includes/LinkCache.php

   1 <?php
   2 # Cache for article titles (prefixed DB keys) 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         // Increment $mClassVer whenever old serialized versions of this class
  11         // becomes incompatible with the new version.
  12         /* private */ var $mClassVer = 2;
  13
  14         /* private */ var $mGoodLinks, $mBadLinks, $mActive;
  15         /* private */ var $mImageLinks, $mCategoryLinks;
  16         /* private */ var $mPreFilled, $mOldGoodLinks, $mOldBadLinks;
  17
  18         /* private */ function getKey( $title ) {
  19                 global $wgDBname;
  20                 return "$wgDBname:lc:title:$title";
  21         }
  22
  23         function LinkCache()
  24         {
  25                 $this->mActive = true;
  26                 $this->mPreFilled = false;
  27                 $this->mGoodLinks = array();
  28                 $this->mBadLinks = array();
  29                 $this->mImageLinks = array();
  30                 $this->mCategoryLinks = array();
  31                 $this->mOldGoodLinks = array();
  32                 $this->mOldBadLinks = array();
  33         }
  34
  35         function getGoodLinkID( $title )
  36         {
  37                 if ( array_key_exists( $title, $this->mGoodLinks ) ) {
  38                         return $this->mGoodLinks[$title];
  39                 } else {
  40                         return 0;
  41                 }
  42         }
  43
  44         function isBadLink( $title )
  45         {
  46                 return array_key_exists( $title, $this->mBadLinks );
  47         }
  48
  49         function addGoodLink( $id, $title )
  50         {
  51                 if ( $this->mActive ) {
  52                         $this->mGoodLinks[$title] = $id;
  53                 }
  54         }
  55
  56         function addBadLink( $title )
  57         {
  58                 if ( $this->mActive && ( ! $this->isBadLink( $title ) ) ) {
  59                         $this->mBadLinks[$title] = 1;
  60                 }
  61         }
  62
  63         function addImageLink( $title )
  64         {
  65                 if ( $this->mActive ) { $this->mImageLinks[$title] = 1; }
  66         }
  67
  68         function addImageLinkObj( $nt )
  69         {
  70                 if ( $this->mActive ) { $this->mImageLinks[$nt->getDBkey()] = 1; }
  71         }
  72
  73         function addCategoryLink( $title, $sortkey ) {
  74                 if ( $this->mActive ) { $this->mCategoryLinks[$title] = $sortkey; }
  75         }
  76
  77         function addCategoryLinkObj( &$nt, $sortkey ) {
  78                 $this->addCategoryLink( $nt->getDBkey(), $sortkey );
  79         }
  80
  81         function clearBadLink( $title )
  82         {
  83                 unset( $this->mBadLinks[$title] );
  84                 $this->clearLink( $title );
  85         }
  86
  87         function clearLink( $title )
  88         {
  89                 global $wgMemc, $wgLinkCacheMemcached;
  90                 if( $wgLinkCacheMemcached )
  91                         $wgMemc->delete( $this->getKey( $title ) );
  92         }
  93
  94         function suspend() { $this->mActive = false; }
  95         function resume() { $this->mActive = true; }
  96         function getGoodLinks() { return $this->mGoodLinks; }
  97         function getBadLinks() { return array_keys( $this->mBadLinks ); }
  98         function getImageLinks() { return $this->mImageLinks; }
  99         function getCategoryLinks() { return $this->mCategoryLinks; }
 100
 101         function addLink( $title )
 102         {
 103                 $nt = Title::newFromDBkey( $title );
 104                 if( $nt ) {
 105                         return $this->addLinkObj( $nt );
 106                 } else {
 107                         return 0;
 108                 }
 109         }
 110
 111         function addLinkObj( &$nt )
 112         {
 113                 global $wgMemc, $wgLinkCacheMemcached;
 114                 $title = $nt->getPrefixedDBkey();
 115                 if ( $this->isBadLink( $title ) ) { return 0; }
 116                 $id = $this->getGoodLinkID( $title );
 117                 if ( 0 != $id ) { return $id; }
 118
 119                 $fname = "LinkCache::addLinkObj";
 120                 wfProfileIn( $fname );
 121
 122                 $ns = $nt->getNamespace();
 123                 $t = $nt->getDBkey();
 124
 125                 if ( "" == $title ) {
 126                         wfProfileOut( $fname );
 127                         return 0;
 128                 }
 129
 130                 $id = NULL;
 131                 if( $wgLinkCacheMemcached )
 132                         $id = $wgMemc->get( $key = $this->getKey( $title ) );
 133                 if( ! is_integer( $id ) ) {
 134                         $sql = "SELECT cur_id FROM cur WHERE cur_namespace=" .
 135                           "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
 136                         $res = wfQuery( $sql, DB_READ, "LinkCache::addLink" );
 137
 138                         if ( 0 == wfNumRows( $res ) ) {
 139                                 $id = 0;
 140                         } else {
 141                                 $s = wfFetchObject( $res );
 142                                 $id = $s->cur_id;
 143                         }
 144                         if( $wgLinkCacheMemcached )
 145                                 $wgMemc->add( $key, $id, 3600*24 );
 146                 }
 147
 148                 if ( 0 == $id ) { $this->addBadLink( $title ); }
 149                 else { $this->addGoodLink( $id, $title ); }
 150                 wfProfileOut( $fname );
 151                 return $id;
 152         }
 153
 154         function preFill( &$fromtitle )
 155         {
 156                 global $wgEnablePersistentLC;
 157
 158                 $fname = "LinkCache::preFill";
 159                 wfProfileIn( $fname );
 160                 # Note -- $fromtitle is a Title *object*
 161
 162                 $this->suspend();
 163                 $id = $fromtitle->getArticleID();
 164                 $this->resume();
 165
 166                 if( $id == 0 ) {
 167                         wfDebug( "$fname - got id 0 for title '" . $fromtitle->getPrefixedDBkey() . "'\n" );
 168                         wfProfileOut( $fname );
 169                         return;
 170                 }
 171
 172                 if ( $wgEnablePersistentLC ) {
 173                         if( $this->fillFromLinkscc( $id ) ){
 174                                 wfProfileOut( $fname );
 175                                 return;
 176                         }
 177                 }
 178
 179                 $sql = "SELECT cur_id,cur_namespace,cur_title
 180                         FROM cur,links
 181                         WHERE cur_id=l_to AND l_from=$id";
 182                 $res = wfQuery( $sql, DB_READ, $fname );
 183                 while( $s = wfFetchObject( $res ) ) {
 184                         $this->addGoodLink( $s->cur_id,
 185                                 Title::makeName( $s->cur_namespace, $s->cur_title )
 186                                 );
 187                 }
 188
 189                 $sql = "SELECT bl_to
 190                         FROM brokenlinks
 191                         WHERE bl_from='{$id}'";
 192                 $res = wfQuery( $sql, DB_READ, "LinkCache::preFill" );
 193                 while( $s = wfFetchObject( $res ) ) {
 194                         $this->addBadLink( $s->bl_to );
 195                 }
 196
 197                 $this->mOldBadLinks = $this->mBadLinks;
 198                 $this->mOldGoodLinks = $this->mGoodLinks;
 199                 $this->mPreFilled = true;
 200
 201                 if ( $wgEnablePersistentLC ) {
 202                         $this->saveToLinkscc( $id );
 203                 }
 204                 wfProfileOut( $fname );
 205         }
 206
 207         function getGoodAdditions()
 208         {
 209                 return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
 210         }
 211
 212         function getBadAdditions()
 213         {
 214                 #wfDebug( "mOldBadLinks: " . implode( ', ', array_keys( $this->mOldBadLinks ) ) . "\n" );
 215                 #wfDebug( "mBadLinks: " . implode( ', ', array_keys( $this->mBadLinks ) ) . "\n" );
 216                 return array_values( array_diff( array_keys( $this->mBadLinks ), array_keys( $this->mOldBadLinks ) ) );
 217         }
 218
 219         function getImageAdditions()
 220         {
 221                 return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
 222         }
 223
 224         function getGoodDeletions()
 225         {
 226                 return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
 227         }
 228
 229         function getBadDeletions()
 230         {
 231                 return array_values( array_diff( array_keys( $this->mOldBadLinks ), array_keys( $this->mBadLinks ) ));
 232         }
 233
 234         function getImageDeletions()
 235         {
 236                 return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
 237         }
 238
 239         #     Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
 240         # the incremental update arrays which will be filled. Returns whether or not it's
 241         # worth doing the incremental version. For example, if [[List of mathematical topics]]
 242         # was blanked, it would take a long, long time to do incrementally.
 243         function incrementalSetup( $which, &$del, &$add )
 244         {
 245                 if ( ! $this->mPreFilled ) {
 246                         return false;
 247                 }
 248
 249                 switch ( $which ) {
 250                         case LINKCACHE_GOOD:
 251                                 $old =& $this->mOldGoodLinks;
 252                                 $cur =& $this->mGoodLinks;
 253                                 $del = $this->getGoodDeletions();
 254                                 $add = $this->getGoodAdditions();
 255                                 break;
 256                         case LINKCACHE_BAD:
 257                                 $old =& $this->mOldBadLinks;
 258                                 $cur =& $this->mBadLinks;
 259                                 $del = $this->getBadDeletions();
 260                                 $add = $this->getBadAdditions();
 261                                 break;
 262                         default: # LINKCACHE_IMAGE
 263                                 return false;
 264                 }
 265
 266                 return true;
 267         }
 268
 269         # Clears cache but leaves old preFill copies alone
 270         function clear()
 271         {
 272                 $this->mGoodLinks = array();
 273                 $this->mBadLinks = array();
 274                 $this->mImageLinks = array();
 275         }
 276
 277         /* private */ function fillFromLinkscc( $id ){
 278                 $id = IntVal( $id );
 279                 $res = wfQuery("SELECT lcc_cacheobj FROM linkscc WHERE lcc_pageid = $id",
 280                         DB_READ);
 281                 $row = wfFetchObject( $res );
 282                 if( $row == FALSE)
 283                         return false;
 284
 285                 $cacheobj = false;
 286                 if( function_exists( "gzuncompress" ) )
 287                         $cacheobj = @gzuncompress( $row->lcc_cacheobj );
 288
 289                 if($cacheobj == FALSE){
 290                         $cacheobj = $row->lcc_cacheobj;
 291                 }
 292                 $cc = @unserialize( $cacheobj );
 293                 if( isset( $cc->mClassVer ) and ($cc->mClassVer == $this->mClassVer ) ){
 294                         $this->mOldGoodLinks = $this->mGoodLinks = $cc->mGoodLinks;
 295                         $this->mOldBadLinks = $this->mBadLinks = $cc->mBadLinks;
 296                         $this->mPreFilled = true;
 297                         return TRUE;
 298                 } else {
 299                         return FALSE;
 300                 }
 301
 302         }
 303
 304         /* private */ function saveToLinkscc( $pid ){
 305                 global $wgCompressedPersistentLC, $wgIsMySQL;
 306                 if( $wgCompressedPersistentLC and function_exists( "gzcompress" ) ) {
 307                         $ser = wfStrencode( gzcompress( serialize( $this ), 3 ));
 308                 } else {
 309                         $ser = wfStrencode( serialize( $this ) );
 310                 }
 311                 if ($wgIsMySQL) {
 312                         wfQuery("REPLACE INTO linkscc(lcc_pageid,lcc_cacheobj) " .
 313                                 "VALUES({$pid}, '{$ser}')", DB_WRITE);
 314                 } else {
 315                         wfQuery("DELETE FROM linkscc WHERE lcc_pageid={$pid}",DB_WRITE);
 316                         wfQuery("INSERT INTO linkscc(lcc_pageid,lcc_cacheobj) " .
 317                                 "VALUES({$pid}, '{$ser}')", DB_WRITE);
 318                 }
 319         }
 320
 321         # $pid is a page id
 322         /* static */ function linksccClearLinksTo( $pid ){
 323                 global $wgEnablePersistentLC, $wgIsMySQL;
 324                 if ( $wgEnablePersistentLC ) {
 325                         $pid = intval( $pid );
 326                         if ($wgIsMySQL) {
 327                                 wfQuery("DELETE linkscc FROM linkscc,links ".
 328                                         "WHERE lcc_pageid=links.l_from AND l_to={$pid}", DB_WRITE);
 329                         } else {
 330                                 wfQuery("DELETE FROM linkscc WHERE lcc_pageid IN ".
 331                                         "(SELECT l_from FROM links WHERE l_to={$pid})", DB_WRITE);
 332                         }
 333                         wfQuery("DELETE FROM linkscc WHERE lcc_pageid='{$pid}'", DB_WRITE);
 334                 }
 335         }
 336
 337         # $title is a prefixed db title, for example like Title->getPrefixedDBkey() returns.
 338         /* static */ function linksccClearBrokenLinksTo( $title ){
 339                 global $wgEnablePersistentLC,$wgIsMySQL;
 340                 if ( $wgEnablePersistentLC ) {
 341                         $title = wfStrencode( $title );
 342                         if ($wgIsMySQL) {
 343                                 wfQuery("DELETE linkscc FROM linkscc,brokenlinks ".
 344                                         "WHERE lcc_pageid=bl_from AND bl_to='{$title}'", DB_WRITE);
 345                         } else {
 346                                 wfQuery("DELETE FROM linkscc WHERE lcc_pageid IN ".
 347                                         "(SELECT bl_from FROM brokenlinks ".
 348                                         "WHERE bl_to='{$title}')",DB_WRITE);
 349                         }
 350                 }
 351         }
 352
 353         # $pid is a page id
 354         /* static */ function linksccClearPage( $pid ){
 355                 global $wgEnablePersistentLC;
 356                 if ( $wgEnablePersistentLC ) {
 357                         $pid = intval( $pid );
 358                         wfQuery("DELETE FROM linkscc WHERE lcc_pageid='{$pid}'", DB_WRITE);
 359                 }
 360         }
 361 }
 362 ?>