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         function LinkCache()
  16         {
  17                 $this->mActive = true;
  18                 $this->mPreFilled = false;
  19                 $this->mGoodLinks = array();
  20                 $this->mBadLinks = array();
  21                 $this->mImageLinks = array();
  22                 $this->mOldGoodLinks = array();
  23                 $this->mOldBadLinks = array();
  24         }
  25
  26         function getGoodLinkID( $title )
  27         {
  28                 if ( array_key_exists( $title, $this->mGoodLinks ) ) {
  29                         return $this->mGoodLinks[$title];
  30                 } else {
  31                         return 0;
  32                 }
  33         }
  34
  35         function isBadLink( $title )
  36         {
  37                 return in_array( $title, $this->mBadLinks );
  38         }
  39
  40         function addGoodLink( $id, $title )
  41         {
  42                 if ( $this->mActive ) {
  43                         $this->mGoodLinks[$title] = $id;
  44                 }
  45         }
  46
  47         function addBadLink( $title )
  48         {
  49                 if ( $this->mActive && ( ! $this->isBadLink( $title ) ) ) {
  50                         array_push( $this->mBadLinks, $title );
  51                 }
  52         }
  53
  54         function addImageLink( $title )
  55         {
  56                 if ( $this->mActive ) { $this->mImageLinks[$title] = 1; }
  57         }
  58
  59         function clearBadLink( $title )
  60         {
  61                 $index = array_search( $title, $this->mBadLinks );
  62                 if ( isset( $index ) ) {
  63                         unset( $this->mBadLinks[$index] );
  64                 }
  65                 global $wgMemc, $wgDBname;
  66                 $wgMemc->delete( "$wgDBname:linkcache:title:$title" );
  67         }
  68
  69         function suspend() { $this->mActive = false; }
  70         function resume() { $this->mActive = true; }
  71         function getGoodLinks() { return $this->mGoodLinks; }
  72         function getBadLinks() { return $this->mBadLinks; }
  73         function getImageLinks() { return $this->mImageLinks; }
  74
  75         function addLink( $title )
  76         {
  77                 if ( $this->isBadLink( $title ) ) { return 0; }
  78                 $id = $this->getGoodLinkID( $title );
  79                 if ( 0 != $id ) { return $id; }
  80
  81                 global $wgMemc, $wgDBname;
  82                 wfProfileIn( "LinkCache::addLink-checkdatabase" );
  83
  84                 $nt = Title::newFromDBkey( $title );
  85                 $ns = $nt->getNamespace();
  86                 $t = $nt->getDBkey();
  87
  88                 if ( "" == $t ) { return 0; }
  89
  90                 $id = $wgMemc->get( $key = "$wgDBname:linkcache:title:$title" );
  91                 if( $id === FALSE ) {
  92                         $sql = "SELECT HIGH_PRIORITY cur_id FROM cur WHERE cur_namespace=" .
  93                           "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
  94                         $res = wfQuery( $sql, "LinkCache::addLink" );
  95
  96                         if ( 0 == wfNumRows( $res ) ) {
  97                                 $id = 0;
  98                         } else {
  99                                 $s = wfFetchObject( $res );
 100                                 $id = $s->cur_id;
 101                         }
 102                         $wgMemc->add( $key, $id, time()+3600 );
 103                 }
 104                 if ( 0 == $id ) { $this->addBadLink( $title ); }
 105                 else { $this->addGoodLink( $id, $title ); }
 106                 wfProfileOut();
 107                 return $id;
 108         }
 109
 110         function preFill( $fromtitle )
 111         {
 112                 wfProfileIn( "LinkCache::preFill" );
 113                 # Note -- $fromtitle is a Title *object*
 114                 $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
 115                 $sql = "SELECT HIGH_PRIORITY cur_id,cur_namespace,cur_title
 116                         FROM cur,links
 117                         WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
 118                 $res = wfQuery( $sql, "LinkCache::preFill" );
 119                 while( $s = wfFetchObject( $res ) ) {
 120                         $this->addGoodLink( $s->cur_id,
 121                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 122                                 );
 123                 }
 124
 125                 $this->suspend();
 126                 $id = $fromtitle->getArticleID();
 127                 $this->resume();
 128
 129                 $sql = "SELECT HIGH_PRIORITY bl_to
 130                         FROM brokenlinks
 131                         WHERE bl_from='{$id}'";
 132                 $res = wfQuery( $sql, "LinkCache::preFill" );
 133                 while( $s = wfFetchObject( $res ) ) {
 134                         $this->addBadLink( $s->bl_to );
 135                 }
 136
 137                 $this->mOldBadLinks = $this->mBadLinks;
 138                 $this->mOldGoodLinks = $this->mGoodLinks;
 139                 $this->mPreFilled = true;
 140
 141                 wfProfileOut();
 142         }
 143
 144         function getGoodAdditions()
 145         {
 146                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 147         }
 148
 149         function getBadAdditions()
 150         {
 151                 return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
 152         }
 153
 154         function getImageAdditions()
 155         {
 156                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 157         }
 158
 159         function getGoodDeletions()
 160         {
 161                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 162         }
 163
 164         function getBadDeletions()
 165         {
 166                 return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
 167         }
 168
 169         function getImageDeletions()
 170         {
 171                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 172         }
 173
 174         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 175         # the incremental update arrays which will be filled. Returns whether or not it's
 176         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 177         # was blanked, it would take a long, long time to do incrementally.
 178         function incrementalSetup( $which, &$del, &$add )
 179         {
 180                 if ( ! $this->mPreFilled ) {
 181                         return false;
 182                 }
 183
 184                 switch ( $which ) {
 185                         case LINKCACHE_GOOD:
 186                                 $old =& $this->mOldGoodLinks;
 187                                 $cur =& $this->mGoodLinks;
 188                                 $del = $this->getGoodDeletions();
 189                                 $add = $this->getGoodAdditions();
 190                                 break;
 191                         case LINKCACHE_BAD:
 192                                 $old =& $this->mOldBadLinks;
 193                                 $cur =& $this->mBadLinks;
 194                                 $del = $this->getBadDeletions();
 195                                 $add = $this->getBadAdditions();
 196                                 break;
 197                         default: # LINKCACHE_IMAGE
 198                                 return false;
 199                 }
 200
 201                 return true;
 202         }
 203
 204         # Clears cache but leaves old preFill copies alone
 205         function clear()
 206         {
 207                 $this->mGoodLinks = array();
 208                 $this->mBadLinks = array();
 209                 $this->mImageLinks = array();
 210         }
 211
 212 }
 213 ?>