X-Git-Url: https://scripts.mit.edu/gitweb/autoinstalls/mediawiki.git/blobdiff_plain/74c929b24b048c9f1e31e17db757ae4195cd7673..83d871ca0d985c6d586b323bf96161afb510ebf6:/maintenance/dumpTextPass.php

diff --git a/maintenance/dumpTextPass.php b/maintenance/dumpTextPass.php
index e85fe421..2b79b546 100644
--- a/maintenance/dumpTextPass.php
+++ b/maintenance/dumpTextPass.php
@@ -1,7 +1,9 @@
 <?php
 /**
+ * BackupDumper that postprocesses XML dumps from dumpBackup.php to add page text
+ *
  * Copyright (C) 2005 Brion Vibber <brion@pobox.com>
- * http://www.mediawiki.org/
+ * https://www.mediawiki.org/
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -22,201 +24,400 @@
  * @ingroup Maintenance
  */
 
-$originalDir = getcwd();
+require_once __DIR__ . '/backup.inc';
+require_once __DIR__ . '/../includes/export/WikiExporter.php';
 
-require_once( 'commandLine.inc' );
-require_once( 'backup.inc' );
+use Wikimedia\Rdbms\IMaintainableDatabase;
 
 /**
- * Stream wrapper around 7za filter program.
- * Required since we can't pass an open file resource to XMLReader->open()
- * which is used for the text prefetch.
- *
  * @ingroup Maintenance
  */
-class SevenZipStream {
-	var $stream;
-	
-	private function stripPath( $path ) {
-		$prefix = 'mediawiki.compress.7z://';
-		return substr( $path, strlen( $prefix ) );
-	}
-	
-	function stream_open( $path, $mode, $options, &$opened_path ) {
-		if( $mode{0} == 'r' ) {
-			$options = 'e -bd -so';
-		} elseif( $mode{0} == 'w' ) {
-			$options = 'a -bd -si';
-		} else {
-			return false;
-		}
-		$arg = wfEscapeShellArg( $this->stripPath( $path ) );
-		$command = "7za $options $arg";
-		if( !wfIsWindows() ) {
-			// Suppress the stupid messages on stderr
-			$command .= ' 2>/dev/null';
+class TextPassDumper extends BackupDumper {
+	/** @var BaseDump */
+	public $prefetch = null;
+	/** @var string|bool */
+	private $thisPage;
+	/** @var string|bool */
+	private $thisRev;
+
+	// when we spend more than maxTimeAllowed seconds on this run, we continue
+	// processing until we write out the next complete page, then save output file(s),
+	// rename it/them and open new one(s)
+	public $maxTimeAllowed = 0; // 0 = no limit
+
+	protected $input = "php://stdin";
+	protected $history = WikiExporter::FULL;
+	protected $fetchCount = 0;
+	protected $prefetchCount = 0;
+	protected $prefetchCountLast = 0;
+	protected $fetchCountLast = 0;
+
+	protected $maxFailures = 5;
+	protected $maxConsecutiveFailedTextRetrievals = 200;
+	protected $failureTimeout = 5; // Seconds to sleep after db failure
+
+	protected $bufferSize = 524288; // In bytes. Maximum size to read from the stub in on go.
+
+	protected $php = "php";
+	protected $spawn = false;
+
+	/**
+	 * @var bool|resource
+	 */
+	protected $spawnProc = false;
+
+	/**
+	 * @var bool|resource
+	 */
+	protected $spawnWrite = false;
+
+	/**
+	 * @var bool|resource
+	 */
+	protected $spawnRead = false;
+
+	/**
+	 * @var bool|resource
+	 */
+	protected $spawnErr = false;
+
+	/**
+	 * @var bool|XmlDumpWriter
+	 */
+	protected $xmlwriterobj = false;
+
+	protected $timeExceeded = false;
+	protected $firstPageWritten = false;
+	protected $lastPageWritten = false;
+	protected $checkpointJustWritten = false;
+	protected $checkpointFiles = [];
+
+	/**
+	 * @var IMaintainableDatabase
+	 */
+	protected $db;
+
+	/**
+	 * @param array $args For backward compatibility
+	 */
+	function __construct( $args = null ) {
+		parent::__construct();
+
+		$this->addDescription( <<<TEXT
+This script postprocesses XML dumps from dumpBackup.php to add
+page text which was stubbed out (using --stub).
+
+XML input is accepted on stdin.
+XML output is sent to stdout; progress reports are sent to stderr.
+TEXT
+		);
+		$this->stderr = fopen( "php://stderr", "wt" );
+
+		$this->addOption( 'stub', 'To load a compressed stub dump instead of stdin. ' .
+			'Specify as --stub=<type>:<file>.', false, true );
+		$this->addOption( 'prefetch', 'Use a prior dump file as a text source, to savepressure on the ' .
+			'database. (Requires the XMLReader extension). Specify as --prefetch=<type>:<file>',
+			false, true );
+		$this->addOption( 'maxtime', 'Write out checkpoint file after this many minutes (writing' .
+			'out complete page, closing xml file properly, and opening new one' .
+			'with header).  This option requires the checkpointfile option.', false, true );
+		$this->addOption( 'checkpointfile', 'Use this string for checkpoint filenames,substituting ' .
+			'first pageid written for the first %s (required) and the last pageid written for the ' .
+			'second %s if it exists.', false, true, false, true ); // This can be specified multiple times
+		$this->addOption( 'quiet', 'Don\'t dump status reports to stderr.' );
+		$this->addOption( 'current', 'Base ETA on number of pages in database instead of all revisions' );
+		$this->addOption( 'spawn', 'Spawn a subprocess for loading text records' );
+		$this->addOption( 'buffersize', 'Buffer size in bytes to use for reading the stub. ' .
+			'(Default: 512KB, Minimum: 4KB)', false, true );
+
+		if ( $args ) {
+			$this->loadWithArgv( $args );
+			$this->processOptions();
 		}
-		$this->stream = popen( $command, $mode );
-		return ($this->stream !== false);
-	}
-	
-	function url_stat( $path, $flags ) {
-		return stat( $this->stripPath( $path ) );
 	}
-	
-	// This is all so lame; there should be a default class we can extend
-	
-	function stream_close() {
-		return fclose( $this->stream );
-	}
-	
-	function stream_flush() {
-		return fflush( $this->stream );
-	}
-	
-	function stream_read( $count ) {
-		return fread( $this->stream, $count );
-	}
-	
-	function stream_write( $data ) {
-		return fwrite( $this->stream, $data );
+
+	function execute() {
+		$this->processOptions();
+		$this->dump( true );
 	}
-	
-	function stream_tell() {
-		return ftell( $this->stream );
+
+	function processOptions() {
+		global $IP;
+
+		parent::processOptions();
+
+		if ( $this->hasOption( 'buffersize' ) ) {
+			$this->bufferSize = max( intval( $this->getOption( 'buffersize' ) ), 4 * 1024 );
+		}
+
+		if ( $this->hasOption( 'prefetch' ) ) {
+			require_once "$IP/maintenance/backupPrefetch.inc";
+			$url = $this->processFileOpt( $this->getOption( 'prefetch' ) );
+			$this->prefetch = new BaseDump( $url );
+		}
+
+		if ( $this->hasOption( 'stub' ) ) {
+			$this->input = $this->processFileOpt( $this->getOption( 'stub' ) );
+		}
+
+		if ( $this->hasOption( 'maxtime' ) ) {
+			$this->maxTimeAllowed = intval( $this->getOption( 'maxtime' ) ) * 60;
+		}
+
+		if ( $this->hasOption( 'checkpointfile' ) ) {
+			$this->checkpointFiles = $this->getOption( 'checkpointfile' );
+		}
+
+		if ( $this->hasOption( 'current' ) ) {
+			$this->history = WikiExporter::CURRENT;
+		}
+
+		if ( $this->hasOption( 'full' ) ) {
+			$this->history = WikiExporter::FULL;
+		}
+
+		if ( $this->hasOption( 'spawn' ) ) {
+			$this->spawn = true;
+			$val = $this->getOption( 'spawn' );
+			if ( $val !== 1 ) {
+				$this->php = $val;
+			}
+		}
 	}
-	
-	function stream_eof() {
-		return feof( $this->stream );
+
+	/**
+	 * Drop the database connection $this->db and try to get a new one.
+	 *
+	 * This function tries to get a /different/ connection if this is
+	 * possible. Hence, (if this is possible) it switches to a different
+	 * failover upon each call.
+	 *
+	 * This function resets $this->lb and closes all connections on it.
+	 *
+	 * @throws MWException
+	 */
+	function rotateDb() {
+		// Cleaning up old connections
+		if ( isset( $this->lb ) ) {
+			$this->lb->closeAll();
+			unset( $this->lb );
+		}
+
+		if ( $this->forcedDb !== null ) {
+			$this->db = $this->forcedDb;
+
+			return;
+		}
+
+		if ( isset( $this->db ) && $this->db->isOpen() ) {
+			throw new MWException( 'DB is set and has not been closed by the Load Balancer' );
+		}
+
+		unset( $this->db );
+
+		// Trying to set up new connection.
+		// We do /not/ retry upon failure, but delegate to encapsulating logic, to avoid
+		// individually retrying at different layers of code.
+
+		try {
+			$this->lb = wfGetLBFactory()->newMainLB();
+		} catch ( Exception $e ) {
+			throw new MWException( __METHOD__
+				. " rotating DB failed to obtain new load balancer (" . $e->getMessage() . ")" );
+		}
+
+		try {
+			$this->db = $this->lb->getConnection( DB_REPLICA, 'dump' );
+		} catch ( Exception $e ) {
+			throw new MWException( __METHOD__
+				. " rotating DB failed to obtain new database (" . $e->getMessage() . ")" );
+		}
 	}
-	
-	function stream_seek( $offset, $whence ) {
-		return fseek( $this->stream, $offset, $whence );
+
+	function initProgress( $history = WikiExporter::FULL ) {
+		parent::initProgress();
+		$this->timeOfCheckpoint = $this->startTime;
 	}
-}
-stream_wrapper_register( 'mediawiki.compress.7z', 'SevenZipStream' );
 
-/**
- * @ingroup Maintenance
- */
-class TextPassDumper extends BackupDumper {
-	var $prefetch = null;
-	var $input = "php://stdin";
-	var $history = WikiExporter::FULL;
-	var $fetchCount = 0;
-	var $prefetchCount = 0;
-	
-	var $failures = 0;
-	var $maxFailures = 200;
-	var $failureTimeout = 5; // Seconds to sleep after db failure
-	
-	var $php = "php";
-	var $spawn = false;
-	var $spawnProc = false;
-	var $spawnWrite = false;
-	var $spawnRead = false;
-	var $spawnErr = false;
-
-	function dump() {
-		# This shouldn't happen if on console... ;)
-		header( 'Content-type: text/html; charset=UTF-8' );
-
-		# Notice messages will foul up your XML output even if they're
-		# relatively harmless.
-		if( ini_get( 'display_errors' ) )
+	function dump( $history, $text = WikiExporter::TEXT ) {
+		// Notice messages will foul up your XML output even if they're
+		// relatively harmless.
+		if ( ini_get( 'display_errors' ) ) {
 			ini_set( 'display_errors', 'stderr' );
+		}
 
 		$this->initProgress( $this->history );
 
-		$this->db = $this->backupDb();
+		// We are trying to get an initial database connection to avoid that the
+		// first try of this request's first call to getText fails. However, if
+		// obtaining a good DB connection fails it's not a serious issue, as
+		// getText does retry upon failure and can start without having a working
+		// DB connection.
+		try {
+			$this->rotateDb();
+		} catch ( Exception $e ) {
+			// We do not even count this as failure. Just let eventual
+			// watchdogs know.
+			$this->progress( "Getting initial DB connection failed (" .
+				$e->getMessage() . ")" );
+		}
 
 		$this->egress = new ExportProgressFilter( $this->sink, $this );
 
+		// it would be nice to do it in the constructor, oh well. need egress set
+		$this->finalOptionCheck();
+
+		// we only want this so we know how to close a stream :-P
+		$this->xmlwriterobj = new XmlDumpWriter();
+
 		$input = fopen( $this->input, "rt" );
-		$result = $this->readDump( $input );
+		$this->readDump( $input );
 
-		if( WikiError::isError( $result ) ) {
-			wfDie( $result->getMessage() );
-		}
-		
-		if( $this->spawnProc ) {
+		if ( $this->spawnProc ) {
 			$this->closeSpawn();
 		}
 
 		$this->report( true );
 	}
 
-	function processOption( $opt, $val, $param ) {
-		$url = $this->processFileOpt( $val, $param );
-		
-		switch( $opt ) {
-		case 'prefetch':
-			global $IP;
-			require_once "$IP/maintenance/backupPrefetch.inc";
-			$this->prefetch = new BaseDump( $url );
-			break;
-		case 'stub':
-			$this->input = $url;
-			break;
-		case 'current':
-			$this->history = WikiExporter::CURRENT;
-			break;
-		case 'full':
-			$this->history = WikiExporter::FULL;
-			break;
-		case 'spawn':
-			$this->spawn = true;
-			if( $val ) {
-				$this->php = $val;
-			}
-			break;
+	function processFileOpt( $opt ) {
+		$split = explode( ':', $opt, 2 );
+		$val = $split[0];
+		$param = '';
+		if ( count( $split ) === 2 ) {
+			$param = $split[1];
 		}
-	}
-	
-	function processFileOpt( $val, $param ) {
-		switch( $val ) {
-		case "file":
-			return $param;
-		case "gzip":
-			return "compress.zlib://$param";
-		case "bzip2":
-			return "compress.bzip2://$param";
-		case "7zip":
-			return "mediawiki.compress.7z://$param";
-		default:
-			return $val;
+		$fileURIs = explode( ';', $param );
+		foreach ( $fileURIs as $URI ) {
+			switch ( $val ) {
+				case "file":
+					$newURI = $URI;
+					break;
+				case "gzip":
+					$newURI = "compress.zlib://$URI";
+					break;
+				case "bzip2":
+					$newURI = "compress.bzip2://$URI";
+					break;
+				case "7zip":
+					$newURI = "mediawiki.compress.7z://$URI";
+					break;
+				default:
+					$newURI = $URI;
+			}
+			$newFileURIs[] = $newURI;
 		}
+		$val = implode( ';', $newFileURIs );
+
+		return $val;
 	}
 
 	/**
 	 * Overridden to include prefetch ratio if enabled.
 	 */
 	function showReport() {
-		if( !$this->prefetch ) {
-			return parent::showReport();
+		if ( !$this->prefetch ) {
+			parent::showReport();
+
+			return;
 		}
-		
-		if( $this->reporting ) {
-			$delta = wfTime() - $this->startTime;
+
+		if ( $this->reporting ) {
 			$now = wfTimestamp( TS_DB );
-			if( $delta ) {
-				$rate = $this->pageCount / $delta;
-				$revrate = $this->revCount / $delta;
+			$nowts = microtime( true );
+			$deltaAll = $nowts - $this->startTime;
+			$deltaPart = $nowts - $this->lastTime;
+			$this->pageCountPart = $this->pageCount - $this->pageCountLast;
+			$this->revCountPart = $this->revCount - $this->revCountLast;
+
+			if ( $deltaAll ) {
 				$portion = $this->revCount / $this->maxCount;
-				$eta = $this->startTime + $delta / $portion;
+				$eta = $this->startTime + $deltaAll / $portion;
 				$etats = wfTimestamp( TS_DB, intval( $eta ) );
-				$fetchrate = 100.0 * $this->prefetchCount / $this->fetchCount;
+				if ( $this->fetchCount ) {
+					$fetchRate = 100.0 * $this->prefetchCount / $this->fetchCount;
+				} else {
+					$fetchRate = '-';
+				}
+				$pageRate = $this->pageCount / $deltaAll;
+				$revRate = $this->revCount / $deltaAll;
 			} else {
-				$rate = '-';
-				$revrate = '-';
+				$pageRate = '-';
+				$revRate = '-';
 				$etats = '-';
-				$fetchrate = '-';
+				$fetchRate = '-';
+			}
+			if ( $deltaPart ) {
+				if ( $this->fetchCountLast ) {
+					$fetchRatePart = 100.0 * $this->prefetchCountLast / $this->fetchCountLast;
+				} else {
+					$fetchRatePart = '-';
+				}
+				$pageRatePart = $this->pageCountPart / $deltaPart;
+				$revRatePart = $this->revCountPart / $deltaPart;
+			} else {
+				$fetchRatePart = '-';
+				$pageRatePart = '-';
+				$revRatePart = '-';
 			}
-			$this->progress( sprintf( "%s: %s %d pages (%0.3f/sec), %d revs (%0.3f/sec), %0.1f%% prefetched, ETA %s [max %d]",
-				$now, wfWikiID(), $this->pageCount, $rate, $this->revCount, $revrate, $fetchrate, $etats, $this->maxCount ) );
+			$this->progress( sprintf(
+				"%s: %s (ID %d) %d pages (%0.1f|%0.1f/sec all|curr), "
+					. "%d revs (%0.1f|%0.1f/sec all|curr), %0.1f%%|%0.1f%% "
+					. "prefetched (all|curr), ETA %s [max %d]",
+				$now, wfWikiID(), $this->ID, $this->pageCount, $pageRate,
+				$pageRatePart, $this->revCount, $revRate, $revRatePart,
+				$fetchRate, $fetchRatePart, $etats, $this->maxCount
+			) );
+			$this->lastTime = $nowts;
+			$this->revCountLast = $this->revCount;
+			$this->prefetchCountLast = $this->prefetchCount;
+			$this->fetchCountLast = $this->fetchCount;
 		}
 	}
 
+	function setTimeExceeded() {
+		$this->timeExceeded = true;
+	}
+
+	function checkIfTimeExceeded() {
+		if ( $this->maxTimeAllowed
+			&& ( $this->lastTime - $this->timeOfCheckpoint > $this->maxTimeAllowed )
+		) {
+			return true;
+		}
+
+		return false;
+	}
+
+	function finalOptionCheck() {
+		if ( ( $this->checkpointFiles && !$this->maxTimeAllowed )
+			|| ( $this->maxTimeAllowed && !$this->checkpointFiles )
+		) {
+			throw new MWException( "Options checkpointfile and maxtime must be specified together.\n" );
+		}
+		foreach ( $this->checkpointFiles as $checkpointFile ) {
+			$count = substr_count( $checkpointFile, "%s" );
+			if ( $count != 2 ) {
+				throw new MWException( "Option checkpointfile must contain two '%s' "
+					. "for substitution of first and last pageids, count is $count instead, "
+					. "file is $checkpointFile.\n" );
+			}
+		}
+
+		if ( $this->checkpointFiles ) {
+			$filenameList = (array)$this->egress->getFilenames();
+			if ( count( $filenameList ) != count( $this->checkpointFiles ) ) {
+				throw new MWException( "One checkpointfile must be specified "
+					. "for each output option, if maxtime is used.\n" );
+			}
+		}
+	}
+
+	/**
+	 * @throws MWException Failure to parse XML input
+	 * @param string $input
+	 * @return bool
+	 */
 	function readDump( $input ) {
 		$this->buffer = "";
 		$this->openElement = false;
@@ -225,249 +426,530 @@ class TextPassDumper extends BackupDumper {
 		$this->lastName = "";
 		$this->thisPage = 0;
 		$this->thisRev = 0;
+		$this->thisRevModel = null;
+		$this->thisRevFormat = null;
 
 		$parser = xml_parser_create( "UTF-8" );
 		xml_parser_set_option( $parser, XML_OPTION_CASE_FOLDING, false );
 
-		xml_set_element_handler( $parser, array( &$this, 'startElement' ), array( &$this, 'endElement' ) );
-		xml_set_character_data_handler( $parser, array( &$this, 'characterData' ) );
+		xml_set_element_handler(
+			$parser,
+			[ $this, 'startElement' ],
+			[ $this, 'endElement' ]
+		);
+		xml_set_character_data_handler( $parser, [ $this, 'characterData' ] );
 
 		$offset = 0; // for context extraction on error reporting
-		$bufferSize = 512 * 1024;
 		do {
-			$chunk = fread( $input, $bufferSize );
-			if( !xml_parse( $parser, $chunk, feof( $input ) ) ) {
+			if ( $this->checkIfTimeExceeded() ) {
+				$this->setTimeExceeded();
+			}
+			$chunk = fread( $input, $this->bufferSize );
+			if ( !xml_parse( $parser, $chunk, feof( $input ) ) ) {
 				wfDebug( "TextDumpPass::readDump encountered XML parsing error\n" );
-				return new WikiXmlError( $parser, 'XML import parse failure', $chunk, $offset );
+
+				$byte = xml_get_current_byte_index( $parser );
+				$msg = wfMessage( 'xml-error-string',
+					'XML import parse failure',
+					xml_get_current_line_number( $parser ),
+					xml_get_current_column_number( $parser ),
+					$byte . ( is_null( $chunk ) ? null : ( '; "' . substr( $chunk, $byte - $offset, 16 ) . '"' ) ),
+					xml_error_string( xml_get_error_code( $parser ) ) )->escaped();
+
+				xml_parser_free( $parser );
+
+				throw new MWException( $msg );
 			}
 			$offset += strlen( $chunk );
-		} while( $chunk !== false && !feof( $input ) );
+		} while ( $chunk !== false && !feof( $input ) );
+		if ( $this->maxTimeAllowed ) {
+			$filenameList = (array)$this->egress->getFilenames();
+			// we wrote some stuff after last checkpoint that needs renamed
+			if ( file_exists( $filenameList[0] ) ) {
+				$newFilenames = [];
+				# we might have just written the header and footer and had no
+				# pages or revisions written... perhaps they were all deleted
+				# there's no pageID 0 so we use that. the caller is responsible
+				# for deciding what to do with a file containing only the
+				# siteinfo information and the mw tags.
+				if ( !$this->firstPageWritten ) {
+					$firstPageID = str_pad( 0, 9, "0", STR_PAD_LEFT );
+					$lastPageID = str_pad( 0, 9, "0", STR_PAD_LEFT );
+				} else {
+					$firstPageID = str_pad( $this->firstPageWritten, 9, "0", STR_PAD_LEFT );
+					$lastPageID = str_pad( $this->lastPageWritten, 9, "0", STR_PAD_LEFT );
+				}
+
+				$filenameCount = count( $filenameList );
+				for ( $i = 0; $i < $filenameCount; $i++ ) {
+					$checkpointNameFilledIn = sprintf( $this->checkpointFiles[$i], $firstPageID, $lastPageID );
+					$fileinfo = pathinfo( $filenameList[$i] );
+					$newFilenames[] = $fileinfo['dirname'] . '/' . $checkpointNameFilledIn;
+				}
+				$this->egress->closeAndRename( $newFilenames );
+			}
+		}
 		xml_parser_free( $parser );
-		
+
 		return true;
 	}
 
-	function getText( $id ) {
-		$this->fetchCount++;
-		if( isset( $this->prefetch ) ) {
-			$text = $this->prefetch->prefetch( $this->thisPage, $this->thisRev );
-			if( $text === null ) {
-				// Entry missing from prefetch dump
-			} elseif( $text === "" ) {
-				// Blank entries may indicate that the prior dump was broken.
-				// To be safe, reload it.
-			} else {
-				$this->prefetchCount++;
-				return $text;
-			}
+	/**
+	 * Applies applicable export transformations to $text.
+	 *
+	 * @param string $text
+	 * @param string $model
+	 * @param string|null $format
+	 *
+	 * @return string
+	 */
+	private function exportTransform( $text, $model, $format = null ) {
+		try {
+			$handler = ContentHandler::getForModelID( $model );
+			$text = $handler->exportTransform( $text, $format );
 		}
-		return $this->doGetText( $id );
-	}
-	
-	private function doGetText( $id ) {
-		if( $this->spawn ) {
-			return $this->getTextSpawned( $id );
-		} else {
-			return $this->getTextDbSafe( $id );
+		catch ( MWException $ex ) {
+			$this->progress(
+				"Unable to apply export transformation for content model '$model': " .
+				$ex->getMessage()
+			);
 		}
+
+		return $text;
 	}
-	
+
 	/**
-	 * Fetch a text revision from the database, retrying in case of failure.
-	 * This may survive some transitory errors by reconnecting, but
-	 * may not survive a long-term server outage.
+	 * Tries to get the revision text for a revision id.
+	 * Export transformations are applied if the content model can is given or can be
+	 * determined from the database.
+	 *
+	 * Upon errors, retries (Up to $this->maxFailures tries each call).
+	 * If still no good revision get could be found even after this retrying, "" is returned.
+	 * If no good revision text could be returned for
+	 * $this->maxConsecutiveFailedTextRetrievals consecutive calls to getText, MWException
+	 * is thrown.
+	 *
+	 * @param string $id The revision id to get the text for
+	 * @param string|bool|null $model The content model used to determine
+	 *  applicable export transformations.
+	 *  If $model is null, it will be determined from the database.
+	 * @param string|null $format The content format used when applying export transformations.
+	 *
+	 * @throws MWException
+	 * @return string The revision text for $id, or ""
 	 */
-	private function getTextDbSafe( $id ) {
-		while( true ) {
+	function getText( $id, $model = null, $format = null ) {
+		global $wgContentHandlerUseDB;
+
+		$prefetchNotTried = true; // Whether or not we already tried to get the text via prefetch.
+		$text = false; // The candidate for a good text. false if no proper value.
+		$failures = 0; // The number of times, this invocation of getText already failed.
+
+		// The number of times getText failed without yielding a good text in between.
+		static $consecutiveFailedTextRetrievals = 0;
+
+		$this->fetchCount++;
+
+		// To allow to simply return on success and do not have to worry about book keeping,
+		// we assume, this fetch works (possible after some retries). Nevertheless, we koop
+		// the old value, so we can restore it, if problems occur (See after the while loop).
+		$oldConsecutiveFailedTextRetrievals = $consecutiveFailedTextRetrievals;
+		$consecutiveFailedTextRetrievals = 0;
+
+		if ( $model === null && $wgContentHandlerUseDB ) {
+			$row = $this->db->selectRow(
+				'revision',
+				[ 'rev_content_model', 'rev_content_format' ],
+				[ 'rev_id' => $this->thisRev ],
+				__METHOD__
+			);
+
+			if ( $row ) {
+				$model = $row->rev_content_model;
+				$format = $row->rev_content_format;
+			}
+		}
+
+		if ( $model === null || $model === '' ) {
+			$model = false;
+		}
+
+		while ( $failures < $this->maxFailures ) {
+			// As soon as we found a good text for the $id, we will return immediately.
+			// Hence, if we make it past the try catch block, we know that we did not
+			// find a good text.
+
 			try {
-				$text = $this->getTextDb( $id );
-				$ex = new MWException("Graceful storage failure");
-			} catch (DBQueryError $ex) {
+				// Step 1: Get some text (or reuse from previous iteratuon if checking
+				//         for plausibility failed)
+
+				// Trying to get prefetch, if it has not been tried before
+				if ( $text === false && isset( $this->prefetch ) && $prefetchNotTried ) {
+					$prefetchNotTried = false;
+					$tryIsPrefetch = true;
+					$text = $this->prefetch->prefetch( (int)$this->thisPage, (int)$this->thisRev );
+
+					if ( $text === null ) {
+						$text = false;
+					}
+
+					if ( is_string( $text ) && $model !== false ) {
+						// Apply export transformation to text coming from an old dump.
+						// The purpose of this transformation is to convert up from legacy
+						// formats, which may still be used in the older dump that is used
+						// for pre-fetching. Applying the transformation again should not
+						// interfere with content that is already in the correct form.
+						$text = $this->exportTransform( $text, $model, $format );
+					}
+				}
+
+				if ( $text === false ) {
+					// Fallback to asking the database
+					$tryIsPrefetch = false;
+					if ( $this->spawn ) {
+						$text = $this->getTextSpawned( $id );
+					} else {
+						$text = $this->getTextDb( $id );
+					}
+
+					if ( $text !== false && $model !== false ) {
+						// Apply export transformation to text coming from the database.
+						// Prefetched text should already have transformations applied.
+						$text = $this->exportTransform( $text, $model, $format );
+					}
+
+					// No more checks for texts from DB for now.
+					// If we received something that is not false,
+					// We treat it as good text, regardless of whether it actually is or is not
+					if ( $text !== false ) {
+						return $text;
+					}
+				}
+
+				if ( $text === false ) {
+					throw new MWException( "Generic error while obtaining text for id " . $id );
+				}
+
+				// We received a good candidate for the text of $id via some method
+
+				// Step 2: Checking for plausibility and return the text if it is
+				//         plausible
+				$revID = intval( $this->thisRev );
+				if ( !isset( $this->db ) ) {
+					throw new MWException( "No database available" );
+				}
+
+				if ( $model !== CONTENT_MODEL_WIKITEXT ) {
+					$revLength = strlen( $text );
+				} else {
+					$revLength = $this->db->selectField( 'revision', 'rev_len', [ 'rev_id' => $revID ] );
+				}
+
+				if ( strlen( $text ) == $revLength ) {
+					if ( $tryIsPrefetch ) {
+						$this->prefetchCount++;
+					}
+
+					return $text;
+				}
+
 				$text = false;
+				throw new MWException( "Received text is unplausible for id " . $id );
+			} catch ( Exception $e ) {
+				$msg = "getting/checking text " . $id . " failed (" . $e->getMessage() . ")";
+				if ( $failures + 1 < $this->maxFailures ) {
+					$msg .= " (Will retry " . ( $this->maxFailures - $failures - 1 ) . " more times)";
+				}
+				$this->progress( $msg );
 			}
-			if( $text === false ) {
-				$this->failures++;
-				if( $this->failures > $this->maxFailures ) {
-					throw $ex;
-				} else {
-					$this->progress( "Database failure $this->failures " .
-						"of allowed $this->maxFailures for revision $id! " .
-						"Pausing $this->failureTimeout seconds..." );
-					sleep( $this->failureTimeout );
+
+			// Something went wrong; we did not a text that was plausible :(
+			$failures++;
+
+			// A failure in a prefetch hit does not warrant resetting db connection etc.
+			if ( !$tryIsPrefetch ) {
+				// After backing off for some time, we try to reboot the whole process as
+				// much as possible to not carry over failures from one part to the other
+				// parts
+				sleep( $this->failureTimeout );
+				try {
+					$this->rotateDb();
+					if ( $this->spawn ) {
+						$this->closeSpawn();
+						$this->openSpawn();
+					}
+				} catch ( Exception $e ) {
+					$this->progress( "Rebooting getText infrastructure failed (" . $e->getMessage() . ")" .
+						" Trying to continue anyways" );
 				}
-			} else {
-				return $text;
 			}
 		}
+
+		// Retirieving a good text for $id failed (at least) maxFailures times.
+		// We abort for this $id.
+
+		// Restoring the consecutive failures, and maybe aborting, if the dump
+		// is too broken.
+		$consecutiveFailedTextRetrievals = $oldConsecutiveFailedTextRetrievals + 1;
+		if ( $consecutiveFailedTextRetrievals > $this->maxConsecutiveFailedTextRetrievals ) {
+			throw new MWException( "Graceful storage failure" );
+		}
+
+		return "";
 	}
-	
+
 	/**
 	 * May throw a database error if, say, the server dies during query.
+	 * @param int $id
+	 * @return bool|string
+	 * @throws MWException
 	 */
 	private function getTextDb( $id ) {
-		$id = intval( $id );
+		global $wgContLang;
+		if ( !isset( $this->db ) ) {
+			throw new MWException( __METHOD__ . "No database available" );
+		}
 		$row = $this->db->selectRow( 'text',
-			array( 'old_text', 'old_flags' ),
-			array( 'old_id' => $id ),
-			'TextPassDumper::getText' );
+			[ 'old_text', 'old_flags' ],
+			[ 'old_id' => $id ],
+			__METHOD__ );
 		$text = Revision::getRevisionText( $row );
-		if( $text === false ) {
+		if ( $text === false ) {
 			return false;
 		}
 		$stripped = str_replace( "\r", "", $text );
-		$normalized = UtfNormal::cleanUp( $stripped );
+		$normalized = $wgContLang->normalize( $stripped );
+
 		return $normalized;
 	}
-	
+
 	private function getTextSpawned( $id ) {
-		wfSuppressWarnings();
-		if( !$this->spawnProc ) {
+		MediaWiki\suppressWarnings();
+		if ( !$this->spawnProc ) {
 			// First time?
 			$this->openSpawn();
 		}
-		while( true ) {
-			
-			$text = $this->getTextSpawnedOnce( $id );
-			if( !is_string( $text ) ) {
-				$this->progress("Database subprocess failed. Respawning...");
-				
-				$this->closeSpawn();
-				sleep( $this->failureTimeout );
-				$this->openSpawn();
-				
-				continue;
-			}
-			wfRestoreWarnings();
-			return $text;
-		}
+		$text = $this->getTextSpawnedOnce( $id );
+		MediaWiki\restoreWarnings();
+
+		return $text;
 	}
-	
+
 	function openSpawn() {
-		global $IP, $wgDBname;
-		
-		$cmd = implode( " ",
-			array_map( 'wfEscapeShellArg',
-				array(
-					$this->php,
-					"$IP/maintenance/fetchText.php",
-					$wgDBname ) ) );
-		$spec = array(
-			0 => array( "pipe", "r" ),
-			1 => array( "pipe", "w" ),
-			2 => array( "file", "/dev/null", "a" ) );
-		$pipes = array();
-		
+		global $IP;
+
+		if ( file_exists( "$IP/../multiversion/MWScript.php" ) ) {
+			$cmd = implode( " ",
+				array_map( 'wfEscapeShellArg',
+					[
+						$this->php,
+						"$IP/../multiversion/MWScript.php",
+						"fetchText.php",
+						'--wiki', wfWikiID() ] ) );
+		} else {
+			$cmd = implode( " ",
+				array_map( 'wfEscapeShellArg',
+					[
+						$this->php,
+						"$IP/maintenance/fetchText.php",
+						'--wiki', wfWikiID() ] ) );
+		}
+		$spec = [
+			0 => [ "pipe", "r" ],
+			1 => [ "pipe", "w" ],
+			2 => [ "file", "/dev/null", "a" ] ];
+		$pipes = [];
+
 		$this->progress( "Spawning database subprocess: $cmd" );
 		$this->spawnProc = proc_open( $cmd, $spec, $pipes );
-		if( !$this->spawnProc ) {
-			// shit
+		if ( !$this->spawnProc ) {
 			$this->progress( "Subprocess spawn failed." );
+
 			return false;
 		}
 		list(
 			$this->spawnWrite, // -> stdin
-			$this->spawnRead,  // <- stdout
+			$this->spawnRead, // <- stdout
 		) = $pipes;
-		
+
 		return true;
 	}
-	
+
 	private function closeSpawn() {
-		wfSuppressWarnings();
-		if( $this->spawnRead )
+		MediaWiki\suppressWarnings();
+		if ( $this->spawnRead ) {
 			fclose( $this->spawnRead );
+		}
 		$this->spawnRead = false;
-		if( $this->spawnWrite )
+		if ( $this->spawnWrite ) {
 			fclose( $this->spawnWrite );
+		}
 		$this->spawnWrite = false;
-		if( $this->spawnErr )
+		if ( $this->spawnErr ) {
 			fclose( $this->spawnErr );
+		}
 		$this->spawnErr = false;
-		if( $this->spawnProc )
+		if ( $this->spawnProc ) {
 			pclose( $this->spawnProc );
+		}
 		$this->spawnProc = false;
-		wfRestoreWarnings();
+		MediaWiki\restoreWarnings();
 	}
-	
+
 	private function getTextSpawnedOnce( $id ) {
+		global $wgContLang;
+
 		$ok = fwrite( $this->spawnWrite, "$id\n" );
-		//$this->progress( ">> $id" );
-		if( !$ok ) return false;
-		
+		// $this->progress( ">> $id" );
+		if ( !$ok ) {
+			return false;
+		}
+
 		$ok = fflush( $this->spawnWrite );
-		//$this->progress( ">> [flush]" );
-		if( !$ok ) return false;
-		
+		// $this->progress( ">> [flush]" );
+		if ( !$ok ) {
+			return false;
+		}
+
+		// check that the text id they are sending is the one we asked for
+		// this avoids out of sync revision text errors we have encountered in the past
+		$newId = fgets( $this->spawnRead );
+		if ( $newId === false ) {
+			return false;
+		}
+		if ( $id != intval( $newId ) ) {
+			return false;
+		}
+
 		$len = fgets( $this->spawnRead );
-		//$this->progress( "<< " . trim( $len ) );
-		if( $len === false ) return false;
-		
+		// $this->progress( "<< " . trim( $len ) );
+		if ( $len === false ) {
+			return false;
+		}
+
 		$nbytes = intval( $len );
+		// actual error, not zero-length text
+		if ( $nbytes < 0 ) {
+			return false;
+		}
+
 		$text = "";
-		
+
 		// Subprocess may not send everything at once, we have to loop.
-		while( $nbytes > strlen( $text ) ) {
+		while ( $nbytes > strlen( $text ) ) {
 			$buffer = fread( $this->spawnRead, $nbytes - strlen( $text ) );
-			if( $text === false ) break;
+			if ( $buffer === false ) {
+				break;
+			}
 			$text .= $buffer;
 		}
-		
+
 		$gotbytes = strlen( $text );
-		if( $gotbytes != $nbytes ) {
-			$this->progress( "Expected $nbytes bytes from database subprocess, got $gotbytes ");
+		if ( $gotbytes != $nbytes ) {
+			$this->progress( "Expected $nbytes bytes from database subprocess, got $gotbytes " );
+
 			return false;
 		}
-		
+
 		// Do normalization in the dump thread...
 		$stripped = str_replace( "\r", "", $text );
-		$normalized = UtfNormal::cleanUp( $stripped );
+		$normalized = $wgContLang->normalize( $stripped );
+
 		return $normalized;
 	}
 
 	function startElement( $parser, $name, $attribs ) {
+		$this->checkpointJustWritten = false;
+
 		$this->clearOpenElement( null );
 		$this->lastName = $name;
 
-		if( $name == 'revision' ) {
+		if ( $name == 'revision' ) {
 			$this->state = $name;
 			$this->egress->writeOpenPage( null, $this->buffer );
 			$this->buffer = "";
-		} elseif( $name == 'page' ) {
+		} elseif ( $name == 'page' ) {
 			$this->state = $name;
-			if( $this->atStart ) {
+			if ( $this->atStart ) {
 				$this->egress->writeOpenStream( $this->buffer );
 				$this->buffer = "";
 				$this->atStart = false;
 			}
 		}
 
-		if( $name == "text" && isset( $attribs['id'] ) ) {
-			$text = $this->getText( $attribs['id'] );
-			$this->openElement = array( $name, array( 'xml:space' => 'preserve' ) );
-			if( strlen( $text ) > 0 ) {
+		if ( $name == "text" && isset( $attribs['id'] ) ) {
+			$id = $attribs['id'];
+			$model = trim( $this->thisRevModel );
+			$format = trim( $this->thisRevFormat );
+
+			$model = $model === '' ? null : $model;
+			$format = $format === '' ? null : $format;
+
+			$text = $this->getText( $id, $model, $format );
+			$this->openElement = [ $name, [ 'xml:space' => 'preserve' ] ];
+			if ( strlen( $text ) > 0 ) {
 				$this->characterData( $parser, $text );
 			}
 		} else {
-			$this->openElement = array( $name, $attribs );
+			$this->openElement = [ $name, $attribs ];
 		}
 	}
 
 	function endElement( $parser, $name ) {
-		if( $this->openElement ) {
+		$this->checkpointJustWritten = false;
+
+		if ( $this->openElement ) {
 			$this->clearOpenElement( "" );
 		} else {
 			$this->buffer .= "</$name>";
 		}
 
-		if( $name == 'revision' ) {
+		if ( $name == 'revision' ) {
 			$this->egress->writeRevision( null, $this->buffer );
 			$this->buffer = "";
 			$this->thisRev = "";
-		} elseif( $name == 'page' ) {
-			$this->egress->writeClosePage( $this->buffer );
-			$this->buffer = "";
-			$this->thisPage = "";
-		} elseif( $name == 'mediawiki' ) {
+			$this->thisRevModel = null;
+			$this->thisRevFormat = null;
+		} elseif ( $name == 'page' ) {
+			if ( !$this->firstPageWritten ) {
+				$this->firstPageWritten = trim( $this->thisPage );
+			}
+			$this->lastPageWritten = trim( $this->thisPage );
+			if ( $this->timeExceeded ) {
+				$this->egress->writeClosePage( $this->buffer );
+				// nasty hack, we can't just write the chardata after the
+				// page tag, it will include leading blanks from the next line
+				$this->egress->sink->write( "\n" );
+
+				$this->buffer = $this->xmlwriterobj->closeStream();
+				$this->egress->writeCloseStream( $this->buffer );
+
+				$this->buffer = "";
+				$this->thisPage = "";
+				// this could be more than one file if we had more than one output arg
+
+				$filenameList = (array)$this->egress->getFilenames();
+				$newFilenames = [];
+				$firstPageID = str_pad( $this->firstPageWritten, 9, "0", STR_PAD_LEFT );
+				$lastPageID = str_pad( $this->lastPageWritten, 9, "0", STR_PAD_LEFT );
+				$filenamesCount = count( $filenameList );
+				for ( $i = 0; $i < $filenamesCount; $i++ ) {
+					$checkpointNameFilledIn = sprintf( $this->checkpointFiles[$i], $firstPageID, $lastPageID );
+					$fileinfo = pathinfo( $filenameList[$i] );
+					$newFilenames[] = $fileinfo['dirname'] . '/' . $checkpointNameFilledIn;
+				}
+				$this->egress->closeRenameAndReopen( $newFilenames );
+				$this->buffer = $this->xmlwriterobj->openStream();
+				$this->timeExceeded = false;
+				$this->timeOfCheckpoint = $this->lastTime;
+				$this->firstPageWritten = false;
+				$this->checkpointJustWritten = true;
+			} else {
+				$this->egress->writeClosePage( $this->buffer );
+				$this->buffer = "";
+				$this->thisPage = "";
+			}
+		} elseif ( $name == 'mediawiki' ) {
 			$this->egress->writeCloseStream( $this->buffer );
 			$this->buffer = "";
 		}
@@ -475,51 +957,36 @@ class TextPassDumper extends BackupDumper {
 
 	function characterData( $parser, $data ) {
 		$this->clearOpenElement( null );
-		if( $this->lastName == "id" ) {
-			if( $this->state == "revision" ) {
+		if ( $this->lastName == "id" ) {
+			if ( $this->state == "revision" ) {
 				$this->thisRev .= $data;
-			} elseif( $this->state == "page" ) {
+			} elseif ( $this->state == "page" ) {
 				$this->thisPage .= $data;
 			}
+		} elseif ( $this->lastName == "model" ) {
+			$this->thisRevModel .= $data;
+		} elseif ( $this->lastName == "format" ) {
+			$this->thisRevFormat .= $data;
+		}
+
+		// have to skip the newline left over from closepagetag line of
+		// end of checkpoint files. nasty hack!!
+		if ( $this->checkpointJustWritten ) {
+			if ( $data[0] == "\n" ) {
+				$data = substr( $data, 1 );
+			}
+			$this->checkpointJustWritten = false;
 		}
 		$this->buffer .= htmlspecialchars( $data );
 	}
 
 	function clearOpenElement( $style ) {
-		if( $this->openElement ) {
+		if ( $this->openElement ) {
 			$this->buffer .= Xml::element( $this->openElement[0], $this->openElement[1], $style );
 			$this->openElement = false;
 		}
 	}
 }
 
-
-$dumper = new TextPassDumper( $argv );
-
-if( true ) {
-	$dumper->dump();
-} else {
-	$dumper->progress( <<<ENDS
-This script postprocesses XML dumps from dumpBackup.php to add
-page text which was stubbed out (using --stub).
-
-XML input is accepted on stdin.
-XML output is sent to stdout; progress reports are sent to stderr.
-
-Usage: php dumpTextPass.php [<options>]
-Options:
-  --stub=<type>:<file> To load a compressed stub dump instead of stdin
-  --prefetch=<type>:<file> Use a prior dump file as a text source, to save
-              pressure on the database.
-              (Requires PHP 5.0+ and the XMLReader PECL extension)
-  --quiet     Don't dump status reports to stderr.
-  --report=n  Report position and speed after every n pages processed.
-              (Default: 100)
-  --server=h  Force reading from MySQL server h
-  --current   Base ETA on number of pages in database instead of all revisions
-  --spawn     Spawn a subprocess for loading text records
-ENDS
-);
-}
-
-
+$maintClass = 'TextPassDumper';
+require_once RUN_MAINTENANCE_IF_MAIN;