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