includes/export/WikiExporter.php
<?php
/**
* Base class for exporting
*
* Copyright © 2003, 2005, 2006 Brooke Vibber <bvibber@wikimedia.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
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
/**
* @defgroup Dump Dump
*/
use MediaWiki\CommentStore\CommentStore;
use MediaWiki\Debug\MWDebug;
use MediaWiki\HookContainer\HookContainer;
use MediaWiki\HookContainer\HookRunner;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Page\PageIdentity;
use MediaWiki\Revision\RevisionAccessException;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\Revision\RevisionStore;
use MediaWiki\Title\MalformedTitleException;
use MediaWiki\Title\TitleParser;
use Wikimedia\Rdbms\IReadableDatabase;
use Wikimedia\Rdbms\IResultWrapper;
/**
* @ingroup SpecialPage Dump
*/
class WikiExporter {
/** @var bool Return distinct author list (when not returning full history) */
public $list_authors = false;
/** @var bool */
public $dumpUploads = false;
/** @var bool */
public $dumpUploadFileContents = false;
/** @var string */
public $author_list = "";
public const FULL = 1;
public const CURRENT = 2;
public const STABLE = 4; // extension defined
public const LOGS = 8;
public const RANGE = 16;
public const TEXT = XmlDumpWriter::WRITE_CONTENT;
public const STUB = XmlDumpWriter::WRITE_STUB;
protected const BATCH_SIZE = 10000;
/** @var int */
public $text;
/** @var DumpOutput */
public $sink;
/** @var XmlDumpWriter */
private $writer;
/** @var IReadableDatabase */
protected $db;
/** @var array|int */
protected $history;
/** @var array|null */
protected $limitNamespaces;
/** @var RevisionStore */
private $revisionStore;
/** @var TitleParser */
private $titleParser;
/** @var HookRunner */
private $hookRunner;
/** @var CommentStore */
private $commentStore;
/**
* Returns the default export schema version, as defined by the XmlDumpSchemaVersion setting.
* @return string
*/
public static function schemaVersion() {
return MediaWikiServices::getInstance()->getMainConfig()->get(
MainConfigNames::XmlDumpSchemaVersion );
}
/**
* @param IReadableDatabase $db
* @param CommentStore $commentStore
* @param HookContainer $hookContainer
* @param RevisionStore $revisionStore
* @param TitleParser $titleParser
* @param int|array $history One of WikiExporter::FULL, WikiExporter::CURRENT,
* WikiExporter::RANGE or WikiExporter::STABLE, or an associative array:
* - offset: non-inclusive offset at which to start the query
* - limit: maximum number of rows to return
* - dir: "asc" or "desc" timestamp order
* @param int $text One of WikiExporter::TEXT or WikiExporter::STUB
* @param null|array $limitNamespaces List of namespace numbers to limit results
*/
public function __construct(
$db,
CommentStore $commentStore,
HookContainer $hookContainer,
RevisionStore $revisionStore,
TitleParser $titleParser,
$history = self::CURRENT,
$text = self::TEXT,
$limitNamespaces = null
) {
$this->db = $db;
$this->commentStore = $commentStore;
$this->history = $history;
$this->writer = new XmlDumpWriter(
$text,
self::schemaVersion(),
$hookContainer,
$commentStore
);
$this->sink = new DumpOutput();
$this->text = $text;
$this->limitNamespaces = $limitNamespaces;
$this->hookRunner = new HookRunner( $hookContainer );
$this->revisionStore = $revisionStore;
$this->titleParser = $titleParser;
}
/**
* @param string $schemaVersion which schema version the generated XML should comply to.
* One of the values from self::$supportedSchemas, using the XML_DUMP_SCHEMA_VERSION_XX
* constants.
*/
public function setSchemaVersion( $schemaVersion ) {
$this->writer = new XmlDumpWriter( $this->text, $schemaVersion );
}
/**
* Set the DumpOutput or DumpFilter object which will receive
* various row objects and XML output for filtering. Filters
* can be chained or used as callbacks.
*
* @param DumpOutput|DumpFilter &$sink
*/
public function setOutputSink( &$sink ) {
$this->sink =& $sink;
}
public function openStream() {
$output = $this->writer->openStream();
$this->sink->writeOpenStream( $output );
}
public function closeStream() {
$output = $this->writer->closeStream();
$this->sink->writeCloseStream( $output );
}
/**
* Dumps a series of page and revision records for all pages
* in the database, either including complete history or only
* the most recent version.
*/
public function allPages() {
$this->dumpFrom( '' );
}
/**
* Dumps a series of page and revision records for those pages
* in the database falling within the page_id range given.
* @param int $start Inclusive lower limit (this id is included)
* @param int $end Exclusive upper limit (this id is not included)
* If 0, no upper limit.
* @param bool $orderRevs order revisions within pages in ascending order
*/
public function pagesByRange( $start, $end, $orderRevs ) {
if ( $orderRevs ) {
$condition = 'rev_page >= ' . intval( $start );
if ( $end ) {
$condition .= ' AND rev_page < ' . intval( $end );
}
} else {
$condition = 'page_id >= ' . intval( $start );
if ( $end ) {
$condition .= ' AND page_id < ' . intval( $end );
}
}
$this->dumpFrom( $condition, $orderRevs );
}
/**
* Dumps a series of page and revision records for those pages
* in the database with revisions falling within the rev_id range given.
* @param int $start Inclusive lower limit (this id is included)
* @param int $end Exclusive upper limit (this id is not included)
* If 0, no upper limit.
*/
public function revsByRange( $start, $end ) {
$condition = 'rev_id >= ' . intval( $start );
if ( $end ) {
$condition .= ' AND rev_id < ' . intval( $end );
}
$this->dumpFrom( $condition );
}
/**
* @param PageIdentity $page
*/
public function pageByTitle( PageIdentity $page ) {
$this->dumpFrom(
'page_namespace=' . $page->getNamespace() .
' AND page_title=' . $this->db->addQuotes( $page->getDBkey() ) );
}
/**
* @param string $name
*/
public function pageByName( $name ) {
try {
$link = $this->titleParser->parseTitle( $name );
$this->dumpFrom(
'page_namespace=' . $link->getNamespace() .
' AND page_title=' . $this->db->addQuotes( $link->getDBkey() ) );
} catch ( MalformedTitleException $ex ) {
throw new RuntimeException( "Can't export invalid title" );
}
}
/**
* @param string[] $names
*/
public function pagesByName( $names ) {
foreach ( $names as $name ) {
$this->pageByName( $name );
}
}
public function allLogs() {
$this->dumpFrom( '' );
}
/**
* @param int $start
* @param int $end
*/
public function logsByRange( $start, $end ) {
$condition = 'log_id >= ' . intval( $start );
if ( $end ) {
$condition .= ' AND log_id < ' . intval( $end );
}
$this->dumpFrom( $condition );
}
/**
* Generates the distinct list of authors of an article
* Not called by default (depends on $this->list_authors)
* Can be set by Special:Export when not exporting whole history
*
* @param string $cond
*/
protected function do_list_authors( $cond ) {
$this->author_list = "<contributors>";
// rev_deleted
$res = $this->revisionStore->newSelectQueryBuilder( $this->db )
->joinPage()
->distinct()
->where( $this->db->bitAnd( 'rev_deleted', RevisionRecord::DELETED_USER ) . ' = 0' )
->andWhere( $cond )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
$this->author_list .= "<contributor>" .
"<username>" .
htmlspecialchars( $row->rev_user_text ) .
"</username>" .
"<id>" .
( (int)$row->rev_user ) .
"</id>" .
"</contributor>";
}
$this->author_list .= "</contributors>";
}
/**
* @param string $cond
* @param bool $orderRevs
*/
protected function dumpFrom( $cond = '', $orderRevs = false ) {
if ( is_int( $this->history ) && ( $this->history & self::LOGS ) ) {
$this->dumpLogs( $cond );
} else {
$this->dumpPages( $cond, $orderRevs );
}
}
/**
* @param string $cond
*/
protected function dumpLogs( $cond ) {
$where = [];
# Hide private logs
$hideLogs = LogEventsList::getExcludeClause( $this->db );
if ( $hideLogs ) {
$where[] = $hideLogs;
}
# Add on any caller specified conditions
if ( $cond ) {
$where[] = $cond;
}
$commentQuery = $this->commentStore->getJoin( 'log_comment' );
$lastLogId = 0;
while ( true ) {
$result = $this->db->newSelectQueryBuilder()
->select( [
'log_id', 'log_type', 'log_action', 'log_timestamp', 'log_namespace',
'log_title', 'log_params', 'log_deleted', 'actor_user', 'actor_name'
] )
->from( 'logging' )
->join( 'actor', null, 'actor_id=log_actor' )
->where( $where )
->andWhere( $this->db->expr( 'log_id', '>', intval( $lastLogId ) ) )
->orderBy( 'log_id' )
->useIndex( [ 'logging' => 'PRIMARY' ] )
->limit( self::BATCH_SIZE )
->queryInfo( $commentQuery )
->caller( __METHOD__ )
->fetchResultSet();
if ( !$result->numRows() ) {
break;
}
$lastLogId = $this->outputLogStream( $result );
$this->reloadDBConfig();
}
}
/**
* @param string $cond
* @param bool $orderRevs
*/
protected function dumpPages( $cond, $orderRevs ) {
$revQuery = $this->revisionStore->getQueryInfo( [ 'page' ] );
$slotQuery = $this->revisionStore->getSlotsQueryInfo( [ 'content' ] );
// We want page primary rather than revision.
// We also want to join in the slots and content tables.
// NOTE: This means we may get multiple rows per revision, and more rows
// than the batch size! Should be ok, since the max number of slots is
// fixed and low (dozens at worst).
$tables = array_merge( [ 'page' ], array_diff( $revQuery['tables'], [ 'page' ] ) );
$tables = array_merge( $tables, array_diff( $slotQuery['tables'], $tables ) );
$join = $revQuery['joins'] + [
'revision' => $revQuery['joins']['page'],
'slots' => [ 'JOIN', [ 'slot_revision_id = rev_id' ] ],
'content' => [ 'JOIN', [ 'content_id = slot_content_id' ] ],
];
unset( $join['page'] );
$fields = array_merge( $revQuery['fields'], $slotQuery['fields'] );
if ( $this->text != self::STUB ) {
$fields['_load_content'] = '1';
}
$conds = [];
if ( $cond !== '' ) {
$conds[] = $cond;
}
$opts = [ 'ORDER BY' => [ 'rev_page ASC', 'rev_id ASC' ] ];
$opts['USE INDEX'] = [];
$op = '>';
if ( is_array( $this->history ) ) {
# Time offset/limit for all pages/history...
# Set time order
if ( $this->history['dir'] == 'asc' ) {
$opts['ORDER BY'] = 'rev_timestamp ASC';
} else {
$op = '<';
$opts['ORDER BY'] = 'rev_timestamp DESC';
}
# Set offset
if ( !empty( $this->history['offset'] ) ) {
$conds[] = "rev_timestamp $op " .
$this->db->addQuotes( $this->db->timestamp( $this->history['offset'] ) );
}
# Set query limit
if ( !empty( $this->history['limit'] ) ) {
$maxRowCount = intval( $this->history['limit'] );
}
} elseif ( $this->history & self::FULL ) {
# Full history dumps...
# query optimization for history stub dumps
if ( $this->text == self::STUB ) {
$opts[] = 'STRAIGHT_JOIN';
unset( $join['revision'] );
$join['page'] = [ 'JOIN', 'rev_page=page_id' ];
}
} elseif ( $this->history & self::CURRENT ) {
# Latest revision dumps...
if ( $this->list_authors && $cond != '' ) { // List authors, if so desired
$this->do_list_authors( $cond );
}
$join['revision'] = [ 'JOIN', 'page_id=rev_page AND page_latest=rev_id' ];
$opts[ 'ORDER BY' ] = [ 'page_id ASC' ];
} elseif ( $this->history & self::STABLE ) {
# "Stable" revision dumps...
# Default JOIN, to be overridden...
$join['revision'] = [ 'JOIN', 'page_id=rev_page AND page_latest=rev_id' ];
# One, and only one hook should set this, and return false
if ( $this->hookRunner->onWikiExporter__dumpStableQuery( $tables, $opts, $join ) ) {
throw new LogicException( __METHOD__ . " given invalid history dump type." );
}
} elseif ( $this->history & self::RANGE ) {
# Dump of revisions within a specified range. Condition already set in revsByRange().
} else {
# Unknown history specification parameter?
throw new UnexpectedValueException( __METHOD__ . " given invalid history dump type." );
}
$done = false;
$lastRow = null;
$revPage = 0;
$revId = 0;
$rowCount = 0;
$opts['LIMIT'] = self::BATCH_SIZE;
$this->hookRunner->onModifyExportQuery(
$this->db, $tables, $cond, $opts, $join, $conds );
while ( !$done ) {
// If necessary, impose the overall maximum and stop looping after this iteration.
if ( !empty( $maxRowCount ) && $rowCount + self::BATCH_SIZE > $maxRowCount ) {
$opts['LIMIT'] = $maxRowCount - $rowCount;
$done = true;
}
# Do the query and process any results, remembering max ids for the next iteration.
$result = $this->db->newSelectQueryBuilder()
->tables( $tables )
->fields( $fields )
->where( $conds )
->andWhere( $this->db->expr( 'rev_page', '>', intval( $revPage ) )->orExpr(
$this->db->expr( 'rev_page', '=', intval( $revPage ) )->and( 'rev_id', $op, intval( $revId ) )
) )
->caller( __METHOD__ )
->options( $opts )
->joinConds( $join )
->fetchResultSet();
if ( $result->numRows() > 0 ) {
$lastRow = $this->outputPageStreamBatch( $result, $lastRow );
$rowCount += $result->numRows();
$revPage = $lastRow->rev_page;
$revId = $lastRow->rev_id;
} else {
$done = true;
}
// If we are finished, close off final page element (if any).
if ( $done && $lastRow ) {
$this->finishPageStreamOutput( $lastRow );
}
if ( !$done ) {
$this->reloadDBConfig();
}
}
}
/**
* Runs through a query result set dumping page, revision, and slot records.
* The result set should join the page, revision, slots, and content tables,
* and be sorted/grouped by page and revision to avoid duplicate page records in the output.
*
* @param IResultWrapper $results
* @param stdClass|null $lastRow the last row output from the previous call (or null if none)
* @return stdClass the last row processed
*/
protected function outputPageStreamBatch( $results, $lastRow ) {
$rowCarry = null;
while ( true ) {
$slotRows = $this->getSlotRowBatch( $results, $rowCarry );
if ( !$slotRows ) {
break;
}
// All revision info is present in all slot rows.
// Use the first slot row as the revision row.
$revRow = $slotRows[0];
if ( $this->limitNamespaces &&
!in_array( $revRow->page_namespace, $this->limitNamespaces ) ) {
$lastRow = $revRow;
continue;
}
if ( $lastRow === null ||
$lastRow->page_namespace !== $revRow->page_namespace ||
$lastRow->page_title !== $revRow->page_title ) {
if ( $lastRow !== null ) {
$output = '';
if ( $this->dumpUploads ) {
$output .= $this->writer->writeUploads( $lastRow, $this->dumpUploadFileContents );
}
$output .= $this->writer->closePage();
$this->sink->writeClosePage( $output );
}
$output = $this->writer->openPage( $revRow );
$this->sink->writeOpenPage( $revRow, $output );
}
try {
$output = $this->writer->writeRevision( $revRow, $slotRows );
$this->sink->writeRevision( $revRow, $output );
} catch ( RevisionAccessException $ex ) {
MWDebug::warning( 'Problem encountered retrieving rev and slot metadata for'
. ' revision ' . $revRow->rev_id . ': ' . $ex->getMessage() );
}
$lastRow = $revRow;
}
if ( $rowCarry ) {
throw new LogicException( 'Error while processing a stream of slot rows' );
}
// @phan-suppress-next-line PhanTypeMismatchReturnNullable False positive
return $lastRow;
}
/**
* Returns all slot rows for a revision.
* Takes and returns a carry row from the last batch;
*
* @param IResultWrapper|array $results
* @param null|stdClass &$carry A row carried over from the last call to getSlotRowBatch()
*
* @return stdClass[]
*/
protected function getSlotRowBatch( $results, &$carry = null ) {
$slotRows = [];
$prev = null;
if ( $carry ) {
$slotRows[] = $carry;
$prev = $carry;
$carry = null;
}
// Reading further rows from the result set for the same rev id
// phpcs:ignore Generic.CodeAnalysis.AssignmentInCondition.FoundInWhileCondition
while ( $row = $results->fetchObject() ) {
if ( $prev && $prev->rev_id !== $row->rev_id ) {
$carry = $row;
break;
}
$slotRows[] = $row;
$prev = $row;
}
return $slotRows;
}
/**
* Final page stream output, after all batches are complete
*
* @param stdClass $lastRow the last row output from the last batch (or null if none)
*/
protected function finishPageStreamOutput( $lastRow ) {
$output = '';
if ( $this->dumpUploads ) {
$output .= $this->writer->writeUploads( $lastRow, $this->dumpUploadFileContents );
}
$output .= $this->author_list;
$output .= $this->writer->closePage();
$this->sink->writeClosePage( $output );
}
/**
* @param IResultWrapper $resultset
* @return int|null the log_id value of the last item output, or null if none
*/
protected function outputLogStream( $resultset ) {
foreach ( $resultset as $row ) {
$output = $this->writer->writeLogItem( $row );
$this->sink->writeLogItem( $row, $output );
}
return $row->log_id ?? null;
}
/**
* Attempt to reload the database configuration, so any changes can take effect.
* Dynamic reloading can be enabled by setting $wgLBFactoryConf['configCallback']
* to a function that returns an array of any keys that should be updated
* in LBFactoryConf.
*/
private function reloadDBConfig() {
MediaWikiServices::getInstance()->getDBLoadBalancerFactory()
->autoReconfigure();
}
}