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         function __construct( $prefix = null, $url = '', $local = 0, $trans = 0 )
  21         {
  22                 $this->mPrefix = $prefix;
  23                 $this->mURL = $url;
  24                 $this->mLocal = $local;
  25                 $this->mTrans = $trans;
  26         }
  27
  28         /**
  29          * Check whether an interwiki prefix exists
  30          *
  31          * @return bool Whether it exists
  32          * @param $prefix string Interwiki prefix to use
  33          */
  34         static public function isValidInterwiki( $prefix ){
  35                 $result = self::fetch( $prefix );
  36                 return (bool)$result;
  37         }
  38
  39         /**
  40          * Fetch an Interwiki object
  41          *
  42          * @return Interwiki Object, or null if not valid
  43          * @param $prefix string Interwiki prefix to use
  44          */
  45         static public function fetch( $prefix ) {
  46                 global $wgContLang;
  47                 if( $prefix == '' ) {
  48                         return null;
  49                 }
  50                 $prefix = $wgContLang->lc( $prefix );
  51                 if( isset( self::$smCache[$prefix] ) ){
  52                         return self::$smCache[$prefix];
  53                 }
  54                 global $wgInterwikiCache;
  55                 if ($wgInterwikiCache) {
  56                         return Interwiki::getInterwikiCached( $key );
  57                 }
  58                 $iw = Interwiki::load( $prefix );
  59                 if( !$iw ){
  60                         $iw = false;
  61                 }
  62                 if( self::CACHE_LIMIT && count( self::$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 $key \type{\string} Database key
  76          * @return \type{\Interwiki} An interwiki object
  77          */
  78         protected static function getInterwikiCached( $key ) {
  79                 $value = self::getInterwikiCacheEntry( $key );
  80
  81                 $s = new Interwiki( $key );
  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                         $s = false;
  89                 }
  90                 if( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ){
  91                         reset( self::$smCache );
  92                         unset( self::$smCache[ key( self::$smCache ) ] );
  93                 }
  94                 self::$smCache[$prefix] = $s;
  95                 return $s;
  96         }
  97
  98         /**
  99          * Get entry from interwiki cache
 100          *
 101          * @note More logic is explained in DefaultSettings.
 102          *
 103          * @param $key \type{\string} Database key
 104          * @return \type{\string) The entry
 105          */
 106         protected static function getInterwikiCacheEntry( $key ){
 107                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 108                 static $db, $site;
 109
 110                 if( !$db ){
 111                         $db = dba_open( $wgInterwikiCache, 'r', 'cdb' );
 112                 }
 113                 /* Resolve site name */
 114                 if( $wgInterwikiScopes>=3 && !$site ) {
 115                         $site = dba_fetch( '__sites:' . wfWikiID(), $db );
 116                         if ( $site == "" ){
 117                                 $site = $wgInterwikiFallbackSite;
 118                         }
 119                 }
 120
 121                 $value = dba_fetch( wfMemcKey( $key ), $db );
 122                 // Site level
 123                 if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 124                         $value = dba_fetch( "_{$site}:{$key}", $db );
 125                 }
 126                 // Global Level
 127                 if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 128                         $value = dba_fetch( "__global:{$key}", $db );
 129                 }
 130                 if ( $value == 'undef' )
 131                         $value = '';
 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 bool The prefix is valid
 141          * @static
 142          *
 143          */
 144         protected static function load( $prefix ) {
 145                 global $wgMemc;
 146                 $key = wfMemcKey( 'interwiki', $prefix );
 147                 $mc = $wgMemc->get( $key );
 148                 $iw = false;
 149                 if( $mc && is_array( $mc ) ){ // is_array is hack for old keys
 150                         $iw = Interwiki::loadFromArray( $mc );
 151                         if( $iw ){
 152                                 return $iw;
 153                         }
 154                 }
 155
 156                 $db = wfGetDB( DB_SLAVE );
 157
 158                 $row = $db->fetchRow( $db->select( 'interwiki', '*', array( 'iw_prefix' => $prefix ),
 159                         __METHOD__ ) );
 160                 $iw = Interwiki::loadFromArray( $row );
 161                 if ( $iw ) {
 162                         $mc = array( 'iw_url' => $iw->mURL, 'iw_local' => $iw->mLocal, 'iw_trans' => $iw->mTrans );
 163                         $wgMemc->add( $key, $mc );
 164                         return $iw;
 165                 }
 166
 167                 return false;
 168         }
 169
 170         /**
 171          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 172          *
 173          * @return bool Whether everything was there
 174          * @param $res ResultWrapper Row from the interwiki table
 175          * @static
 176          */
 177         protected static function loadFromArray( $mc ) {
 178                 if( isset( $mc['iw_url'] ) && isset( $mc['iw_local'] ) && isset( $mc['iw_trans'] ) ){
 179                         $iw = new Interwiki();
 180                         $iw->mURL = $mc['iw_url'];
 181                         $iw->mLocal = $mc['iw_local'];
 182                         $iw->mTrans = $mc['iw_trans'];
 183                         return $iw;
 184                 }
 185                 return false;
 186         }
 187
 188         /**
 189          * Get the URL for a particular title (or with $1 if no title given)
 190          *
 191          * @param $title string What text to put for the article name
 192          * @return string The URL
 193          */
 194         function getURL( $title = null ){
 195                 $url = $this->mURL;
 196                 if( $title != null ){
 197                         $url = str_replace( "$1", $title, $url );
 198                 }
 199                 return $url;
 200         }
 201
 202         function isLocal(){
 203                 return $this->mLocal;
 204         }
 205
 206         function isTranscludable(){
 207                 return $this->mTrans;
 208         }
 209
 210 }