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