1 files changed, 202 insertions, 0 deletions
diff --git a/maintenance/convertLinks.inc b/maintenance/convertLinks.inc
new file mode 100644
index 000000000000..3a25930ff4ca
--- /dev/null
+++ b/maintenance/convertLinks.inc
@@ -0,0 +1,202 @@
+<?php
+
+function convertLinks() {
+	print "Converting links table to ID-ID...\n";
+	
+	global $wgLang, $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname;
+	global $noKeys, $logPerformance, $fh;
+	
+	$numRows = $tuplesAdded = $numBadLinks = $curRowsRead = 0; #counters etc
+	$totalTuplesInserted = 0; # total tuples INSERTed into links_temp
+
+	$reportCurReadProgress = true; #whether or not to give progress reports while reading IDs from cur table
+	$curReadReportInterval = 1000; #number of rows between progress reports
+
+	$reportLinksConvProgress = true; #whether or not to give progress reports during conversion
+	$linksConvInsertInterval = 1000; #number of rows per INSERT
+
+	$initialRowOffset = 0;
+	#$finalRowOffset = 0; # not used yet; highest row number from links table to process
+
+	# Overwrite the old links table with the new one.  If this is set to false,
+	# the new table will be left at links_temp.
+	$overwriteLinksTable = true;
+
+	# Don't create keys, and so allow duplicates in the new links table.
+	# This gives a huge speed improvement for very large links tables which are MyISAM. (What about InnoDB?)
+	$noKeys = false;
+
+
+	$logPerformance = false; # output performance data to a file
+	$perfLogFilename = "convLinksPerf.txt";
+	#--------------------------------------------------------------------
+
+	$res = wfQuery( "SELECT l_from FROM links LIMIT 1", DB_READ );
+	if ( mysql_field_type( $res, 0 ) == "int" ) {
+		print "Schema already converted\n";
+		return;
+	}
+	
+	$res = wfQuery( "SELECT COUNT(*) AS count FROM links", DB_WRITE );
+	$row = wfFetchObject($res);
+	$numRows = $row->count;
+	wfFreeResult( $res );
+
+	if ( $numRows == 0 ) {
+		print "Updating schema (no rows to convert)...\n";
+		createTempTable();
+	} else {
+		if ( $logPerformance ) { $fh = fopen ( $perfLogFilename, "w" ); }
+		$baseTime = $startTime = getMicroTime();
+		# Create a title -> cur_id map
+		print "Loading IDs from cur table...\n";
+		performanceLog ( "Reading $numRows rows from cur table...\n" );
+		performanceLog ( "rows read vs seconds elapsed:\n" );
+		wfBufferSQLResults( false );
+		$res = wfQuery( "SELECT cur_namespace,cur_title,cur_id FROM cur", DB_WRITE );
+		$ids = array();
+
+		while ( $row = wfFetchObject( $res ) ) {
+			$title = $row->cur_title;
+			if ( $row->cur_namespace ) {
+				$title = $wgLang->getNsText( $row->cur_namespace ) . ":$title";
+			}
+			$ids[$title] = $row->cur_id;
+			$curRowsRead++;
+			if ($reportCurReadProgress) {
+				if (($curRowsRead % $curReadReportInterval) == 0) {
+					performanceLog( $curRowsRead . " " . (getMicroTime() - $baseTime) . "\n" );
+					print "\t$curRowsRead rows of cur table read.\n";	
+				}
+			}
+		}
+		wfFreeResult( $res );
+		wfBufferSQLResults( true );
+		print "Finished loading IDs.\n\n";
+		performanceLog( "Took " . (getMicroTime() - $baseTime) . " seconds to load IDs.\n\n" );
+	#--------------------------------------------------------------------
+
+		# Now, step through the links table (in chunks of $linksConvInsertInterval rows),
+		# convert, and write to the new table.
+		createTempTable();
+		performanceLog( "Resetting timer.\n\n" );
+		$baseTime = getMicroTime();
+		print "Processing $numRows rows from links table...\n";
+		performanceLog( "Processing $numRows rows from links table...\n" );
+		performanceLog( "rows inserted vs seconds elapsed:\n" );
+		
+		for ($rowOffset = $initialRowOffset; $rowOffset < $numRows; $rowOffset += $linksConvInsertInterval) {
+			$sqlRead = "SELECT * FROM links ".wfLimitResult($linksConvInsertInterval,$rowOffset);
+			$res = wfQuery($sqlRead, DB_READ);
+			if ( $noKeys ) {
+				$sqlWrite = array("INSERT INTO links_temp(l_from,l_to) VALUES ");
+			} else {
+				$sqlWrite = array("INSERT IGNORE INTO links_temp(l_from,l_to) VALUES ");
+			}
+			
+			$tuplesAdded = 0; # no tuples added to INSERT yet
+			while ( $row = wfFetchObject($res) ) {
+				$fromTitle = $row->l_from; 
+				if ( array_key_exists( $fromTitle, $ids ) ) { # valid title
+					$from = $ids[$fromTitle];
+					$to = $row->l_to;
+					if ( $tuplesAdded != 0 ) {
+						$sqlWrite[] = ",";
+					}
+					$sqlWrite[] = "($from,$to)";
+					$tuplesAdded++;				
+				} else { # invalid title
+					$numBadLinks++;
+				}
+			}
+			wfFreeResult($res);
+			#print "rowOffset: $rowOffset\ttuplesAdded: $tuplesAdded\tnumBadLinks: $numBadLinks\n";
+			if ( $tuplesAdded != 0  ) {
+				if ($reportLinksConvProgress) {
+					print "Inserting $tuplesAdded tuples into links_temp...";
+				}
+				wfQuery( implode("",$sqlWrite) , DB_WRITE );
+				$totalTuplesInserted += $tuplesAdded;
+				if ($reportLinksConvProgress)
+					print " done. Total $totalTuplesInserted tuples inserted.\n";
+					performanceLog( $totalTuplesInserted . " " . (getMicroTime() - $baseTime) . "\n"  );
+			}
+		}
+		print "$totalTuplesInserted valid titles and $numBadLinks invalid titles were processed.\n\n";
+		performanceLog( "$totalTuplesInserted valid titles and $numBadLinks invalid titles were processed.\n" );
+		performanceLog( "Total execution time: " . (getMicroTime() - $startTime) . " seconds.\n" );
+		if ( $logPerformance ) { fclose ( $fh ); }
+	}
+	#--------------------------------------------------------------------
+
+	if ( $overwriteLinksTable ) {
+		$dbConn = Database::newFromParams( $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname );
+		if (!($dbConn->isOpen())) {
+			print "Opening connection to database failed.\n";
+			return;
+		}
+		# Check for existing links_backup, and delete it if it exists.
+		print "Dropping backup links table if it exists...";
+		$dbConn->query( "DROP TABLE IF EXISTS links_backup", DB_WRITE);
+		print " done.\n";
+		
+		# Swap in the new table, and move old links table to links_backup
+		print "Swapping tables 'links' to 'links_backup'; 'links_temp' to 'links'...";
+		$dbConn->query( "RENAME TABLE links TO links_backup, links_temp TO links", DB_WRITE );
+		print " done.\n\n";
+		
+		$dbConn->close();
+		print "Conversion complete. The old table remains at links_backup;\n";
+		print "delete at your leisure.\n";
+	} else {
+		print "Conversion complete.  The converted table is at links_temp;\n";
+		print "the original links table is unchanged.\n";
+	}
+}
+
+#--------------------------------------------------------------------
+
+function createTempTable() {
+	global $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname;
+	global $noKeys;
+	$dbConn = Database::newFromParams( $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname );
+	
+	if (!($dbConn->isOpen())) {
+		print "Opening connection to database failed.\n";
+		return;
+	}
+	
+	print "Dropping temporary links table if it exists...";
+	$dbConn->query( "DROP TABLE IF EXISTS links_temp", DB_WRITE);
+	print " done.\n";
+	
+	print "Creating temporary links table...";
+	if ( $noKeys ) {
+		$dbConn->query( "CREATE TABLE links_temp ( " .
+		"l_from int(8) unsigned NOT NULL default '0', " .
+		"l_to int(8) unsigned NOT NULL default '0')", DB_WRITE);
+	} else {
+		$dbConn->query( "CREATE TABLE links_temp ( " .
+		"l_from int(8) unsigned NOT NULL default '0', " .
+		"l_to int(8) unsigned NOT NULL default '0', " .
+		"UNIQUE KEY l_from(l_from,l_to), " .
+		"KEY (l_to))", DB_WRITE);
+	}
+	print " done.\n\n";
+}
+
+function performanceLog( $text ) {
+	global $logPerformance, $fh;
+	if ( $logPerformance ) {
+		fwrite( $fh, $text );
+	}
+}
+
+function getMicroTime() { # return time in seconds, with microsecond accuracy
+	list($usec, $sec) = explode(" ", microtime());
+	return ((float)$usec + (float)$sec);
+}
+
+
+
+?>