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\LoadBalancer;
  49 use WikiPage;
  50
  51 /**
  52  * Controller-like object for creating and updating pages by creating new revisions.
  53  *
  54  * PageUpdater instances provide compare-and-swap (CAS) protection against concurrent updates
  55  * between the time grabParentRevision() is called and saveRevision() inserts a new revision.
  56  * This allows application logic to safely perform edit conflict resolution using the parent
  57  * revision's content.
  58  *
  59  * @see docs/pageupdater.txt for more information.
  60  *
  61  * MCR migration note: this replaces the relevant methods in WikiPage.
  62  *
  63  * @since 1.32
  64  * @ingroup Page
  65  */
  66 class PageUpdater {
  67
  68         /**
  69          * @var User
  70          */
  71         private $user;
  72
  73         /**
  74          * @var WikiPage
  75          */
  76         private $wikiPage;
  77
  78         /**
  79          * @var DerivedPageDataUpdater
  80          */
  81         private $derivedDataUpdater;
  82
  83         /**
  84          * @var LoadBalancer
  85          */
  86         private $loadBalancer;
  87
  88         /**
  89          * @var RevisionStore
  90          */
  91         private $revisionStore;
  92
  93         /**
  94          * @var boolean see $wgUseAutomaticEditSummaries
  95          * @see $wgUseAutomaticEditSummaries
  96          */
  97         private $useAutomaticEditSummaries = true;
  98
  99         /**
 100          * @var int the RC patrol status the new revision should be marked with.
 101          */
 102         private $rcPatrolStatus = RecentChange::PRC_UNPATROLLED;
 103
 104         /**
 105          * @var bool whether to create a log entry for new page creations.
 106          */
 107         private $usePageCreationLog = true;
 108
 109         /**
 110          * @var boolean see $wgAjaxEditStash
 111          */
 112         private $ajaxEditStash = true;
 113
 114         /**
 115          * @var bool|int
 116          */
 117         private $originalRevId = false;
 118
 119         /**
 120          * @var array
 121          */
 122         private $tags = [];
 123
 124         /**
 125          * @var int
 126          */
 127         private $undidRevId = 0;
 128
 129         /**
 130          * @var RevisionSlotsUpdate
 131          */
 132         private $slotsUpdate;
 133
 134         /**
 135          * @var Status|null
 136          */
 137         private $status = null;
 138
 139         /**
 140          * @param User $user
 141          * @param WikiPage $wikiPage
 142          * @param DerivedPageDataUpdater $derivedDataUpdater
 143          * @param LoadBalancer $loadBalancer
 144          * @param RevisionStore $revisionStore
 145          */
 146         public function __construct(
 147                 User $user,
 148                 WikiPage $wikiPage,
 149                 DerivedPageDataUpdater $derivedDataUpdater,
 150                 LoadBalancer $loadBalancer,
 151                 RevisionStore $revisionStore
 152         ) {
 153                 $this->user = $user;
 154                 $this->wikiPage = $wikiPage;
 155                 $this->derivedDataUpdater = $derivedDataUpdater;
 156
 157                 $this->loadBalancer = $loadBalancer;
 158                 $this->revisionStore = $revisionStore;
 159
 160                 $this->slotsUpdate = new RevisionSlotsUpdate();
 161         }
 162
 163         /**
 164          * Can be used to enable or disable automatic summaries that are applied to certain kinds of
 165          * changes, like completely blanking a page.
 166          *
 167          * @param bool $useAutomaticEditSummaries
 168          * @see $wgUseAutomaticEditSummaries
 169          */
 170         public function setUseAutomaticEditSummaries( $useAutomaticEditSummaries ) {
 171                 $this->useAutomaticEditSummaries = $useAutomaticEditSummaries;
 172         }
 173
 174         /**
 175          * Sets the "patrolled" status of the edit.
 176          * Callers should check the "patrol" and "autopatrol" permissions as appropriate.
 177          *
 178          * @see $wgUseRCPatrol
 179          * @see $wgUseNPPatrol
 180          *
 181          * @param int $status RC patrol status, e.g. RecentChange::PRC_AUTOPATROLLED.
 182          */
 183         public function setRcPatrolStatus( $status ) {
 184                 $this->rcPatrolStatus = $status;
 185         }
 186
 187         /**
 188          * Whether to create a log entry for new page creations.
 189          *
 190          * @see $wgPageCreationLog
 191          *
 192          * @param bool $use
 193          */
 194         public function setUsePageCreationLog( $use ) {
 195                 $this->usePageCreationLog = $use;
 196         }
 197
 198         /**
 199          * @param bool $ajaxEditStash
 200          * @see $wgAjaxEditStash
 201          */
 202         public function setAjaxEditStash( $ajaxEditStash ) {
 203                 $this->ajaxEditStash = $ajaxEditStash;
 204         }
 205
 206         private function getWikiId() {
 207                 return false; // TODO: get from RevisionStore!
 208         }
 209
 210         /**
 211          * @param int $mode DB_MASTER or DB_REPLICA
 212          *
 213          * @return DBConnRef
 214          */
 215         private function getDBConnectionRef( $mode ) {
 216                 return $this->loadBalancer->getConnectionRef( $mode, [], $this->getWikiId() );
 217         }
 218
 219         /**
 220          * @return LinkTarget
 221          */
 222         private function getLinkTarget() {
 223                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 224                 return $this->wikiPage->getTitle();
 225         }
 226
 227         /**
 228          * @return Title
 229          */
 230         private function getTitle() {
 231                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 232                 return $this->wikiPage->getTitle();
 233         }
 234
 235         /**
 236          * @return WikiPage
 237          */
 238         private function getWikiPage() {
 239                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 240                 return $this->wikiPage;
 241         }
 242
 243         /**
 244          * Checks whether this update conflicts with another update performed between the client
 245          * loading data to prepare an edit, and the client committing the edit. This is intended to
 246          * detect user level "edit conflict" when the latest revision known to the client
 247          * is no longer the current revision when processing the update.
 248          *
 249          * An update expected to create a new page can be checked by setting $expectedParentRevision = 0.
 250          * Such an update is considered to have a conflict if a current revision exists (that is,
 251          * the page was created since the edit was initiated on the client).
 252          *
 253          * This method returning true indicates to calling code that edit conflict resolution should
 254          * be applied before saving any data. It does not prevent the update from being performed, and
 255          * it should not be confused with a "late" conflict indicated by the "edit-conflict" status.
 256          * A "late" conflict is a CAS failure caused by an update being performed concurrently between
 257          * the time grabParentRevision() was called and the time saveRevision() trying to insert the
 258          * new revision.
 259          *
 260          * @note A user level edit conflict is not the same as the "edit-conflict" status triggered by
 261          * a CAS failure. Calling this method establishes the CAS token, it does not check against it:
 262          * This method calls grabParentRevision(), and thus causes the expected parent revision
 263          * for the update to be fixed to the page's current revision at this point in time.
 264          * It acts as a compare-and-swap (CAS) token in that it is guaranteed that saveRevision()
 265          * will fail with the "edit-conflict" status if the current revision of the page changes after
 266          * hasEditConflict() (or grabParentRevision()) was called and before saveRevision() could insert
 267          * a new revision.
 268          *
 269          * @see grabParentRevision()
 270          *
 271          * @param int $expectedParentRevision The ID of the revision the client expects to be the
 272          *        current one. Use 0 to indicate that the page is expected to not yet exist.
 273          *
 274          * @return bool
 275          */
 276         public function hasEditConflict( $expectedParentRevision ) {
 277                 $parent = $this->grabParentRevision();
 278                 $parentId = $parent ? $parent->getId() : 0;
 279
 280                 return $parentId !== $expectedParentRevision;
 281         }
 282
 283         /**
 284          * Returns the revision that was the page's current revision when grabParentRevision()
 285          * was first called. This revision is the expected parent revision of the update, and will be
 286          * recorded as the new revision's parent revision (unless no new revision is created because
 287          * the content was not changed).
 288          *
 289          * This method MUST not be called after saveRevision() was called!
 290          *
 291          * The current revision determined by the first call to this methods effectively acts a
 292          * compare-and-swap (CAS) token which is checked by saveRevision(), which fails if any
 293          * concurrent updates created a new revision.
 294          *
 295          * Application code should call this method before applying transformations to the new
 296          * content that depend on the parent revision, e.g. adding/replacing sections, or resolving
 297          * conflicts via a 3-way merge. This protects against race conditions triggered by concurrent
 298          * updates.
 299          *
 300          * @see DerivedPageDataUpdater::grabCurrentRevision()
 301          *
 302          * @note The expected parent revision is not to be confused with the logical base revision.
 303          * The base revision is specified by the client, the parent revision is determined from the
 304          * database. If base revision and parent revision are not the same, the updates is considered
 305          * to require edit conflict resolution.
 306          *
 307          * @throws LogicException if called after saveRevision().
 308          * @return RevisionRecord|null the parent revision, or null of the page does not yet exist.
 309          */
 310         public function grabParentRevision() {
 311                 return $this->derivedDataUpdater->grabCurrentRevision();
 312         }
 313
 314         /**
 315          * @return string
 316          */
 317         private function getTimestampNow() {
 318                 // TODO: allow an override to be injected for testing
 319                 return wfTimestampNow();
 320         }
 321
 322         /**
 323          * Check flags and add EDIT_NEW or EDIT_UPDATE to them as needed.
 324          *
 325          * @param int $flags
 326          * @return int Updated $flags
 327          */
 328         private function checkFlags( $flags ) {
 329                 if ( !( $flags & EDIT_NEW ) && !( $flags & EDIT_UPDATE ) ) {
 330                         $flags |= ( $this->derivedDataUpdater->pageExisted() ) ? EDIT_UPDATE : EDIT_NEW;
 331                 }
 332
 333                 return $flags;
 334         }
 335
 336         /**
 337          * Set the new content for the given slot role
 338          *
 339          * @param string $role A slot role name (such as "main")
 340          * @param Content $content
 341          */
 342         public function setContent( $role, Content $content ) {
 343                 // TODO: MCR: check the role and the content's model against the list of supported
 344                 // roles, see T194046.
 345
 346                 if ( $role !== 'main' ) {
 347                         throw new InvalidArgumentException( 'Only the main slot is presently supported' );
 348                 }
 349
 350                 $this->slotsUpdate->modifyContent( $role, $content );
 351         }
 352
 353         /**
 354          * Explicitly inherit a slot from some earlier revision.
 355          *
 356          * The primary use case for this is rollbacks, when slots are to be inherited from
 357          * the rollback target, overriding the content from the parent revision (which is the
 358          * revision being rolled back).
 359          *
 360          * This should typically not be used to inherit slots from the parent revision, which
 361          * happens implicitly. Using this method causes the given slot to be treated as "modified"
 362          * during revision creation, even if it has the same content as in the parent revision.
 363          *
 364          * @param SlotRecord $originalSlot A slot already existing in the database, to be inherited
 365          *        by the new revision.
 366          */
 367         public function inheritSlot( SlotRecord $originalSlot ) {
 368                 // NOTE: this slot is inherited from some other revision, but it's
 369                 // a "modified" slot for the RevisionSlotsUpdate and DerivedPageDataUpdater,
 370                 // since it's not implicitly inherited from the parent revision.
 371                 $inheritedSlot = SlotRecord::newInherited( $originalSlot );
 372                 $this->slotsUpdate->modifySlot( $inheritedSlot );
 373         }
 374
 375         /**
 376          * Removes the slot with the given role.
 377          *
 378          * This discontinues the "stream" of slots with this role on the page,
 379          * preventing the new revision, and any subsequent revisions, from
 380          * inheriting the slot with this role.
 381          *
 382          * @param string $role A slot role name (but not "main")
 383          */
 384         public function removeSlot( $role ) {
 385                 if ( $role === 'main' ) {
 386                         throw new InvalidArgumentException( 'Cannot remove the main slot!' );
 387                 }
 388
 389                 $this->slotsUpdate->removeSlot( $role );
 390         }
 391
 392         /**
 393          * Returns the ID of an earlier revision that is being repeated or restored by this update.
 394          *
 395          * @return bool|int The original revision id, or false if no earlier revision is known to be
 396          * repeated or restored by this update.
 397          */
 398         public function getOriginalRevisionId() {
 399                 return $this->originalRevId;
 400         }
 401
 402         /**
 403          * Sets the ID of an earlier revision that is being repeated or restored by this update.
 404          * The new revision is expected to have the exact same content as the given original revision.
 405          * This is used with rollbacks and with dummy "null" revisions which are created to record
 406          * things like page moves.
 407          *
 408          * This value is passed to the PageContentSaveComplete and NewRevisionFromEditComplete hooks.
 409          *
 410          * @param int|bool $originalRevId The original revision id, or false if no earlier revision
 411          * is known to be repeated or restored by this update.
 412          */
 413         public function setOriginalRevisionId( $originalRevId ) {
 414                 Assert::parameterType( 'integer|boolean', $originalRevId, '$originalRevId' );
 415                 $this->originalRevId = $originalRevId;
 416         }
 417
 418         /**
 419          * Returns the revision ID set by setUndidRevisionId(), indicating what revision is being
 420          * undone by this edit.
 421          *
 422          * @return int
 423          */
 424         public function getUndidRevisionId() {
 425                 return $this->undidRevId;
 426         }
 427
 428         /**
 429          * Sets the ID of revision that was undone by the present update.
 430          * This is used with the "undo" action, and is expected to hold the oldest revision ID
 431          * in case more then one revision is being undone.
 432          *
 433          * @param int $undidRevId
 434          */
 435         public function setUndidRevisionId( $undidRevId ) {
 436                 Assert::parameterType( 'integer', $undidRevId, '$undidRevId' );
 437                 $this->undidRevId = $undidRevId;
 438         }
 439
 440         /**
 441          * Sets a tag to apply to this update.
 442          * Callers are responsible for permission checks,
 443          * using ChangeTags::canAddTagsAccompanyingChange.
 444          * @param string $tag
 445          */
 446         public function addTag( $tag ) {
 447                 Assert::parameterType( 'string', $tag, '$tag' );
 448                 $this->tags[] = trim( $tag );
 449         }
 450
 451         /**
 452          * Sets tags to apply to this update.
 453          * Callers are responsible for permission checks,
 454          * using ChangeTags::canAddTagsAccompanyingChange.
 455          * @param string[] $tags
 456          */
 457         public function addTags( array $tags ) {
 458                 Assert::parameterElementType( 'string', $tags, '$tags' );
 459                 foreach ( $tags as $tag ) {
 460                         $this->addTag( $tag );
 461                 }
 462         }
 463
 464         /**
 465          * Returns the list of tags set using the addTag() method.
 466          *
 467          * @return string[]
 468          */
 469         public function getExplicitTags() {
 470                 return $this->tags;
 471         }
 472
 473         /**
 474          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 475          * @return string[]
 476          */
 477         private function computeEffectiveTags( $flags ) {
 478                 $tags = $this->tags;
 479
 480                 foreach ( $this->slotsUpdate->getModifiedRoles() as $role ) {
 481                         $old_content = $this->getParentContent( $role );
 482
 483                         $handler = $this->getContentHandler( $role );
 484                         $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 485
 486                         // TODO: MCR: Do this for all slots. Also add tags for removing roles!
 487                         $tag = $handler->getChangeTag( $old_content, $content, $flags );
 488                         // If there is no applicable tag, null is returned, so we need to check
 489                         if ( $tag ) {
 490                                 $tags[] = $tag;
 491                         }
 492                 }
 493
 494                 // Check for undo tag
 495                 if ( $this->undidRevId !== 0 && in_array( 'mw-undo', ChangeTags::getSoftwareTags() ) ) {
 496                         $tags[] = 'mw-undo';
 497                 }
 498
 499                 return array_unique( $tags );
 500         }
 501
 502         /**
 503          * Returns the content of the given slot of the parent revision, with no audience checks applied.
 504          * If there is no parent revision or the slot is not defined, this returns null.
 505          *
 506          * @param string $role slot role name
 507          * @return Content|null
 508          */
 509         private function getParentContent( $role ) {
 510                 $parent = $this->grabParentRevision();
 511
 512                 if ( $parent && $parent->hasSlot( $role ) ) {
 513                         return $parent->getContent( $role, RevisionRecord::RAW );
 514                 }
 515
 516                 return null;
 517         }
 518
 519         /**
 520          * @param string $role slot role name
 521          * @return ContentHandler
 522          */
 523         private function getContentHandler( $role ) {
 524                 // TODO: inject something like a ContentHandlerRegistry
 525                 if ( $this->slotsUpdate->isModifiedSlot( $role ) ) {
 526                         $slot = $this->slotsUpdate->getModifiedSlot( $role );
 527                 } else {
 528                         $parent = $this->grabParentRevision();
 529
 530                         if ( $parent ) {
 531                                 $slot = $parent->getSlot( $role, RevisionRecord::RAW );
 532                         } else {
 533                                 throw new RevisionAccessException( 'No such slot: ' . $role );
 534                         }
 535                 }
 536
 537                 return ContentHandler::getForModelID( $slot->getModel() );
 538         }
 539
 540         /**
 541          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 542          *
 543          * @return CommentStoreComment
 544          */
 545         private function makeAutoSummary( $flags ) {
 546                 if ( !$this->useAutomaticEditSummaries || ( $flags & EDIT_AUTOSUMMARY ) === 0 ) {
 547                         return CommentStoreComment::newUnsavedComment( '' );
 548                 }
 549
 550                 // NOTE: this generates an auto-summary for SOME RANDOM changed slot!
 551                 // TODO: combine auto-summaries for multiple slots!
 552                 // XXX: this logic should not be in the storage layer!
 553                 $roles = $this->slotsUpdate->getModifiedRoles();
 554                 $role = reset( $roles );
 555
 556                 if ( $role === false ) {
 557                         return CommentStoreComment::newUnsavedComment( '' );
 558                 }
 559
 560                 $handler = $this->getContentHandler( $role );
 561                 $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 562                 $old_content = $this->getParentContent( $role );
 563                 $summary = $handler->getAutosummary( $old_content, $content, $flags );
 564
 565                 return CommentStoreComment::newUnsavedComment( $summary );
 566         }
 567
 568         /**
 569          * Change an existing article or create a new article. Updates RC and all necessary caches,
 570          * optionally via the deferred update array. This does not check user permissions.
 571          *
 572          * It is guaranteed that saveRevision() will fail if the current revision of the page
 573          * changes after grabParentRevision() was called and before saveRevision() can insert
 574          * a new revision, as per the CAS mechanism described above.
 575          *
 576          * The caller is however responsible for calling hasEditConflict() to detect a
 577          * user-level edit conflict, and to adjust the content of the new revision accordingly,
 578          * e.g. by using a 3-way-merge.
 579          *
 580          * MCR migration note: this replaces WikiPage::doEditContent. Callers that change to using
 581          * saveRevision() now need to check the "minoredit" themselves before using EDIT_MINOR.
 582          *
 583          * @param CommentStoreComment $summary Edit summary
 584          * @param int $flags Bitfield:
 585          *      EDIT_NEW
 586          *          Create a new page, or fail with "edit-already-exists" if the page exists.
 587          *      EDIT_UPDATE
 588          *          Create a new revision, or fail with "edit-gone-missing" if the page does not exist.
 589          *      EDIT_MINOR
 590          *          Mark this revision as minor
 591          *      EDIT_SUPPRESS_RC
 592          *          Do not log the change in recentchanges
 593          *      EDIT_FORCE_BOT
 594          *          Mark the revision as automated ("bot edit")
 595          *      EDIT_AUTOSUMMARY
 596          *          Fill in blank summaries with generated text where possible
 597          *      EDIT_INTERNAL
 598          *          Signal that the page retrieve/save cycle happened entirely in this request.
 599          *
 600          * If neither EDIT_NEW nor EDIT_UPDATE is specified, the expected state is detected
 601          * automatically via grabParentRevision(). In this case, the "edit-already-exists" or
 602          * "edit-gone-missing" errors may still be triggered due to race conditions, if the page
 603          * was unexpectedly created or deleted while revision creation is in progress. This can be
 604          * viewed as part of the CAS mechanism described above.
 605          *
 606          * @return RevisionRecord|null The new revision, or null if no new revision was created due
 607          *         to a failure or a null-edit. Use isUnchanged(), wasSuccessful() and getStatus()
 608          *         to determine the outcome of the revision creation.
 609          *
 610          * @throws MWException
 611          * @throws RuntimeException
 612          */
 613         public function saveRevision( CommentStoreComment $summary, $flags = 0 ) {
 614                 // Defend against mistakes caused by differences with the
 615                 // signature of WikiPage::doEditContent.
 616                 Assert::parameterType( 'integer', $flags, '$flags' );
 617                 Assert::parameterType( 'CommentStoreComment', $summary, '$summary' );
 618
 619                 if ( $this->wasCommitted() ) {
 620                         throw new RuntimeException( 'saveRevision() has already been called on this PageUpdater!' );
 621                 }
 622
 623                 // Low-level sanity check
 624                 if ( $this->getLinkTarget()->getText() === '' ) {
 625                         throw new RuntimeException( 'Something is trying to edit an article with an empty title' );
 626                 }
 627
 628                 // TODO: MCR: check the role and the content's model against the list of supported
 629                 // and required roles, see T194046.
 630
 631                 // Make sure the given content type is allowed for this page
 632                 // TODO: decide: Extend check to other slots? Consider the role in check? [PageType]
 633                 $mainContentHandler = $this->getContentHandler( 'main' );
 634                 if ( !$mainContentHandler->canBeUsedOn( $this->getTitle() ) ) {
 635                         $this->status = Status::newFatal( 'content-not-allowed-here',
 636                                 ContentHandler::getLocalizedName( $mainContentHandler->getModelID() ),
 637                                 $this->getTitle()->getPrefixedText()
 638                         );
 639                         return null;
 640                 }
 641
 642                 // Load the data from the master database if needed. Needed to check flags.
 643                 // NOTE: This grabs the parent revision as the CAS token, if grabParentRevision
 644                 // wasn't called yet. If the page is modified by another process before we are done with
 645                 // it, this method must fail (with status 'edit-conflict')!
 646                 // NOTE: The parent revision may be different from $this->baseRevisionId.
 647                 $this->grabParentRevision();
 648                 $flags = $this->checkFlags( $flags );
 649
 650                 // Avoid statsd noise and wasted cycles check the edit stash (T136678)
 651                 if ( ( $flags & EDIT_INTERNAL ) || ( $flags & EDIT_FORCE_BOT ) ) {
 652                         $useStashed = false;
 653                 } else {
 654                         $useStashed = $this->ajaxEditStash;
 655                 }
 656
 657                 // TODO: use this only for the legacy hook, and only if something uses the legacy hook
 658                 $wikiPage = $this->getWikiPage();
 659
 660                 $user = $this->user;
 661
 662                 // Prepare the update. This performs PST and generates the canonical ParserOutput.
 663                 $this->derivedDataUpdater->prepareContent(
 664                         $this->user,
 665                         $this->slotsUpdate,
 666                         $useStashed
 667                 );
 668
 669                 // TODO: don't force initialization here!
 670                 // This is a hack to work around the fact that late initialization of the ParserOutput
 671                 // causes ApiFlowEditHeaderTest::testCache to fail. Whether that failure indicates an
 672                 // actual problem, or is just an issue with the test setup, remains to be determined
 673                 // [dk, 2018-03].
 674                 // Anomie said in 2018-03:
 675                 /*
 676                         I suspect that what's breaking is this:
 677
 678                         The old version of WikiPage::doEditContent() called prepareContentForEdit() which
 679                         generated the ParserOutput right then, so when doEditUpdates() gets called from the
 680                         DeferredUpdate scheduled by WikiPage::doCreate() there's no need to parse. I note
 681                         there's a comment there that says "Get the pre-save transform content and final
 682                         parser output".
 683                         The new version of WikiPage::doEditContent() makes a PageUpdater and calls its
 684                         saveRevision(), which calls DerivedPageDataUpdater::prepareContent() and
 685                         PageUpdater::doCreate() without ever having to actually generate a ParserOutput.
 686                         Thus, when DerivedPageDataUpdater::doUpdates() is called from the DeferredUpdate
 687                         scheduled by PageUpdater::doCreate(), it does find that it needs to parse at that point.
 688
 689                         And the order of operations in that Flow test is presumably:
 690
 691                         - Create a page with a call to WikiPage::doEditContent(), in a way that somehow avoids
 692                         processing the DeferredUpdate.
 693                         - Set up the "no set!" mock cache in Flow\Tests\Api\ApiTestCase::expectCacheInvalidate()
 694                         - Then, during the course of doing that test, a $db->commit() results in the
 695                         DeferredUpdates being run.
 696                  */
 697                 $this->derivedDataUpdater->getCanonicalParserOutput();
 698
 699                 $mainContent = $this->derivedDataUpdater->getSlots()->getContent( 'main' );
 700
 701                 // Trigger pre-save hook (using provided edit summary)
 702                 $hookStatus = Status::newGood( [] );
 703                 // TODO: replace legacy hook!
 704                 // TODO: avoid pass-by-reference, see T193950
 705                 $hook_args = [ &$wikiPage, &$user, &$mainContent, &$summary,
 706                         $flags & EDIT_MINOR, null, null, &$flags, &$hookStatus ];
 707                 // Check if the hook rejected the attempted save
 708                 if ( !Hooks::run( 'PageContentSave', $hook_args ) ) {
 709                         if ( $hookStatus->isOK() ) {
 710                                 // Hook returned false but didn't call fatal(); use generic message
 711                                 $hookStatus->fatal( 'edit-hook-aborted' );
 712                         }
 713
 714                         $this->status = $hookStatus;
 715                         return null;
 716                 }
 717
 718                 // Provide autosummaries if one is not provided and autosummaries are enabled
 719                 // XXX: $summary == null seems logical, but the empty string may actually come from the user
 720                 // XXX: Move this logic out of the storage layer! It does not belong here! Use a callback?
 721                 if ( $summary->text === '' && $summary->data === null ) {
 722                         $summary = $this->makeAutoSummary( $flags );
 723                 }
 724
 725                 // Actually create the revision and create/update the page.
 726                 // Do NOT yet set $this->status!
 727                 if ( $flags & EDIT_UPDATE ) {
 728                         $status = $this->doModify( $summary, $this->user, $flags );
 729                 } else {
 730                         $status = $this->doCreate( $summary, $this->user, $flags );
 731                 }
 732
 733                 // Promote user to any groups they meet the criteria for
 734                 DeferredUpdates::addCallableUpdate( function () use ( $user ) {
 735                         $user->addAutopromoteOnceGroups( 'onEdit' );
 736                         $user->addAutopromoteOnceGroups( 'onView' ); // b/c
 737                 } );
 738
 739                 // NOTE: set $this->status only after all hooks have been called,
 740                 // so wasCommitted doesn't return true wehn called indirectly from a hook handler!
 741                 $this->status = $status;
 742
 743                 // TODO: replace bad status with Exceptions!
 744                 return ( $this->status && $this->status->isOK() )
 745                         ? $this->status->value['revision-record']
 746                         : null;
 747         }
 748
 749         /**
 750          * Whether saveRevision() has been called on this instance
 751          *
 752          * @return bool
 753          */
 754         public function wasCommitted() {
 755                 return $this->status !== null;
 756         }
 757
 758         /**
 759          * The Status object indicating whether saveRevision() was successful, or null if
 760          * saveRevision() was not yet called on this instance.
 761          *
 762          * @note This is here for compatibility with WikiPage::doEditContent. It may be deprecated
 763          * soon.
 764          *
 765          * Possible status errors:
 766          *     edit-hook-aborted: The ArticleSave hook aborted the update but didn't
 767          *       set the fatal flag of $status.
 768          *     edit-gone-missing: In update mode, but the article didn't exist.
 769          *     edit-conflict: In update mode, the article changed unexpectedly.
 770          *     edit-no-change: Warning that the text was the same as before.
 771          *     edit-already-exists: In creation mode, but the article already exists.
 772          *
 773          *  Extensions may define additional errors.
 774          *
 775          *  $return->value will contain an associative array with members as follows:
 776          *     new: Boolean indicating if the function attempted to create a new article.
 777          *     revision: The revision object for the inserted revision, or null.
 778          *
 779          * @return null|Status
 780          */
 781         public function getStatus() {
 782                 return $this->status;
 783         }
 784
 785         /**
 786          * Whether saveRevision() completed successfully
 787          *
 788          * @return bool
 789          */
 790         public function wasSuccessful() {
 791                 return $this->status && $this->status->isOK();
 792         }
 793
 794         /**
 795          * Whether saveRevision() was called and created a new page.
 796          *
 797          * @return bool
 798          */
 799         public function isNew() {
 800                 return $this->status && $this->status->isOK() && $this->status->value['new'];
 801         }
 802
 803         /**
 804          * Whether saveRevision() did not create a revision because the content didn't change
 805          * (null-edit). Whether the content changed or not is determined by
 806          * DerivedPageDataUpdater::isChange().
 807          *
 808          * @return bool
 809          */
 810         public function isUnchanged() {
 811                 return $this->status
 812                         && $this->status->isOK()
 813                         && $this->status->value['revision-record'] === null;
 814         }
 815
 816         /**
 817          * The new revision created by saveRevision(), or null if saveRevision() has not yet been
 818          * called, failed, or did not create a new revision because the content did not change.
 819          *
 820          * @return RevisionRecord|null
 821          */
 822         public function getNewRevision() {
 823                 return ( $this->status && $this->status->isOK() )
 824                         ? $this->status->value['revision-record']
 825                         : null;
 826         }
 827
 828         /**
 829          * Constructs a MutableRevisionRecord based on the Content prepared by the
 830          * DerivedPageDataUpdater. This takes care of inheriting slots, updating slots
 831          * with PST applied, and removing discontinued slots.
 832          *
 833          * This calls Content::prepareSave() to verify that the slot content can be saved.
 834          * The $status parameter is updated with any errors or warnings found by Content::prepareSave().
 835          *
 836          * @param CommentStoreComment $comment
 837          * @param User $user
 838          * @param string $timestamp
 839          * @param int $flags
 840          * @param Status $status
 841          *
 842          * @return MutableRevisionRecord
 843          */
 844         private function makeNewRevision(
 845                 CommentStoreComment $comment,
 846                 User $user,
 847                 $timestamp,
 848                 $flags,
 849                 Status $status
 850         ) {
 851                 $wikiPage = $this->getWikiPage();
 852                 $title = $this->getTitle();
 853                 $parent = $this->grabParentRevision();
 854
 855                 $rev = new MutableRevisionRecord( $title, $this->getWikiId() );
 856                 $rev->setPageId( $title->getArticleID() );
 857
 858                 if ( $parent ) {
 859                         $oldid = $parent->getId();
 860                         $rev->setParentId( $oldid );
 861                 } else {
 862                         $oldid = 0;
 863                 }
 864
 865                 $rev->setComment( $comment );
 866                 $rev->setUser( $user );
 867                 $rev->setTimestamp( $timestamp );
 868                 $rev->setMinorEdit( ( $flags & EDIT_MINOR ) > 0 );
 869
 870                 foreach ( $this->derivedDataUpdater->getSlots()->getSlots() as $slot ) {
 871                         $content = $slot->getContent();
 872
 873                         // XXX: We may push this up to the "edit controller" level, see T192777.
 874                         // TODO: change the signature of PrepareSave to not take a WikiPage!
 875                         $prepStatus = $content->prepareSave( $wikiPage, $flags, $oldid, $user );
 876
 877                         if ( $prepStatus->isOK() ) {
 878                                 $rev->setSlot( $slot );
 879                         }
 880
 881                         // TODO: MCR: record which problem arose in which slot.
 882                         $status->merge( $prepStatus );
 883                 }
 884
 885                 return $rev;
 886         }
 887
 888         /**
 889          * @param CommentStoreComment $summary The edit summary
 890          * @param User $user The revision's author
 891          * @param int $flags EXIT_XXX constants
 892          *
 893          * @throws MWException
 894          * @return Status
 895          */
 896         private function doModify( CommentStoreComment $summary, User $user, $flags ) {
 897                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
 898
 899                 // Update article, but only if changed.
 900                 $status = Status::newGood( [ 'new' => false, 'revision' => null, 'revision-record' => null ] );
 901
 902                 // Convenience variables
 903                 $now = $this->getTimestampNow();
 904
 905                 $oldRev = $this->grabParentRevision();
 906                 $oldid = $oldRev ? $oldRev->getId() : 0;
 907
 908                 if ( !$oldRev ) {
 909                         // Article gone missing
 910                         $status->fatal( 'edit-gone-missing' );
 911
 912                         return $status;
 913                 }
 914
 915                 $newRevisionRecord = $this->makeNewRevision(
 916                         $summary,
 917                         $user,
 918                         $now,
 919                         $flags,
 920                         $status
 921                 );
 922
 923                 if ( !$status->isOK() ) {
 924                         return $status;
 925                 }
 926
 927                 // XXX: we may want a flag that allows a null revision to be forced!
 928                 $changed = $this->derivedDataUpdater->isChange();
 929                 $mainContent = $newRevisionRecord->getContent( 'main' );
 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                 } else {
 999                         // T34948: revision ID must be set to page {{REVISIONID}} and
1000                         // related variables correctly. Likewise for {{REVISIONUSER}} (T135261).
1001                         // Since we don't insert a new revision into the database, the least
1002                         // error-prone way is to reuse given old revision.
1003                         $newRevisionRecord = $oldRev;
1004                         $newLegacyRevision = new Revision( $newRevisionRecord );
1005                 }
1006
1007                 if ( $changed ) {
1008                         // Return the new revision to the caller
1009                         $status->value['revision-record'] = $newRevisionRecord;
1010
1011                         // TODO: globally replace usages of 'revision' with getNewRevision()
1012                         $status->value['revision'] = $newLegacyRevision;
1013                 } else {
1014                         $status->warning( 'edit-no-change' );
1015                         // Update page_touched as updateRevisionOn() was not called.
1016                         // Other cache updates are managed in WikiPage::onArticleEdit()
1017                         // via WikiPage::doEditUpdates().
1018                         $this->getTitle()->invalidateCache( $now );
1019                 }
1020
1021                 // Do secondary updates once the main changes have been committed...
1022                 // NOTE: the updates have to be processed before sending the response to the client
1023                 // (DeferredUpdates::PRESEND), otherwise the client may already be following the
1024                 // HTTP redirect to the standard view before dervide data has been created - most
1025                 // importantly, before the parser cache has been updated. This would cause the
1026                 // content to be parsed a second time, or may cause stale content to be shown.
1027                 DeferredUpdates::addUpdate(
1028                         new AtomicSectionUpdate(
1029                                 $dbw,
1030                                 __METHOD__,
1031                                 function () use (
1032                                         $wikiPage, $newRevisionRecord, $newLegacyRevision, $user, $mainContent,
1033                                         $summary, $flags, $changed, $status
1034                                 ) {
1035                                         // Update links tables, site stats, etc.
1036                                         $this->derivedDataUpdater->prepareUpdate(
1037                                                 $newRevisionRecord,
1038                                                 [
1039                                                         'changed' => $changed,
1040                                                 ]
1041                                         );
1042                                         $this->derivedDataUpdater->doUpdates();
1043
1044                                         // Trigger post-save hook
1045                                         // TODO: replace legacy hook!
1046                                         // TODO: avoid pass-by-reference, see T193950
1047                                         $params = [ &$wikiPage, &$user, $mainContent, $summary->text, $flags & EDIT_MINOR,
1048                                                 null, null, &$flags, $newLegacyRevision, &$status, $this->getOriginalRevisionId(),
1049                                                 $this->undidRevId ];
1050                                         Hooks::run( 'PageContentSaveComplete', $params );
1051                                 }
1052                         ),
1053                         DeferredUpdates::PRESEND
1054                 );
1055
1056                 return $status;
1057         }
1058
1059         /**
1060          * @param CommentStoreComment $summary The edit summary
1061          * @param User $user The revision's author
1062          * @param int $flags EXIT_XXX constants
1063          *
1064          * @throws DBUnexpectedError
1065          * @throws MWException
1066          * @return Status
1067          */
1068         private function doCreate( CommentStoreComment $summary, User $user, $flags ) {
1069                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
1070
1071                 if ( !$this->derivedDataUpdater->getSlots()->hasSlot( 'main' ) ) {
1072                         throw new PageUpdateException( 'Must provide a main slot when creating a page!' );
1073                 }
1074
1075                 $status = Status::newGood( [ 'new' => true, 'revision' => null, 'revision-record' => null ] );
1076
1077                 $now = $this->getTimestampNow();
1078
1079                 $newRevisionRecord = $this->makeNewRevision(
1080                         $summary,
1081                         $user,
1082                         $now,
1083                         $flags,
1084                         $status
1085                 );
1086
1087                 if ( !$status->isOK() ) {
1088                         return $status;
1089                 }
1090
1091                 $dbw = $this->getDBConnectionRef( DB_MASTER );
1092                 $dbw->startAtomic( __METHOD__ );
1093
1094                 // Add the page record unless one already exists for the title
1095                 // TODO: move to storage service
1096                 $newid = $wikiPage->insertOn( $dbw );
1097                 if ( $newid === false ) {
1098                         $dbw->endAtomic( __METHOD__ ); // nothing inserted
1099                         $status->fatal( 'edit-already-exists' );
1100
1101                         return $status; // nothing done
1102                 }
1103
1104                 // At this point we are now comitted to returning an OK
1105                 // status unless some DB query error or other exception comes up.
1106                 // This way callers don't have to call rollback() if $status is bad
1107                 // unless they actually try to catch exceptions (which is rare).
1108                 $newRevisionRecord->setPageId( $newid );
1109
1110                 // Save the revision text...
1111                 $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
1112                 $newLegacyRevision = new Revision( $newRevisionRecord );
1113
1114                 // Update the page record with revision data
1115                 // TODO: move to storage service
1116                 if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, 0 ) ) {
1117                         throw new PageUpdateException( "Failed to update page row to use new revision." );
1118                 }
1119
1120                 // TODO: replace legacy hook!
1121                 $tags = $this->computeEffectiveTags( $flags );
1122                 Hooks::run(
1123                         'NewRevisionFromEditComplete',
1124                         [ $wikiPage, $newLegacyRevision, false, $user, &$tags ]
1125                 );
1126
1127                 // Update recentchanges
1128                 if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
1129                         // Add RC row to the DB
1130                         RecentChange::notifyNew(
1131                                 $now,
1132                                 $this->getTitle(),
1133                                 $newRevisionRecord->isMinor(),
1134                                 $user,
1135                                 $summary->text, // TODO: pass object when that becomes possible
1136                                 ( $flags & EDIT_FORCE_BOT ) > 0,
1137                                 '',
1138                                 $newRevisionRecord->getSize(),
1139                                 $newRevisionRecord->getId(),
1140                                 $this->rcPatrolStatus,
1141                                 $tags
1142                         );
1143                 }
1144
1145                 $user->incEditCount();
1146
1147                 if ( $this->usePageCreationLog ) {
1148                         // Log the page creation
1149                         // @TODO: Do we want a 'recreate' action?
1150                         $logEntry = new ManualLogEntry( 'create', 'create' );
1151                         $logEntry->setPerformer( $user );
1152                         $logEntry->setTarget( $this->getTitle() );
1153                         $logEntry->setComment( $summary->text );
1154                         $logEntry->setTimestamp( $now );
1155                         $logEntry->setAssociatedRevId( $newRevisionRecord->getId() );
1156                         $logEntry->insert();
1157                         // Note that we don't publish page creation events to recentchanges
1158                         // (i.e. $logEntry->publish()) since this would create duplicate entries,
1159                         // one for the edit and one for the page creation.
1160                 }
1161
1162                 $dbw->endAtomic( __METHOD__ );
1163
1164                 // Return the new revision to the caller
1165                 // TODO: globally replace usages of 'revision' with getNewRevision()
1166                 $status->value['revision'] = $newLegacyRevision;
1167                 $status->value['revision-record'] = $newRevisionRecord;
1168
1169                 // XXX: make sure we are not loading the Content from the DB
1170                 $mainContent = $newRevisionRecord->getContent( 'main' );
1171
1172                 // Do secondary updates once the main changes have been committed...
1173                 DeferredUpdates::addUpdate(
1174                         new AtomicSectionUpdate(
1175                                 $dbw,
1176                                 __METHOD__,
1177                                 function () use (
1178                                         $wikiPage,
1179                                         $newRevisionRecord,
1180                                         $newLegacyRevision,
1181                                         $user,
1182                                         $mainContent,
1183                                         $summary,
1184                                         $flags,
1185                                         $status
1186                                 ) {
1187                                         // Update links, etc.
1188                                         $this->derivedDataUpdater->prepareUpdate(
1189                                                 $newRevisionRecord,
1190                                                 [ 'created' => true ]
1191                                         );
1192                                         $this->derivedDataUpdater->doUpdates();
1193
1194                                         // Trigger post-create hook
1195                                         // TODO: replace legacy hook!
1196                                         // TODO: avoid pass-by-reference, see T193950
1197                                         $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1198                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision ];
1199                                         Hooks::run( 'PageContentInsertComplete', $params );
1200                                         // Trigger post-save hook
1201                                         // TODO: replace legacy hook!
1202                                         $params = array_merge( $params, [ &$status, $this->getOriginalRevisionId(), 0 ] );
1203                                         Hooks::run( 'PageContentSaveComplete', $params );
1204                                 }
1205                         ),
1206                         DeferredUpdates::PRESEND
1207                 );
1208
1209                 return $status;
1210         }
1211
1212 }