includes/LinkCache.php

   1 <?
   2 # Cache for article titles and ids linked from one source
   3
   4 # These are used in incrementalSetup()
   5 define ('LINKCACHE_GOOD', 0);
   6 define ('LINKCACHE_BAD', 1);
   7 define ('LINKCACHE_IMAGE', 2);
   8
   9 class LinkCache {
  10
  11         /* private */ var $mGoodLinks, $mBadLinks, $mActive;
  12         /* private */ var $mImageLinks;
  13         /* private */ var $mPreFilled, $mOldGoodLinks, $mOldBadLinks;
  14
  15         /* private */ function getKey( $title ) {
  16                 global $wgDBname;
  17                 return "$wgDBname:lc:title:$title";
  18         }
  19
  20         function LinkCache()
  21         {
  22                 $this->mActive = true;
  23                 $this->mPreFilled = false;
  24                 $this->mGoodLinks = array();
  25                 $this->mBadLinks = array();
  26                 $this->mImageLinks = array();
  27                 $this->mOldGoodLinks = array();
  28                 $this->mOldBadLinks = array();
  29         }
  30
  31         function getGoodLinkID( $title )
  32         {
  33                 if ( array_key_exists( $title, $this->mGoodLinks ) ) {
  34                         return $this->mGoodLinks[$title];
  35                 } else {
  36                         return 0;
  37                 }
  38         }
  39
  40         function isBadLink( $title )
  41         {
  42                 return in_array( $title, $this->mBadLinks );
  43         }
  44
  45         function addGoodLink( $id, $title )
  46         {
  47                 if ( $this->mActive ) {
  48                         $this->mGoodLinks[$title] = $id;
  49                 }
  50         }
  51
  52         function addBadLink( $title )
  53         {
  54                 if ( $this->mActive && ( ! $this->isBadLink( $title ) ) ) {
  55                         array_push( $this->mBadLinks, $title );
  56                 }
  57         }
  58
  59         function addImageLink( $title )
  60         {
  61                 if ( $this->mActive ) { $this->mImageLinks[$title] = 1; }
  62         }
  63
  64         function addImageLinkObj( $nt )
  65         {
  66                 if ( $this->mActive ) { $this->mImageLinks[$nt->getDBkey()] = 1; }
  67         }
  68
  69         function clearBadLink( $title )
  70         {
  71                 $index = array_search( $title, $this->mBadLinks );
  72                 if ( isset( $index ) ) {
  73                         unset( $this->mBadLinks[$index] );
  74                 }
  75                 $this->clearLink( $title );
  76         }
  77
  78         function clearLink( $title )
  79         {
  80                 global $wgMemc, $wgLinkCacheMemcached;
  81                 if( $wgLinkCacheMemcached )
  82                         $wgMemc->delete( $this->getKey( $title ) );
  83         }
  84
  85         function suspend() { $this->mActive = false; }
  86         function resume() { $this->mActive = true; }
  87         function getGoodLinks() { return $this->mGoodLinks; }
  88         function getBadLinks() { return $this->mBadLinks; }
  89         function getImageLinks() { return $this->mImageLinks; }
  90
  91         function addLink( $title )
  92         {
  93                 $nt = Title::newFromDBkey( $title );
  94                 if( $nt ) {
  95                         return $this->addLinkObj( $nt );
  96                 } else {
  97                         return 0;
  98                 }
  99         }
 100
 101         function addLinkObj( &$nt )
 102         {
 103                 $title = $nt->getPrefixedDBkey();
 104                 if ( $this->isBadLink( $title ) ) { return 0; }
 105                 $id = $this->getGoodLinkID( $title );
 106                 if ( 0 != $id ) { return $id; }
 107
 108                 global $wgMemc;
 109                 $fname = "LinkCache::addLinkObj";
 110                 wfProfileIn( $fname );
 111
 112                 $ns = $nt->getNamespace();
 113                 $t = $nt->getDBkey();
 114
 115                 if ( "" == $title ) {
 116                         wfProfileOut( $fname );
 117                         return 0;
 118                 }
 119
 120                 $id = FALSE;
 121                 if( $wgLinkCacheMemcached )
 122                         $id = $wgMemc->get( $key = $this->getKey( $title ) );
 123
 124                 if( $id === FALSE ) {
 125                         $sql = "SELECT cur_id FROM cur WHERE cur_namespace=" .
 126                           "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
 127                         $res = wfQuery( $sql, DB_READ, "LinkCache::addLink" );
 128
 129                         if ( 0 == wfNumRows( $res ) ) {
 130                                 $id = 0;
 131                         } else {
 132                                 $s = wfFetchObject( $res );
 133                                 $id = $s->cur_id;
 134                         }
 135                         if( $wgLinkCacheMemcached )
 136                                 $wgMemc->add( $key, $id, time()+3600 );
 137                 }
 138                 if ( 0 == $id ) { $this->addBadLink( $title ); }
 139                 else { $this->addGoodLink( $id, $title ); }
 140                 wfProfileOut( $fname );
 141                 return $id;
 142         }
 143
 144         function preFill( &$fromtitle )
 145         {
 146                 global $wgEnablePersistentLC;
 147
 148                 $fname = "LinkCache::preFill";
 149                 wfProfileIn( $fname );
 150                 # Note -- $fromtitle is a Title *object*
 151                 $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
 152
 153                 if ( $wgEnablePersistentLC ) {
 154                         $res = wfQuery("SELECT lcc_cacheobj FROM linkscc WHERE lcc_title = '{$dbkeyfrom}'",
 155                                 DB_READ);
 156                         $row = wfFetchObject( $res );
 157                         if( $row != FALSE){
 158                                 $cacheobj = gzuncompress( $row->lcc_cacheobj );
 159                                 $cc = unserialize( $cacheobj );
 160                                 $this->mGoodLinks = $cc->mGoodLinks;
 161                                 $this->mBadLinks = $cc->mBadLinks;
 162                                 $this->mPreFilled = true;
 163                                 wfProfileOut( $fname );
 164                                 return;
 165                         }
 166                 }
 167
 168
 169                 $sql = "SELECT cur_id,cur_namespace,cur_title
 170                         FROM cur,links
 171                         WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
 172                 $res = wfQuery( $sql, DB_READ, $fname );
 173                 while( $s = wfFetchObject( $res ) ) {
 174                         $this->addGoodLink( $s->cur_id,
 175                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 176                                 );
 177                 }
 178
 179                 $this->suspend();
 180                 $id = $fromtitle->getArticleID();
 181                 $this->resume();
 182
 183                 $sql = "SELECT bl_to
 184                         FROM brokenlinks
 185                         WHERE bl_from='{$id}'";
 186                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 187                 while( $s = wfFetchObject( $res ) ) {
 188                         $this->addBadLink( $s->bl_to );
 189                 }
 190
 191                 $this->mOldBadLinks = $this->mBadLinks;
 192                 $this->mOldGoodLinks = $this->mGoodLinks;
 193                 $this->mPreFilled = true;
 194
 195                 if ( $wgEnablePersistentLC ) {
 196                         // put fetched link data into cache
 197                         $serCachegz = wfStrencode( gzcompress( serialize( $this ), 3) );
 198                         wfQuery("REPLACE INTO linkscc VALUES({$id}, '{$dbkeyfrom}', '{$serCachegz}')",
 199                                 DB_WRITE);
 200                 }
 201
 202                 wfProfileOut( $fname );
 203         }
 204
 205         function getGoodAdditions()
 206         {
 207                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 208         }
 209
 210         function getBadAdditions()
 211         {
 212                 return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
 213         }
 214
 215         function getImageAdditions()
 216         {
 217                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 218         }
 219
 220         function getGoodDeletions()
 221         {
 222                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 223         }
 224
 225         function getBadDeletions()
 226         {
 227                 return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
 228         }
 229
 230         function getImageDeletions()
 231         {
 232                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 233         }
 234
 235         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 236         # the incremental update arrays which will be filled. Returns whether or not it's
 237         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 238         # was blanked, it would take a long, long time to do incrementally.
 239         function incrementalSetup( $which, &$del, &$add )
 240         {
 241                 if ( ! $this->mPreFilled ) {
 242                         return false;
 243                 }
 244
 245                 switch ( $which ) {
 246                         case LINKCACHE_GOOD:
 247                                 $old =& $this->mOldGoodLinks;
 248                                 $cur =& $this->mGoodLinks;
 249                                 $del = $this->getGoodDeletions();
 250                                 $add = $this->getGoodAdditions();
 251                                 break;
 252                         case LINKCACHE_BAD:
 253                                 $old =& $this->mOldBadLinks;
 254                                 $cur =& $this->mBadLinks;
 255                                 $del = $this->getBadDeletions();
 256                                 $add = $this->getBadAdditions();
 257                                 break;
 258                         default: # LINKCACHE_IMAGE
 259                                 return false;
 260                 }
 261
 262                 return true;
 263         }
 264
 265         # Clears cache but leaves old preFill copies alone
 266         function clear()
 267         {
 268                 $this->mGoodLinks = array();
 269                 $this->mBadLinks = array();
 270                 $this->mImageLinks = array();
 271         }
 272
 273 }
 274 ?>