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                 $this->mLocal = (bool)$local;
  64                 $this->mTrans = (bool)$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 $iw;
 115         }
 116
 117         /**
 118          * Resets locally cached Interwiki objects. This is intended for use during testing only.
 119          * This does not invalidate entries in the persistent cache, as invalidateCache() does.
 120          * @since 1.27
 121          */
 122         public static function resetLocalCache() {
 123                 static::$smCache = [];
 124         }
 125
 126         /**
 127          * Purge the cache (local and persistent) for an interwiki prefix.
 128          * @param string $prefix
 129          * @since 1.26
 130          */
 131         public static function invalidateCache( $prefix ) {
 132                 $cache = ObjectCache::getMainWANInstance();
 133                 $key = wfMemcKey( 'interwiki', $prefix );
 134                 $cache->delete( $key );
 135                 unset( static::$smCache[$prefix] );
 136         }
 137
 138         /**
 139          * Fetch interwiki prefix data from local cache in constant database.
 140          *
 141          * @note More logic is explained in DefaultSettings.
 142          *
 143          * @param string $prefix Interwiki prefix
 144          * @return Interwiki
 145          */
 146         protected static function getInterwikiCached( $prefix ) {
 147                 $value = self::getInterwikiCacheEntry( $prefix );
 148
 149                 $s = new Interwiki( $prefix );
 150                 if ( $value ) {
 151                         // Split values
 152                         list( $local, $url ) = explode( ' ', $value, 2 );
 153                         $s->mURL = $url;
 154                         $s->mLocal = (bool)$local;
 155                 } else {
 156                         $s = false;
 157                 }
 158
 159                 return $s;
 160         }
 161
 162         /**
 163          * Get entry from interwiki cache
 164          *
 165          * @note More logic is explained in DefaultSettings.
 166          *
 167          * @param string $prefix Database key
 168          * @return bool|string The interwiki entry or false if not found
 169          */
 170         protected static function getInterwikiCacheEntry( $prefix ) {
 171                 global $wgInterwikiScopes, $wgInterwikiFallbackSite;
 172                 static $site;
 173
 174                 $value = false;
 175                 try {
 176                         // Resolve site name
 177                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 178                                 $site = self::getCacheValue( '__sites:' . wfWikiID() );
 179                                 if ( $site == '' ) {
 180                                         $site = $wgInterwikiFallbackSite;
 181                                 }
 182                         }
 183
 184                         $value = self::getCacheValue( wfMemcKey( $prefix ) );
 185                         // Site level
 186                         if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 187                                 $value = self::getCacheValue( "_{$site}:{$prefix}" );
 188                         }
 189                         // Global Level
 190                         if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 191                                 $value = self::getCacheValue( "__global:{$prefix}" );
 192                         }
 193                         if ( $value == 'undef' ) {
 194                                 $value = '';
 195                         }
 196                 } catch ( CdbException $e ) {
 197                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 198                                 . $e->getMessage() );
 199                 }
 200
 201                 return $value;
 202         }
 203
 204         private static function getCacheValue( $key ) {
 205                 global $wgInterwikiCache;
 206                 static $reader;
 207                 if ( $reader === null ) {
 208                         $reader = is_array( $wgInterwikiCache ) ? false : CdbReader::open( $wgInterwikiCache );
 209                 }
 210                 if ( $reader ) {
 211                         return $reader->get( $key );
 212                 } else {
 213                         return isset( $wgInterwikiCache[$key] ) ? $wgInterwikiCache[$key] : false;
 214                 }
 215         }
 216
 217         /**
 218          * Load the interwiki, trying first memcached then the DB
 219          *
 220          * @param string $prefix The interwiki prefix
 221          * @return Interwiki|bool Interwiki if $prefix is valid, otherwise false
 222          */
 223         protected static function load( $prefix ) {
 224                 global $wgInterwikiExpiry;
 225
 226                 $iwData = [];
 227                 if ( !Hooks::run( 'InterwikiLoadPrefix', [ $prefix, &$iwData ] ) ) {
 228                         return Interwiki::loadFromArray( $iwData );
 229                 }
 230
 231                 if ( is_array( $iwData ) ) {
 232                         $iw = Interwiki::loadFromArray( $iwData );
 233                         if ( $iw ) {
 234                                 return $iw; // handled by hook
 235                         }
 236                 }
 237
 238                 $iwData = ObjectCache::getMainWANInstance()->getWithSetCallback(
 239                         wfMemcKey( 'interwiki', $prefix ),
 240                         $wgInterwikiExpiry,
 241                         function ( $oldValue, &$ttl, array &$setOpts ) use ( $prefix ) {
 242                                 $dbr = wfGetDB( DB_SLAVE );
 243
 244                                 $setOpts += Database::getCacheSetOptions( $dbr );
 245
 246                                 $row = $dbr->selectRow(
 247                                         'interwiki',
 248                                         Interwiki::selectFields(),
 249                                         [ 'iw_prefix' => $prefix ],
 250                                         __METHOD__
 251                                 );
 252
 253                                 return $row ? (array)$row : '!NONEXISTENT';
 254                         }
 255                 );
 256
 257                 if ( is_array( $iwData ) ) {
 258                         return Interwiki::loadFromArray( $iwData ) ?: false;
 259                 }
 260
 261                 return false;
 262         }
 263
 264         /**
 265          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 266          *
 267          * @param array $mc Associative array: row from the interwiki table
 268          * @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
 269          */
 270         protected static function loadFromArray( $mc ) {
 271                 if ( isset( $mc['iw_url'] ) ) {
 272                         $iw = new Interwiki();
 273                         $iw->mURL = $mc['iw_url'];
 274                         $iw->mLocal = isset( $mc['iw_local'] ) ? (bool)$mc['iw_local'] : false;
 275                         $iw->mTrans = isset( $mc['iw_trans'] ) ? (bool)$mc['iw_trans'] : false;
 276                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 277                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 278
 279                         return $iw;
 280                 }
 281
 282                 return false;
 283         }
 284
 285         /**
 286          * Fetch all interwiki prefixes from interwiki cache
 287          *
 288          * @param null|string $local If not null, limits output to local/non-local interwikis
 289          * @return array List of prefixes
 290          * @since 1.19
 291          */
 292         protected static function getAllPrefixesCached( $local ) {
 293                 global $wgInterwikiScopes, $wgInterwikiFallbackSite;
 294                 static $site;
 295
 296                 wfDebug( __METHOD__ . "()\n" );
 297                 $data = [];
 298                 try {
 299                         /* Resolve site name */
 300                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 301                                 $site = self::getCacheValue( '__sites:' . wfWikiID() );
 302
 303                                 if ( $site == '' ) {
 304                                         $site = $wgInterwikiFallbackSite;
 305                                 }
 306                         }
 307
 308                         // List of interwiki sources
 309                         $sources = [];
 310                         // Global Level
 311                         if ( $wgInterwikiScopes >= 2 ) {
 312                                 $sources[] = '__global';
 313                         }
 314                         // Site level
 315                         if ( $wgInterwikiScopes >= 3 ) {
 316                                 $sources[] = '_' . $site;
 317                         }
 318                         $sources[] = wfWikiID();
 319
 320                         foreach ( $sources as $source ) {
 321                                 $list = self::getCacheValue( '__list:' . $source );
 322                                 foreach ( explode( ' ', $list ) as $iw_prefix ) {
 323                                         $row = self::getCacheValue( "{$source}:{$iw_prefix}" );
 324                                         if ( !$row ) {
 325                                                 continue;
 326                                         }
 327
 328                                         list( $iw_local, $iw_url ) = explode( ' ', $row );
 329
 330                                         if ( $local !== null && $local != $iw_local ) {
 331                                                 continue;
 332                                         }
 333
 334                                         $data[$iw_prefix] = [
 335                                                 'iw_prefix' => $iw_prefix,
 336                                                 'iw_url' => $iw_url,
 337                                                 'iw_local' => $iw_local,
 338                                         ];
 339                                 }
 340                         }
 341                 } catch ( CdbException $e ) {
 342                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 343                                 . $e->getMessage() );
 344                 }
 345
 346                 ksort( $data );
 347
 348                 return array_values( $data );
 349         }
 350
 351         /**
 352          * Fetch all interwiki prefixes from DB
 353          *
 354          * @param string|null $local If not null, limits output to local/non-local interwikis
 355          * @return array List of prefixes
 356          * @since 1.19
 357          */
 358         protected static function getAllPrefixesDB( $local ) {
 359                 $db = wfGetDB( DB_SLAVE );
 360
 361                 $where = [];
 362
 363                 if ( $local !== null ) {
 364                         if ( $local == 1 ) {
 365                                 $where['iw_local'] = 1;
 366                         } elseif ( $local == 0 ) {
 367                                 $where['iw_local'] = 0;
 368                         }
 369                 }
 370
 371                 $res = $db->select( 'interwiki',
 372                         self::selectFields(),
 373                         $where, __METHOD__, [ 'ORDER BY' => 'iw_prefix' ]
 374                 );
 375
 376                 $retval = [];
 377                 foreach ( $res as $row ) {
 378                         $retval[] = (array)$row;
 379                 }
 380
 381                 return $retval;
 382         }
 383
 384         /**
 385          * Returns all interwiki prefixes
 386          *
 387          * @param string|null $local If set, limits output to local/non-local interwikis
 388          * @return array List of prefixes
 389          * @since 1.19
 390          */
 391         public static function getAllPrefixes( $local = null ) {
 392                 global $wgInterwikiCache;
 393
 394                 if ( $wgInterwikiCache ) {
 395                         return self::getAllPrefixesCached( $local );
 396                 }
 397
 398                 return self::getAllPrefixesDB( $local );
 399         }
 400
 401         /**
 402          * Get the URL for a particular title (or with $1 if no title given)
 403          *
 404          * @param string $title What text to put for the article name
 405          * @return string The URL
 406          * @note Prior to 1.19 The getURL with an argument was broken.
 407          *       If you if you use this arg in an extension that supports MW earlier
 408          *       than 1.19 please wfUrlencode and substitute $1 on your own.
 409          */
 410         public function getURL( $title = null ) {
 411                 $url = $this->mURL;
 412                 if ( $title !== null ) {
 413                         $url = str_replace( "$1", wfUrlencode( $title ), $url );
 414                 }
 415
 416                 return $url;
 417         }
 418
 419         /**
 420          * Get the API URL for this wiki
 421          *
 422          * @return string The URL
 423          */
 424         public function getAPI() {
 425                 return $this->mAPI;
 426         }
 427
 428         /**
 429          * Get the DB name for this wiki
 430          *
 431          * @return string The DB name
 432          */
 433         public function getWikiID() {
 434                 return $this->mWikiID;
 435         }
 436
 437         /**
 438          * Is this a local link from a sister project, or is
 439          * it something outside, like Google
 440          *
 441          * @return bool
 442          */
 443         public function isLocal() {
 444                 return $this->mLocal;
 445         }
 446
 447         /**
 448          * Can pages from this wiki be transcluded?
 449          * Still requires $wgEnableScaryTransclusion
 450          *
 451          * @return bool
 452          */
 453         public function isTranscludable() {
 454                 return $this->mTrans;
 455         }
 456
 457         /**
 458          * Get the name for the interwiki site
 459          *
 460          * @return string
 461          */
 462         public function getName() {
 463                 $msg = wfMessage( 'interwiki-name-' . $this->mPrefix )->inContentLanguage();
 464
 465                 return !$msg->exists() ? '' : $msg->text();
 466         }
 467
 468         /**
 469          * Get a description for this interwiki
 470          *
 471          * @return string
 472          */
 473         public function getDescription() {
 474                 $msg = wfMessage( 'interwiki-desc-' . $this->mPrefix )->inContentLanguage();
 475
 476                 return !$msg->exists() ? '' : $msg->text();
 477         }
 478
 479         /**
 480          * Return the list of interwiki fields that should be selected to create
 481          * a new Interwiki object.
 482          * @return string[]
 483          */
 484         public static function selectFields() {
 485                 return [
 486                         'iw_prefix',
 487                         'iw_url',
 488                         'iw_api',
 489                         'iw_wikiid',
 490                         'iw_local',
 491                         'iw_trans'
 492                 ];
 493         }
 494 }