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