includes/export/WikiExporter.php

   1 <?php
   2 /**
   3  * Base class for exporting
   4  *
   5  * Copyright © 2003, 2005, 2006 Brion Vibber <brion@pobox.com>
   6  * https://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  */
  25
  26 /**
  27  * @defgroup Dump Dump
  28  */
  29
  30 use Wikimedia\Rdbms\ResultWrapper;
  31 use Wikimedia\Rdbms\IDatabase;
  32
  33 /**
  34  * @ingroup SpecialPage Dump
  35  */
  36 class WikiExporter {
  37         /** @var bool Return distinct author list (when not returning full history) */
  38         public $list_authors = false;
  39
  40         /** @var bool */
  41         public $dumpUploads = false;
  42
  43         /** @var bool */
  44         public $dumpUploadFileContents = false;
  45
  46         /** @var string */
  47         public $author_list = "";
  48
  49         const FULL = 1;
  50         const CURRENT = 2;
  51         const STABLE = 4; // extension defined
  52         const LOGS = 8;
  53         const RANGE = 16;
  54
  55         const BUFFER = 0;
  56         const STREAM = 1;
  57
  58         const TEXT = 0;
  59         const STUB = 1;
  60
  61         /** @var int */
  62         public $buffer;
  63
  64         /** @var int */
  65         public $text;
  66
  67         /** @var DumpOutput */
  68         public $sink;
  69
  70         /**
  71          * Returns the export schema version.
  72          * @return string
  73          */
  74         public static function schemaVersion() {
  75                 return "0.10";
  76         }
  77
  78         /**
  79          * If using WikiExporter::STREAM to stream a large amount of data,
  80          * provide a database connection which is not managed by
  81          * LoadBalancer to read from: some history blob types will
  82          * make additional queries to pull source data while the
  83          * main query is still running.
  84          *
  85          * @param IDatabase $db
  86          * @param int|array $history One of WikiExporter::FULL, WikiExporter::CURRENT,
  87          *   WikiExporter::RANGE or WikiExporter::STABLE, or an associative array:
  88          *   - offset: non-inclusive offset at which to start the query
  89          *   - limit: maximum number of rows to return
  90          *   - dir: "asc" or "desc" timestamp order
  91          * @param int $buffer One of WikiExporter::BUFFER or WikiExporter::STREAM
  92          * @param int $text One of WikiExporter::TEXT or WikiExporter::STUB
  93          */
  94         function __construct( $db, $history = self::CURRENT,
  95                         $buffer = self::BUFFER, $text = self::TEXT ) {
  96                 $this->db = $db;
  97                 $this->history = $history;
  98                 $this->buffer = $buffer;
  99                 $this->writer = new XmlDumpWriter();
 100                 $this->sink = new DumpOutput();
 101                 $this->text = $text;
 102         }
 103
 104         /**
 105          * Set the DumpOutput or DumpFilter object which will receive
 106          * various row objects and XML output for filtering. Filters
 107          * can be chained or used as callbacks.
 108          *
 109          * @param DumpOutput &$sink
 110          */
 111         public function setOutputSink( &$sink ) {
 112                 $this->sink =& $sink;
 113         }
 114
 115         public function openStream() {
 116                 $output = $this->writer->openStream();
 117                 $this->sink->writeOpenStream( $output );
 118         }
 119
 120         public function closeStream() {
 121                 $output = $this->writer->closeStream();
 122                 $this->sink->writeCloseStream( $output );
 123         }
 124
 125         /**
 126          * Dumps a series of page and revision records for all pages
 127          * in the database, either including complete history or only
 128          * the most recent version.
 129          */
 130         public function allPages() {
 131                 $this->dumpFrom( '' );
 132         }
 133
 134         /**
 135          * Dumps a series of page and revision records for those pages
 136          * in the database falling within the page_id range given.
 137          * @param int $start Inclusive lower limit (this id is included)
 138          * @param int $end Exclusive upper limit (this id is not included)
 139          *   If 0, no upper limit.
 140          * @param bool $orderRevs order revisions within pages in ascending order
 141          */
 142         public function pagesByRange( $start, $end, $orderRevs ) {
 143                 if ( $orderRevs ) {
 144                         $condition = 'rev_page >= ' . intval( $start );
 145                         if ( $end ) {
 146                                 $condition .= ' AND rev_page < ' . intval( $end );
 147                         }
 148                 } else {
 149                         $condition = 'page_id >= ' . intval( $start );
 150                         if ( $end ) {
 151                                 $condition .= ' AND page_id < ' . intval( $end );
 152                         }
 153                 }
 154                 $this->dumpFrom( $condition, $orderRevs );
 155         }
 156
 157         /**
 158          * Dumps a series of page and revision records for those pages
 159          * in the database with revisions falling within the rev_id range given.
 160          * @param int $start Inclusive lower limit (this id is included)
 161          * @param int $end Exclusive upper limit (this id is not included)
 162          *   If 0, no upper limit.
 163          */
 164         public function revsByRange( $start, $end ) {
 165                 $condition = 'rev_id >= ' . intval( $start );
 166                 if ( $end ) {
 167                         $condition .= ' AND rev_id < ' . intval( $end );
 168                 }
 169                 $this->dumpFrom( $condition );
 170         }
 171
 172         /**
 173          * @param Title $title
 174          */
 175         public function pageByTitle( $title ) {
 176                 $this->dumpFrom(
 177                         'page_namespace=' . $title->getNamespace() .
 178                         ' AND page_title=' . $this->db->addQuotes( $title->getDBkey() ) );
 179         }
 180
 181         /**
 182          * @param string $name
 183          * @throws MWException
 184          */
 185         public function pageByName( $name ) {
 186                 $title = Title::newFromText( $name );
 187                 if ( is_null( $title ) ) {
 188                         throw new MWException( "Can't export invalid title" );
 189                 } else {
 190                         $this->pageByTitle( $title );
 191                 }
 192         }
 193
 194         /**
 195          * @param array $names
 196          */
 197         public function pagesByName( $names ) {
 198                 foreach ( $names as $name ) {
 199                         $this->pageByName( $name );
 200                 }
 201         }
 202
 203         public function allLogs() {
 204                 $this->dumpFrom( '' );
 205         }
 206
 207         /**
 208          * @param int $start
 209          * @param int $end
 210          */
 211         public function logsByRange( $start, $end ) {
 212                 $condition = 'log_id >= ' . intval( $start );
 213                 if ( $end ) {
 214                         $condition .= ' AND log_id < ' . intval( $end );
 215                 }
 216                 $this->dumpFrom( $condition );
 217         }
 218
 219         /**
 220          * Generates the distinct list of authors of an article
 221          * Not called by default (depends on $this->list_authors)
 222          * Can be set by Special:Export when not exporting whole history
 223          *
 224          * @param array $cond
 225          */
 226         protected function do_list_authors( $cond ) {
 227                 $this->author_list = "<contributors>";
 228                 // rev_deleted
 229
 230                 $revQuery = Revision::getQueryInfo( [ 'page' ] );
 231                 $res = $this->db->select(
 232                         $revQuery['tables'],
 233                         [
 234                                 'rev_user_text' => $revQuery['fields']['rev_user_text'],
 235                                 'rev_user' => $revQuery['fields']['rev_user'],
 236                         ],
 237                         [
 238                                 $this->db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0',
 239                                 $cond,
 240                         ],
 241                         __METHOD__,
 242                         [ 'DISTINCT' ],
 243                         $revQuery['joins']
 244                 );
 245
 246                 foreach ( $res as $row ) {
 247                         $this->author_list .= "<contributor>" .
 248                                 "<username>" .
 249                                 htmlentities( $row->rev_user_text ) .
 250                                 "</username>" .
 251                                 "<id>" .
 252                                 $row->rev_user .
 253                                 "</id>" .
 254                                 "</contributor>";
 255                 }
 256                 $this->author_list .= "</contributors>";
 257         }
 258
 259         /**
 260          * @param string $cond
 261          * @param bool $orderRevs
 262          * @throws MWException
 263          * @throws Exception
 264          */
 265         protected function dumpFrom( $cond = '', $orderRevs = false ) {
 266                 global $wgMultiContentRevisionSchemaMigrationStage;
 267
 268                 # For logging dumps...
 269                 if ( $this->history & self::LOGS ) {
 270                         $where = [];
 271                         # Hide private logs
 272                         $hideLogs = LogEventsList::getExcludeClause( $this->db );
 273                         if ( $hideLogs ) {
 274                                 $where[] = $hideLogs;
 275                         }
 276                         # Add on any caller specified conditions
 277                         if ( $cond ) {
 278                                 $where[] = $cond;
 279                         }
 280                         # Get logging table name for logging.* clause
 281                         $logging = $this->db->tableName( 'logging' );
 282
 283                         if ( $this->buffer == self::STREAM ) {
 284                                 $prev = $this->db->bufferResults( false );
 285                         }
 286                         $result = null; // Assuring $result is not undefined, if exception occurs early
 287
 288                         $commentQuery = CommentStore::getStore()->getJoin( 'log_comment' );
 289                         $actorQuery = ActorMigration::newMigration()->getJoin( 'log_user' );
 290
 291                         try {
 292                                 $result = $this->db->select(
 293                                         array_merge( [ 'logging' ], $commentQuery['tables'], $actorQuery['tables'], [ 'user' ] ),
 294                                         [ "{$logging}.*", 'user_name' ] + $commentQuery['fields'] + $actorQuery['fields'],
 295                                         $where,
 296                                         __METHOD__,
 297                                         [ 'ORDER BY' => 'log_id', 'USE INDEX' => [ 'logging' => 'PRIMARY' ] ],
 298                                         [
 299                                                 'user' => [ 'JOIN', 'user_id = ' . $actorQuery['fields']['log_user'] ]
 300                                         ] + $commentQuery['joins'] + $actorQuery['joins']
 301                                 );
 302                                 $this->outputLogStream( $result );
 303                                 if ( $this->buffer == self::STREAM ) {
 304                                         $this->db->bufferResults( $prev );
 305                                 }
 306                         } catch ( Exception $e ) {
 307                                 // Throwing the exception does not reliably free the resultset, and
 308                                 // would also leave the connection in unbuffered mode.
 309
 310                                 // Freeing result
 311                                 try {
 312                                         if ( $result ) {
 313                                                 $result->free();
 314                                         }
 315                                 } catch ( Exception $e2 ) {
 316                                         // Already in panic mode -> ignoring $e2 as $e has
 317                                         // higher priority
 318                                 }
 319
 320                                 // Putting database back in previous buffer mode
 321                                 try {
 322                                         if ( $this->buffer == self::STREAM ) {
 323                                                 $this->db->bufferResults( $prev );
 324                                         }
 325                                 } catch ( Exception $e2 ) {
 326                                         // Already in panic mode -> ignoring $e2 as $e has
 327                                         // higher priority
 328                                 }
 329
 330                                 // Inform caller about problem
 331                                 throw $e;
 332                         }
 333                 # For page dumps...
 334                 } else {
 335                         if ( !( $wgMultiContentRevisionSchemaMigrationStage & SCHEMA_COMPAT_WRITE_OLD ) ) {
 336                                 // TODO: Make XmlDumpWriter use a RevisionStore! (see T198706 and T174031)
 337                                 throw new MWException(
 338                                         'Cannot use WikiExporter with SCHEMA_COMPAT_WRITE_OLD mode disabled!'
 339                                         . ' Support for dumping from the new schema is not implemented yet!'
 340                                 );
 341                         }
 342
 343                         $revOpts = [ 'page' ];
 344                         if ( $this->text != self::STUB ) {
 345                                 // TODO: remove the text and make XmlDumpWriter use a RevisionStore instead! (T198706)
 346                                 $revOpts[] = 'text';
 347                         }
 348                         $revQuery = Revision::getQueryInfo( $revOpts );
 349
 350                         // We want page primary rather than revision
 351                         $tables = array_merge( [ 'page' ], array_diff( $revQuery['tables'], [ 'page' ] ) );
 352                         $join = $revQuery['joins'] + [
 353                                 'revision' => $revQuery['joins']['page']
 354                         ];
 355                         unset( $join['page'] );
 356
 357                         // TODO: remove rev_text_id and make XmlDumpWriter use a RevisionStore instead! (T198706)
 358                         $fields = array_merge( $revQuery['fields'], [ 'page_restrictions, rev_text_id' ] );
 359
 360                         $conds = [];
 361                         if ( $cond !== '' ) {
 362                                 $conds[] = $cond;
 363                         }
 364                         $opts = [ 'ORDER BY' => 'page_id ASC' ];
 365                         $opts['USE INDEX'] = [];
 366                         if ( is_array( $this->history ) ) {
 367                                 # Time offset/limit for all pages/history...
 368                                 # Set time order
 369                                 if ( $this->history['dir'] == 'asc' ) {
 370                                         $op = '>';
 371                                         $opts['ORDER BY'] = 'rev_timestamp ASC';
 372                                 } else {
 373                                         $op = '<';
 374                                         $opts['ORDER BY'] = 'rev_timestamp DESC';
 375                                 }
 376                                 # Set offset
 377                                 if ( !empty( $this->history['offset'] ) ) {
 378                                         $conds[] = "rev_timestamp $op " .
 379                                                 $this->db->addQuotes( $this->db->timestamp( $this->history['offset'] ) );
 380                                 }
 381                                 # Set query limit
 382                                 if ( !empty( $this->history['limit'] ) ) {
 383                                         $opts['LIMIT'] = intval( $this->history['limit'] );
 384                                 }
 385                         } elseif ( $this->history & self::FULL ) {
 386                                 # Full history dumps...
 387                                 # query optimization for history stub dumps
 388                                 if ( $this->text == self::STUB && $orderRevs ) {
 389                                         $tables = $revQuery['tables'];
 390                                         $opts['ORDER BY'] = [ 'rev_page ASC', 'rev_id ASC' ];
 391                                         $opts['USE INDEX']['revision'] = 'rev_page_id';
 392                                         unset( $join['revision'] );
 393                                         $join['page'] = [ 'INNER JOIN', 'rev_page=page_id' ];
 394                                 }
 395                         } elseif ( $this->history & self::CURRENT ) {
 396                                 # Latest revision dumps...
 397                                 if ( $this->list_authors && $cond != '' ) { // List authors, if so desired
 398                                         $this->do_list_authors( $cond );
 399                                 }
 400                                 $join['revision'] = [ 'INNER JOIN', 'page_id=rev_page AND page_latest=rev_id' ];
 401                         } elseif ( $this->history & self::STABLE ) {
 402                                 # "Stable" revision dumps...
 403                                 # Default JOIN, to be overridden...
 404                                 $join['revision'] = [ 'INNER JOIN', 'page_id=rev_page AND page_latest=rev_id' ];
 405                                 # One, and only one hook should set this, and return false
 406                                 if ( Hooks::run( 'WikiExporter::dumpStableQuery', [ &$tables, &$opts, &$join ] ) ) {
 407                                         throw new MWException( __METHOD__ . " given invalid history dump type." );
 408                                 }
 409                         } elseif ( $this->history & self::RANGE ) {
 410                                 # Dump of revisions within a specified range
 411                                 $opts['ORDER BY'] = [ 'rev_page ASC', 'rev_id ASC' ];
 412                         } else {
 413                                 # Unknown history specification parameter?
 414                                 throw new MWException( __METHOD__ . " given invalid history dump type." );
 415                         }
 416
 417                         if ( $this->buffer == self::STREAM ) {
 418                                 $prev = $this->db->bufferResults( false );
 419                         }
 420                         $result = null; // Assuring $result is not undefined, if exception occurs early
 421                         try {
 422                                 Hooks::run( 'ModifyExportQuery',
 423                                                 [ $this->db, &$tables, &$cond, &$opts, &$join ] );
 424
 425                                 # Do the query!
 426                                 $result = $this->db->select(
 427                                         $tables,
 428                                         $fields,
 429                                         $conds,
 430                                         __METHOD__,
 431                                         $opts,
 432                                         $join
 433                                 );
 434                                 # Output dump results
 435                                 $this->outputPageStream( $result );
 436
 437                                 if ( $this->buffer == self::STREAM ) {
 438                                         $this->db->bufferResults( $prev );
 439                                 }
 440                         } catch ( Exception $e ) {
 441                                 // Throwing the exception does not reliably free the resultset, and
 442                                 // would also leave the connection in unbuffered mode.
 443
 444                                 // Freeing result
 445                                 try {
 446                                         if ( $result ) {
 447                                                 $result->free();
 448                                         }
 449                                 } catch ( Exception $e2 ) {
 450                                         // Already in panic mode -> ignoring $e2 as $e has
 451                                         // higher priority
 452                                 }
 453
 454                                 // Putting database back in previous buffer mode
 455                                 try {
 456                                         if ( $this->buffer == self::STREAM ) {
 457                                                 $this->db->bufferResults( $prev );
 458                                         }
 459                                 } catch ( Exception $e2 ) {
 460                                         // Already in panic mode -> ignoring $e2 as $e has
 461                                         // higher priority
 462                                 }
 463
 464                                 // Inform caller about problem
 465                                 throw $e;
 466                         }
 467                 }
 468         }
 469
 470         /**
 471          * Runs through a query result set dumping page and revision records.
 472          * The result set should be sorted/grouped by page to avoid duplicate
 473          * page records in the output.
 474          *
 475          * Should be safe for
 476          * streaming (non-buffered) queries, as long as it was made on a
 477          * separate database connection not managed by LoadBalancer; some
 478          * blob storage types will make queries to pull source data.
 479          *
 480          * @param ResultWrapper $resultset
 481          */
 482         protected function outputPageStream( $resultset ) {
 483                 $last = null;
 484                 foreach ( $resultset as $row ) {
 485                         if ( $last === null ||
 486                                 $last->page_namespace != $row->page_namespace ||
 487                                 $last->page_title != $row->page_title ) {
 488                                 if ( $last !== null ) {
 489                                         $output = '';
 490                                         if ( $this->dumpUploads ) {
 491                                                 $output .= $this->writer->writeUploads( $last, $this->dumpUploadFileContents );
 492                                         }
 493                                         $output .= $this->writer->closePage();
 494                                         $this->sink->writeClosePage( $output );
 495                                 }
 496                                 $output = $this->writer->openPage( $row );
 497                                 $this->sink->writeOpenPage( $row, $output );
 498                                 $last = $row;
 499                         }
 500                         $output = $this->writer->writeRevision( $row );
 501                         $this->sink->writeRevision( $row, $output );
 502                 }
 503                 if ( $last !== null ) {
 504                         $output = '';
 505                         if ( $this->dumpUploads ) {
 506                                 $output .= $this->writer->writeUploads( $last, $this->dumpUploadFileContents );
 507                         }
 508                         $output .= $this->author_list;
 509                         $output .= $this->writer->closePage();
 510                         $this->sink->writeClosePage( $output );
 511                 }
 512         }
 513
 514         /**
 515          * @param ResultWrapper $resultset
 516          */
 517         protected function outputLogStream( $resultset ) {
 518                 foreach ( $resultset as $row ) {
 519                         $output = $this->writer->writeLogItem( $row );
 520                         $this->sink->writeLogItem( $row, $output );
 521                 }
 522         }
 523 }