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                 $cache = ObjectCache::getMainWANInstance();
 213
 214                 if ( !$iwData ) {
 215                         $key = wfMemcKey( 'interwiki', $prefix );
 216                         $iwData = $cache->get( $key );
 217                         if ( $iwData === '!NONEXISTENT' ) {
 218                                 // negative cache hit
 219                                 return false;
 220                         }
 221                 }
 222
 223                 // is_array is hack for old keys
 224                 if ( $iwData && is_array( $iwData ) ) {
 225                         $iw = Interwiki::loadFromArray( $iwData );
 226                         if ( $iw ) {
 227                                 return $iw;
 228                         }
 229                 }
 230
 231                 $db = wfGetDB( DB_SLAVE );
 232
 233                 $row = $db->fetchRow( $db->select(
 234                         'interwiki',
 235                         self::selectFields(),
 236                         array( 'iw_prefix' => $prefix ),
 237                         __METHOD__
 238                 ) );
 239
 240                 $iw = Interwiki::loadFromArray( $row );
 241                 if ( $iw ) {
 242                         $mc = array(
 243                                 'iw_url' => $iw->mURL,
 244                                 'iw_api' => $iw->mAPI,
 245                                 'iw_local' => $iw->mLocal,
 246                                 'iw_trans' => $iw->mTrans
 247                         );
 248                         $cache->set( $key, $mc, $wgInterwikiExpiry );
 249
 250                         return $iw;
 251                 }
 252
 253                 // negative cache hit
 254                 $cache->set( $key, '!NONEXISTENT', $wgInterwikiExpiry );
 255
 256                 return false;
 257         }
 258
 259         /**
 260          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 261          *
 262          * @param array $mc Associative array: row from the interwiki table
 263          * @return Interwiki|bool Interwiki object or false if $mc['iw_url'] is not set
 264          */
 265         protected static function loadFromArray( $mc ) {
 266                 if ( isset( $mc['iw_url'] ) ) {
 267                         $iw = new Interwiki();
 268                         $iw->mURL = $mc['iw_url'];
 269                         $iw->mLocal = isset( $mc['iw_local'] ) ? $mc['iw_local'] : 0;
 270                         $iw->mTrans = isset( $mc['iw_trans'] ) ? $mc['iw_trans'] : 0;
 271                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 272                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 273
 274                         return $iw;
 275                 }
 276
 277                 return false;
 278         }
 279
 280         /**
 281          * Fetch all interwiki prefixes from interwiki cache
 282          *
 283          * @param null|string $local If not null, limits output to local/non-local interwikis
 284          * @return array List of prefixes
 285          * @since 1.19
 286          */
 287         protected static function getAllPrefixesCached( $local ) {
 288                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 289                 static $db, $site;
 290
 291                 wfDebug( __METHOD__ . "()\n" );
 292                 $data = array();
 293                 try {
 294                         if ( !$db ) {
 295                                 $db = CdbReader::open( $wgInterwikiCache );
 296                         }
 297                         /* Resolve site name */
 298                         if ( $wgInterwikiScopes >= 3 && !$site ) {
 299                                 $site = $db->get( '__sites:' . wfWikiID() );
 300                                 if ( $site == '' ) {
 301                                         $site = $wgInterwikiFallbackSite;
 302                                 }
 303                         }
 304
 305                         // List of interwiki sources
 306                         $sources = array();
 307                         // Global Level
 308                         if ( $wgInterwikiScopes >= 2 ) {
 309                                 $sources[] = '__global';
 310                         }
 311                         // Site level
 312                         if ( $wgInterwikiScopes >= 3 ) {
 313                                 $sources[] = '_' . $site;
 314                         }
 315                         $sources[] = wfWikiID();
 316
 317                         foreach ( $sources as $source ) {
 318                                 $list = $db->get( "__list:{$source}" );
 319                                 foreach ( explode( ' ', $list ) as $iw_prefix ) {
 320                                         $row = $db->get( "{$source}:{$iw_prefix}" );
 321                                         if ( !$row ) {
 322                                                 continue;
 323                                         }
 324
 325                                         list( $iw_local, $iw_url ) = explode( ' ', $row );
 326
 327                                         if ( $local !== null && $local != $iw_local ) {
 328                                                 continue;
 329                                         }
 330
 331                                         $data[$iw_prefix] = array(
 332                                                 'iw_prefix' => $iw_prefix,
 333                                                 'iw_url' => $iw_url,
 334                                                 'iw_local' => $iw_local,
 335                                         );
 336                                 }
 337                         }
 338                 } catch ( CdbException $e ) {
 339                         wfDebug( __METHOD__ . ": CdbException caught, error message was "
 340                                 . $e->getMessage() );
 341                 }
 342
 343                 ksort( $data );
 344
 345                 return array_values( $data );
 346         }
 347
 348         /**
 349          * Fetch all interwiki prefixes from DB
 350          *
 351          * @param string|null $local If not null, limits output to local/non-local interwikis
 352          * @return array List of prefixes
 353          * @since 1.19
 354          */
 355         protected static function getAllPrefixesDB( $local ) {
 356                 $db = wfGetDB( DB_SLAVE );
 357
 358                 $where = array();
 359
 360                 if ( $local !== null ) {
 361                         if ( $local == 1 ) {
 362                                 $where['iw_local'] = 1;
 363                         } elseif ( $local == 0 ) {
 364                                 $where['iw_local'] = 0;
 365                         }
 366                 }
 367
 368                 $res = $db->select( 'interwiki',
 369                         self::selectFields(),
 370                         $where, __METHOD__, array( 'ORDER BY' => 'iw_prefix' )
 371                 );
 372
 373                 $retval = array();
 374                 foreach ( $res as $row ) {
 375                         $retval[] = (array)$row;
 376                 }
 377
 378                 return $retval;
 379         }
 380
 381         /**
 382          * Returns all interwiki prefixes
 383          *
 384          * @param string|null $local If set, limits output to local/non-local interwikis
 385          * @return array List of prefixes
 386          * @since 1.19
 387          */
 388         public static function getAllPrefixes( $local = null ) {
 389                 global $wgInterwikiCache;
 390
 391                 if ( $wgInterwikiCache ) {
 392                         return self::getAllPrefixesCached( $local );
 393                 }
 394
 395                 return self::getAllPrefixesDB( $local );
 396         }
 397
 398         /**
 399          * Get the URL for a particular title (or with $1 if no title given)
 400          *
 401          * @param string $title What text to put for the article name
 402          * @return string The URL
 403          * @note Prior to 1.19 The getURL with an argument was broken.
 404          *       If you if you use this arg in an extension that supports MW earlier
 405          *       than 1.19 please wfUrlencode and substitute $1 on your own.
 406          */
 407         public function getURL( $title = null ) {
 408                 $url = $this->mURL;
 409                 if ( $title !== null ) {
 410                         $url = str_replace( "$1", wfUrlencode( $title ), $url );
 411                 }
 412
 413                 return $url;
 414         }
 415
 416         /**
 417          * Get the API URL for this wiki
 418          *
 419          * @return string The URL
 420          */
 421         public function getAPI() {
 422                 return $this->mAPI;
 423         }
 424
 425         /**
 426          * Get the DB name for this wiki
 427          *
 428          * @return string The DB name
 429          */
 430         public function getWikiID() {
 431                 return $this->mWikiID;
 432         }
 433
 434         /**
 435          * Is this a local link from a sister project, or is
 436          * it something outside, like Google
 437          *
 438          * @return bool
 439          */
 440         public function isLocal() {
 441                 return $this->mLocal;
 442         }
 443
 444         /**
 445          * Can pages from this wiki be transcluded?
 446          * Still requires $wgEnableScaryTransclusion
 447          *
 448          * @return bool
 449          */
 450         public function isTranscludable() {
 451                 return $this->mTrans;
 452         }
 453
 454         /**
 455          * Get the name for the interwiki site
 456          *
 457          * @return string
 458          */
 459         public function getName() {
 460                 $msg = wfMessage( 'interwiki-name-' . $this->mPrefix )->inContentLanguage();
 461
 462                 return !$msg->exists() ? '' : $msg;
 463         }
 464
 465         /**
 466          * Get a description for this interwiki
 467          *
 468          * @return string
 469          */
 470         public function getDescription() {
 471                 $msg = wfMessage( 'interwiki-desc-' . $this->mPrefix )->inContentLanguage();
 472
 473                 return !$msg->exists() ? '' : $msg;
 474         }
 475
 476         /**
 477          * Return the list of interwiki fields that should be selected to create
 478          * a new Interwiki object.
 479          * @return string[]
 480          */
 481         public static function selectFields() {
 482                 return array(
 483                         'iw_prefix',
 484                         'iw_url',
 485                         'iw_api',
 486                         'iw_wikiid',
 487                         'iw_local',
 488                         'iw_trans'
 489                 );
 490         }
 491 }