatball", or the language prefix "de") */
  37         protected $mPrefix;
  38
  39         /** @var string The URL of the wiki, with "$1" as a placeholder for an article name. */
  40         protected $mURL;
  41
  42         /** @var string The URL of the file api.php  */
  43         protected $mAPI;
  44
  45         /** @var string The name of the database (for a connection to be established
  46          *    with wfGetLB( 'wikiid' ))
  47          */
  48         protected $mWikiID;
  49
  50         /** @var bool Whether the wiki is in this project */
  51         protected $mLocal;
  52
  53         /** @var bool Whether interwiki transclusions are allowed */
  54         protected $mTrans;
  55
  56         public function __construct( $prefix = null, $url = '', $api = '', $wikiId = '', $local = 0,
  57                 $trans = 0
  58         ) {
  59                 $this->mPrefix = $prefix;
  60                 $this->mURL = $url;
  61                 $this->mAPI = $api;
  62                 $this->mWikiID = $wikiId;
  63                 $this->mLocal = $local;
  64                 $this->mTrans = $trans;
  65         }
  66
  67         /**
  68          * Check whether an interwiki prefix exists
  69          *
  70          * @param string $prefix Interwiki prefix to use
  71          * @return bool Whether it exists
  72          */
  73         public static function isValidInterwiki( $prefix ) {
  74                 $result = self::fetch( $prefix );
  75
  76                 return (bool)$result;
  77         }
  78
  79         /**
  80          * Fetch an Interwiki object
  81          *
  82          * @param string $prefix Interwiki prefix to use
  83          * @return Interwiki|null|bool
  84          */
  85         public static function fetch( $prefix ) {
  86                 global $wgContLang;
  87
  88                 if ( $prefix == '' ) {
  89                         return null;
  90                 }
  91
  92                 $prefix = $wgContLang->lc( $prefix );
  93                 if ( isset( self::$smCache[$prefix] ) ) {
  94                         return self::$smCache[$prefix];
  95                 }
  96
  97                 global $wgInterwikiCache;
  98                 if ( $wgInterwikiCache ) {
  99                         $iw = Interwiki::getInterwikiCached( $prefix );
 100                 } else {
 101                         $iw = Interwiki::load( $prefix );
 102                         if ( !$iw ) {
 103                                 $iw = false;
 104                         }
 105                 }
 106
 107                 if ( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ) {
 108                         reset( self::$smCache );
 109                         unset( self::$smCache[key( self::$smCache )] );
 110                 }
 111
 112                 self::$smCache[$prefix] = $iw;
 113
 114                 return $iw;
 115         }
 116
 117         /**
 118          * Purge the cache for an interwiki prefix
 119          * @param string $prefix
 120          * @since 1.26
 121          */
 122         public static function invalidateCache( $prefix ) {
 123                 $cache = ObjectCache::getMainWANInstance();
 124                 $key = wfMemcKey( 'interwiki', $prefix );
 125                 $cache->delete( $key );
 126         }
 127
 128         /**
 129          * Fetch interwiki prefix data from local cache in constant database.
 130          *
 131          * @note More logic is explained in DefaultSettings.
 132          *
 133          * @param string $prefix Interwiki prefix
 134          * @return Interwiki
 135          */
 136         protected static function getInterwikiCached( $prefix ) {
 137                 $value = self::getInterwikiCacheEntry( $prefix );
 138
 139                 $s = new Interwiki( $prefix );
 140                 if ( $value ) {
 141                         // Split values
 142                         list( $local, $url ) = explode( ' ', $value, 2 );
 143                         $s->mURL = $url;
 144                         $s->mLocal = (int)$local;
 145                 } else {
 146                         $s = false;
 147                 }
 148
 149                 return $s;
 150         }
 151
 152         /**
 153          * Get entry from interwiki cache
 154          *
 155          * @note More logic is explained in DefaultSettings.
 156          *
 157          * @param string $prefix Database key
 158          * @return bool|string The interwiki entry or false if not found
 159          */
 160         protected static function getInterwikiCacheEntry( $prefix ) {
 161                 global $wgInterwikiScopes, $wgInterwikiFallbackSite;
 162                 static $site;
 163
 164                 wfDebug( __METHOD__ . "( $prefix )\n" );
 165                 $value = false;
 166                 try {
 167                         // Resolve site name
 168                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 169                                 $site = self::getCacheValue( '__sites:' . wfWikiID() );
 170                                 if ( $site == '' ) {
 171                                         $site = $wgInterwikiFallbackSite;
 172                                 }
 173                         }
 174
 175                         $value = self::getCacheValue( wfMemcKey( $prefix ) );
 176                         // Site level
 177                         if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 178                                 $value = self::getCacheValue( "_{$site}:{$prefix}" );
 179                         }
 180                         // Global Level
 181                         if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 182                                 $value = self::getCacheValue( "__global:{$prefix}" );
 183                         }
 184                         if ( $value == 'undef' ) {
 185                                 $value = '';
 186                         }
 187                 } catch ( CdbException $e ) {
 188                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 189                                 . $e->getMessage() );
 190                 }
 191
 192                 return $value;
 193         }
 194
 195         private static function getCacheValue( $key ) {
 196                 global $wgInterwikiCache;
 197                 static $reader;
 198                 if ( $reader === null ) {
 199                         $reader = is_array( $wgInterwikiCache ) ? false : CdbReader::open( $wgInterwikiCache );
 200                 }
 201                 if ( $reader ) {
 202                         return $reader->get( $key );
 203                 } else {
 204                         return isset( $wgInterwikiCache[$key] ) ? $wgInterwikiCache[$key] : false;
 205                 }
 206         }
 207
 208         /**
 209          * Load the interwiki, trying first memcached then the DB
 210          *
 211          * @param string $prefix The interwiki prefix
 212          * @return Interwiki|bool Interwiki if $prefix is valid, otherwise false
 213          */
 214         protected static function load( $prefix ) {
 215                 global $wgInterwikiExpiry;
 216
 217                 $iwData = [];
 218                 if ( !Hooks::run( 'InterwikiLoadPrefix', [ $prefix, &$iwData ] ) ) {
 219                         return Interwiki::loadFromArray( $iwData );
 220                 }
 221
 222                 if ( is_array( $iwData ) ) {
 223                         $iw = Interwiki::loadFromArray( $iwData );
 224                         if ( $iw ) {
 225                                 return $iw; // handled by hook
 226                         }
 227                 }
 228
 229                 $iwData = ObjectCache::getMainWANInstance()->getWithSetCallback(
 230                         wfMemcKey( 'interwiki', $prefix ),
 231                         $wgInterwikiExpiry,
 232                         function ( $oldValue, &$ttl, array &$setOpts ) use ( $prefix ) {
 233                                 $dbr = wfGetDB( DB_SLAVE );
 234
 235                                 $setOpts += Database::getCacheSetOptions( $dbr );
 236
 237                                 $row = $dbr->selectRow(
 238                                         'interwiki',
 239                                         Interwiki::selectFields(),
 240                                         [ 'iw_prefix' => $prefix ],
 241                                         __METHOD__
 242                                 );
 243
 244                                 return $row ? (array)$row : '!NONEXISTENT';
 245                         }
 246                 );
 247
 248                 if ( is_array( $iwData ) ) {
 249                         return Interwiki::loadFromArray( $iwData ) ?: false;
 250                 }
 251
 252                 return false;
 253         }
 254
 255         /**
 256          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 257          *
 258          * @param array $mc Associative array: row from the interwiki table
 259          * @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
 260          */
 261         protected static function loadFromArray( $mc ) {
 262                 if ( isset( $mc['iw_url'] ) ) {
 263                         $iw = new Interwiki();
 264                         $iw->mURL = $mc['iw_url'];
 265                         $iw->mLocal = isset( $mc['iw_local'] ) ? $mc['iw_local'] : 0;
 266                         $iw->mTrans = isset( $mc['iw_trans'] ) ? $mc['iw_trans'] : 0;
 267                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 268                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 269
 270                         return $iw;
 271                 }
 272
 273                 return false;
 274         }
 275
 276         /**
 277          * Fetch all interwiki prefixes from interwiki cache
 278          *
 279          * @param null|string $local If not null, limits output to local/non-local interwikis
 280          * @return array List of prefixes
 281          * @since 1.19
 282          */
 283         protected static function getAllPrefixesCached( $local ) {
 284                 global $wgInterwikiScopes, $wgInterwikiFallbackSite;
 285                 static $site;
 286
 287                 wfDebug( __METHOD__ . "()\n" );
 288                 $data = [];
 289                 try {
 290                         /* Resolve site name */
 291                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 292                                 $site = self::getCacheValue( '__sites:' . wfWikiID() );
 293
 294                                 if ( $site == '' ) {
 295                                         $site = $wgInterwikiFallbackSite;
 296                                 }
 297                         }
 298
 299                         // List of interwiki sources
 300                         $sources = [];
 301                         // Global Level
 302                         if ( $wgInterwikiScopes >= 2 ) {
 303                                 $sources[] = '__global';
 304                         }
 305                         // Site level
 306                         if ( $wgInterwikiScopes >= 3 ) {
 307                                 $sources[] = '_' . $site;
 308                         }
 309                         $sources[] = wfWikiID();
 310
 311                         foreach ( $sources as $source ) {
 312                                 $list = self::getCacheValue( '__list:' . $source );
 313                                 foreach ( explode( ' ', $list ) as $iw_prefix ) {
 314                                         $row = self::getCacheValue( "{$source}:{$iw_prefix}" );
 315                                         if ( !$row ) {
 316                                                 continue;
 317                                         }
 318
 319                                         list( $iw_local, $iw_url ) = explode( ' ', $row );
 320
 321                                         if ( $local !== null && $local != $iw_local ) {
 322                                                 continue;
 323                                         }
 324
 325                                         $data[$iw_prefix] = [
 326                                                 'iw_prefix' => $iw_prefix,
 327                                                 'iw_url' => $iw_url,
 328                                                 'iw_local' => $iw_local,
 329                                         ];
 330                                 }
 331                         }
 332                 } catch ( CdbException $e ) {
 333                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 334                                 . $e->getMessage() );
 335                 }
 336
 337                 ksort( $data );
 338
 339                 return array_values( $data );
 340         }
 341
 342         /**
 343          * Fetch all interwiki prefixes from DB
 344          *
 345          * @param string|null $local If not null, limits output to local/non-local interwikis
 346          * @return array List of prefixes
 347          * @since 1.19
 348          */
 349         protected static function getAllPrefixesDB( $local ) {
 350                 $db = wfGetDB( DB_SLAVE );
 351
 352                 $where = [];
 353
 354                 if ( $local !== null ) {
 355                         if ( $local == 1 ) {
 356                                 $where['iw_local'] = 1;
 357                         } elseif ( $local == 0 ) {
 358                                 $where['iw_local'] = 0;
 359                         }
 360                 }
 361
 362                 $res = $db->select( 'interwiki',
 363                         self::selectFields(),
 364                         $where, __METHOD__, [ 'ORDER BY' => 'iw_prefix' ]
 365                 );
 366
 367                 $retval = [];
 368                 foreach ( $res as $row ) {
 369                         $retval[] = (array)$row;
 370                 }
 371
 372                 return $retval;
 373         }
 374
 375         /**
 376          * Returns all interwiki prefixes
 377          *
 378          * @param string|null $local If set, limits output to local/non-local interwikis
 379          * @return array List of prefixes
 380          * @since 1.19
 381          */
 382         public static function getAllPrefixes( $local = null ) {
 383                 global $wgInterwikiCache;
 384
 385                 if ( $wgInterwikiCache ) {
 386                         return self::getAllPrefixesCached( $local );
 387                 }
 388
 389                 return self::getAllPrefixesDB( $local );
 390         }
 391
 392         /**
 393          * Get the URL for a particular title (or with $1 if no title given)
 394          *
 395          * @param string $title What text to put for the article name
 396          * @return string The URL
 397          * @note Prior to 1.19 The getURL with an argument was broken.
 398          *       If you if you use this arg in an extension that supports MW earlier
 399          *       than 1.19 please wfUrlencode and substitute $1 on your own.
 400          */
 401         public function getURL( $title = null ) {
 402                 $url = $this->mURL;
 403                 if ( $title !== null ) {
 404                         $url = str_replace( "$1", wfUrlencode( $title ), $url );
 405                 }
 406
 407                 return $url;
 408         }
 409
 410         /**
 411          * Get the API URL for this wiki
 412          *
 413          * @return string The URL
 414          */
 415         public function getAPI() {
 416                 return $this->mAPI;
 417         }
 418
 419         /**
 420          * Get the DB name for this wiki
 421          *
 422          * @return string The DB name
 423          */
 424         public function getWikiID() {
 425                 return $this->mWikiID;
 426         }
 427
 428         /**
 429          * Is this a local link from a sister project, or is
 430          * it something outside, like Google
 431          *
 432          * @return bool
 433          */
 434         public function isLocal() {
 435                 return $this->mLocal;
 436         }
 437
 438         /**
 439          * Can pages from this wiki be transcluded?
 440          * Still requires $wgEnableScaryTransclusion
 441          *
 442          * @return bool
 443          */
 444         public function isTranscludable() {
 445                 return $this->mTrans;
 446         }
 447
 448         /**
 449          * Get the name for the interwiki site
 450          *
 451          * @return string
 452          */
 453         public function getName() {
 454                 $msg = wfMessage( 'interwiki-name-' . $this->mPrefix )->inContentLanguage();
 455
 456                 return !$msg->exists() ? '' : $msg;
 457         }
 458
 459         /**
 460          * Get a description for this interwiki
 461          *
 462          * @return string
 463          */
 464         public function getDescription() {
 465                 $msg = wfMessage( 'interwiki-desc-' . $this->mPrefix )->inContentLanguage();
 466
 467                 return !$msg->exists() ? '' : $msg;
 468         }
 469
 470         /**
 471          * Return the list of interwiki fields that should be selected to create
 472          * a new Interwiki object.
 473          * @return string[]
 474          */
 475         public static function selectFields() {
 476                 return [
 477                         'iw_prefix',
 478                         'iw_url',
 479                         'iw_api',
 480                         'iw_wikiid',
 481                         'iw_local',
 482                         'iw_trans'
 483                 ];
 484         }
 485 }