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         }
  66
  67         function suspend() { $this->mActive = false; }
  68         function resume() { $this->mActive = true; }
  69         function getGoodLinks() { return $this->mGoodLinks; }
  70         function getBadLinks() { return $this->mBadLinks; }
  71         function getImageLinks() { return $this->mImageLinks; }
  72
  73         function addLink( $title )
  74         {
  75                 if ( $this->isBadLink( $title ) ) { return 0; }
  76                 $id = $this->getGoodLinkID( $title );
  77                 if ( 0 != $id ) { return $id; }
  78
  79                 wfProfileIn( "LinkCache::addLink-checkdatabase" );
  80
  81                 $nt = Title::newFromDBkey( $title );
  82                 $ns = $nt->getNamespace();
  83                 $t = $nt->getDBkey();
  84
  85                 if ( "" == $t ) { return 0; }
  86                 $sql = "SELECT HIGH_PRIORITY cur_id FROM cur WHERE cur_namespace=" .
  87                   "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
  88                 $res = wfQuery( $sql, "LinkCache::addLink" );
  89
  90                 if ( 0 == wfNumRows( $res ) ) {
  91                         $id = 0;
  92                 } else {
  93                         $s = wfFetchObject( $res );
  94                         $id = $s->cur_id;
  95                 }
  96                 if ( 0 == $id ) { $this->addBadLink( $title ); }
  97                 else { $this->addGoodLink( $id, $title ); }
  98                 wfProfileOut();
  99                 return $id;
 100         }
 101
 102         function preFill( $fromtitle )
 103         {
 104                 wfProfileIn( "LinkCache::preFill" );
 105                 # Note -- $fromtitle is a Title *object*
 106                 $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
 107                 $sql = "SELECT HIGH_PRIORITY cur_id,cur_namespace,cur_title
 108                         FROM cur,links
 109                         WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
 110                 $res = wfQuery( $sql, "LinkCache::preFill" );
 111                 while( $s = wfFetchObject( $res ) ) {
 112                         $this->addGoodLink( $s->cur_id,
 113                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 114                                 );
 115                 }
 116
 117                 $this->suspend();
 118                 $id = $fromtitle->getArticleID();
 119                 $this->resume();
 120
 121                 $sql = "SELECT HIGH_PRIORITY bl_to
 122                         FROM brokenlinks
 123                         WHERE bl_from='{$id}'";
 124                 $res = wfQuery( $sql, "LinkCache::preFill" );
 125                 while( $s = wfFetchObject( $res ) ) {
 126                         $this->addBadLink( $s->bl_to );
 127                 }
 128
 129                 $this->mOldBadLinks = $this->mBadLinks;
 130                 $this->mOldGoodLinks = $this->mGoodLinks;
 131                 $this->mPreFilled = true;
 132
 133                 wfProfileOut();
 134         }
 135
 136         function getGoodAdditions()
 137         {
 138                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 139         }
 140
 141         function getBadAdditions()
 142         {
 143                 return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
 144         }
 145
 146         function getImageAdditions()
 147         {
 148                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 149         }
 150
 151         function getGoodDeletions()
 152         {
 153                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 154         }
 155
 156         function getBadDeletions()
 157         {
 158                 return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
 159         }
 160
 161         function getImageDeletions()
 162         {
 163                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 164         }
 165
 166         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 167         # the incremental update arrays which will be filled. Returns whether or not it's
 168         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 169         # was blanked, it would take a long, long time to do incrementally.
 170         function incrementalSetup( $which, &$del, &$add )
 171         {
 172                 if ( ! $this->mPreFilled ) {
 173                         return false;
 174                 }
 175
 176                 switch ( $which ) {
 177                         case LINKCACHE_GOOD:
 178                                 $old =& $this->mOldGoodLinks;
 179                                 $cur =& $this->mGoodLinks;
 180                                 $del = $this->getGoodDeletions();
 181                                 $add = $this->getGoodAdditions();
 182                                 break;
 183                         case LINKCACHE_BAD:
 184                                 $old =& $this->mOldBadLinks;
 185                                 $cur =& $this->mBadLinks;
 186                                 $del = $this->getBadDeletions();
 187                                 $add = $this->getBadAdditions();
 188                                 break;
 189                         default: # LINKCACHE_IMAGE
 190                                 return false;
 191                 }
 192
 193                 return true;
 194         }
 195
 196         # Clears cache but leaves old preFill copies alone
 197         function clear()
 198         {
 199                 $this->mGoodLinks = array();
 200                 $this->mBadLinks = array();
 201                 $this->mImageLinks = array();
 202         }
 203 }
 204 ?>