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
  23 /**
  24  * The interwiki class
  25  * All information is loaded on creation when called by Interwiki::fetch( $prefix ).
  26  * All work is done on slave, because this should *never* change (except during
  27  * schema updates etc, which aren't wiki-related)
  28  */
  29 class Interwiki {
  30         // Cache - removes oldest entry when it hits limit
  31         protected static $smCache = array();
  32         const CACHE_LIMIT = 100; // 0 means unlimited, any other value is max number of entries.
  33
  34         protected $mPrefix, $mURL, $mAPI, $mWikiID, $mLocal, $mTrans;
  35
  36         public function __construct( $prefix = null, $url = '', $api = '', $wikiId = '', $local = 0,
  37                 $trans = 0
  38         ) {
  39                 $this->mPrefix = $prefix;
  40                 $this->mURL = $url;
  41                 $this->mAPI = $api;
  42                 $this->mWikiID = $wikiId;
  43                 $this->mLocal = $local;
  44                 $this->mTrans = $trans;
  45         }
  46
  47         /**
  48          * Check whether an interwiki prefix exists
  49          *
  50          * @param string $prefix Interwiki prefix to use
  51          * @return bool Whether it exists
  52          */
  53         public static function isValidInterwiki( $prefix ) {
  54                 $result = self::fetch( $prefix );
  55                 return (bool)$result;
  56         }
  57
  58         /**
  59          * Fetch an Interwiki object
  60          *
  61          * @param string $prefix Interwiki prefix to use
  62          * @return Interwiki|null|bool
  63          */
  64         public static function fetch( $prefix ) {
  65                 global $wgContLang;
  66                 if ( $prefix == '' ) {
  67                         return null;
  68                 }
  69                 $prefix = $wgContLang->lc( $prefix );
  70                 if ( isset( self::$smCache[$prefix] ) ) {
  71                         return self::$smCache[$prefix];
  72                 }
  73                 global $wgInterwikiCache;
  74                 if ( $wgInterwikiCache ) {
  75                         $iw = Interwiki::getInterwikiCached( $prefix );
  76                 } else {
  77                         $iw = Interwiki::load( $prefix );
  78                         if ( !$iw ) {
  79                                 $iw = false;
  80                         }
  81                 }
  82                 if ( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ) {
  83                         reset( self::$smCache );
  84                         unset( self::$smCache[key( self::$smCache )] );
  85                 }
  86                 self::$smCache[$prefix] = $iw;
  87                 return $iw;
  88         }
  89
  90         /**
  91          * Fetch interwiki prefix data from local cache in constant database.
  92          *
  93          * @note More logic is explained in DefaultSettings.
  94          *
  95          * @param string $prefix Interwiki prefix
  96          * @return Interwiki object
  97          */
  98         protected static function getInterwikiCached( $prefix ) {
  99                 $value = self::getInterwikiCacheEntry( $prefix );
 100
 101                 $s = new Interwiki( $prefix );
 102                 if ( $value != '' ) {
 103                         // Split values
 104                         list( $local, $url ) = explode( ' ', $value, 2 );
 105                         $s->mURL = $url;
 106                         $s->mLocal = (int)$local;
 107                 } else {
 108                         $s = false;
 109                 }
 110                 return $s;
 111         }
 112
 113         /**
 114          * Get entry from interwiki cache
 115          *
 116          * @note More logic is explained in DefaultSettings.
 117          *
 118          * @param string $prefix Database key
 119          * @return string The interwiki entry
 120          */
 121         protected static function getInterwikiCacheEntry( $prefix ) {
 122                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 123                 static $db, $site;
 124
 125                 wfDebug( __METHOD__ . "( $prefix )\n" );
 126                 $value = false;
 127                 try {
 128                         if ( !$db ) {
 129                                 $db = CdbReader::open( $wgInterwikiCache );
 130                         }
 131                         /* Resolve site name */
 132                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 133                                 $site = $db->get( '__sites:' . wfWikiID() );
 134                                 if ( $site == '' ) {
 135                                         $site = $wgInterwikiFallbackSite;
 136                                 }
 137                         }
 138
 139                         $value = $db->get( wfMemcKey( $prefix ) );
 140                         // Site level
 141                         if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 142                                 $value = $db->get( "_{$site}:{$prefix}" );
 143                         }
 144                         // Global Level
 145                         if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 146                                 $value = $db->get( "__global:{$prefix}" );
 147                         }
 148                         if ( $value == 'undef' ) {
 149                                 $value = '';
 150                         }
 151                 } catch ( CdbException $e ) {
 152                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 153                                 . $e->getMessage() );
 154                 }
 155
 156                 return $value;
 157         }
 158
 159         /**
 160          * Load the interwiki, trying first memcached then the DB
 161          *
 162          * @param string $prefix The interwiki prefix
 163          * @return bool If $prefix is valid
 164          */
 165         protected static function load( $prefix ) {
 166                 global $wgMemc, $wgInterwikiExpiry;
 167
 168                 $iwData = false;
 169                 if ( !wfRunHooks( 'InterwikiLoadPrefix', array( $prefix, &$iwData ) ) ) {
 170                         return Interwiki::loadFromArray( $iwData );
 171                 }
 172
 173                 if ( !$iwData ) {
 174                         $key = wfMemcKey( 'interwiki', $prefix );
 175                         $iwData = $wgMemc->get( $key );
 176                         if ( $iwData === '!NONEXISTENT' ) {
 177                                 return false; // negative cache hit
 178                         }
 179                 }
 180
 181                 if ( $iwData && is_array( $iwData ) ) { // is_array is hack for old keys
 182                         $iw = Interwiki::loadFromArray( $iwData );
 183                         if ( $iw ) {
 184                                 return $iw;
 185                         }
 186                 }
 187
 188                 $db = wfGetDB( DB_SLAVE );
 189
 190                 $row = $db->fetchRow( $db->select( 'interwiki', self::selectFields(), array( 'iw_prefix' => $prefix ),
 191                         __METHOD__ ) );
 192                 $iw = Interwiki::loadFromArray( $row );
 193                 if ( $iw ) {
 194                         $mc = array(
 195                                 'iw_url' => $iw->mURL,
 196                                 'iw_api' => $iw->mAPI,
 197                                 'iw_local' => $iw->mLocal,
 198                                 'iw_trans' => $iw->mTrans
 199                         );
 200                         $wgMemc->add( $key, $mc, $wgInterwikiExpiry );
 201                         return $iw;
 202                 } else {
 203                         $wgMemc->add( $key, '!NONEXISTENT', $wgInterwikiExpiry ); // negative cache hit
 204                 }
 205
 206                 return false;
 207         }
 208
 209         /**
 210          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 211          *
 212          * @param array $mc Associative array: row from the interwiki table
 213          * @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
 214          */
 215         protected static function loadFromArray( $mc ) {
 216                 if ( isset( $mc['iw_url'] ) ) {
 217                         $iw = new Interwiki();
 218                         $iw->mURL = $mc['iw_url'];
 219                         $iw->mLocal = isset( $mc['iw_local'] ) ? $mc['iw_local'] : 0;
 220                         $iw->mTrans = isset( $mc['iw_trans'] ) ? $mc['iw_trans'] : 0;
 221                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 222                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 223
 224                         return $iw;
 225                 }
 226                 return false;
 227         }
 228
 229         /**
 230          * Fetch all interwiki prefixes from interwiki cache
 231          *
 232          * @param null|string $local If not null, limits output to local/non-local interwikis
 233          * @return array List of prefixes
 234          * @since 1.19
 235          */
 236         protected static function getAllPrefixesCached( $local ) {
 237                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 238                 static $db, $site;
 239
 240                 wfDebug( __METHOD__ . "()\n" );
 241                 $data = array();
 242                 try {
 243                         if ( !$db ) {
 244                                 $db = CdbReader::open( $wgInterwikiCache );
 245                         }
 246                         /* Resolve site name */
 247                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 248                                 $site = $db->get( '__sites:' . wfWikiID() );
 249                                 if ( $site == '' ) {
 250                                         $site = $wgInterwikiFallbackSite;
 251                                 }
 252                         }
 253
 254                         // List of interwiki sources
 255                         $sources = array();
 256                         // Global Level
 257                         if ( $wgInterwikiScopes >= 2 ) {
 258                                 $sources[] = '__global';
 259                         }
 260                         // Site level
 261                         if ( $wgInterwikiScopes >= 3 ) {
 262                                 $sources[] = '_' . $site;
 263                         }
 264                         $sources[] = wfWikiID();
 265
 266                         foreach ( $sources as $source ) {
 267                                 $list = $db->get( "__list:{$source}" );
 268                                 foreach ( explode( ' ', $list ) as $iw_prefix ) {
 269                                         $row = $db->get( "{$source}:{$iw_prefix}" );
 270                                         if ( !$row ) {
 271                                                 continue;
 272                                         }
 273
 274                                         list( $iw_local, $iw_url ) = explode( ' ', $row );
 275
 276                                         if ( $local !== null && $local != $iw_local ) {
 277                                                 continue;
 278                                         }
 279
 280                                         $data[$iw_prefix] = array(
 281                                                 'iw_prefix' => $iw_prefix,
 282                                                 'iw_url' => $iw_url,
 283                                                 'iw_local' => $iw_local,
 284                                         );
 285                                 }
 286                         }
 287                 } catch ( CdbException $e ) {
 288                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 289                                 . $e->getMessage() );
 290                 }
 291
 292                 ksort( $data );
 293
 294                 return array_values( $data );
 295         }
 296
 297         /**
 298          * Fetch all interwiki prefixes from DB
 299          *
 300          * @param string|null $local If not null, limits output to local/non-local interwikis
 301          * @return array List of prefixes
 302          * @since 1.19
 303          */
 304         protected static function getAllPrefixesDB( $local ) {
 305                 $db = wfGetDB( DB_SLAVE );
 306
 307                 $where = array();
 308
 309                 if ( $local !== null ) {
 310                         if ( $local == 1 ) {
 311                                 $where['iw_local'] = 1;
 312                         } elseif ( $local == 0 ) {
 313                                 $where['iw_local'] = 0;
 314                         }
 315                 }
 316
 317                 $res = $db->select( 'interwiki',
 318                         self::selectFields(),
 319                         $where, __METHOD__, array( 'ORDER BY' => 'iw_prefix' )
 320                 );
 321                 $retval = array();
 322                 foreach ( $res as $row ) {
 323                         $retval[] = (array)$row;
 324                 }
 325                 return $retval;
 326         }
 327
 328         /**
 329          * Returns all interwiki prefixes
 330          *
 331          * @param string|null $local If set, limits output to local/non-local interwikis
 332          * @return array List of prefixes
 333          * @since 1.19
 334          */
 335         public static function getAllPrefixes( $local = null ) {
 336                 global $wgInterwikiCache;
 337
 338                 if ( $wgInterwikiCache ) {
 339                         return self::getAllPrefixesCached( $local );
 340                 } else {
 341                         return self::getAllPrefixesDB( $local );
 342                 }
 343         }
 344
 345         /**
 346          * Get the URL for a particular title (or with $1 if no title given)
 347          *
 348          * @param string $title What text to put for the article name
 349          * @return string The URL
 350          * @note Prior to 1.19 The getURL with an argument was broken.
 351          *       If you if you use this arg in an extension that supports MW earlier
 352          *       than 1.19 please wfUrlencode and substitute $1 on your own.
 353          */
 354         public function getURL( $title = null ) {
 355                 $url = $this->mURL;
 356                 if ( $title !== null ) {
 357                         $url = str_replace( "$1", wfUrlencode( $title ), $url );
 358                 }
 359                 return $url;
 360         }
 361
 362         /**
 363          * Get the API URL for this wiki
 364          *
 365          * @return string The URL
 366          */
 367         public function getAPI() {
 368                 return $this->mAPI;
 369         }
 370
 371         /**
 372          * Get the DB name for this wiki
 373          *
 374          * @return string The DB name
 375          */
 376         public function getWikiID() {
 377                 return $this->mWikiID;
 378         }
 379
 380         /**
 381          * Is this a local link from a sister project, or is
 382          * it something outside, like Google
 383          *
 384          * @return bool
 385          */
 386         public function isLocal() {
 387                 return $this->mLocal;
 388         }
 389
 390         /**
 391          * Can pages from this wiki be transcluded?
 392          * Still requires $wgEnableScaryTransclusion
 393          *
 394          * @return bool
 395          */
 396         public function isTranscludable() {
 397                 return $this->mTrans;
 398         }
 399
 400         /**
 401          * Get the name for the interwiki site
 402          *
 403          * @return string
 404          */
 405         public function getName() {
 406                 $msg = wfMessage( 'interwiki-name-' . $this->mPrefix )->inContentLanguage();
 407                 return !$msg->exists() ? '' : $msg;
 408         }
 409
 410         /**
 411          * Get a description for this interwiki
 412          *
 413          * @return string
 414          */
 415         public function getDescription() {
 416                 $msg = wfMessage( 'interwiki-desc-' . $this->mPrefix )->inContentLanguage();
 417                 return !$msg->exists() ? '' : $msg;
 418         }
 419
 420         /**
 421          * Return the list of interwiki fields that should be selected to create
 422          * a new Interwiki object.
 423          * @return string[]
 424          */
 425         public static function selectFields() {
 426                 return array(
 427                         'iw_prefix',
 428                         'iw_url',
 429                         'iw_api',
 430                         'iw_wikiid',
 431                         'iw_local',
 432                         'iw_trans'
 433                 );
 434         }
 435 }