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