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