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                 if ( $role !== 'main' ) {
 348                         throw new InvalidArgumentException( 'Only the main slot is presently supported' );
 349                 }
 350
 351                 $this->slotsUpdate->modifyContent( $role, $content );
 352         }
 353
 354         /**
 355          * Explicitly inherit a slot from some earlier revision.
 356          *
 357          * The primary use case for this is rollbacks, when slots are to be inherited from
 358          * the rollback target, overriding the content from the parent revision (which is the
 359          * revision being rolled back).
 360          *
 361          * This should typically not be used to inherit slots from the parent revision, which
 362          * happens implicitly. Using this method causes the given slot to be treated as "modified"
 363          * during revision creation, even if it has the same content as in the parent revision.
 364          *
 365          * @param SlotRecord $originalSlot A slot already existing in the database, to be inherited
 366          *        by the new revision.
 367          */
 368         public function inheritSlot( SlotRecord $originalSlot ) {
 369                 // NOTE: this slot is inherited from some other revision, but it's
 370                 // a "modified" slot for the RevisionSlotsUpdate and DerivedPageDataUpdater,
 371                 // since it's not implicitly inherited from the parent revision.
 372                 $inheritedSlot = SlotRecord::newInherited( $originalSlot );
 373                 $this->slotsUpdate->modifySlot( $inheritedSlot );
 374         }
 375
 376         /**
 377          * Removes the slot with the given role.
 378          *
 379          * This discontinues the "stream" of slots with this role on the page,
 380          * preventing the new revision, and any subsequent revisions, from
 381          * inheriting the slot with this role.
 382          *
 383          * @param string $role A slot role name (but not "main")
 384          */
 385         public function removeSlot( $role ) {
 386                 if ( $role === 'main' ) {
 387                         throw new InvalidArgumentException( 'Cannot remove the main slot!' );
 388                 }
 389
 390                 $this->slotsUpdate->removeSlot( $role );
 391         }
 392
 393         /**
 394          * Returns the ID of an earlier revision that is being repeated or restored by this update.
 395          *
 396          * @return bool|int The original revision id, or false if no earlier revision is known to be
 397          * repeated or restored by this update.
 398          */
 399         public function getOriginalRevisionId() {
 400                 return $this->originalRevId;
 401         }
 402
 403         /**
 404          * Sets the ID of an earlier revision that is being repeated or restored by this update.
 405          * The new revision is expected to have the exact same content as the given original revision.
 406          * This is used with rollbacks and with dummy "null" revisions which are created to record
 407          * things like page moves.
 408          *
 409          * This value is passed to the PageContentSaveComplete and NewRevisionFromEditComplete hooks.
 410          *
 411          * @param int|bool $originalRevId The original revision id, or false if no earlier revision
 412          * is known to be repeated or restored by this update.
 413          */
 414         public function setOriginalRevisionId( $originalRevId ) {
 415                 Assert::parameterType( 'integer|boolean', $originalRevId, '$originalRevId' );
 416                 $this->originalRevId = $originalRevId;
 417         }
 418
 419         /**
 420          * Returns the revision ID set by setUndidRevisionId(), indicating what revision is being
 421          * undone by this edit.
 422          *
 423          * @return int
 424          */
 425         public function getUndidRevisionId() {
 426                 return $this->undidRevId;
 427         }
 428
 429         /**
 430          * Sets the ID of revision that was undone by the present update.
 431          * This is used with the "undo" action, and is expected to hold the oldest revision ID
 432          * in case more then one revision is being undone.
 433          *
 434          * @param int $undidRevId
 435          */
 436         public function setUndidRevisionId( $undidRevId ) {
 437                 Assert::parameterType( 'integer', $undidRevId, '$undidRevId' );
 438                 $this->undidRevId = $undidRevId;
 439         }
 440
 441         /**
 442          * Sets a tag to apply to this update.
 443          * Callers are responsible for permission checks,
 444          * using ChangeTags::canAddTagsAccompanyingChange.
 445          * @param string $tag
 446          */
 447         public function addTag( $tag ) {
 448                 Assert::parameterType( 'string', $tag, '$tag' );
 449                 $this->tags[] = trim( $tag );
 450         }
 451
 452         /**
 453          * Sets tags to apply to this update.
 454          * Callers are responsible for permission checks,
 455          * using ChangeTags::canAddTagsAccompanyingChange.
 456          * @param string[] $tags
 457          */
 458         public function addTags( array $tags ) {
 459                 Assert::parameterElementType( 'string', $tags, '$tags' );
 460                 foreach ( $tags as $tag ) {
 461                         $this->addTag( $tag );
 462                 }
 463         }
 464
 465         /**
 466          * Returns the list of tags set using the addTag() method.
 467          *
 468          * @return string[]
 469          */
 470         public function getExplicitTags() {
 471                 return $this->tags;
 472         }
 473
 474         /**
 475          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 476          * @return string[]
 477          */
 478         private function computeEffectiveTags( $flags ) {
 479                 $tags = $this->tags;
 480
 481                 foreach ( $this->slotsUpdate->getModifiedRoles() as $role ) {
 482                         $old_content = $this->getParentContent( $role );
 483
 484                         $handler = $this->getContentHandler( $role );
 485                         $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 486
 487                         // TODO: MCR: Do this for all slots. Also add tags for removing roles!
 488                         $tag = $handler->getChangeTag( $old_content, $content, $flags );
 489                         // If there is no applicable tag, null is returned, so we need to check
 490                         if ( $tag ) {
 491                                 $tags[] = $tag;
 492                         }
 493                 }
 494
 495                 // Check for undo tag
 496                 if ( $this->undidRevId !== 0 && in_array( 'mw-undo', ChangeTags::getSoftwareTags() ) ) {
 497                         $tags[] = 'mw-undo';
 498                 }
 499
 500                 return array_unique( $tags );
 501         }
 502
 503         /**
 504          * Returns the content of the given slot of the parent revision, with no audience checks applied.
 505          * If there is no parent revision or the slot is not defined, this returns null.
 506          *
 507          * @param string $role slot role name
 508          * @return Content|null
 509          */
 510         private function getParentContent( $role ) {
 511                 $parent = $this->grabParentRevision();
 512
 513                 if ( $parent && $parent->hasSlot( $role ) ) {
 514                         return $parent->getContent( $role, RevisionRecord::RAW );
 515                 }
 516
 517                 return null;
 518         }
 519
 520         /**
 521          * @param string $role slot role name
 522          * @return ContentHandler
 523          */
 524         private function getContentHandler( $role ) {
 525                 // TODO: inject something like a ContentHandlerRegistry
 526                 if ( $this->slotsUpdate->isModifiedSlot( $role ) ) {
 527                         $slot = $this->slotsUpdate->getModifiedSlot( $role );
 528                 } else {
 529                         $parent = $this->grabParentRevision();
 530
 531                         if ( $parent ) {
 532                                 $slot = $parent->getSlot( $role, RevisionRecord::RAW );
 533                         } else {
 534                                 throw new RevisionAccessException( 'No such slot: ' . $role );
 535                         }
 536                 }
 537
 538                 return ContentHandler::getForModelID( $slot->getModel() );
 539         }
 540
 541         /**
 542          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 543          *
 544          * @return CommentStoreComment
 545          */
 546         private function makeAutoSummary( $flags ) {
 547                 if ( !$this->useAutomaticEditSummaries || ( $flags & EDIT_AUTOSUMMARY ) === 0 ) {
 548                         return CommentStoreComment::newUnsavedComment( '' );
 549                 }
 550
 551                 // NOTE: this generates an auto-summary for SOME RANDOM changed slot!
 552                 // TODO: combine auto-summaries for multiple slots!
 553                 // XXX: this logic should not be in the storage layer!
 554                 $roles = $this->slotsUpdate->getModifiedRoles();
 555                 $role = reset( $roles );
 556
 557                 if ( $role === false ) {
 558                         return CommentStoreComment::newUnsavedComment( '' );
 559                 }
 560
 561                 $handler = $this->getContentHandler( $role );
 562                 $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 563                 $old_content = $this->getParentContent( $role );
 564                 $summary = $handler->getAutosummary( $old_content, $content, $flags );
 565
 566                 return CommentStoreComment::newUnsavedComment( $summary );
 567         }
 568
 569         /**
 570          * Change an existing article or create a new article. Updates RC and all necessary caches,
 571          * optionally via the deferred update array. This does not check user permissions.
 572          *
 573          * It is guaranteed that saveRevision() will fail if the current revision of the page
 574          * changes after grabParentRevision() was called and before saveRevision() can insert
 575          * a new revision, as per the CAS mechanism described above.
 576          *
 577          * The caller is however responsible for calling hasEditConflict() to detect a
 578          * user-level edit conflict, and to adjust the content of the new revision accordingly,
 579          * e.g. by using a 3-way-merge.
 580          *
 581          * MCR migration note: this replaces WikiPage::doEditContent. Callers that change to using
 582          * saveRevision() now need to check the "minoredit" themselves before using EDIT_MINOR.
 583          *
 584          * @param CommentStoreComment $summary Edit summary
 585          * @param int $flags Bitfield:
 586          *      EDIT_NEW
 587          *          Create a new page, or fail with "edit-already-exists" if the page exists.
 588          *      EDIT_UPDATE
 589          *          Create a new revision, or fail with "edit-gone-missing" if the page does not exist.
 590          *      EDIT_MINOR
 591          *          Mark this revision as minor
 592          *      EDIT_SUPPRESS_RC
 593          *          Do not log the change in recentchanges
 594          *      EDIT_FORCE_BOT
 595          *          Mark the revision as automated ("bot edit")
 596          *      EDIT_AUTOSUMMARY
 597          *          Fill in blank summaries with generated text where possible
 598          *      EDIT_INTERNAL
 599          *          Signal that the page retrieve/save cycle happened entirely in this request.
 600          *
 601          * If neither EDIT_NEW nor EDIT_UPDATE is specified, the expected state is detected
 602          * automatically via grabParentRevision(). In this case, the "edit-already-exists" or
 603          * "edit-gone-missing" errors may still be triggered due to race conditions, if the page
 604          * was unexpectedly created or deleted while revision creation is in progress. This can be
 605          * viewed as part of the CAS mechanism described above.
 606          *
 607          * @return RevisionRecord|null The new revision, or null if no new revision was created due
 608          *         to a failure or a null-edit. Use isUnchanged(), wasSuccessful() and getStatus()
 609          *         to determine the outcome of the revision creation.
 610          *
 611          * @throws MWException
 612          * @throws RuntimeException
 613          */
 614         public function saveRevision( CommentStoreComment $summary, $flags = 0 ) {
 615                 // Defend against mistakes caused by differences with the
 616                 // signature of WikiPage::doEditContent.
 617                 Assert::parameterType( 'integer', $flags, '$flags' );
 618                 Assert::parameterType( 'CommentStoreComment', $summary, '$summary' );
 619
 620                 if ( $this->wasCommitted() ) {
 621                         throw new RuntimeException( 'saveRevision() has already been called on this PageUpdater!' );
 622                 }
 623
 624                 // Low-level sanity check
 625                 if ( $this->getLinkTarget()->getText() === '' ) {
 626                         throw new RuntimeException( 'Something is trying to edit an article with an empty title' );
 627                 }
 628
 629                 // TODO: MCR: check the role and the content's model against the list of supported
 630                 // and required roles, see T194046.
 631
 632                 // Make sure the given content type is allowed for this page
 633                 // TODO: decide: Extend check to other slots? Consider the role in check? [PageType]
 634                 $mainContentHandler = $this->getContentHandler( 'main' );
 635                 if ( !$mainContentHandler->canBeUsedOn( $this->getTitle() ) ) {
 636                         $this->status = Status::newFatal( 'content-not-allowed-here',
 637                                 ContentHandler::getLocalizedName( $mainContentHandler->getModelID() ),
 638                                 $this->getTitle()->getPrefixedText()
 639                         );
 640                         return null;
 641                 }
 642
 643                 // Load the data from the master database if needed. Needed to check flags.
 644                 // NOTE: This grabs the parent revision as the CAS token, if grabParentRevision
 645                 // wasn't called yet. If the page is modified by another process before we are done with
 646                 // it, this method must fail (with status 'edit-conflict')!
 647                 // NOTE: The parent revision may be different from $this->originalRevisionId.
 648                 $this->grabParentRevision();
 649                 $flags = $this->checkFlags( $flags );
 650
 651                 // Avoid statsd noise and wasted cycles check the edit stash (T136678)
 652                 if ( ( $flags & EDIT_INTERNAL ) || ( $flags & EDIT_FORCE_BOT ) ) {
 653                         $useStashed = false;
 654                 } else {
 655                         $useStashed = $this->ajaxEditStash;
 656                 }
 657
 658                 // TODO: use this only for the legacy hook, and only if something uses the legacy hook
 659                 $wikiPage = $this->getWikiPage();
 660
 661                 $user = $this->user;
 662
 663                 // Prepare the update. This performs PST and generates the canonical ParserOutput.
 664                 $this->derivedDataUpdater->prepareContent(
 665                         $this->user,
 666                         $this->slotsUpdate,
 667                         $useStashed
 668                 );
 669
 670                 // TODO: don't force initialization here!
 671                 // This is a hack to work around the fact that late initialization of the ParserOutput
 672                 // causes ApiFlowEditHeaderTest::testCache to fail. Whether that failure indicates an
 673                 // actual problem, or is just an issue with the test setup, remains to be determined
 674                 // [dk, 2018-03].
 675                 // Anomie said in 2018-03:
 676                 /*
 677                         I suspect that what's breaking is this:
 678
 679                         The old version of WikiPage::doEditContent() called prepareContentForEdit() which
 680                         generated the ParserOutput right then, so when doEditUpdates() gets called from the
 681                         DeferredUpdate scheduled by WikiPage::doCreate() there's no need to parse. I note
 682                         there's a comment there that says "Get the pre-save transform content and final
 683                         parser output".
 684                         The new version of WikiPage::doEditContent() makes a PageUpdater and calls its
 685                         saveRevision(), which calls DerivedPageDataUpdater::prepareContent() and
 686                         PageUpdater::doCreate() without ever having to actually generate a ParserOutput.
 687                         Thus, when DerivedPageDataUpdater::doUpdates() is called from the DeferredUpdate
 688                         scheduled by PageUpdater::doCreate(), it does find that it needs to parse at that point.
 689
 690                         And the order of operations in that Flow test is presumably:
 691
 692                         - Create a page with a call to WikiPage::doEditContent(), in a way that somehow avoids
 693                         processing the DeferredUpdate.
 694                         - Set up the "no set!" mock cache in Flow\Tests\Api\ApiTestCase::expectCacheInvalidate()
 695                         - Then, during the course of doing that test, a $db->commit() results in the
 696                         DeferredUpdates being run.
 697                  */
 698                 $this->derivedDataUpdater->getCanonicalParserOutput();
 699
 700                 $mainContent = $this->derivedDataUpdater->getSlots()->getContent( 'main' );
 701
 702                 // Trigger pre-save hook (using provided edit summary)
 703                 $hookStatus = Status::newGood( [] );
 704                 // TODO: replace legacy hook!
 705                 // TODO: avoid pass-by-reference, see T193950
 706                 $hook_args = [ &$wikiPage, &$user, &$mainContent, &$summary,
 707                         $flags & EDIT_MINOR, null, null, &$flags, &$hookStatus ];
 708                 // Check if the hook rejected the attempted save
 709                 if ( !Hooks::run( 'PageContentSave', $hook_args ) ) {
 710                         if ( $hookStatus->isOK() ) {
 711                                 // Hook returned false but didn't call fatal(); use generic message
 712                                 $hookStatus->fatal( 'edit-hook-aborted' );
 713                         }
 714
 715                         $this->status = $hookStatus;
 716                         return null;
 717                 }
 718
 719                 // Provide autosummaries if one is not provided and autosummaries are enabled
 720                 // XXX: $summary == null seems logical, but the empty string may actually come from the user
 721                 // XXX: Move this logic out of the storage layer! It does not belong here! Use a callback?
 722                 if ( $summary->text === '' && $summary->data === null ) {
 723                         $summary = $this->makeAutoSummary( $flags );
 724                 }
 725
 726                 // Actually create the revision and create/update the page.
 727                 // Do NOT yet set $this->status!
 728                 if ( $flags & EDIT_UPDATE ) {
 729                         $status = $this->doModify( $summary, $this->user, $flags );
 730                 } else {
 731                         $status = $this->doCreate( $summary, $this->user, $flags );
 732                 }
 733
 734                 // Promote user to any groups they meet the criteria for
 735                 DeferredUpdates::addCallableUpdate( function () use ( $user ) {
 736                         $user->addAutopromoteOnceGroups( 'onEdit' );
 737                         $user->addAutopromoteOnceGroups( 'onView' ); // b/c
 738                 } );
 739
 740                 // NOTE: set $this->status only after all hooks have been called,
 741                 // so wasCommitted doesn't return true wehn called indirectly from a hook handler!
 742                 $this->status = $status;
 743
 744                 // TODO: replace bad status with Exceptions!
 745                 return ( $this->status && $this->status->isOK() )
 746                         ? $this->status->value['revision-record']
 747                         : null;
 748         }
 749
 750         /**
 751          * Whether saveRevision() has been called on this instance
 752          *
 753          * @return bool
 754          */
 755         public function wasCommitted() {
 756                 return $this->status !== null;
 757         }
 758
 759         /**
 760          * The Status object indicating whether saveRevision() was successful, or null if
 761          * saveRevision() was not yet called on this instance.
 762          *
 763          * @note This is here for compatibility with WikiPage::doEditContent. It may be deprecated
 764          * soon.
 765          *
 766          * Possible status errors:
 767          *     edit-hook-aborted: The ArticleSave hook aborted the update but didn't
 768          *       set the fatal flag of $status.
 769          *     edit-gone-missing: In update mode, but the article didn't exist.
 770          *     edit-conflict: In update mode, the article changed unexpectedly.
 771          *     edit-no-change: Warning that the text was the same as before.
 772          *     edit-already-exists: In creation mode, but the article already exists.
 773          *
 774          *  Extensions may define additional errors.
 775          *
 776          *  $return->value will contain an associative array with members as follows:
 777          *     new: Boolean indicating if the function attempted to create a new article.
 778          *     revision: The revision object for the inserted revision, or null.
 779          *
 780          * @return null|Status
 781          */
 782         public function getStatus() {
 783                 return $this->status;
 784         }
 785
 786         /**
 787          * Whether saveRevision() completed successfully
 788          *
 789          * @return bool
 790          */
 791         public function wasSuccessful() {
 792                 return $this->status && $this->status->isOK();
 793         }
 794
 795         /**
 796          * Whether saveRevision() was called and created a new page.
 797          *
 798          * @return bool
 799          */
 800         public function isNew() {
 801                 return $this->status && $this->status->isOK() && $this->status->value['new'];
 802         }
 803
 804         /**
 805          * Whether saveRevision() did not create a revision because the content didn't change
 806          * (null-edit). Whether the content changed or not is determined by
 807          * DerivedPageDataUpdater::isChange().
 808          *
 809          * @return bool
 810          */
 811         public function isUnchanged() {
 812                 return $this->status
 813                         && $this->status->isOK()
 814                         && $this->status->value['revision-record'] === null;
 815         }
 816
 817         /**
 818          * The new revision created by saveRevision(), or null if saveRevision() has not yet been
 819          * called, failed, or did not create a new revision because the content did not change.
 820          *
 821          * @return RevisionRecord|null
 822          */
 823         public function getNewRevision() {
 824                 return ( $this->status && $this->status->isOK() )
 825                         ? $this->status->value['revision-record']
 826                         : null;
 827         }
 828
 829         /**
 830          * Constructs a MutableRevisionRecord based on the Content prepared by the
 831          * DerivedPageDataUpdater. This takes care of inheriting slots, updating slots
 832          * with PST applied, and removing discontinued slots.
 833          *
 834          * This calls Content::prepareSave() to verify that the slot content can be saved.
 835          * The $status parameter is updated with any errors or warnings found by Content::prepareSave().
 836          *
 837          * @param CommentStoreComment $comment
 838          * @param User $user
 839          * @param string $timestamp
 840          * @param int $flags
 841          * @param Status $status
 842          *
 843          * @return MutableRevisionRecord
 844          */
 845         private function makeNewRevision(
 846                 CommentStoreComment $comment,
 847                 User $user,
 848                 $timestamp,
 849                 $flags,
 850                 Status $status
 851         ) {
 852                 $wikiPage = $this->getWikiPage();
 853                 $title = $this->getTitle();
 854                 $parent = $this->grabParentRevision();
 855
 856                 $rev = new MutableRevisionRecord( $title, $this->getWikiId() );
 857                 $rev->setPageId( $title->getArticleID() );
 858
 859                 if ( $parent ) {
 860                         $oldid = $parent->getId();
 861                         $rev->setParentId( $oldid );
 862                 } else {
 863                         $oldid = 0;
 864                 }
 865
 866                 $rev->setComment( $comment );
 867                 $rev->setUser( $user );
 868                 $rev->setTimestamp( $timestamp );
 869                 $rev->setMinorEdit( ( $flags & EDIT_MINOR ) > 0 );
 870
 871                 foreach ( $this->derivedDataUpdater->getSlots()->getSlots() as $slot ) {
 872                         $content = $slot->getContent();
 873
 874                         // XXX: We may push this up to the "edit controller" level, see T192777.
 875                         // TODO: change the signature of PrepareSave to not take a WikiPage!
 876                         $prepStatus = $content->prepareSave( $wikiPage, $flags, $oldid, $user );
 877
 878                         if ( $prepStatus->isOK() ) {
 879                                 $rev->setSlot( $slot );
 880                         }
 881
 882                         // TODO: MCR: record which problem arose in which slot.
 883                         $status->merge( $prepStatus );
 884                 }
 885
 886                 return $rev;
 887         }
 888
 889         /**
 890          * @param CommentStoreComment $summary The edit summary
 891          * @param User $user The revision's author
 892          * @param int $flags EXIT_XXX constants
 893          *
 894          * @throws MWException
 895          * @return Status
 896          */
 897         private function doModify( CommentStoreComment $summary, User $user, $flags ) {
 898                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
 899
 900                 // Update article, but only if changed.
 901                 $status = Status::newGood( [ 'new' => false, 'revision' => null, 'revision-record' => null ] );
 902
 903                 // Convenience variables
 904                 $now = $this->getTimestampNow();
 905
 906                 $oldRev = $this->grabParentRevision();
 907                 $oldid = $oldRev ? $oldRev->getId() : 0;
 908
 909                 if ( !$oldRev ) {
 910                         // Article gone missing
 911                         $status->fatal( 'edit-gone-missing' );
 912
 913                         return $status;
 914                 }
 915
 916                 $newRevisionRecord = $this->makeNewRevision(
 917                         $summary,
 918                         $user,
 919                         $now,
 920                         $flags,
 921                         $status
 922                 );
 923
 924                 if ( !$status->isOK() ) {
 925                         return $status;
 926                 }
 927
 928                 // XXX: we may want a flag that allows a null revision to be forced!
 929                 $changed = $this->derivedDataUpdater->isChange();
 930
 931                 $dbw = $this->getDBConnectionRef( DB_MASTER );
 932
 933                 if ( $changed ) {
 934                         $dbw->startAtomic( __METHOD__ );
 935
 936                         // Get the latest page_latest value while locking it.
 937                         // Do a CAS style check to see if it's the same as when this method
 938                         // started. If it changed then bail out before touching the DB.
 939                         $latestNow = $wikiPage->lockAndGetLatest(); // TODO: move to storage service, pass DB
 940                         if ( $latestNow != $oldid ) {
 941                                 // We don't need to roll back, since we did not modify the database yet.
 942                                 // XXX: Or do we want to rollback, any transaction started by calling
 943                                 // code will fail? If we want that, we should probably throw an exception.
 944                                 $dbw->endAtomic( __METHOD__ );
 945                                 // Page updated or deleted in the mean time
 946                                 $status->fatal( 'edit-conflict' );
 947
 948                                 return $status;
 949                         }
 950
 951                         // At this point we are now comitted to returning an OK
 952                         // status unless some DB query error or other exception comes up.
 953                         // This way callers don't have to call rollback() if $status is bad
 954                         // unless they actually try to catch exceptions (which is rare).
 955
 956                         // Save revision content and meta-data
 957                         $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
 958                         $newLegacyRevision = new Revision( $newRevisionRecord );
 959
 960                         // Update page_latest and friends to reflect the new revision
 961                         // TODO: move to storage service
 962                         $wasRedirect = $this->derivedDataUpdater->wasRedirect();
 963                         if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, null, $wasRedirect ) ) {
 964                                 throw new PageUpdateException( "Failed to update page row to use new revision." );
 965                         }
 966
 967                         // TODO: replace legacy hook!
 968                         $tags = $this->computeEffectiveTags( $flags );
 969                         Hooks::run(
 970                                 'NewRevisionFromEditComplete',
 971                                 [ $wikiPage, $newLegacyRevision, $this->getOriginalRevisionId(), $user, &$tags ]
 972                         );
 973
 974                         // Update recentchanges
 975                         if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
 976                                 // Add RC row to the DB
 977                                 RecentChange::notifyEdit(
 978                                         $now,
 979                                         $this->getTitle(),
 980                                         $newRevisionRecord->isMinor(),
 981                                         $user,
 982                                         $summary->text, // TODO: pass object when that becomes possible
 983                                         $oldid,
 984                                         $newRevisionRecord->getTimestamp(),
 985                                         ( $flags & EDIT_FORCE_BOT ) > 0,
 986                                         '',
 987                                         $oldRev->getSize(),
 988                                         $newRevisionRecord->getSize(),
 989                                         $newRevisionRecord->getId(),
 990                                         $this->rcPatrolStatus,
 991                                         $tags
 992                                 );
 993                         }
 994
 995                         $user->incEditCount();
 996
 997                         $dbw->endAtomic( __METHOD__ );
 998
 999                         // Return the new revision to the caller
1000                         $status->value['revision-record'] = $newRevisionRecord;
1001
1002                         // TODO: globally replace usages of 'revision' with getNewRevision()
1003                         $status->value['revision'] = $newLegacyRevision;
1004                 } else {
1005                         // T34948: revision ID must be set to page {{REVISIONID}} and
1006                         // related variables correctly. Likewise for {{REVISIONUSER}} (T135261).
1007                         // Since we don't insert a new revision into the database, the least
1008                         // error-prone way is to reuse given old revision.
1009                         $newRevisionRecord = $oldRev;
1010
1011                         $status->warning( 'edit-no-change' );
1012                         // Update page_touched as updateRevisionOn() was not called.
1013                         // Other cache updates are managed in WikiPage::onArticleEdit()
1014                         // via WikiPage::doEditUpdates().
1015                         $this->getTitle()->invalidateCache( $now );
1016                 }
1017
1018                 // Do secondary updates once the main changes have been committed...
1019                 // NOTE: the updates have to be processed before sending the response to the client
1020                 // (DeferredUpdates::PRESEND), otherwise the client may already be following the
1021                 // HTTP redirect to the standard view before dervide data has been created - most
1022                 // importantly, before the parser cache has been updated. This would cause the
1023                 // content to be parsed a second time, or may cause stale content to be shown.
1024                 DeferredUpdates::addUpdate(
1025                         $this->getAtomicSectionUpdate(
1026                                 $dbw,
1027                                 $wikiPage,
1028                                 $newRevisionRecord,
1029                                 $user,
1030                                 $summary,
1031                                 $flags,
1032                                 $status,
1033                                 [ 'changed' => $changed, ]
1034                         ),
1035                         DeferredUpdates::PRESEND
1036                 );
1037
1038                 return $status;
1039         }
1040
1041         /**
1042          * @param CommentStoreComment $summary The edit summary
1043          * @param User $user The revision's author
1044          * @param int $flags EXIT_XXX constants
1045          *
1046          * @throws DBUnexpectedError
1047          * @throws MWException
1048          * @return Status
1049          */
1050         private function doCreate( CommentStoreComment $summary, User $user, $flags ) {
1051                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
1052
1053                 if ( !$this->derivedDataUpdater->getSlots()->hasSlot( 'main' ) ) {
1054                         throw new PageUpdateException( 'Must provide a main slot when creating a page!' );
1055                 }
1056
1057                 $status = Status::newGood( [ 'new' => true, 'revision' => null, 'revision-record' => null ] );
1058
1059                 $now = $this->getTimestampNow();
1060
1061                 $newRevisionRecord = $this->makeNewRevision(
1062                         $summary,
1063                         $user,
1064                         $now,
1065                         $flags,
1066                         $status
1067                 );
1068
1069                 if ( !$status->isOK() ) {
1070                         return $status;
1071                 }
1072
1073                 $dbw = $this->getDBConnectionRef( DB_MASTER );
1074                 $dbw->startAtomic( __METHOD__ );
1075
1076                 // Add the page record unless one already exists for the title
1077                 // TODO: move to storage service
1078                 $newid = $wikiPage->insertOn( $dbw );
1079                 if ( $newid === false ) {
1080                         $dbw->endAtomic( __METHOD__ ); // nothing inserted
1081                         $status->fatal( 'edit-already-exists' );
1082
1083                         return $status; // nothing done
1084                 }
1085
1086                 // At this point we are now comitted to returning an OK
1087                 // status unless some DB query error or other exception comes up.
1088                 // This way callers don't have to call rollback() if $status is bad
1089                 // unless they actually try to catch exceptions (which is rare).
1090                 $newRevisionRecord->setPageId( $newid );
1091
1092                 // Save the revision text...
1093                 $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
1094                 $newLegacyRevision = new Revision( $newRevisionRecord );
1095
1096                 // Update the page record with revision data
1097                 // TODO: move to storage service
1098                 if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, 0 ) ) {
1099                         throw new PageUpdateException( "Failed to update page row to use new revision." );
1100                 }
1101
1102                 // TODO: replace legacy hook!
1103                 $tags = $this->computeEffectiveTags( $flags );
1104                 Hooks::run(
1105                         'NewRevisionFromEditComplete',
1106                         [ $wikiPage, $newLegacyRevision, false, $user, &$tags ]
1107                 );
1108
1109                 // Update recentchanges
1110                 if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
1111                         // Add RC row to the DB
1112                         RecentChange::notifyNew(
1113                                 $now,
1114                                 $this->getTitle(),
1115                                 $newRevisionRecord->isMinor(),
1116                                 $user,
1117                                 $summary->text, // TODO: pass object when that becomes possible
1118                                 ( $flags & EDIT_FORCE_BOT ) > 0,
1119                                 '',
1120                                 $newRevisionRecord->getSize(),
1121                                 $newRevisionRecord->getId(),
1122                                 $this->rcPatrolStatus,
1123                                 $tags
1124                         );
1125                 }
1126
1127                 $user->incEditCount();
1128
1129                 if ( $this->usePageCreationLog ) {
1130                         // Log the page creation
1131                         // @TODO: Do we want a 'recreate' action?
1132                         $logEntry = new ManualLogEntry( 'create', 'create' );
1133                         $logEntry->setPerformer( $user );
1134                         $logEntry->setTarget( $this->getTitle() );
1135                         $logEntry->setComment( $summary->text );
1136                         $logEntry->setTimestamp( $now );
1137                         $logEntry->setAssociatedRevId( $newRevisionRecord->getId() );
1138                         $logEntry->insert();
1139                         // Note that we don't publish page creation events to recentchanges
1140                         // (i.e. $logEntry->publish()) since this would create duplicate entries,
1141                         // one for the edit and one for the page creation.
1142                 }
1143
1144                 $dbw->endAtomic( __METHOD__ );
1145
1146                 // Return the new revision to the caller
1147                 // TODO: globally replace usages of 'revision' with getNewRevision()
1148                 $status->value['revision'] = $newLegacyRevision;
1149                 $status->value['revision-record'] = $newRevisionRecord;
1150
1151                 // Do secondary updates once the main changes have been committed...
1152                 DeferredUpdates::addUpdate(
1153                         $this->getAtomicSectionUpdate(
1154                                 $dbw,
1155                                 $wikiPage,
1156                                 $newRevisionRecord,
1157                                 $user,
1158                                 $summary,
1159                                 $flags,
1160                                 $status,
1161                                 [ 'created' => true ]
1162                         ),
1163                         DeferredUpdates::PRESEND
1164                 );
1165
1166                 return $status;
1167         }
1168
1169         private function getAtomicSectionUpdate(
1170                 IDatabase $dbw,
1171                 WikiPage $wikiPage,
1172                 RevisionRecord $newRevisionRecord,
1173                 User $user,
1174                 CommentStoreComment $summary,
1175                 $flags,
1176                 Status $status,
1177                 $hints = []
1178         ) {
1179                 return new AtomicSectionUpdate(
1180                         $dbw,
1181                         __METHOD__,
1182                         function () use (
1183                                 $wikiPage, $newRevisionRecord, $user,
1184                                 $summary, $flags, $status, $hints
1185                         ) {
1186                                 $newLegacyRevision = new Revision( $newRevisionRecord );
1187                                 $mainContent = $newRevisionRecord->getContent( 'main', RevisionRecord::RAW );
1188
1189                                 // Update links tables, site stats, etc.
1190                                 $this->derivedDataUpdater->prepareUpdate( $newRevisionRecord, $hints );
1191                                 $this->derivedDataUpdater->doUpdates();
1192
1193                                 // TODO: replace legacy hook!
1194                                 // TODO: avoid pass-by-reference, see T193950
1195
1196                                 if ( $hints['created'] ?? false ) {
1197                                         // Trigger post-create hook
1198                                         $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1199                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision ];
1200                                         Hooks::run( 'PageContentInsertComplete', $params );
1201                                 }
1202
1203                                 // Trigger post-save hook
1204                                 $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1205                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision,
1206                                                 &$status, $this->getOriginalRevisionId(), $this->undidRevId ];
1207                                 Hooks::run( 'PageContentSaveComplete', $params );
1208                         }
1209                 );
1210         }
1211
1212 }