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                 global $wgMemc;
  80                 $wgMemc->delete( $this->getKey( $title ) );
  81         }
  82
  83         function suspend() { $this->mActive = false; }
  84         function resume() { $this->mActive = true; }
  85         function getGoodLinks() { return $this->mGoodLinks; }
  86         function getBadLinks() { return $this->mBadLinks; }
  87         function getImageLinks() { return $this->mImageLinks; }
  88
  89         function addLink( $title )
  90         {
  91                 $nt = Title::newFromDBkey( $title );
  92                 if( $nt ) {
  93                         return $this->addLinkObj( $nt );
  94                 } else {
  95                         return 0;
  96                 }
  97         }
  98
  99         function addLinkObj( &$nt )
 100         {
 101                 $title = $nt->getPrefixedDBkey();
 102                 if ( $this->isBadLink( $title ) ) { return 0; }
 103                 $id = $this->getGoodLinkID( $title );
 104                 if ( 0 != $id ) { return $id; }
 105
 106                 global $wgMemc;
 107                 $fname = "LinkCache::addLinkObj";
 108                 wfProfileIn( $fname );
 109
 110                 $ns = $nt->getNamespace();
 111                 $t = $nt->getDBkey();
 112
 113                 if ( "" == $title ) {
 114                         wfProfileOut( $fname );
 115                         return 0;
 116                 }
 117
 118                 $id = $wgMemc->get( $key = $this->getKey( $title ) );
 119                 if( $id === FALSE ) {
 120                         $sql = "SELECT cur_id FROM cur WHERE cur_namespace=" .
 121                           "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
 122                         $res = wfQuery( $sql, DB_READ, "LinkCache::addLink" );
 123
 124                         if ( 0 == wfNumRows( $res ) ) {
 125                                 $id = 0;
 126                         } else {
 127                                 $s = wfFetchObject( $res );
 128                                 $id = $s->cur_id;
 129                         }
 130                         $wgMemc->add( $key, $id, time()+3600 );
 131                 }
 132                 if ( 0 == $id ) { $this->addBadLink( $title ); }
 133                 else { $this->addGoodLink( $id, $title ); }
 134                 wfProfileOut( $fname );
 135                 return $id;
 136         }
 137
 138         function preFill( &$fromtitle )
 139         {
 140                 $fname = "LinkCache::preFill";
 141                 wfProfileIn( $fname );
 142                 # Note -- $fromtitle is a Title *object*
 143                 $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
 144                 $sql = "SELECT cur_id,cur_namespace,cur_title
 145                         FROM cur,links
 146                         WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
 147                 $res = wfQuery( $sql, DB_READ, $fname );
 148                 while( $s = wfFetchObject( $res ) ) {
 149                         $this->addGoodLink( $s->cur_id,
 150                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 151                                 );
 152                 }
 153
 154                 $this->suspend();
 155                 $id = $fromtitle->getArticleID();
 156                 $this->resume();
 157
 158                 $sql = "SELECT bl_to
 159                         FROM brokenlinks
 160                         WHERE bl_from='{$id}'";
 161                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 162                 while( $s = wfFetchObject( $res ) ) {
 163                         $this->addBadLink( $s->bl_to );
 164                 }
 165
 166                 $this->mOldBadLinks = $this->mBadLinks;
 167                 $this->mOldGoodLinks = $this->mGoodLinks;
 168                 $this->mPreFilled = true;
 169
 170                 wfProfileOut( $fname );
 171         }
 172
 173         function getGoodAdditions()
 174         {
 175                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 176         }
 177
 178         function getBadAdditions()
 179         {
 180                 return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
 181         }
 182
 183         function getImageAdditions()
 184         {
 185                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 186         }
 187
 188         function getGoodDeletions()
 189         {
 190                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 191         }
 192
 193         function getBadDeletions()
 194         {
 195                 return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
 196         }
 197
 198         function getImageDeletions()
 199         {
 200                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 201         }
 202
 203         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 204         # the incremental update arrays which will be filled. Returns whether or not it's
 205         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 206         # was blanked, it would take a long, long time to do incrementally.
 207         function incrementalSetup( $which, &$del, &$add )
 208         {
 209                 if ( ! $this->mPreFilled ) {
 210                         return false;
 211                 }
 212
 213                 switch ( $which ) {
 214                         case LINKCACHE_GOOD:
 215                                 $old =& $this->mOldGoodLinks;
 216                                 $cur =& $this->mGoodLinks;
 217                                 $del = $this->getGoodDeletions();
 218                                 $add = $this->getGoodAdditions();
 219                                 break;
 220                         case LINKCACHE_BAD:
 221                                 $old =& $this->mOldBadLinks;
 222                                 $cur =& $this->mBadLinks;
 223                                 $del = $this->getBadDeletions();
 224                                 $add = $this->getBadAdditions();
 225                                 break;
 226                         default: # LINKCACHE_IMAGE
 227                                 return false;
 228                 }
 229
 230                 return true;
 231         }
 232
 233         # Clears cache but leaves old preFill copies alone
 234         function clear()
 235         {
 236                 $this->mGoodLinks = array();
 237                 $this->mBadLinks = array();
 238                 $this->mImageLinks = array();
 239         }
 240
 241 }
 242 ?>