includes/interwiki/Interwiki.php

   1 <?php
   2 /**
   3  * @file
   4  * Interwiki table entry
   5  */
   6
   7 /**
   8  * The interwiki class
   9  * All information is loaded on creation when called by Interwiki::fetch( $prefix ).
  10  * All work is done on slave, because this should *never* change (except during
  11  * schema updates etc, which aren't wiki-related)
  12  */
  13 class Interwiki {
  14
  15         // Cache - removes oldest entry when it hits limit
  16         protected static $smCache = array();
  17         const CACHE_LIMIT = 100; // 0 means unlimited, any other value is max number of entries.
  18
  19         protected $mPrefix, $mURL, $mAPI, $mWikiID, $mLocal, $mTrans;
  20
  21         public function __construct( $prefix = null, $url = '', $api = '', $wikiId = '', $local = 0, $trans = 0 ) {
  22                 $this->mPrefix = $prefix;
  23                 $this->mURL = $url;
  24                 $this->mAPI = $api;
  25                 $this->mWikiID = $wikiId;
  26                 $this->mLocal = $local;
  27                 $this->mTrans = $trans;
  28         }
  29
  30         /**
  31          * Check whether an interwiki prefix exists
  32          *
  33          * @param $prefix String: interwiki prefix to use
  34          * @return Boolean: whether it exists
  35          */
  36         static public function isValidInterwiki( $prefix ) {
  37                 $result = self::fetch( $prefix );
  38                 return (bool)$result;
  39         }
  40
  41         /**
  42          * Fetch an Interwiki object
  43          *
  44          * @param $prefix String: interwiki prefix to use
  45          * @return Interwiki Object, or null if not valid
  46          */
  47         static public function fetch( $prefix ) {
  48                 global $wgContLang;
  49                 if( $prefix == '' ) {
  50                         return null;
  51                 }
  52                 $prefix = $wgContLang->lc( $prefix );
  53                 if( isset( self::$smCache[$prefix] ) ) {
  54                         return self::$smCache[$prefix];
  55                 }
  56                 global $wgInterwikiCache;
  57                 if( $wgInterwikiCache ) {
  58                         $iw = Interwiki::getInterwikiCached( $prefix );
  59                 } else {
  60                         $iw = Interwiki::load( $prefix );
  61                         if( !$iw ) {
  62                                 $iw = false;
  63                         }
  64                 }
  65                 if( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ) {
  66                         reset( self::$smCache );
  67                         unset( self::$smCache[key( self::$smCache )] );
  68                 }
  69                 self::$smCache[$prefix] = $iw;
  70                 return $iw;
  71         }
  72
  73         /**
  74          * Fetch interwiki prefix data from local cache in constant database.
  75          *
  76          * @note More logic is explained in DefaultSettings.
  77          *
  78          * @param $prefix String: interwiki prefix
  79          * @return Interwiki object
  80          */
  81         protected static function getInterwikiCached( $prefix ) {
  82                 $value = self::getInterwikiCacheEntry( $prefix );
  83
  84                 $s = new Interwiki( $prefix );
  85                 if ( $value != '' ) {
  86                         // Split values
  87                         list( $local, $url ) = explode( ' ', $value, 2 );
  88                         $s->mURL = $url;
  89                         $s->mLocal = (int)$local;
  90                 } else {
  91                         $s = false;
  92                 }
  93                 return $s;
  94         }
  95
  96         /**
  97          * Get entry from interwiki cache
  98          *
  99          * @note More logic is explained in DefaultSettings.
 100          *
 101          * @param $prefix String: database key
 102          * @return String: the entry
 103          */
 104         protected static function getInterwikiCacheEntry( $prefix ) {
 105                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 106                 static $db, $site;
 107
 108                 wfDebug( __METHOD__ . "( $prefix )\n" );
 109                 if( !$db ) {
 110                         $db = CdbReader::open( $wgInterwikiCache );
 111                 }
 112                 /* Resolve site name */
 113                 if( $wgInterwikiScopes >= 3 && !$site ) {
 114                         $site = $db->get( '__sites:' . wfWikiID() );
 115                         if ( $site == '' ) {
 116                                 $site = $wgInterwikiFallbackSite;
 117                         }
 118                 }
 119
 120                 $value = $db->get( wfMemcKey( $prefix ) );
 121                 // Site level
 122                 if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 123                         $value = $db->get( "_{$site}:{$prefix}" );
 124                 }
 125                 // Global Level
 126                 if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 127                         $value = $db->get( "__global:{$prefix}" );
 128                 }
 129                 if ( $value == 'undef' ) {
 130                         $value = '';
 131                 }
 132
 133                 return $value;
 134         }
 135
 136         /**
 137          * Load the interwiki, trying first memcached then the DB
 138          *
 139          * @param $prefix The interwiki prefix
 140          * @return Boolean: the prefix is valid
 141          */
 142         protected static function load( $prefix ) {
 143                 global $wgMemc, $wgInterwikiExpiry;
 144
 145                 $iwData = false;
 146                 if ( !wfRunHooks( 'InterwikiLoadPrefix', array( $prefix, &$iwData ) ) ) {
 147                         return Interwiki::loadFromArray( $iwData );
 148                 }
 149
 150                 if ( !$iwData ) {
 151                         $key = wfMemcKey( 'interwiki', $prefix );
 152                         $iwData = $wgMemc->get( $key );
 153                 }
 154
 155                 if( $iwData && is_array( $iwData ) ) { // is_array is hack for old keys
 156                         $iw = Interwiki::loadFromArray( $iwData );
 157                         if( $iw ) {
 158                                 return $iw;
 159                         }
 160                 }
 161
 162                 $db = wfGetDB( DB_SLAVE );
 163
 164                 $row = $db->fetchRow( $db->select( 'interwiki', '*', array( 'iw_prefix' => $prefix ),
 165                         __METHOD__ ) );
 166                 $iw = Interwiki::loadFromArray( $row );
 167                 if ( $iw ) {
 168                         $mc = array(
 169                                 'iw_url' => $iw->mURL,
 170                                 'iw_api' => $iw->mAPI,
 171                                 'iw_local' => $iw->mLocal,
 172                                 'iw_trans' => $iw->mTrans
 173                         );
 174                         $wgMemc->add( $key, $mc, $wgInterwikiExpiry );
 175                         return $iw;
 176                 }
 177
 178                 return false;
 179         }
 180
 181         /**
 182          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 183          *
 184          * @param $mc Associative array: row from the interwiki table
 185          * @return Boolean: whether everything was there
 186          */
 187         protected static function loadFromArray( $mc ) {
 188                 if( isset( $mc['iw_url'] ) ) {
 189                         $iw = new Interwiki();
 190                         $iw->mURL = $mc['iw_url'];
 191                         $iw->mLocal = isset( $mc['iw_local'] ) ? $mc['iw_local'] : 0;
 192                         $iw->mTrans = isset( $mc['iw_trans'] ) ? $mc['iw_trans'] : 0;
 193                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 194                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 195
 196                         return $iw;
 197                 }
 198                 return false;
 199         }
 200
 201         /**
 202          * Fetch all interwiki prefixes from interwiki cache
 203          *
 204          * @param $local If not null, limits output to local/non-local interwikis
 205          * @return Array List of prefixes
 206          * @since 1.19
 207          */
 208         protected static function getAllPrefixesCached( $local ) {
 209                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 210                 static $db, $site;
 211
 212                 wfDebug( __METHOD__ . "()\n" );
 213                 if( !$db ) {
 214                         $db = CdbReader::open( $wgInterwikiCache );
 215                 }
 216                 /* Resolve site name */
 217                 if( $wgInterwikiScopes >= 3 && !$site ) {
 218                         $site = $db->get( '__sites:' . wfWikiID() );
 219                         if ( $site == '' ) {
 220                                 $site = $wgInterwikiFallbackSite;
 221                         }
 222                 }
 223
 224                 // List of interwiki sources
 225                 $sources = array();
 226                 // Global Level
 227                 if ( $wgInterwikiScopes >= 2 ) {
 228                         $sources[] = '__global';
 229                 }
 230                 // Site level
 231                 if ( $wgInterwikiScopes >= 3 ) {
 232                         $sources[] = '_' . $site;
 233                 }
 234                 $sources[] = wfWikiID();
 235
 236                 $data = array();
 237
 238                 foreach( $sources as $source ) {
 239                         $list = $db->get( "__list:{$source}" );
 240                         foreach ( explode( ' ', $list ) as $iw_prefix ) {
 241                                 $row = $db->get( "{$source}:{$iw_prefix}" );
 242                                 if( !$row ) {
 243                                         continue;
 244                                 }
 245
 246                                 list( $iw_local, $iw_url ) = explode( ' ', $row );
 247
 248                                 if ( $local !== null && $local != $iw_local ) {
 249                                         continue;
 250                                 }
 251
 252                                 $data[$iw_prefix] = array(
 253                                         'iw_prefix' => $iw_prefix,
 254                                         'iw_url'    => $iw_url,
 255                                         'iw_local'  => $iw_local,
 256                                 );
 257                         }
 258                 }
 259
 260                 ksort( $data );
 261
 262                 return array_values( $data );
 263         }
 264
 265         /**
 266          * Fetch all interwiki prefixes from DB
 267          *
 268          * @param $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 getAllPrefixesDB( $local ) {
 273                 $db = wfGetDB( DB_SLAVE );
 274
 275                 $where = array();
 276
 277                 if ( $local !== null ) {
 278                         if ( $local == 1 ) {
 279                                 $where['iw_local'] = 1;
 280                         } elseif ( $local == 0 ) {
 281                                 $where['iw_local'] = 0;
 282                         }
 283                 }
 284
 285                 $res = $db->select( 'interwiki',
 286                         array( 'iw_prefix', 'iw_url', 'iw_api', 'iw_wikiid', 'iw_local', 'iw_trans' ),
 287                         $where, __METHOD__, array( 'ORDER BY' => 'iw_prefix' )
 288                 );
 289                 $retval = array();
 290                 foreach ( $res as $row ) {
 291                         $retval[] = (array)$row;
 292                 }
 293                 return $retval;
 294         }
 295
 296         /**
 297          * Returns all interwiki prefixes
 298          *
 299          * @param $local If set, limits output to local/non-local interwikis
 300          * @return Array List of prefixes
 301          * @since 1.19
 302          */
 303         public static function getAllPrefixes( $local = null ) {
 304                 global $wgInterwikiCache;
 305
 306                 if ( $wgInterwikiCache ) {
 307                         return self::getAllPrefixesCached( $local );
 308                 } else {
 309                         return self::getAllPrefixesDB( $local );
 310                 }
 311         }
 312
 313         /**
 314          * Get the URL for a particular title (or with $1 if no title given)
 315          *
 316          * @param $title String: what text to put for the article name
 317          * @return String: the URL
 318          * @note Prior to 1.19 The getURL with an argument was broken.
 319          *       If you if you use this arg in an extension that supports MW earlier
 320          *       than 1.19 please wfUrlencode and substitute $1 on your own.
 321          */
 322         public function getURL( $title = null ) {
 323                 $url = $this->mURL;
 324                 if( $title !== null ) {
 325                         $url = str_replace( "$1", wfUrlencode( $title ), $url );
 326                 }
 327                 return $url;
 328         }
 329
 330         /**
 331          * Get the API URL for this wiki
 332          *
 333          * @return String: the URL
 334          */
 335         public function getAPI() {
 336                 return $this->mAPI;
 337         }
 338
 339         /**
 340          * Get the DB name for this wiki
 341          *
 342          * @return String: the DB name
 343          */
 344         public function getWikiID() {
 345                 return $this->mWikiID;
 346         }
 347
 348         /**
 349          * Is this a local link from a sister project, or is
 350          * it something outside, like Google
 351          *
 352          * @return Boolean
 353          */
 354         public function isLocal() {
 355                 return $this->mLocal;
 356         }
 357
 358         /**
 359          * Can pages from this wiki be transcluded?
 360          * Still requires $wgEnableScaryTransclusion
 361          *
 362          * @return Boolean
 363          */
 364         public function isTranscludable() {
 365                 return $this->mTrans;
 366         }
 367
 368         /**
 369          * Get the name for the interwiki site
 370          *
 371          * @return String
 372          */
 373         public function getName() {
 374                 $msg = wfMessage( 'interwiki-name-' . $this->mPrefix )->inContentLanguage();
 375                 return !$msg->exists() ? '' : $msg;
 376         }
 377
 378         /**
 379          * Get a description for this interwiki
 380          *
 381          * @return String
 382          */
 383         public function getDescription() {
 384                 $msg = wfMessage( 'interwiki-desc-' . $this->mPrefix )->inContentLanguage();
 385                 return !$msg->exists() ? '' : $msg;
 386         }
 387 }