includes/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                 $key = wfMemcKey( 'interwiki', $prefix );
 145                 $mc = $wgMemc->get( $key );
 146
 147                 if( $mc && is_array( $mc ) ) { // is_array is hack for old keys
 148                         $iw = Interwiki::loadFromArray( $mc );
 149                         if( $iw ) {
 150                                 return $iw;
 151                         }
 152                 }
 153
 154                 $db = wfGetDB( DB_SLAVE );
 155
 156                 $row = $db->fetchRow( $db->select( 'interwiki', '*', array( 'iw_prefix' => $prefix ),
 157                         __METHOD__ ) );
 158                 $iw = Interwiki::loadFromArray( $row );
 159                 if ( $iw ) {
 160                         $mc = array(
 161                                 'iw_url' => $iw->mURL,
 162                                 'iw_api' => $iw->mAPI,
 163                                 'iw_local' => $iw->mLocal,
 164                                 'iw_trans' => $iw->mTrans
 165                         );
 166                         $wgMemc->add( $key, $mc, $wgInterwikiExpiry );
 167                         return $iw;
 168                 }
 169
 170                 return false;
 171         }
 172
 173         /**
 174          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 175          *
 176          * @param $mc Associative array: row from the interwiki table
 177          * @return Boolean: whether everything was there
 178          */
 179         protected static function loadFromArray( $mc ) {
 180                 if( isset( $mc['iw_url'] ) && isset( $mc['iw_local'] ) && isset( $mc['iw_trans'] ) ) {
 181                         $iw = new Interwiki();
 182                         $iw->mURL = $mc['iw_url'];
 183                         $iw->mLocal = $mc['iw_local'];
 184                         $iw->mTrans = $mc['iw_trans'];
 185                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 186                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 187
 188                         return $iw;
 189                 }
 190                 return false;
 191         }
 192
 193         /**
 194          * Get the URL for a particular title (or with $1 if no title given)
 195          *
 196          * @param $title String: what text to put for the article name
 197          * @return String: the URL
 198          */
 199         public function getURL( $title = null ) {
 200                 $url = $this->mURL;
 201                 if( $title != null ) {
 202                         $url = str_replace( "$1", $title, $url );
 203                 }
 204                 return $url;
 205         }
 206
 207         /**
 208          * Get the API URL for this wiki
 209          *
 210          * @return String: the URL
 211          */
 212         public function getAPI() {
 213                 return $this->mAPI;
 214         }
 215
 216         /**
 217          * Get the DB name for this wiki
 218          *
 219          * @return String: the DB name
 220          */
 221         public function getWikiID() {
 222                 return $this->mWikiID;
 223         }
 224
 225         /**
 226          * Is this a local link from a sister project, or is
 227          * it something outside, like Google
 228          *
 229          * @return Boolean
 230          */
 231         public function isLocal() {
 232                 return $this->mLocal;
 233         }
 234
 235         /**
 236          * Can pages from this wiki be transcluded?
 237          * Still requires $wgEnableScaryTransclusion
 238          *
 239          * @return Boolean
 240          */
 241         public function isTranscludable() {
 242                 return $this->mTrans;
 243         }
 244
 245         /**
 246          * Get the name for the interwiki site
 247          *
 248          * @return String
 249          */
 250         public function getName() {
 251                 $key = 'interwiki-name-' . $this->mPrefix;
 252                 $msg = wfMsgForContent( $key );
 253                 return wfEmptyMsg( $key, $msg ) ? '' : $msg;
 254         }
 255
 256         /**
 257          * Get a description for this interwiki
 258          *
 259          * @return String
 260          */
 261         public function getDescription() {
 262                 $key = 'interwiki-desc-' . $this->mPrefix;
 263                 $msg = wfMsgForContent( $key );
 264                 return wfEmptyMsg( $key, $msg ) ? '' : $msg;
 265         }
 266 }