maintenance/rebuildlinks.inc

   1 <?
   2
   3 # Functions for rebuilding the link tracking tables; must
   4 # be included within a script that also includes the Setup.
   5 # See rebuildlinks.php, for example.
   6 #
   7
   8 # Buffer this many rows before inserting them all in one sweep. More
   9 # than about 1000 will probably not increase speed significantly on
  10 # most setups.
  11 /* private */ $rowbuf_size = 1000; // 1000 rows ~40 kB
  12
  13 function rebuildLinkTables()
  14 {
  15         error_reporting (E_ALL);
  16         global $wgLang, $wgLinkCache, $rowbuf_size;
  17
  18         print "This script may take several hours to complete. If you abort during that time,\n";
  19         print "your wiki will be in an inconsistent state. If you are going to abort, this is\n";
  20         print "the time to do it.\n\n";
  21         print "Press control-c to abort (will proceed automatically in 15 seconds)\n";
  22         sleep(15);
  23
  24         $count = 0;
  25         print "Rebuilding link tables.\n";
  26
  27         print "Setting AUTOCOMMIT=1\n";
  28         wfQuery("SET SESSION AUTOCOMMIT=1", DB_WRITE);
  29
  30         print "Locking tables\n";
  31         $sql = "LOCK TABLES cur READ, interwiki READ, user_newtalk READ, " .
  32                 "links WRITE, brokenlinks WRITE, imagelinks WRITE";
  33         wfQuery( $sql, DB_WRITE );
  34
  35         print "Deleting old data in links table.\n";
  36         $sql = "DELETE FROM links";
  37         wfQuery( $sql, DB_WRITE );
  38
  39         print "Deleting old data in brokenlinks table.\n";
  40         $sql = "DELETE FROM brokenlinks";
  41         wfQuery( $sql, DB_WRITE );
  42
  43         print "Deleting old data in imagelinks table.\n";
  44         $sql = "DELETE FROM imagelinks";
  45         wfQuery( $sql, DB_WRITE );
  46
  47         print "Finding number of articles to process... ";
  48         $sql = "SELECT COUNT(*) as count FROM cur";
  49         $res = wfQuery( $sql, DB_READ );
  50         $obj = wfFetchObject( $res );
  51         $total = $obj->count;
  52         print "$total\n";
  53
  54         print "Finding highest article id\n";
  55         $sql = "SELECT MIN(cur_id) AS min, MAX(cur_id) AS max FROM cur";
  56         $res = wfQuery( $sql, DB_READ );
  57         $obj = wfFetchObject( $res );
  58
  59         $cur_pulser = new SelectPulser("SELECT cur_id,cur_namespace,cur_title,cur_text " .
  60                 "FROM cur WHERE cur_id ",
  61                 $obj->min, $obj->max, 100);
  62
  63         $brokenlinks_inserter = new InsertBuffer(
  64                 "INSERT IGNORE INTO brokenlinks (bl_from,bl_to) VALUES " , $rowbuf_size);
  65
  66         $links_inserter = new InsertBuffer(
  67                 "INSERT IGNORE INTO links (l_from,l_to) VALUES ", $rowbuf_size);
  68
  69         $imagelinks_inserter = new InsertBuffer("INSERT IGNORE INTO imagelinks ".
  70                 "(il_from,il_to) VALUES ", $rowbuf_size);
  71
  72         print "Starting processing\n";
  73
  74         $ins = $wgLang->getNsText( Namespace::getImage() );
  75         $inslen = strlen($ins)+1;
  76
  77         $tc = Title::legalChars();
  78
  79         $titleCache = new MRUCache( 10000 );
  80         $titlecount = 0;
  81         $start_time = time();
  82
  83         while ( $row = $cur_pulser->next() ) {
  84
  85                 $from_id = intval($row->cur_id);
  86                 $ns = $wgLang->getNsText( $row->cur_namespace );
  87                 $from_full_title = $row->cur_title;
  88                 if ( "" != $ns ) {
  89                         $from_full_title = "$ns:{$from_full_title}";
  90                 }
  91                 $from_full_title_with_slashes = addslashes( $from_full_title );
  92                 $text = $row->cur_text;
  93
  94                 $numlinks = preg_match_all( "/\\[\\[([{$tc}]+)(]|\\|)/", $text,
  95                   $m, PREG_PATTERN_ORDER );
  96
  97                 $seen_dbtitles = array(); // seen links (normalized and with ns, see below)
  98                 $titles_ready_for_insertion = array();
  99                 $titles_needing_curdata = array();
 100                 $titles_needing_curdata_pos = array();
 101                 $links_corresponding_to_titles = array();
 102
 103                 for ( $i = 0 ; $i < $numlinks; ++$i ) {
 104                         $link = $m[1][$i];
 105                         if( preg_match( '/^(http|https|ftp|mailto|news):/', $m[1][$i] ) ) {
 106                                 # an URL link; not for us!
 107                                 continue;
 108                         }
 109
 110                         # FIXME: Handle subpage links
 111                         $nt = $titleCache->get( $link );
 112                         if( $nt != false ){
 113                                 // Only process each unique link once per page
 114                                 $nt_key = $nt->getDBkey() . $nt->getNamespace();
 115                                 if( isset( $seen_dbtitles[$nt_key] ) )
 116                                         continue;
 117                                 $seen_dbtitles[$nt_key] = 1;
 118
 119                                 $titles_ready_for_insertion[] = $nt;
 120                         } else {
 121                                 $nt = Title::newFromText( $link );
 122                                 if (! $nt) {
 123                                         print "\nInvalid link in page '{$from_full_title}': '$link'\n";
 124                                         continue;
 125                                 }
 126
 127                                 // Only process each unique link once per page
 128                                 $nt_key = $nt->getDBkey() . $nt->getNamespace();
 129                                 if( isset( $seen_dbtitles[$nt_key] ) )
 130                                         continue;
 131                                 $seen_dbtitles[$nt_key] = 1;
 132
 133                                 if( $nt->getInterwiki() != "" ) {
 134                                         # Interwiki links are not stored in the link tables
 135                                         continue;
 136                                 }
 137                                 if( $nt->getNamespace() == Namespace::getSpecial() ) {
 138                                         # Special links not stored in link tables
 139                                         continue;
 140                                 }
 141                                 if( $nt->getNamespace() == Namespace::getMedia() ) {
 142                                         # treat media: links as image: links
 143                                         $nt = Title::makeTitle( Namespace::getImage(), $nt->getDBkey() );
 144                                 }
 145                                 $nt->mArticleID = 0; // assume broken link until proven otherwise
 146
 147                                 $pos = array_push($titles_needing_curdata, $nt) - 1;
 148                                 $titles_needing_curdata_pos[$nt->getDBkey() . $nt->getNamespace()] = $pos;
 149                                 $links_corresponding_to_titles[] = $link;
 150                                 unset( $link ); // useless outside this loop, but tempting
 151                         }
 152                 }
 153
 154
 155                 if ( count( $titles_needing_curdata ) > 0 ){
 156                         $parts = array();
 157                         foreach ($titles_needing_curdata as $nt ) {
 158                                 $parts[] = " (cur_namespace = " . $nt->getNamespace() . " AND " .
 159                                         "cur_title='" . wfStrencode( $nt->getDBkey() ) . "')";
 160                         }
 161                         $sql = "SELECT cur_namespace, cur_title, cur_id FROM cur WHERE " . implode(" OR ", $parts);
 162                         $res = wfQuery( $sql, DB_WRITE );
 163                         while($row = wfFetchObject( $res ) ){
 164                                 $pos = $titles_needing_curdata_pos[$row->cur_title . $row->cur_namespace];
 165                                 $titles_needing_curdata[$pos]->mArticleID = intval($row->cur_id);
 166                         }
 167                         for( $k = 0; $k < count( $titles_needing_curdata ) ; $k++) {
 168                                 $tmplink = $links_corresponding_to_titles[$k];
 169                                 $titleCache->set( $tmplink, $titles_needing_curdata[$k] );
 170                                 $titles_ready_for_insertion[] = $titles_needing_curdata[$k];
 171                         }
 172                 }
 173
 174                 foreach ( $titles_ready_for_insertion as $nt ) {
 175                         $dest_noslashes = $nt->getPrefixedDBkey();
 176                         $dest = addslashes( $dest_noslashes );
 177                         $dest_id = $nt->getArticleID();
 178                         $from = $from_full_title_with_slashes;
 179
 180                         # print "\nLINK '$from_full_title' ($from_id) -> '$dest' ($dest_id)\n";
 181
 182                         if ( 0 == strncmp( "$ins:", $dest_noslashes, $inslen ) ) {
 183                                 $iname = addslashes( substr( $dest_noslashes, $inslen ) );
 184                                 $imagelinks_inserter->insert( "('{$from}','{$iname}')" );
 185                         } else if ( 0 == $dest_id ) {
 186                                 $brokenlinks_inserter->insert( "({$from_id},'{$dest}')" );
 187                         } else {
 188                                 $links_inserter->insert( "('{$from}',{$dest_id})" );
 189                         }
 190                         $titlecount++;
 191                 }
 192
 193                 if ( ( $count % 20 ) == 0 )
 194                         print ".";
 195
 196                 if ( ( ++$count % 1000 ) == 0 ) {
 197                         $dt = time() - $start_time;
 198                         $start_time = time();
 199                         $rps = persec(1000, $dt);
 200                         $tps = persec($titlecount, $dt);
 201                         $titlecount = 0;
 202                         print "\n$count of $total articles scanned ({$rps} articles ".
 203                                 "and {$tps} titles per second)\n";
 204                         print "Title cache hits: " . $titleCache->getPerformance() . "%\n";
 205
 206                 }
 207
 208         }
 209
 210         print "\nFlushing insertion buffers...";
 211         $imagelinks_inserter->flush();
 212         $links_inserter->flush();
 213         $brokenlinks_inserter->flush();
 214         print "ok\n";
 215
 216         print "$count articles scanned.\n";
 217
 218         $sql = "UNLOCK TABLES";
 219         wfQuery( $sql, DB_WRITE );
 220         print "Done\n";
 221 }
 222
 223 /* private */ function persec($n, $t){
 224         if($n == 0)
 225                 return "zero";
 226         if($t == 0)
 227                 return "lots of";
 228         return intval($n/$t);
 229 }
 230
 231 # InsertBuffer increases performance slightly by inserting many rows
 232 # at once. The gain is small (<5%) when running against a local, idle
 233 # database, but may be significant in other circumstances. It also
 234 # limits the number of inserted rows uppwards, which should avoid
 235 # problems with huge articles and certain mysql settings that limits
 236 # the size of queries. It's also convenient.
 237
 238 class InsertBuffer {
 239         /* private */ var $mBuf, $mSql, $mBufcount, $mMaxsize;
 240
 241         function InsertBuffer( $sql, $bufsize ){
 242                 $this->mSql = $sql;
 243                 $this->mBuf = array();
 244                 $this->mBufcount = 0;
 245                 $this->mMaxsize = $bufsize;
 246         }
 247
 248         function insert( $value ){
 249                 // print $this->mSql . " -> " . $value . "\n";
 250                 $this->mBuf[] = $value;
 251                 $this->mBufcount++;
 252                 if($this->mBufcount > $this->mMaxsize){
 253                         $this->flush();
 254                 }
 255         }
 256
 257         function flush(){
 258                 if( $this->mBufcount > 0 ){
 259                         $sql = $this->mSql . implode(",", $this->mBuf);
 260                         wfQuery( $sql, DB_WRITE );
 261                         $this->mBuf = array();
 262                         $this->mBufcount = 0;
 263                         // print "Wrote query of size " . strlen( $sql ) . "\n";
 264                 }
 265         }
 266
 267 }
 268
 269 # Select parts from a large table by using the "BETWEEN X AND Y"
 270 # operator on the id column. Avoids buffering the whole thing in
 271 # RAM. It's also convenient.
 272
 273 class SelectPulser {
 274         /* private */ var $mSql, $mSetsize, $mPos, $mMax, $mSet;
 275
 276         function SelectPulser( $sql, $min, $max, $setsize) {
 277                 $this->mSql = $sql;
 278                 $this->mSet = array();
 279                 $this->mPos = $min;
 280                 $this->mMax = $max;
 281                 $this->mSetsize = $setsize;
 282         }
 283
 284         function next(){
 285                 $result = current( $this->mSet );
 286                 next( $this->mSet );
 287                 if( false !== $result ){
 288                         return $result;
 289                 }
 290                 while( $this->mPos <= $this->mMax ){
 291                         $this->mSet = array();
 292                         $sql = $this->mSql . " BETWEEN " . $this->mPos .
 293                                 " AND " . ($this->mPos + $this->mSetsize - 1);
 294                         $this->mPos += $this->mSetsize;
 295
 296                         $res = wfQuery( $sql, DB_READ );
 297                         while ( $row = wfFetchObject( $res ) ) {
 298                                 $this->mSet[] = $row;
 299                         }
 300                         wfFreeResult( $res );
 301                         if( count( $this->mSet ) > 0 ){
 302                                 return $this->next();
 303                         }
 304                 }
 305                 return false;
 306         }
 307 }
 308
 309 # A simple MRU for general cacheing.
 310
 311 class MRUCache {
 312         /* private */ var $mMru, $mCache, $mSize, $mPurgefreq, $nexti;
 313         /* private */ var $hits, $misses;
 314
 315         function MRUCache( $size, $purgefreq = -1 ) {
 316                 // purgefreq is 1/10 of $size if not stated
 317                 $purgefreq = ($purgefreq == -1 ? intval($size/10) : $purgefreq);
 318                 $purgefreq = ($purgefreq <= 0 ? 1 : $purgefreq);
 319
 320                 $this->mSize = $size;
 321                 $this->mMru = array();
 322                 $this->mCache = array();
 323                 $this->mPurgefreq = $purgefreq;
 324                 $this->nexti = 1;
 325                 print "purgefreq = " . $this->mPurgefreq . "\n";
 326         }
 327
 328         function get( $key ){
 329                 if ( ! array_key_exists( $key, $this->mCache) ){
 330                         $this->misses++;
 331                         return false;
 332                 }
 333                 $this->hits++;
 334                 $this->mMru[$key] = $this->nexti++;
 335                 return $this->mCache[$key];
 336         }
 337
 338         function set( $key, $value ){
 339                 $this->mMru[$key] = $this->nexti++;
 340                 $this->mCache[$key] = $value;
 341
 342                 if($this->nexti % $this->mPurgefreq == 0)
 343                         $this->purge();
 344         }
 345
 346         function purge(){
 347                 $to_remove = count( $this->mMru ) - $this->mSize;
 348                 if( $to_remove <= 0 ){
 349                         return;
 350                 }
 351                 asort( $this->mMru );
 352                 $removed = array_splice( $this->mMru, 0, $to_remove );
 353                 foreach( array_keys( $removed ) as $key ){
 354                         unset( $this->mCache[$key] );
 355                 }
 356         }
 357
 358         function getPerformance(){
 359                 $tot = $this->hits + $this->misses;
 360                 if($tot > 0)
 361                         return intval(100.0 * $this->hits / $tot);
 362                 else
 363                         return 0;
 364         }
 365 }
 366
 367 ?>