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 schema updates etc, which arent wiki-related)
  11  */
  12 class Interwiki {
  13
  14         // Cache - removes oldest entry when it hits limit
  15         protected static $smCache = array();
  16         const CACHE_LIMIT = 100; // 0 means unlimited, any other value is max number of entries.
  17
  18         protected $mPrefix, $mURL, $mLocal, $mTrans;
  19
  20         public function __construct( $prefix = null, $url = '', $local = 0, $trans = 0 ) {
  21                 $this->mPrefix = $prefix;
  22                 $this->mURL = $url;
  23                 $this->mLocal = $local;
  24                 $this->mTrans = $trans;
  25         }
  26
  27         /**
  28          * Check whether an interwiki prefix exists
  29          *
  30          * @param $prefix String: interwiki prefix to use
  31          * @return Boolean: whether it exists
  32          */
  33         static public function isValidInterwiki( $prefix ) {
  34                 $result = self::fetch( $prefix );
  35                 return (bool)$result;
  36         }
  37
  38         /**
  39          * Fetch an Interwiki object
  40          *
  41          * @param $prefix String: interwiki prefix to use
  42          * @return Interwiki Object, or null if not valid
  43          */
  44         static public function fetch( $prefix ) {
  45                 global $wgContLang;
  46                 if( $prefix == '' ) {
  47                         return null;
  48                 }
  49                 $prefix = $wgContLang->lc( $prefix );
  50                 if( isset( self::$smCache[$prefix] ) ) {
  51                         return self::$smCache[$prefix];
  52                 }
  53                 global $wgInterwikiCache;
  54                 if( $wgInterwikiCache ) {
  55                         $iw = Interwiki::getInterwikiCached( $prefix );
  56                 } else {
  57                         $iw = Interwiki::load( $prefix );
  58                         if( !$iw ) {
  59                                 $iw = false;
  60                         }
  61                 }
  62                 if( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ) {
  63                         reset( self::$smCache );
  64                         unset( self::$smCache[ key( self::$smCache ) ] );
  65                 }
  66                 self::$smCache[$prefix] = $iw;
  67                 return $iw;
  68         }
  69
  70         /**
  71          * Fetch interwiki prefix data from local cache in constant database.
  72          *
  73          * @note More logic is explained in DefaultSettings.
  74          *
  75          * @param $prefix String: interwiki prefix
  76          * @return Interwiki object
  77          */
  78         protected static function getInterwikiCached( $prefix ) {
  79                 $value = self::getInterwikiCacheEntry( $prefix );
  80
  81                 $s = new Interwiki( $prefix );
  82                 if ( $value != '' ) {
  83                         // Split values
  84                         list( $local, $url ) = explode( ' ', $value, 2 );
  85                         $s->mURL = $url;
  86                         $s->mLocal = (int)$local;
  87                 } else {
  88                         $s = false;
  89                 }
  90                 return $s;
  91         }
  92
  93         /**
  94          * Get entry from interwiki cache
  95          *
  96          * @note More logic is explained in DefaultSettings.
  97          *
  98          * @param $prefix String: database key
  99          * @return String: the entry
 100          */
 101         protected static function getInterwikiCacheEntry( $prefix ) {
 102                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 103                 static $db, $site;
 104
 105                 wfDebug( __METHOD__ . "( $prefix )\n" );
 106                 if( !$db ) {
 107                         $db = CdbReader::open( $wgInterwikiCache );
 108                 }
 109                 /* Resolve site name */
 110                 if( $wgInterwikiScopes>=3 && !$site ) {
 111                         $site = $db->get( '__sites:' . wfWikiID() );
 112                         if ( $site == '' ) {
 113                                 $site = $wgInterwikiFallbackSite;
 114                         }
 115                 }
 116
 117                 $value = $db->get( wfMemcKey( $prefix ) );
 118                 // Site level
 119                 if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 120                         $value = $db->get( "_{$site}:{$prefix}" );
 121                 }
 122                 // Global Level
 123                 if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 124                         $value = $db->get( "__global:{$prefix}" );
 125                 }
 126                 if ( $value == 'undef' )
 127                         $value = '';
 128
 129                 return $value;
 130         }
 131
 132         /**
 133          * Load the interwiki, trying first memcached then the DB
 134          *
 135          * @param $prefix The interwiki prefix
 136          * @return Boolean: the prefix is valid
 137          */
 138         protected static function load( $prefix ) {
 139                 global $wgMemc, $wgInterwikiExpiry;
 140                 $key = wfMemcKey( 'interwiki', $prefix );
 141                 $mc = $wgMemc->get( $key );
 142                 $iw = false;
 143                 if( $mc && is_array( $mc ) ) { // is_array is hack for old keys
 144                         $iw = Interwiki::loadFromArray( $mc );
 145                         if( $iw ) {
 146                                 return $iw;
 147                         }
 148                 }
 149
 150                 $db = wfGetDB( DB_SLAVE );
 151
 152                 $row = $db->fetchRow( $db->select( 'interwiki', '*', array( 'iw_prefix' => $prefix ),
 153                         __METHOD__ ) );
 154                 $iw = Interwiki::loadFromArray( $row );
 155                 if ( $iw ) {
 156                         $mc = array( 'iw_url' => $iw->mURL, 'iw_local' => $iw->mLocal, 'iw_trans' => $iw->mTrans );
 157                         $wgMemc->add( $key, $mc, $wgInterwikiExpiry );
 158                         return $iw;
 159                 }
 160
 161                 return false;
 162         }
 163
 164         /**
 165          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 166          *
 167          * @param $mc Associative array: row from the interwiki table
 168          * @return Boolean: whether everything was there
 169          */
 170         protected static function loadFromArray( $mc ) {
 171                 if( isset( $mc['iw_url'] ) && isset( $mc['iw_local'] ) && isset( $mc['iw_trans'] ) ) {
 172                         $iw = new Interwiki();
 173                         $iw->mURL = $mc['iw_url'];
 174                         $iw->mLocal = $mc['iw_local'];
 175                         $iw->mTrans = $mc['iw_trans'];
 176                         return $iw;
 177                 }
 178                 return false;
 179         }
 180
 181         /**
 182          * Get the URL for a particular title (or with $1 if no title given)
 183          *
 184          * @param $title String: what text to put for the article name
 185          * @return String: the URL
 186          */
 187         public function getURL( $title = null ) {
 188                 $url = $this->mURL;
 189                 if( $title != null ) {
 190                         $url = str_replace( "$1", $title, $url );
 191                 }
 192                 return $url;
 193         }
 194
 195         /**
 196          * Is this a local link from a sister project, or is
 197          * it something outside, like Google
 198          *
 199          * @return Boolean
 200          */
 201         public function isLocal() {
 202                 return $this->mLocal;
 203         }
 204
 205         /**
 206          * Can pages from this wiki be transcluded?
 207          * Still requires $wgEnableScaryTransclusion
 208          *
 209          * @return Boolean
 210          */
 211         public function isTranscludable() {
 212                 return $this->mTrans;
 213         }
 214
 215         /**
 216          * Get the name for the interwiki site
 217          *
 218          * @return String
 219          */
 220         public function getName() {
 221                 $key = 'interwiki-name-' . $this->mPrefix;
 222                 $msg = wfMsgForContent( $key );
 223                 return wfEmptyMsg( $key, $msg ) ? '' : $msg;
 224         }
 225
 226         /**
 227          * Get a description for this interwiki
 228          *
 229          * @return String
 230          */
 231         public function getDescription() {
 232                 $key = 'interwiki-desc-' . $this->mPrefix;
 233                 $msg = wfMsgForContent( $key );
 234                 return wfEmptyMsg( $key, $msg ) ? '' : $msg;
 235         }
 236 }