maintenance/convertLinks.inc

   1 <?php
   2
   3 function convertLinks() {
   4         print "Converting links table to ID-ID...\n";
   5
   6         global $wgLang, $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname;
   7         global $noKeys, $logPerformance, $fh;
   8
   9         $numRows = $tuplesAdded = $numBadLinks = $curRowsRead = 0; #counters etc
  10         $totalTuplesInserted = 0; # total tuples INSERTed into links_temp
  11
  12         $reportCurReadProgress = true; #whether or not to give progress reports while reading IDs from cur table
  13         $curReadReportInterval = 1000; #number of rows between progress reports
  14
  15         $reportLinksConvProgress = true; #whether or not to give progress reports during conversion
  16         $linksConvInsertInterval = 1000; #number of rows per INSERT
  17
  18         $initialRowOffset = 0;
  19         #$finalRowOffset = 0; # not used yet; highest row number from links table to process
  20
  21         # Overwrite the old links table with the new one.  If this is set to false,
  22         # the new table will be left at links_temp.
  23         $overwriteLinksTable = true;
  24
  25         # Don't create keys, and so allow duplicates in the new links table.
  26         # This gives a huge speed improvement for very large links tables which are MyISAM. (What about InnoDB?)
  27         $noKeys = false;
  28
  29
  30         $logPerformance = false; # output performance data to a file
  31         $perfLogFilename = "convLinksPerf.txt";
  32         #--------------------------------------------------------------------
  33
  34         $dbw =& wfGetDB( DB_MASTER );
  35         extract( $dbw->tableNames( 'cur', 'links', 'links_temp', 'links_backup' ) );
  36
  37         $res = $dbw->query( "SELECT l_from FROM $links LIMIT 1" );
  38         if ( $dbw->fieldType( $res, 0 ) == "int" ) {
  39                 print "Schema already converted\n";
  40                 return;
  41         }
  42
  43         $res = $dbw->query( "SELECT COUNT(*) AS count FROM $links" );
  44         $row = $dbw->fetchObject($res);
  45         $numRows = $row->count;
  46         $dbw->freeResult( $res );
  47
  48         if ( $numRows == 0 ) {
  49                 print "Updating schema (no rows to convert)...\n";
  50                 createTempTable();
  51         } else {
  52                 if ( $logPerformance ) { $fh = fopen ( $perfLogFilename, "w" ); }
  53                 $baseTime = $startTime = getMicroTime();
  54                 # Create a title -> cur_id map
  55                 print "Loading IDs from $cur table...\n";
  56                 performanceLog ( "Reading $numRows rows from cur table...\n" );
  57                 performanceLog ( "rows read vs seconds elapsed:\n" );
  58
  59                 $dbw->setBufferResults( false );
  60                 $res = $dbw->query( "SELECT cur_namespace,cur_title,cur_id FROM $cur" );
  61                 $ids = array();
  62
  63                 while ( $row = $dbw->fetchObject( $res ) ) {
  64                         $title = $row->cur_title;
  65                         if ( $row->cur_namespace ) {
  66                                 $title = $wgLang->getNsText( $row->cur_namespace ) . ":$title";
  67                         }
  68                         $ids[$title] = $row->cur_id;
  69                         $curRowsRead++;
  70                         if ($reportCurReadProgress) {
  71                                 if (($curRowsRead % $curReadReportInterval) == 0) {
  72                                         performanceLog( $curRowsRead . " " . (getMicroTime() - $baseTime) . "\n" );
  73                                         print "\t$curRowsRead rows of $cur table read.\n";
  74                                 }
  75                         }
  76                 }
  77                 $dbw->freeResult( $res );
  78                 $dbw->setBufferResults( true );
  79                 print "Finished loading IDs.\n\n";
  80                 performanceLog( "Took " . (getMicroTime() - $baseTime) . " seconds to load IDs.\n\n" );
  81         #--------------------------------------------------------------------
  82
  83                 # Now, step through the links table (in chunks of $linksConvInsertInterval rows),
  84                 # convert, and write to the new table.
  85                 createTempTable();
  86                 performanceLog( "Resetting timer.\n\n" );
  87                 $baseTime = getMicroTime();
  88                 print "Processing $numRows rows from $links table...\n";
  89                 performanceLog( "Processing $numRows rows from $links table...\n" );
  90                 performanceLog( "rows inserted vs seconds elapsed:\n" );
  91
  92                 for ($rowOffset = $initialRowOffset; $rowOffset < $numRows; $rowOffset += $linksConvInsertInterval) {
  93                         $sqlRead = "SELECT * FROM $links ".wfLimitResult($linksConvInsertInterval,$rowOffset);
  94                         $res = $dbw->query($sqlRead);
  95                         if ( $noKeys ) {
  96                                 $sqlWrite = array("INSERT INTO $links_temp (l_from,l_to) VALUES ");
  97                         } else {
  98                                 $sqlWrite = array("INSERT IGNORE INTO $links_temp (l_from,l_to) VALUES ");
  99                         }
 100
 101                         $tuplesAdded = 0; # no tuples added to INSERT yet
 102                         while ( $row = $dbw->fetchObject($res) ) {
 103                                 $fromTitle = $row->l_from;
 104                                 if ( array_key_exists( $fromTitle, $ids ) ) { # valid title
 105                                         $from = $ids[$fromTitle];
 106                                         $to = $row->l_to;
 107                                         if ( $tuplesAdded != 0 ) {
 108                                                 $sqlWrite[] = ",";
 109                                         }
 110                                         $sqlWrite[] = "($from,$to)";
 111                                         $tuplesAdded++;
 112                                 } else { # invalid title
 113                                         $numBadLinks++;
 114                                 }
 115                         }
 116                         $dbw->freeResult($res);
 117                         #print "rowOffset: $rowOffset\ttuplesAdded: $tuplesAdded\tnumBadLinks: $numBadLinks\n";
 118                         if ( $tuplesAdded != 0  ) {
 119                                 if ($reportLinksConvProgress) {
 120                                         print "Inserting $tuplesAdded tuples into $links_temp...";
 121                                 }
 122                                 $dbw->query( implode("",$sqlWrite) );
 123                                 $totalTuplesInserted += $tuplesAdded;
 124                                 if ($reportLinksConvProgress)
 125                                         print " done. Total $totalTuplesInserted tuples inserted.\n";
 126                                         performanceLog( $totalTuplesInserted . " " . (getMicroTime() - $baseTime) . "\n"  );
 127                         }
 128                 }
 129                 print "$totalTuplesInserted valid titles and $numBadLinks invalid titles were processed.\n\n";
 130                 performanceLog( "$totalTuplesInserted valid titles and $numBadLinks invalid titles were processed.\n" );
 131                 performanceLog( "Total execution time: " . (getMicroTime() - $startTime) . " seconds.\n" );
 132                 if ( $logPerformance ) { fclose ( $fh ); }
 133         }
 134         #--------------------------------------------------------------------
 135
 136         if ( $overwriteLinksTable ) {
 137                 $dbConn = Database::newFromParams( $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname );
 138                 if (!($dbConn->isOpen())) {
 139                         print "Opening connection to database failed.\n";
 140                         return;
 141                 }
 142                 # Check for existing links_backup, and delete it if it exists.
 143                 print "Dropping backup links table if it exists...";
 144                 $dbConn->query( "DROP TABLE IF EXISTS $links_backup", DB_MASTER);
 145                 print " done.\n";
 146
 147                 # Swap in the new table, and move old links table to links_backup
 148                 print "Swapping tables '$links' to '$links_backup'; '$links_temp' to '$links'...";
 149                 $dbConn->query( "RENAME TABLE links TO $links_backup, $links_temp TO $links", DB_MASTER );
 150                 print " done.\n\n";
 151
 152                 $dbConn->close();
 153                 print "Conversion complete. The old table remains at $links_backup;\n";
 154                 print "delete at your leisure.\n";
 155         } else {
 156                 print "Conversion complete.  The converted table is at $links_temp;\n";
 157                 print "the original links table is unchanged.\n";
 158         }
 159 }
 160
 161 #--------------------------------------------------------------------
 162
 163 function createTempTable() {
 164         global $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname;
 165         global $noKeys;
 166         $dbConn = Database::newFromParams( $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname );
 167
 168         if (!($dbConn->isOpen())) {
 169                 print "Opening connection to database failed.\n";
 170                 return;
 171         }
 172         $links_temp = $dbConn->tableName( 'links_temp' );
 173
 174         print "Dropping temporary links table if it exists...";
 175         $dbConn->query( "DROP TABLE IF EXISTS $links_temp");
 176         print " done.\n";
 177
 178         print "Creating temporary links table...";
 179         if ( $noKeys ) {
 180                 $dbConn->query( "CREATE TABLE $links_temp ( " .
 181                 "l_from int(8) unsigned NOT NULL default '0', " .
 182                 "l_to int(8) unsigned NOT NULL default '0')");
 183         } else {
 184                 $dbConn->query( "CREATE TABLE $links_temp ( " .
 185                 "l_from int(8) unsigned NOT NULL default '0', " .
 186                 "l_to int(8) unsigned NOT NULL default '0', " .
 187                 "UNIQUE KEY l_from(l_from,l_to), " .
 188                 "KEY (l_to))");
 189         }
 190         print " done.\n\n";
 191 }
 192
 193 function performanceLog( $text ) {
 194         global $logPerformance, $fh;
 195         if ( $logPerformance ) {
 196                 fwrite( $fh, $text );
 197         }
 198 }
 199
 200 function getMicroTime() { # return time in seconds, with microsecond accuracy
 201         list($usec, $sec) = explode(" ", microtime());
 202         return ((float)$usec + (float)$sec);
 203 }
 204
 205
 206
 207 ?>