includes/Storage/PageUpdater.php

   1 <?php
   2 /**
   3  * Controller-like object for creating and updating pages by creating new revisions.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  *
  22  * @author Daniel Kinzler
  23  */
  24
  25 namespace MediaWiki\Storage;
  26
  27 use AtomicSectionUpdate;
  28 use ChangeTags;
  29 use CommentStoreComment;
  30 use Content;
  31 use ContentHandler;
  32 use DeferredUpdates;
  33 use Hooks;
  34 use InvalidArgumentException;
  35 use LogicException;
  36 use ManualLogEntry;
  37 use MediaWiki\Linker\LinkTarget;
  38 use MWException;
  39 use RecentChange;
  40 use Revision;
  41 use RuntimeException;
  42 use Status;
  43 use Title;
  44 use User;
  45 use Wikimedia\Assert\Assert;
  46 use Wikimedia\Rdbms\DBConnRef;
  47 use Wikimedia\Rdbms\DBUnexpectedError;
  48 use Wikimedia\Rdbms\IDatabase;
  49 use Wikimedia\Rdbms\LoadBalancer;
  50 use WikiPage;
  51
  52 /**
  53  * Controller-like object for creating and updating pages by creating new revisions.
  54  *
  55  * PageUpdater instances provide compare-and-swap (CAS) protection against concurrent updates
  56  * between the time grabParentRevision() is called and saveRevision() inserts a new revision.
  57  * This allows application logic to safely perform edit conflict resolution using the parent
  58  * revision's content.
  59  *
  60  * @see docs/pageupdater.txt for more information.
  61  *
  62  * MCR migration note: this replaces the relevant methods in WikiPage.
  63  *
  64  * @since 1.32
  65  * @ingroup Page
  66  */
  67 class PageUpdater {
  68
  69         /**
  70          * @var User
  71          */
  72         private $user;
  73
  74         /**
  75          * @var WikiPage
  76          */
  77         private $wikiPage;
  78
  79         /**
  80          * @var DerivedPageDataUpdater
  81          */
  82         private $derivedDataUpdater;
  83
  84         /**
  85          * @var LoadBalancer
  86          */
  87         private $loadBalancer;
  88
  89         /**
  90          * @var RevisionStore
  91          */
  92         private $revisionStore;
  93
  94         /**
  95          * @var boolean see $wgUseAutomaticEditSummaries
  96          * @see $wgUseAutomaticEditSummaries
  97          */
  98         private $useAutomaticEditSummaries = true;
  99
 100         /**
 101          * @var int the RC patrol status the new revision should be marked with.
 102          */
 103         private $rcPatrolStatus = RecentChange::PRC_UNPATROLLED;
 104
 105         /**
 106          * @var bool whether to create a log entry for new page creations.
 107          */
 108         private $usePageCreationLog = true;
 109
 110         /**
 111          * @var boolean see $wgAjaxEditStash
 112          */
 113         private $ajaxEditStash = true;
 114
 115         /**
 116          * @var bool|int
 117          */
 118         private $originalRevId = false;
 119
 120         /**
 121          * @var array
 122          */
 123         private $tags = [];
 124
 125         /**
 126          * @var int
 127          */
 128         private $undidRevId = 0;
 129
 130         /**
 131          * @var RevisionSlotsUpdate
 132          */
 133         private $slotsUpdate;
 134
 135         /**
 136          * @var Status|null
 137          */
 138         private $status = null;
 139
 140         /**
 141          * @param User $user
 142          * @param WikiPage $wikiPage
 143          * @param DerivedPageDataUpdater $derivedDataUpdater
 144          * @param LoadBalancer $loadBalancer
 145          * @param RevisionStore $revisionStore
 146          */
 147         public function __construct(
 148                 User $user,
 149                 WikiPage $wikiPage,
 150                 DerivedPageDataUpdater $derivedDataUpdater,
 151                 LoadBalancer $loadBalancer,
 152                 RevisionStore $revisionStore
 153         ) {
 154                 $this->user = $user;
 155                 $this->wikiPage = $wikiPage;
 156                 $this->derivedDataUpdater = $derivedDataUpdater;
 157
 158                 $this->loadBalancer = $loadBalancer;
 159                 $this->revisionStore = $revisionStore;
 160
 161                 $this->slotsUpdate = new RevisionSlotsUpdate();
 162         }
 163
 164         /**
 165          * Can be used to enable or disable automatic summaries that are applied to certain kinds of
 166          * changes, like completely blanking a page.
 167          *
 168          * @param bool $useAutomaticEditSummaries
 169          * @see $wgUseAutomaticEditSummaries
 170          */
 171         public function setUseAutomaticEditSummaries( $useAutomaticEditSummaries ) {
 172                 $this->useAutomaticEditSummaries = $useAutomaticEditSummaries;
 173         }
 174
 175         /**
 176          * Sets the "patrolled" status of the edit.
 177          * Callers should check the "patrol" and "autopatrol" permissions as appropriate.
 178          *
 179          * @see $wgUseRCPatrol
 180          * @see $wgUseNPPatrol
 181          *
 182          * @param int $status RC patrol status, e.g. RecentChange::PRC_AUTOPATROLLED.
 183          */
 184         public function setRcPatrolStatus( $status ) {
 185                 $this->rcPatrolStatus = $status;
 186         }
 187
 188         /**
 189          * Whether to create a log entry for new page creations.
 190          *
 191          * @see $wgPageCreationLog
 192          *
 193          * @param bool $use
 194          */
 195         public function setUsePageCreationLog( $use ) {
 196                 $this->usePageCreationLog = $use;
 197         }
 198
 199         /**
 200          * @param bool $ajaxEditStash
 201          * @see $wgAjaxEditStash
 202          */
 203         public function setAjaxEditStash( $ajaxEditStash ) {
 204                 $this->ajaxEditStash = $ajaxEditStash;
 205         }
 206
 207         private function getWikiId() {
 208                 return false; // TODO: get from RevisionStore!
 209         }
 210
 211         /**
 212          * @param int $mode DB_MASTER or DB_REPLICA
 213          *
 214          * @return DBConnRef
 215          */
 216         private function getDBConnectionRef( $mode ) {
 217                 return $this->loadBalancer->getConnectionRef( $mode, [], $this->getWikiId() );
 218         }
 219
 220         /**
 221          * @return LinkTarget
 222          */
 223         private function getLinkTarget() {
 224                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 225                 return $this->wikiPage->getTitle();
 226         }
 227
 228         /**
 229          * @return Title
 230          */
 231         private function getTitle() {
 232                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 233                 return $this->wikiPage->getTitle();
 234         }
 235
 236         /**
 237          * @return WikiPage
 238          */
 239         private function getWikiPage() {
 240                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 241                 return $this->wikiPage;
 242         }
 243
 244         /**
 245          * Checks whether this update conflicts with another update performed between the client
 246          * loading data to prepare an edit, and the client committing the edit. This is intended to
 247          * detect user level "edit conflict" when the latest revision known to the client
 248          * is no longer the current revision when processing the update.
 249          *
 250          * An update expected to create a new page can be checked by setting $expectedParentRevision = 0.
 251          * Such an update is considered to have a conflict if a current revision exists (that is,
 252          * the page was created since the edit was initiated on the client).
 253          *
 254          * This method returning true indicates to calling code that edit conflict resolution should
 255          * be applied before saving any data. It does not prevent the update from being performed, and
 256          * it should not be confused with a "late" conflict indicated by the "edit-conflict" status.
 257          * A "late" conflict is a CAS failure caused by an update being performed concurrently between
 258          * the time grabParentRevision() was called and the time saveRevision() trying to insert the
 259          * new revision.
 260          *
 261          * @note A user level edit conflict is not the same as the "edit-conflict" status triggered by
 262          * a CAS failure. Calling this method establishes the CAS token, it does not check against it:
 263          * This method calls grabParentRevision(), and thus causes the expected parent revision
 264          * for the update to be fixed to the page's current revision at this point in time.
 265          * It acts as a compare-and-swap (CAS) token in that it is guaranteed that saveRevision()
 266          * will fail with the "edit-conflict" status if the current revision of the page changes after
 267          * hasEditConflict() (or grabParentRevision()) was called and before saveRevision() could insert
 268          * a new revision.
 269          *
 270          * @see grabParentRevision()
 271          *
 272          * @param int $expectedParentRevision The ID of the revision the client expects to be the
 273          *        current one. Use 0 to indicate that the page is expected to not yet exist.
 274          *
 275          * @return bool
 276          */
 277         public function hasEditConflict( $expectedParentRevision ) {
 278                 $parent = $this->grabParentRevision();
 279                 $parentId = $parent ? $parent->getId() : 0;
 280
 281                 return $parentId !== $expectedParentRevision;
 282         }
 283
 284         /**
 285          * Returns the revision that was the page's current revision when grabParentRevision()
 286          * was first called. This revision is the expected parent revision of the update, and will be
 287          * recorded as the new revision's parent revision (unless no new revision is created because
 288          * the content was not changed).
 289          *
 290          * This method MUST not be called after saveRevision() was called!
 291          *
 292          * The current revision determined by the first call to this methods effectively acts a
 293          * compare-and-swap (CAS) token which is checked by saveRevision(), which fails if any
 294          * concurrent updates created a new revision.
 295          *
 296          * Application code should call this method before applying transformations to the new
 297          * content that depend on the parent revision, e.g. adding/replacing sections, or resolving
 298          * conflicts via a 3-way merge. This protects against race conditions triggered by concurrent
 299          * updates.
 300          *
 301          * @see DerivedPageDataUpdater::grabCurrentRevision()
 302          *
 303          * @note The expected parent revision is not to be confused with the logical base revision.
 304          * The base revision is specified by the client, the parent revision is determined from the
 305          * database. If base revision and parent revision are not the same, the updates is considered
 306          * to require edit conflict resolution.
 307          *
 308          * @throws LogicException if called after saveRevision().
 309          * @return RevisionRecord|null the parent revision, or null of the page does not yet exist.
 310          */
 311         public function grabParentRevision() {
 312                 return $this->derivedDataUpdater->grabCurrentRevision();
 313         }
 314
 315         /**
 316          * @return string
 317          */
 318         private function getTimestampNow() {
 319                 // TODO: allow an override to be injected for testing
 320                 return wfTimestampNow();
 321         }
 322
 323         /**
 324          * Check flags and add EDIT_NEW or EDIT_UPDATE to them as needed.
 325          *
 326          * @param int $flags
 327          * @return int Updated $flags
 328          */
 329         private function checkFlags( $flags ) {
 330                 if ( !( $flags & EDIT_NEW ) && !( $flags & EDIT_UPDATE ) ) {
 331                         $flags |= ( $this->derivedDataUpdater->pageExisted() ) ? EDIT_UPDATE : EDIT_NEW;
 332                 }
 333
 334                 return $flags;
 335         }
 336
 337         /**
 338          * Set the new content for the given slot role
 339          *
 340          * @param string $role A slot role name (such as "main")
 341          * @param Content $content
 342          */
 343         public function setContent( $role, Content $content ) {
 344                 // TODO: MCR: check the role and the content's model against the list of supported
 345                 // roles, see T194046.
 346
 347                 $this->slotsUpdate->modifyContent( $role, $content );
 348         }
 349
 350         /**
 351          * Explicitly inherit a slot from some earlier revision.
 352          *
 353          * The primary use case for this is rollbacks, when slots are to be inherited from
 354          * the rollback target, overriding the content from the parent revision (which is the
 355          * revision being rolled back).
 356          *
 357          * This should typically not be used to inherit slots from the parent revision, which
 358          * happens implicitly. Using this method causes the given slot to be treated as "modified"
 359          * during revision creation, even if it has the same content as in the parent revision.
 360          *
 361          * @param SlotRecord $originalSlot A slot already existing in the database, to be inherited
 362          *        by the new revision.
 363          */
 364         public function inheritSlot( SlotRecord $originalSlot ) {
 365                 // NOTE: this slot is inherited from some other revision, but it's
 366                 // a "modified" slot for the RevisionSlotsUpdate and DerivedPageDataUpdater,
 367                 // since it's not implicitly inherited from the parent revision.
 368                 $inheritedSlot = SlotRecord::newInherited( $originalSlot );
 369                 $this->slotsUpdate->modifySlot( $inheritedSlot );
 370         }
 371
 372         /**
 373          * Removes the slot with the given role.
 374          *
 375          * This discontinues the "stream" of slots with this role on the page,
 376          * preventing the new revision, and any subsequent revisions, from
 377          * inheriting the slot with this role.
 378          *
 379          * @param string $role A slot role name (but not "main")
 380          */
 381         public function removeSlot( $role ) {
 382                 if ( $role === 'main' ) {
 383                         throw new InvalidArgumentException( 'Cannot remove the main slot!' );
 384                 }
 385
 386                 $this->slotsUpdate->removeSlot( $role );
 387         }
 388
 389         /**
 390          * Returns the ID of an earlier revision that is being repeated or restored by this update.
 391          *
 392          * @return bool|int The original revision id, or false if no earlier revision is known to be
 393          * repeated or restored by this update.
 394          */
 395         public function getOriginalRevisionId() {
 396                 return $this->originalRevId;
 397         }
 398
 399         /**
 400          * Sets the ID of an earlier revision that is being repeated or restored by this update.
 401          * The new revision is expected to have the exact same content as the given original revision.
 402          * This is used with rollbacks and with dummy "null" revisions which are created to record
 403          * things like page moves.
 404          *
 405          * This value is passed to the PageContentSaveComplete and NewRevisionFromEditComplete hooks.
 406          *
 407          * @param int|bool $originalRevId The original revision id, or false if no earlier revision
 408          * is known to be repeated or restored by this update.
 409          */
 410         public function setOriginalRevisionId( $originalRevId ) {
 411                 Assert::parameterType( 'integer|boolean', $originalRevId, '$originalRevId' );
 412                 $this->originalRevId = $originalRevId;
 413         }
 414
 415         /**
 416          * Returns the revision ID set by setUndidRevisionId(), indicating what revision is being
 417          * undone by this edit.
 418          *
 419          * @return int
 420          */
 421         public function getUndidRevisionId() {
 422                 return $this->undidRevId;
 423         }
 424
 425         /**
 426          * Sets the ID of revision that was undone by the present update.
 427          * This is used with the "undo" action, and is expected to hold the oldest revision ID
 428          * in case more then one revision is being undone.
 429          *
 430          * @param int $undidRevId
 431          */
 432         public function setUndidRevisionId( $undidRevId ) {
 433                 Assert::parameterType( 'integer', $undidRevId, '$undidRevId' );
 434                 $this->undidRevId = $undidRevId;
 435         }
 436
 437         /**
 438          * Sets a tag to apply to this update.
 439          * Callers are responsible for permission checks,
 440          * using ChangeTags::canAddTagsAccompanyingChange.
 441          * @param string $tag
 442          */
 443         public function addTag( $tag ) {
 444                 Assert::parameterType( 'string', $tag, '$tag' );
 445                 $this->tags[] = trim( $tag );
 446         }
 447
 448         /**
 449          * Sets tags to apply to this update.
 450          * Callers are responsible for permission checks,
 451          * using ChangeTags::canAddTagsAccompanyingChange.
 452          * @param string[] $tags
 453          */
 454         public function addTags( array $tags ) {
 455                 Assert::parameterElementType( 'string', $tags, '$tags' );
 456                 foreach ( $tags as $tag ) {
 457                         $this->addTag( $tag );
 458                 }
 459         }
 460
 461         /**
 462          * Returns the list of tags set using the addTag() method.
 463          *
 464          * @return string[]
 465          */
 466         public function getExplicitTags() {
 467                 return $this->tags;
 468         }
 469
 470         /**
 471          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 472          * @return string[]
 473          */
 474         private function computeEffectiveTags( $flags ) {
 475                 $tags = $this->tags;
 476
 477                 foreach ( $this->slotsUpdate->getModifiedRoles() as $role ) {
 478                         $old_content = $this->getParentContent( $role );
 479
 480                         $handler = $this->getContentHandler( $role );
 481                         $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 482
 483                         // TODO: MCR: Do this for all slots. Also add tags for removing roles!
 484                         $tag = $handler->getChangeTag( $old_content, $content, $flags );
 485                         // If there is no applicable tag, null is returned, so we need to check
 486                         if ( $tag ) {
 487                                 $tags[] = $tag;
 488                         }
 489                 }
 490
 491                 // Check for undo tag
 492                 if ( $this->undidRevId !== 0 && in_array( 'mw-undo', ChangeTags::getSoftwareTags() ) ) {
 493                         $tags[] = 'mw-undo';
 494                 }
 495
 496                 return array_unique( $tags );
 497         }
 498
 499         /**
 500          * Returns the content of the given slot of the parent revision, with no audience checks applied.
 501          * If there is no parent revision or the slot is not defined, this returns null.
 502          *
 503          * @param string $role slot role name
 504          * @return Content|null
 505          */
 506         private function getParentContent( $role ) {
 507                 $parent = $this->grabParentRevision();
 508
 509                 if ( $parent && $parent->hasSlot( $role ) ) {
 510                         return $parent->getContent( $role, RevisionRecord::RAW );
 511                 }
 512
 513                 return null;
 514         }
 515
 516         /**
 517          * @param string $role slot role name
 518          * @return ContentHandler
 519          */
 520         private function getContentHandler( $role ) {
 521                 // TODO: inject something like a ContentHandlerRegistry
 522                 if ( $this->slotsUpdate->isModifiedSlot( $role ) ) {
 523                         $slot = $this->slotsUpdate->getModifiedSlot( $role );
 524                 } else {
 525                         $parent = $this->grabParentRevision();
 526
 527                         if ( $parent ) {
 528                                 $slot = $parent->getSlot( $role, RevisionRecord::RAW );
 529                         } else {
 530                                 throw new RevisionAccessException( 'No such slot: ' . $role );
 531                         }
 532                 }
 533
 534                 return ContentHandler::getForModelID( $slot->getModel() );
 535         }
 536
 537         /**
 538          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 539          *
 540          * @return CommentStoreComment
 541          */
 542         private function makeAutoSummary( $flags ) {
 543                 if ( !$this->useAutomaticEditSummaries || ( $flags & EDIT_AUTOSUMMARY ) === 0 ) {
 544                         return CommentStoreComment::newUnsavedComment( '' );
 545                 }
 546
 547                 // NOTE: this generates an auto-summary for SOME RANDOM changed slot!
 548                 // TODO: combine auto-summaries for multiple slots!
 549                 // XXX: this logic should not be in the storage layer!
 550                 $roles = $this->slotsUpdate->getModifiedRoles();
 551                 $role = reset( $roles );
 552
 553                 if ( $role === false ) {
 554                         return CommentStoreComment::newUnsavedComment( '' );
 555                 }
 556
 557                 $handler = $this->getContentHandler( $role );
 558                 $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 559                 $old_content = $this->getParentContent( $role );
 560                 $summary = $handler->getAutosummary( $old_content, $content, $flags );
 561
 562                 return CommentStoreComment::newUnsavedComment( $summary );
 563         }
 564
 565         /**
 566          * Change an existing article or create a new article. Updates RC and all necessary caches,
 567          * optionally via the deferred update array. This does not check user permissions.
 568          *
 569          * It is guaranteed that saveRevision() will fail if the current revision of the page
 570          * changes after grabParentRevision() was called and before saveRevision() can insert
 571          * a new revision, as per the CAS mechanism described above.
 572          *
 573          * The caller is however responsible for calling hasEditConflict() to detect a
 574          * user-level edit conflict, and to adjust the content of the new revision accordingly,
 575          * e.g. by using a 3-way-merge.
 576          *
 577          * MCR migration note: this replaces WikiPage::doEditContent. Callers that change to using
 578          * saveRevision() now need to check the "minoredit" themselves before using EDIT_MINOR.
 579          *
 580          * @param CommentStoreComment $summary Edit summary
 581          * @param int $flags Bitfield:
 582          *      EDIT_NEW
 583          *          Create a new page, or fail with "edit-already-exists" if the page exists.
 584          *      EDIT_UPDATE
 585          *          Create a new revision, or fail with "edit-gone-missing" if the page does not exist.
 586          *      EDIT_MINOR
 587          *          Mark this revision as minor
 588          *      EDIT_SUPPRESS_RC
 589          *          Do not log the change in recentchanges
 590          *      EDIT_FORCE_BOT
 591          *          Mark the revision as automated ("bot edit")
 592          *      EDIT_AUTOSUMMARY
 593          *          Fill in blank summaries with generated text where possible
 594          *      EDIT_INTERNAL
 595          *          Signal that the page retrieve/save cycle happened entirely in this request.
 596          *
 597          * If neither EDIT_NEW nor EDIT_UPDATE is specified, the expected state is detected
 598          * automatically via grabParentRevision(). In this case, the "edit-already-exists" or
 599          * "edit-gone-missing" errors may still be triggered due to race conditions, if the page
 600          * was unexpectedly created or deleted while revision creation is in progress. This can be
 601          * viewed as part of the CAS mechanism described above.
 602          *
 603          * @return RevisionRecord|null The new revision, or null if no new revision was created due
 604          *         to a failure or a null-edit. Use isUnchanged(), wasSuccessful() and getStatus()
 605          *         to determine the outcome of the revision creation.
 606          *
 607          * @throws MWException
 608          * @throws RuntimeException
 609          */
 610         public function saveRevision( CommentStoreComment $summary, $flags = 0 ) {
 611                 // Defend against mistakes caused by differences with the
 612                 // signature of WikiPage::doEditContent.
 613                 Assert::parameterType( 'integer', $flags, '$flags' );
 614                 Assert::parameterType( 'CommentStoreComment', $summary, '$summary' );
 615
 616                 if ( $this->wasCommitted() ) {
 617                         throw new RuntimeException( 'saveRevision() has already been called on this PageUpdater!' );
 618                 }
 619
 620                 // Low-level sanity check
 621                 if ( $this->getLinkTarget()->getText() === '' ) {
 622                         throw new RuntimeException( 'Something is trying to edit an article with an empty title' );
 623                 }
 624
 625                 // TODO: MCR: check the role and the content's model against the list of supported
 626                 // and required roles, see T194046.
 627
 628                 // Make sure the given content type is allowed for this page
 629                 // TODO: decide: Extend check to other slots? Consider the role in check? [PageType]
 630                 $mainContentHandler = $this->getContentHandler( 'main' );
 631                 if ( !$mainContentHandler->canBeUsedOn( $this->getTitle() ) ) {
 632                         $this->status = Status::newFatal( 'content-not-allowed-here',
 633                                 ContentHandler::getLocalizedName( $mainContentHandler->getModelID() ),
 634                                 $this->getTitle()->getPrefixedText()
 635                         );
 636                         return null;
 637                 }
 638
 639                 // Load the data from the master database if needed. Needed to check flags.
 640                 // NOTE: This grabs the parent revision as the CAS token, if grabParentRevision
 641                 // wasn't called yet. If the page is modified by another process before we are done with
 642                 // it, this method must fail (with status 'edit-conflict')!
 643                 // NOTE: The parent revision may be different from $this->originalRevisionId.
 644                 $this->grabParentRevision();
 645                 $flags = $this->checkFlags( $flags );
 646
 647                 // Avoid statsd noise and wasted cycles check the edit stash (T136678)
 648                 if ( ( $flags & EDIT_INTERNAL ) || ( $flags & EDIT_FORCE_BOT ) ) {
 649                         $useStashed = false;
 650                 } else {
 651                         $useStashed = $this->ajaxEditStash;
 652                 }
 653
 654                 // TODO: use this only for the legacy hook, and only if something uses the legacy hook
 655                 $wikiPage = $this->getWikiPage();
 656
 657                 $user = $this->user;
 658
 659                 // Prepare the update. This performs PST and generates the canonical ParserOutput.
 660                 $this->derivedDataUpdater->prepareContent(
 661                         $this->user,
 662                         $this->slotsUpdate,
 663                         $useStashed
 664                 );
 665
 666                 // TODO: don't force initialization here!
 667                 // This is a hack to work around the fact that late initialization of the ParserOutput
 668                 // causes ApiFlowEditHeaderTest::testCache to fail. Whether that failure indicates an
 669                 // actual problem, or is just an issue with the test setup, remains to be determined
 670                 // [dk, 2018-03].
 671                 // Anomie said in 2018-03:
 672                 /*
 673                         I suspect that what's breaking is this:
 674
 675                         The old version of WikiPage::doEditContent() called prepareContentForEdit() which
 676                         generated the ParserOutput right then, so when doEditUpdates() gets called from the
 677                         DeferredUpdate scheduled by WikiPage::doCreate() there's no need to parse. I note
 678                         there's a comment there that says "Get the pre-save transform content and final
 679                         parser output".
 680                         The new version of WikiPage::doEditContent() makes a PageUpdater and calls its
 681                         saveRevision(), which calls DerivedPageDataUpdater::prepareContent() and
 682                         PageUpdater::doCreate() without ever having to actually generate a ParserOutput.
 683                         Thus, when DerivedPageDataUpdater::doUpdates() is called from the DeferredUpdate
 684                         scheduled by PageUpdater::doCreate(), it does find that it needs to parse at that point.
 685
 686                         And the order of operations in that Flow test is presumably:
 687
 688                         - Create a page with a call to WikiPage::doEditContent(), in a way that somehow avoids
 689                         processing the DeferredUpdate.
 690                         - Set up the "no set!" mock cache in Flow\Tests\Api\ApiTestCase::expectCacheInvalidate()
 691                         - Then, during the course of doing that test, a $db->commit() results in the
 692                         DeferredUpdates being run.
 693                  */
 694                 $this->derivedDataUpdater->getCanonicalParserOutput();
 695
 696                 $mainContent = $this->derivedDataUpdater->getSlots()->getContent( 'main' );
 697
 698                 // Trigger pre-save hook (using provided edit summary)
 699                 $hookStatus = Status::newGood( [] );
 700                 // TODO: replace legacy hook!
 701                 // TODO: avoid pass-by-reference, see T193950
 702                 $hook_args = [ &$wikiPage, &$user, &$mainContent, &$summary,
 703                         $flags & EDIT_MINOR, null, null, &$flags, &$hookStatus ];
 704                 // Check if the hook rejected the attempted save
 705                 if ( !Hooks::run( 'PageContentSave', $hook_args ) ) {
 706                         if ( $hookStatus->isOK() ) {
 707                                 // Hook returned false but didn't call fatal(); use generic message
 708                                 $hookStatus->fatal( 'edit-hook-aborted' );
 709                         }
 710
 711                         $this->status = $hookStatus;
 712                         return null;
 713                 }
 714
 715                 // Provide autosummaries if one is not provided and autosummaries are enabled
 716                 // XXX: $summary == null seems logical, but the empty string may actually come from the user
 717                 // XXX: Move this logic out of the storage layer! It does not belong here! Use a callback?
 718                 if ( $summary->text === '' && $summary->data === null ) {
 719                         $summary = $this->makeAutoSummary( $flags );
 720                 }
 721
 722                 // Actually create the revision and create/update the page.
 723                 // Do NOT yet set $this->status!
 724                 if ( $flags & EDIT_UPDATE ) {
 725                         $status = $this->doModify( $summary, $this->user, $flags );
 726                 } else {
 727                         $status = $this->doCreate( $summary, $this->user, $flags );
 728                 }
 729
 730                 // Promote user to any groups they meet the criteria for
 731                 DeferredUpdates::addCallableUpdate( function () use ( $user ) {
 732                         $user->addAutopromoteOnceGroups( 'onEdit' );
 733                         $user->addAutopromoteOnceGroups( 'onView' ); // b/c
 734                 } );
 735
 736                 // NOTE: set $this->status only after all hooks have been called,
 737                 // so wasCommitted doesn't return true wehn called indirectly from a hook handler!
 738                 $this->status = $status;
 739
 740                 // TODO: replace bad status with Exceptions!
 741                 return ( $this->status && $this->status->isOK() )
 742                         ? $this->status->value['revision-record']
 743                         : null;
 744         }
 745
 746         /**
 747          * Whether saveRevision() has been called on this instance
 748          *
 749          * @return bool
 750          */
 751         public function wasCommitted() {
 752                 return $this->status !== null;
 753         }
 754
 755         /**
 756          * The Status object indicating whether saveRevision() was successful, or null if
 757          * saveRevision() was not yet called on this instance.
 758          *
 759          * @note This is here for compatibility with WikiPage::doEditContent. It may be deprecated
 760          * soon.
 761          *
 762          * Possible status errors:
 763          *     edit-hook-aborted: The ArticleSave hook aborted the update but didn't
 764          *       set the fatal flag of $status.
 765          *     edit-gone-missing: In update mode, but the article didn't exist.
 766          *     edit-conflict: In update mode, the article changed unexpectedly.
 767          *     edit-no-change: Warning that the text was the same as before.
 768          *     edit-already-exists: In creation mode, but the article already exists.
 769          *
 770          *  Extensions may define additional errors.
 771          *
 772          *  $return->value will contain an associative array with members as follows:
 773          *     new: Boolean indicating if the function attempted to create a new article.
 774          *     revision: The revision object for the inserted revision, or null.
 775          *
 776          * @return null|Status
 777          */
 778         public function getStatus() {
 779                 return $this->status;
 780         }
 781
 782         /**
 783          * Whether saveRevision() completed successfully
 784          *
 785          * @return bool
 786          */
 787         public function wasSuccessful() {
 788                 return $this->status && $this->status->isOK();
 789         }
 790
 791         /**
 792          * Whether saveRevision() was called and created a new page.
 793          *
 794          * @return bool
 795          */
 796         public function isNew() {
 797                 return $this->status && $this->status->isOK() && $this->status->value['new'];
 798         }
 799
 800         /**
 801          * Whether saveRevision() did not create a revision because the content didn't change
 802          * (null-edit). Whether the content changed or not is determined by
 803          * DerivedPageDataUpdater::isChange().
 804          *
 805          * @return bool
 806          */
 807         public function isUnchanged() {
 808                 return $this->status
 809                         && $this->status->isOK()
 810                         && $this->status->value['revision-record'] === null;
 811         }
 812
 813         /**
 814          * The new revision created by saveRevision(), or null if saveRevision() has not yet been
 815          * called, failed, or did not create a new revision because the content did not change.
 816          *
 817          * @return RevisionRecord|null
 818          */
 819         public function getNewRevision() {
 820                 return ( $this->status && $this->status->isOK() )
 821                         ? $this->status->value['revision-record']
 822                         : null;
 823         }
 824
 825         /**
 826          * Constructs a MutableRevisionRecord based on the Content prepared by the
 827          * DerivedPageDataUpdater. This takes care of inheriting slots, updating slots
 828          * with PST applied, and removing discontinued slots.
 829          *
 830          * This calls Content::prepareSave() to verify that the slot content can be saved.
 831          * The $status parameter is updated with any errors or warnings found by Content::prepareSave().
 832          *
 833          * @param CommentStoreComment $comment
 834          * @param User $user
 835          * @param string $timestamp
 836          * @param int $flags
 837          * @param Status $status
 838          *
 839          * @return MutableRevisionRecord
 840          */
 841         private function makeNewRevision(
 842                 CommentStoreComment $comment,
 843                 User $user,
 844                 $timestamp,
 845                 $flags,
 846                 Status $status
 847         ) {
 848                 $wikiPage = $this->getWikiPage();
 849                 $title = $this->getTitle();
 850                 $parent = $this->grabParentRevision();
 851
 852                 $rev = new MutableRevisionRecord( $title, $this->getWikiId() );
 853                 $rev->setPageId( $title->getArticleID() );
 854
 855                 if ( $parent ) {
 856                         $oldid = $parent->getId();
 857                         $rev->setParentId( $oldid );
 858                 } else {
 859                         $oldid = 0;
 860                 }
 861
 862                 $rev->setComment( $comment );
 863                 $rev->setUser( $user );
 864                 $rev->setTimestamp( $timestamp );
 865                 $rev->setMinorEdit( ( $flags & EDIT_MINOR ) > 0 );
 866
 867                 foreach ( $this->derivedDataUpdater->getSlots()->getSlots() as $slot ) {
 868                         $content = $slot->getContent();
 869
 870                         // XXX: We may push this up to the "edit controller" level, see T192777.
 871                         // TODO: change the signature of PrepareSave to not take a WikiPage!
 872                         $prepStatus = $content->prepareSave( $wikiPage, $flags, $oldid, $user );
 873
 874                         if ( $prepStatus->isOK() ) {
 875                                 $rev->setSlot( $slot );
 876                         }
 877
 878                         // TODO: MCR: record which problem arose in which slot.
 879                         $status->merge( $prepStatus );
 880                 }
 881
 882                 return $rev;
 883         }
 884
 885         /**
 886          * @param CommentStoreComment $summary The edit summary
 887          * @param User $user The revision's author
 888          * @param int $flags EXIT_XXX constants
 889          *
 890          * @throws MWException
 891          * @return Status
 892          */
 893         private function doModify( CommentStoreComment $summary, User $user, $flags ) {
 894                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
 895
 896                 // Update article, but only if changed.
 897                 $status = Status::newGood( [ 'new' => false, 'revision' => null, 'revision-record' => null ] );
 898
 899                 // Convenience variables
 900                 $now = $this->getTimestampNow();
 901
 902                 $oldRev = $this->grabParentRevision();
 903                 $oldid = $oldRev ? $oldRev->getId() : 0;
 904
 905                 if ( !$oldRev ) {
 906                         // Article gone missing
 907                         $status->fatal( 'edit-gone-missing' );
 908
 909                         return $status;
 910                 }
 911
 912                 $newRevisionRecord = $this->makeNewRevision(
 913                         $summary,
 914                         $user,
 915                         $now,
 916                         $flags,
 917                         $status
 918                 );
 919
 920                 if ( !$status->isOK() ) {
 921                         return $status;
 922                 }
 923
 924                 // XXX: we may want a flag that allows a null revision to be forced!
 925                 $changed = $this->derivedDataUpdater->isChange();
 926
 927                 $dbw = $this->getDBConnectionRef( DB_MASTER );
 928
 929                 if ( $changed ) {
 930                         $dbw->startAtomic( __METHOD__ );
 931
 932                         // Get the latest page_latest value while locking it.
 933                         // Do a CAS style check to see if it's the same as when this method
 934                         // started. If it changed then bail out before touching the DB.
 935                         $latestNow = $wikiPage->lockAndGetLatest(); // TODO: move to storage service, pass DB
 936                         if ( $latestNow != $oldid ) {
 937                                 // We don't need to roll back, since we did not modify the database yet.
 938                                 // XXX: Or do we want to rollback, any transaction started by calling
 939                                 // code will fail? If we want that, we should probably throw an exception.
 940                                 $dbw->endAtomic( __METHOD__ );
 941                                 // Page updated or deleted in the mean time
 942                                 $status->fatal( 'edit-conflict' );
 943
 944                                 return $status;
 945                         }
 946
 947                         // At this point we are now comitted to returning an OK
 948                         // status unless some DB query error or other exception comes up.
 949                         // This way callers don't have to call rollback() if $status is bad
 950                         // unless they actually try to catch exceptions (which is rare).
 951
 952                         // Save revision content and meta-data
 953                         $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
 954                         $newLegacyRevision = new Revision( $newRevisionRecord );
 955
 956                         // Update page_latest and friends to reflect the new revision
 957                         // TODO: move to storage service
 958                         $wasRedirect = $this->derivedDataUpdater->wasRedirect();
 959                         if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, null, $wasRedirect ) ) {
 960                                 throw new PageUpdateException( "Failed to update page row to use new revision." );
 961                         }
 962
 963                         // TODO: replace legacy hook!
 964                         $tags = $this->computeEffectiveTags( $flags );
 965                         Hooks::run(
 966                                 'NewRevisionFromEditComplete',
 967                                 [ $wikiPage, $newLegacyRevision, $this->getOriginalRevisionId(), $user, &$tags ]
 968                         );
 969
 970                         // Update recentchanges
 971                         if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
 972                                 // Add RC row to the DB
 973                                 RecentChange::notifyEdit(
 974                                         $now,
 975                                         $this->getTitle(),
 976                                         $newRevisionRecord->isMinor(),
 977                                         $user,
 978                                         $summary->text, // TODO: pass object when that becomes possible
 979                                         $oldid,
 980                                         $newRevisionRecord->getTimestamp(),
 981                                         ( $flags & EDIT_FORCE_BOT ) > 0,
 982                                         '',
 983                                         $oldRev->getSize(),
 984                                         $newRevisionRecord->getSize(),
 985                                         $newRevisionRecord->getId(),
 986                                         $this->rcPatrolStatus,
 987                                         $tags
 988                                 );
 989                         }
 990
 991                         $user->incEditCount();
 992
 993                         $dbw->endAtomic( __METHOD__ );
 994
 995                         // Return the new revision to the caller
 996                         $status->value['revision-record'] = $newRevisionRecord;
 997
 998                         // TODO: globally replace usages of 'revision' with getNewRevision()
 999                         $status->value['revision'] = $newLegacyRevision;
1000                 } else {
1001                         // T34948: revision ID must be set to page {{REVISIONID}} and
1002                         // related variables correctly. Likewise for {{REVISIONUSER}} (T135261).
1003                         // Since we don't insert a new revision into the database, the least
1004                         // error-prone way is to reuse given old revision.
1005                         $newRevisionRecord = $oldRev;
1006
1007                         $status->warning( 'edit-no-change' );
1008                         // Update page_touched as updateRevisionOn() was not called.
1009                         // Other cache updates are managed in WikiPage::onArticleEdit()
1010                         // via WikiPage::doEditUpdates().
1011                         $this->getTitle()->invalidateCache( $now );
1012                 }
1013
1014                 // Do secondary updates once the main changes have been committed...
1015                 // NOTE: the updates have to be processed before sending the response to the client
1016                 // (DeferredUpdates::PRESEND), otherwise the client may already be following the
1017                 // HTTP redirect to the standard view before dervide data has been created - most
1018                 // importantly, before the parser cache has been updated. This would cause the
1019                 // content to be parsed a second time, or may cause stale content to be shown.
1020                 DeferredUpdates::addUpdate(
1021                         $this->getAtomicSectionUpdate(
1022                                 $dbw,
1023                                 $wikiPage,
1024                                 $newRevisionRecord,
1025                                 $user,
1026                                 $summary,
1027                                 $flags,
1028                                 $status,
1029                                 [ 'changed' => $changed, ]
1030                         ),
1031                         DeferredUpdates::PRESEND
1032                 );
1033
1034                 return $status;
1035         }
1036
1037         /**
1038          * @param CommentStoreComment $summary The edit summary
1039          * @param User $user The revision's author
1040          * @param int $flags EXIT_XXX constants
1041          *
1042          * @throws DBUnexpectedError
1043          * @throws MWException
1044          * @return Status
1045          */
1046         private function doCreate( CommentStoreComment $summary, User $user, $flags ) {
1047                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
1048
1049                 if ( !$this->derivedDataUpdater->getSlots()->hasSlot( 'main' ) ) {
1050                         throw new PageUpdateException( 'Must provide a main slot when creating a page!' );
1051                 }
1052
1053                 $status = Status::newGood( [ 'new' => true, 'revision' => null, 'revision-record' => null ] );
1054
1055                 $now = $this->getTimestampNow();
1056
1057                 $newRevisionRecord = $this->makeNewRevision(
1058                         $summary,
1059                         $user,
1060                         $now,
1061                         $flags,
1062                         $status
1063                 );
1064
1065                 if ( !$status->isOK() ) {
1066                         return $status;
1067                 }
1068
1069                 $dbw = $this->getDBConnectionRef( DB_MASTER );
1070                 $dbw->startAtomic( __METHOD__ );
1071
1072                 // Add the page record unless one already exists for the title
1073                 // TODO: move to storage service
1074                 $newid = $wikiPage->insertOn( $dbw );
1075                 if ( $newid === false ) {
1076                         $dbw->endAtomic( __METHOD__ ); // nothing inserted
1077                         $status->fatal( 'edit-already-exists' );
1078
1079                         return $status; // nothing done
1080                 }
1081
1082                 // At this point we are now comitted to returning an OK
1083                 // status unless some DB query error or other exception comes up.
1084                 // This way callers don't have to call rollback() if $status is bad
1085                 // unless they actually try to catch exceptions (which is rare).
1086                 $newRevisionRecord->setPageId( $newid );
1087
1088                 // Save the revision text...
1089                 $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
1090                 $newLegacyRevision = new Revision( $newRevisionRecord );
1091
1092                 // Update the page record with revision data
1093                 // TODO: move to storage service
1094                 if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, 0 ) ) {
1095                         throw new PageUpdateException( "Failed to update page row to use new revision." );
1096                 }
1097
1098                 // TODO: replace legacy hook!
1099                 $tags = $this->computeEffectiveTags( $flags );
1100                 Hooks::run(
1101                         'NewRevisionFromEditComplete',
1102                         [ $wikiPage, $newLegacyRevision, false, $user, &$tags ]
1103                 );
1104
1105                 // Update recentchanges
1106                 if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
1107                         // Add RC row to the DB
1108                         RecentChange::notifyNew(
1109                                 $now,
1110                                 $this->getTitle(),
1111                                 $newRevisionRecord->isMinor(),
1112                                 $user,
1113                                 $summary->text, // TODO: pass object when that becomes possible
1114                                 ( $flags & EDIT_FORCE_BOT ) > 0,
1115                                 '',
1116                                 $newRevisionRecord->getSize(),
1117                                 $newRevisionRecord->getId(),
1118                                 $this->rcPatrolStatus,
1119                                 $tags
1120                         );
1121                 }
1122
1123                 $user->incEditCount();
1124
1125                 if ( $this->usePageCreationLog ) {
1126                         // Log the page creation
1127                         // @TODO: Do we want a 'recreate' action?
1128                         $logEntry = new ManualLogEntry( 'create', 'create' );
1129                         $logEntry->setPerformer( $user );
1130                         $logEntry->setTarget( $this->getTitle() );
1131                         $logEntry->setComment( $summary->text );
1132                         $logEntry->setTimestamp( $now );
1133                         $logEntry->setAssociatedRevId( $newRevisionRecord->getId() );
1134                         $logEntry->insert();
1135                         // Note that we don't publish page creation events to recentchanges
1136                         // (i.e. $logEntry->publish()) since this would create duplicate entries,
1137                         // one for the edit and one for the page creation.
1138                 }
1139
1140                 $dbw->endAtomic( __METHOD__ );
1141
1142                 // Return the new revision to the caller
1143                 // TODO: globally replace usages of 'revision' with getNewRevision()
1144                 $status->value['revision'] = $newLegacyRevision;
1145                 $status->value['revision-record'] = $newRevisionRecord;
1146
1147                 // Do secondary updates once the main changes have been committed...
1148                 DeferredUpdates::addUpdate(
1149                         $this->getAtomicSectionUpdate(
1150                                 $dbw,
1151                                 $wikiPage,
1152                                 $newRevisionRecord,
1153                                 $user,
1154                                 $summary,
1155                                 $flags,
1156                                 $status,
1157                                 [ 'created' => true ]
1158                         ),
1159                         DeferredUpdates::PRESEND
1160                 );
1161
1162                 return $status;
1163         }
1164
1165         private function getAtomicSectionUpdate(
1166                 IDatabase $dbw,
1167                 WikiPage $wikiPage,
1168                 RevisionRecord $newRevisionRecord,
1169                 User $user,
1170                 CommentStoreComment $summary,
1171                 $flags,
1172                 Status $status,
1173                 $hints = []
1174         ) {
1175                 return new AtomicSectionUpdate(
1176                         $dbw,
1177                         __METHOD__,
1178                         function () use (
1179                                 $wikiPage, $newRevisionRecord, $user,
1180                                 $summary, $flags, $status, $hints
1181                         ) {
1182                                 $newLegacyRevision = new Revision( $newRevisionRecord );
1183                                 $mainContent = $newRevisionRecord->getContent( 'main', RevisionRecord::RAW );
1184
1185                                 // Update links tables, site stats, etc.
1186                                 $this->derivedDataUpdater->prepareUpdate( $newRevisionRecord, $hints );
1187                                 $this->derivedDataUpdater->doUpdates();
1188
1189                                 // TODO: replace legacy hook!
1190                                 // TODO: avoid pass-by-reference, see T193950
1191
1192                                 if ( $hints['created'] ?? false ) {
1193                                         // Trigger post-create hook
1194                                         $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1195                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision ];
1196                                         Hooks::run( 'PageContentInsertComplete', $params );
1197                                 }
1198
1199                                 // Trigger post-save hook
1200                                 $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1201                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision,
1202                                                 &$status, $this->getOriginalRevisionId(), $this->undidRevId ];
1203                                 Hooks::run( 'PageContentSaveComplete', $params );
1204                         }
1205                 );
1206         }
1207
1208 }