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:lc: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                 $fname = "LinkCache::addLink-checkdatabase";
  83                 wfProfileIn( $fname );
  84
  85                 $nt = Title::newFromDBkey( $title );
  86                 $ns = $nt->getNamespace();
  87                 $t = $nt->getDBkey();
  88
  89                 if ( "" == $t ) {
  90                         wfProfileOut( $fname);
  91                         return 0;
  92                 }
  93
  94                 $id = $wgMemc->get( $key = "$wgDBname:lc:title:$title" );
  95                 if( $id === FALSE ) {
  96                         $sql = "SELECT HIGH_PRIORITY cur_id FROM cur WHERE cur_namespace=" .
  97                           "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
  98                         $res = wfQuery( $sql, DB_READ, "LinkCache::addLink" );
  99
 100                         if ( 0 == wfNumRows( $res ) ) {
 101                                 $id = 0;
 102                         } else {
 103                                 $s = wfFetchObject( $res );
 104                                 $id = $s->cur_id;
 105                         }
 106                         $wgMemc->add( $key, $id, time()+3600 );
 107                 }
 108                 if ( 0 == $id ) { $this->addBadLink( $title ); }
 109                 else { $this->addGoodLink( $id, $title ); }
 110                 wfProfileOut( $fname );
 111                 return $id;
 112         }
 113
 114         function preFill( $fromtitle )
 115         {
 116                 $fname = "LinkCache::preFill";
 117                 wfProfileIn( $fname );
 118                 # Note -- $fromtitle is a Title *object*
 119                 $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
 120                 $sql = "SELECT HIGH_PRIORITY cur_id,cur_namespace,cur_title
 121                         FROM cur,links
 122                         WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
 123                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 124                 while( $s = wfFetchObject( $res ) ) {
 125                         $this->addGoodLink( $s->cur_id,
 126                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 127                                 );
 128                 }
 129
 130                 $this->suspend();
 131                 $id = $fromtitle->getArticleID();
 132                 $this->resume();
 133
 134                 $sql = "SELECT HIGH_PRIORITY bl_to
 135                         FROM brokenlinks
 136                         WHERE bl_from='{$id}'";
 137                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 138                 while( $s = wfFetchObject( $res ) ) {
 139                         $this->addBadLink( $s->bl_to );
 140                 }
 141
 142                 $this->mOldBadLinks = $this->mBadLinks;
 143                 $this->mOldGoodLinks = $this->mGoodLinks;
 144                 $this->mPreFilled = true;
 145
 146                 wfProfileOut( $fname );
 147         }
 148
 149         function getGoodAdditions()
 150         {
 151                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 152         }
 153
 154         function getBadAdditions()
 155         {
 156                 return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
 157         }
 158
 159         function getImageAdditions()
 160         {
 161                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 162         }
 163
 164         function getGoodDeletions()
 165         {
 166                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 167         }
 168
 169         function getBadDeletions()
 170         {
 171                 return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
 172         }
 173
 174         function getImageDeletions()
 175         {
 176                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 177         }
 178
 179         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 180         # the incremental update arrays which will be filled. Returns whether or not it's
 181         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 182         # was blanked, it would take a long, long time to do incrementally.
 183         function incrementalSetup( $which, &$del, &$add )
 184         {
 185                 if ( ! $this->mPreFilled ) {
 186                         return false;
 187                 }
 188
 189                 switch ( $which ) {
 190                         case LINKCACHE_GOOD:
 191                                 $old =& $this->mOldGoodLinks;
 192                                 $cur =& $this->mGoodLinks;
 193                                 $del = $this->getGoodDeletions();
 194                                 $add = $this->getGoodAdditions();
 195                                 break;
 196                         case LINKCACHE_BAD:
 197                                 $old =& $this->mOldBadLinks;
 198                                 $cur =& $this->mBadLinks;
 199                                 $del = $this->getBadDeletions();
 200                                 $add = $this->getBadAdditions();
 201                                 break;
 202                         default: # LINKCACHE_IMAGE
 203                                 return false;
 204                 }
 205
 206                 return true;
 207         }
 208
 209         # Clears cache but leaves old preFill copies alone
 210         function clear()
 211         {
 212                 $this->mGoodLinks = array();
 213                 $this->mBadLinks = array();
 214                 $this->mImageLinks = array();
 215         }
 216
 217 }
 218 ?>