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, $mAPI, $mWikiID, $mLocal, $mTrans;
  19
  20         public function __construct( $prefix = null, $url = '', $api = '', $wikiid = '', $local = 0, $trans = 0 ) {
  21                 $this->mPrefix = $prefix;
  22                 $this->mURL = $url;
  23                 $this->mAPI = $api;
  24                 $this->mWikiID = $wikiid;
  25                 $this->mLocal = $local;
  26                 $this->mTrans = $trans;
  27         }
  28
  29         /**
  30          * Check whether an interwiki prefix exists
  31          *
  32          * @param $prefix String: interwiki prefix to use
  33          * @return Boolean: whether it exists
  34          */
  35         static public function isValidInterwiki( $prefix ) {
  36                 $result = self::fetch( $prefix );
  37                 return (bool)$result;
  38         }
  39
  40         /**
  41          * Fetch an Interwiki object
  42          *
  43          * @param $prefix String: interwiki prefix to use
  44          * @return Interwiki Object, or null if not valid
  45          */
  46         static public function fetch( $prefix ) {
  47                 global $wgContLang;
  48                 if( $prefix == '' ) {
  49                         return null;
  50                 }
  51                 $prefix = $wgContLang->lc( $prefix );
  52                 if( isset( self::$smCache[$prefix] ) ) {
  53                         return self::$smCache[$prefix];
  54                 }
  55                 global $wgInterwikiCache;
  56                 if( $wgInterwikiCache ) {
  57                         $iw = Interwiki::getInterwikiCached( $prefix );
  58                 } else {
  59                         $iw = Interwiki::load( $prefix );
  60                         if( !$iw ) {
  61                                 $iw = false;
  62                         }
  63                 }
  64                 if( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ) {
  65                         reset( self::$smCache );
  66                         unset( self::$smCache[ key( self::$smCache ) ] );
  67                 }
  68                 self::$smCache[$prefix] = $iw;
  69                 return $iw;
  70         }
  71
  72         /**
  73          * Fetch interwiki prefix data from local cache in constant database.
  74          *
  75          * @note More logic is explained in DefaultSettings.
  76          *
  77          * @param $prefix String: interwiki prefix
  78          * @return Interwiki object
  79          */
  80         protected static function getInterwikiCached( $prefix ) {
  81                 $value = self::getInterwikiCacheEntry( $prefix );
  82
  83                 $s = new Interwiki( $prefix );
  84                 if ( $value != '' ) {
  85                         // Split values
  86                         list( $local, $url ) = explode( ' ', $value, 2 );
  87                         $s->mURL = $url;
  88                         $s->mLocal = (int)$local;
  89                 } else {
  90                         $s = false;
  91                 }
  92                 return $s;
  93         }
  94
  95         /**
  96          * Get entry from interwiki cache
  97          *
  98          * @note More logic is explained in DefaultSettings.
  99          *
 100          * @param $prefix String: database key
 101          * @return String: the entry
 102          */
 103         protected static function getInterwikiCacheEntry( $prefix ) {
 104                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 105                 static $db, $site;
 106
 107                 wfDebug( __METHOD__ . "( $prefix )\n" );
 108                 if( !$db ) {
 109                         $db = CdbReader::open( $wgInterwikiCache );
 110                 }
 111                 /* Resolve site name */
 112                 if( $wgInterwikiScopes>=3 && !$site ) {
 113                         $site = $db->get( '__sites:' . wfWikiID() );
 114                         if ( $site == '' ) {
 115                                 $site = $wgInterwikiFallbackSite;
 116                         }
 117                 }
 118
 119                 $value = $db->get( wfMemcKey( $prefix ) );
 120                 // Site level
 121                 if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 122                         $value = $db->get( "_{$site}:{$prefix}" );
 123                 }
 124                 // Global Level
 125                 if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 126                         $value = $db->get( "__global:{$prefix}" );
 127                 }
 128                 if ( $value == 'undef' )
 129                         $value = '';
 130
 131                 return $value;
 132         }
 133
 134         /**
 135          * Load the interwiki, trying first memcached then the DB
 136          *
 137          * @param $prefix The interwiki prefix
 138          * @return Boolean: the prefix is valid
 139          */
 140         protected static function load( $prefix ) {
 141                 global $wgMemc, $wgInterwikiExpiry;
 142                 $key = wfMemcKey( 'interwiki', $prefix );
 143                 $mc = $wgMemc->get( $key );
 144                 $iw = false;
 145                 if( $mc && is_array( $mc ) ) { // is_array is hack for old keys
 146                         $iw = Interwiki::loadFromArray( $mc );
 147                         if( $iw ) {
 148                                 return $iw;
 149                         }
 150                 }
 151
 152                 $db = wfGetDB( DB_SLAVE );
 153
 154                 $row = $db->fetchRow( $db->select( 'interwiki', '*', array( 'iw_prefix' => $prefix ),
 155                         __METHOD__ ) );
 156                 $iw = Interwiki::loadFromArray( $row );
 157                 if ( $iw ) {
 158                         $mc = array( 'iw_url' => $iw->mURL, 'iw_api' => $iw->mAPI, 'iw_local' => $iw->mLocal, 'iw_trans' => $iw->mTrans );
 159                         $wgMemc->add( $key, $mc, $wgInterwikiExpiry );
 160                         return $iw;
 161                 }
 162
 163                 return false;
 164         }
 165
 166         /**
 167          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 168          *
 169          * @param $mc Associative array: row from the interwiki table
 170          * @return Boolean: whether everything was there
 171          */
 172         protected static function loadFromArray( $mc ) {
 173                 if( isset( $mc['iw_url'] ) && isset( $mc['iw_local'] ) && isset( $mc['iw_trans'] ) ) {
 174                         $iw = new Interwiki();
 175                         $iw->mURL = $mc['iw_url'];
 176                         $iw->mLocal = $mc['iw_local'];
 177                         $iw->mTrans = $mc['iw_trans'];
 178                         $iw->mAPI = isset( $mc['iw_api'] ) ? $mc['iw_api'] : '';
 179                         $iw->mWikiID = isset( $mc['iw_wikiid'] ) ? $mc['iw_wikiid'] : '';
 180
 181                         return $iw;
 182                 }
 183                 return false;
 184         }
 185
 186         /**
 187          * Get the URL for a particular title (or with $1 if no title given)
 188          *
 189          * @param $title String: what text to put for the article name
 190          * @return String: the URL
 191          */
 192         public function getURL( $title = null ) {
 193                 $url = $this->mURL;
 194                 if( $title != null ) {
 195                         $url = str_replace( "$1", $title, $url );
 196                 }
 197                 return $url;
 198         }
 199
 200         /**
 201          * Get the API URL for this wiki
 202          *
 203          * @return String: the URL
 204          */
 205         public function getAPI( ) {
 206                 return $this->mAPI;
 207         }
 208
 209         /**
 210          * Get the DB name for this wiki
 211          *
 212          * @return String: the DB name
 213          */
 214         public function getWikiID( ) {
 215                 return $this->mWikiID;
 216         }
 217
 218         /**
 219          * Is this a local link from a sister project, or is
 220          * it something outside, like Google
 221          *
 222          * @return Boolean
 223          */
 224         public function isLocal() {
 225                 return $this->mLocal;
 226         }
 227
 228         /**
 229          * Can pages from this wiki be transcluded?
 230          * Still requires $wgEnableScaryTransclusion
 231          *
 232          * @return Boolean
 233          */
 234         public function isTranscludable() {
 235                 return $this->mTrans;
 236         }
 237
 238         /**
 239          * Get the name for the interwiki site
 240          *
 241          * @return String
 242          */
 243         public function getName() {
 244                 $key = 'interwiki-name-' . $this->mPrefix;
 245                 $msg = wfMsgForContent( $key );
 246                 return wfEmptyMsg( $key, $msg ) ? '' : $msg;
 247         }
 248
 249         /**
 250          * Get a description for this interwiki
 251          *
 252          * @return String
 253          */
 254         public function getDescription() {
 255                 $key = 'interwiki-desc-' . $this->mPrefix;
 256                 $msg = wfMsgForContent( $key );
 257                 return wfEmptyMsg( $key, $msg ) ? '' : $msg;
 258         }
 259 }