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                 return $this->addLinkObj( Title::newFromDBkey( $title ) );
  78         }
  79
  80         function addLinkObj( &$nt )
  81         {
  82                 $title = $nt->getDBkey();
  83                 if ( $this->isBadLink( $title ) ) { return 0; }
  84                 $id = $this->getGoodLinkID( $title );
  85                 if ( 0 != $id ) { return $id; }
  86
  87                 global $wgMemc, $wgDBname;
  88                 $fname = "LinkCache::addLink-checkdatabase";
  89                 wfProfileIn( $fname );
  90
  91                 $ns = $nt->getNamespace();
  92
  93                 if ( "" == $title ) {
  94                         wfProfileOut( $fname );
  95                         return 0;
  96                 }
  97
  98                 $id = $wgMemc->get( $key = "$wgDBname:lc:title:$title" );
  99                 if( $id === FALSE ) {
 100                         $sql = "SELECT HIGH_PRIORITY cur_id FROM cur WHERE cur_namespace=" .
 101                           "{$ns} AND cur_title='" . wfStrencode( $title ) . "'";
 102                         $res = wfQuery( $sql, DB_READ, "LinkCache::addLink" );
 103
 104                         if ( 0 == wfNumRows( $res ) ) {
 105                                 $id = 0;
 106                         } else {
 107                                 $s = wfFetchObject( $res );
 108                                 $id = $s->cur_id;
 109                         }
 110                         $wgMemc->add( $key, $id, time()+3600 );
 111                 }
 112                 if ( 0 == $id ) { $this->addBadLink( $title ); }
 113                 else { $this->addGoodLink( $id, $title ); }
 114                 wfProfileOut( $fname );
 115                 return $id;
 116         }
 117
 118         function preFill( &$fromtitle )
 119         {
 120                 $fname = "LinkCache::preFill";
 121                 wfProfileIn( $fname );
 122                 # Note -- $fromtitle is a Title *object*
 123                 $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
 124                 $sql = "SELECT HIGH_PRIORITY cur_id,cur_namespace,cur_title
 125                         FROM cur,links
 126                         WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
 127                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 128                 while( $s = wfFetchObject( $res ) ) {
 129                         $this->addGoodLink( $s->cur_id,
 130                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 131                                 );
 132                 }
 133
 134                 $this->suspend();
 135                 $id = $fromtitle->getArticleID();
 136                 $this->resume();
 137
 138                 $sql = "SELECT HIGH_PRIORITY bl_to
 139                         FROM brokenlinks
 140                         WHERE bl_from='{$id}'";
 141                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 142                 while( $s = wfFetchObject( $res ) ) {
 143                         $this->addBadLink( $s->bl_to );
 144                 }
 145
 146                 $this->mOldBadLinks = $this->mBadLinks;
 147                 $this->mOldGoodLinks = $this->mGoodLinks;
 148                 $this->mPreFilled = true;
 149
 150                 wfProfileOut( $fname );
 151         }
 152
 153         function getGoodAdditions()
 154         {
 155                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 156         }
 157
 158         function getBadAdditions()
 159         {
 160                 return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
 161         }
 162
 163         function getImageAdditions()
 164         {
 165                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 166         }
 167
 168         function getGoodDeletions()
 169         {
 170                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 171         }
 172
 173         function getBadDeletions()
 174         {
 175                 return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
 176         }
 177
 178         function getImageDeletions()
 179         {
 180                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 181         }
 182
 183         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 184         # the incremental update arrays which will be filled. Returns whether or not it's
 185         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 186         # was blanked, it would take a long, long time to do incrementally.
 187         function incrementalSetup( $which, &$del, &$add )
 188         {
 189                 if ( ! $this->mPreFilled ) {
 190                         return false;
 191                 }
 192
 193                 switch ( $which ) {
 194                         case LINKCACHE_GOOD:
 195                                 $old =& $this->mOldGoodLinks;
 196                                 $cur =& $this->mGoodLinks;
 197                                 $del = $this->getGoodDeletions();
 198                                 $add = $this->getGoodAdditions();
 199                                 break;
 200                         case LINKCACHE_BAD:
 201                                 $old =& $this->mOldBadLinks;
 202                                 $cur =& $this->mBadLinks;
 203                                 $del = $this->getBadDeletions();
 204                                 $add = $this->getBadAdditions();
 205                                 break;
 206                         default: # LINKCACHE_IMAGE
 207                                 return false;
 208                 }
 209
 210                 return true;
 211         }
 212
 213         # Clears cache but leaves old preFill copies alone
 214         function clear()
 215         {
 216                 $this->mGoodLinks = array();
 217                 $this->mBadLinks = array();
 218                 $this->mImageLinks = array();
 219         }
 220
 221 }
 222 ?>