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 MediaWiki\Revision\MutableRevisionRecord;
  39 use MediaWiki\Revision\RevisionAccessException;
  40 use MediaWiki\Revision\RevisionRecord;
  41 use MediaWiki\Revision\RevisionStore;
  42 use MediaWiki\Revision\SlotRecord;
  43 use MWException;
  44 use RecentChange;
  45 use Revision;
  46 use RuntimeException;
  47 use Status;
  48 use Title;
  49 use User;
  50 use Wikimedia\Assert\Assert;
  51 use Wikimedia\Rdbms\DBConnRef;
  52 use Wikimedia\Rdbms\DBUnexpectedError;
  53 use Wikimedia\Rdbms\IDatabase;
  54 use Wikimedia\Rdbms\LoadBalancer;
  55 use WikiPage;
  56
  57 /**
  58  * Controller-like object for creating and updating pages by creating new revisions.
  59  *
  60  * PageUpdater instances provide compare-and-swap (CAS) protection against concurrent updates
  61  * between the time grabParentRevision() is called and saveRevision() inserts a new revision.
  62  * This allows application logic to safely perform edit conflict resolution using the parent
  63  * revision's content.
  64  *
  65  * @see docs/pageupdater.txt for more information.
  66  *
  67  * MCR migration note: this replaces the relevant methods in WikiPage.
  68  *
  69  * @since 1.32
  70  * @ingroup Page
  71  */
  72 class PageUpdater {
  73
  74         /**
  75          * @var User
  76          */
  77         private $user;
  78
  79         /**
  80          * @var WikiPage
  81          */
  82         private $wikiPage;
  83
  84         /**
  85          * @var DerivedPageDataUpdater
  86          */
  87         private $derivedDataUpdater;
  88
  89         /**
  90          * @var LoadBalancer
  91          */
  92         private $loadBalancer;
  93
  94         /**
  95          * @var RevisionStore
  96          */
  97         private $revisionStore;
  98
  99         /**
 100          * @var boolean see $wgUseAutomaticEditSummaries
 101          * @see $wgUseAutomaticEditSummaries
 102          */
 103         private $useAutomaticEditSummaries = true;
 104
 105         /**
 106          * @var int the RC patrol status the new revision should be marked with.
 107          */
 108         private $rcPatrolStatus = RecentChange::PRC_UNPATROLLED;
 109
 110         /**
 111          * @var bool whether to create a log entry for new page creations.
 112          */
 113         private $usePageCreationLog = true;
 114
 115         /**
 116          * @var boolean see $wgAjaxEditStash
 117          */
 118         private $ajaxEditStash = true;
 119
 120         /**
 121          * @var bool|int
 122          */
 123         private $originalRevId = false;
 124
 125         /**
 126          * @var array
 127          */
 128         private $tags = [];
 129
 130         /**
 131          * @var int
 132          */
 133         private $undidRevId = 0;
 134
 135         /**
 136          * @var RevisionSlotsUpdate
 137          */
 138         private $slotsUpdate;
 139
 140         /**
 141          * @var Status|null
 142          */
 143         private $status = null;
 144
 145         /**
 146          * @param User $user
 147          * @param WikiPage $wikiPage
 148          * @param DerivedPageDataUpdater $derivedDataUpdater
 149          * @param LoadBalancer $loadBalancer
 150          * @param RevisionStore $revisionStore
 151          */
 152         public function __construct(
 153                 User $user,
 154                 WikiPage $wikiPage,
 155                 DerivedPageDataUpdater $derivedDataUpdater,
 156                 LoadBalancer $loadBalancer,
 157                 RevisionStore $revisionStore
 158         ) {
 159                 $this->user = $user;
 160                 $this->wikiPage = $wikiPage;
 161                 $this->derivedDataUpdater = $derivedDataUpdater;
 162
 163                 $this->loadBalancer = $loadBalancer;
 164                 $this->revisionStore = $revisionStore;
 165
 166                 $this->slotsUpdate = new RevisionSlotsUpdate();
 167         }
 168
 169         /**
 170          * Can be used to enable or disable automatic summaries that are applied to certain kinds of
 171          * changes, like completely blanking a page.
 172          *
 173          * @param bool $useAutomaticEditSummaries
 174          * @see $wgUseAutomaticEditSummaries
 175          */
 176         public function setUseAutomaticEditSummaries( $useAutomaticEditSummaries ) {
 177                 $this->useAutomaticEditSummaries = $useAutomaticEditSummaries;
 178         }
 179
 180         /**
 181          * Sets the "patrolled" status of the edit.
 182          * Callers should check the "patrol" and "autopatrol" permissions as appropriate.
 183          *
 184          * @see $wgUseRCPatrol
 185          * @see $wgUseNPPatrol
 186          *
 187          * @param int $status RC patrol status, e.g. RecentChange::PRC_AUTOPATROLLED.
 188          */
 189         public function setRcPatrolStatus( $status ) {
 190                 $this->rcPatrolStatus = $status;
 191         }
 192
 193         /**
 194          * Whether to create a log entry for new page creations.
 195          *
 196          * @see $wgPageCreationLog
 197          *
 198          * @param bool $use
 199          */
 200         public function setUsePageCreationLog( $use ) {
 201                 $this->usePageCreationLog = $use;
 202         }
 203
 204         /**
 205          * @param bool $ajaxEditStash
 206          * @see $wgAjaxEditStash
 207          */
 208         public function setAjaxEditStash( $ajaxEditStash ) {
 209                 $this->ajaxEditStash = $ajaxEditStash;
 210         }
 211
 212         private function getWikiId() {
 213                 return false; // TODO: get from RevisionStore!
 214         }
 215
 216         /**
 217          * @param int $mode DB_MASTER or DB_REPLICA
 218          *
 219          * @return DBConnRef
 220          */
 221         private function getDBConnectionRef( $mode ) {
 222                 return $this->loadBalancer->getConnectionRef( $mode, [], $this->getWikiId() );
 223         }
 224
 225         /**
 226          * @return LinkTarget
 227          */
 228         private function getLinkTarget() {
 229                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 230                 return $this->wikiPage->getTitle();
 231         }
 232
 233         /**
 234          * @return Title
 235          */
 236         private function getTitle() {
 237                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 238                 return $this->wikiPage->getTitle();
 239         }
 240
 241         /**
 242          * @return WikiPage
 243          */
 244         private function getWikiPage() {
 245                 // NOTE: eventually, we won't get a WikiPage passed into the constructor any more
 246                 return $this->wikiPage;
 247         }
 248
 249         /**
 250          * Checks whether this update conflicts with another update performed between the client
 251          * loading data to prepare an edit, and the client committing the edit. This is intended to
 252          * detect user level "edit conflict" when the latest revision known to the client
 253          * is no longer the current revision when processing the update.
 254          *
 255          * An update expected to create a new page can be checked by setting $expectedParentRevision = 0.
 256          * Such an update is considered to have a conflict if a current revision exists (that is,
 257          * the page was created since the edit was initiated on the client).
 258          *
 259          * This method returning true indicates to calling code that edit conflict resolution should
 260          * be applied before saving any data. It does not prevent the update from being performed, and
 261          * it should not be confused with a "late" conflict indicated by the "edit-conflict" status.
 262          * A "late" conflict is a CAS failure caused by an update being performed concurrently between
 263          * the time grabParentRevision() was called and the time saveRevision() trying to insert the
 264          * new revision.
 265          *
 266          * @note A user level edit conflict is not the same as the "edit-conflict" status triggered by
 267          * a CAS failure. Calling this method establishes the CAS token, it does not check against it:
 268          * This method calls grabParentRevision(), and thus causes the expected parent revision
 269          * for the update to be fixed to the page's current revision at this point in time.
 270          * It acts as a compare-and-swap (CAS) token in that it is guaranteed that saveRevision()
 271          * will fail with the "edit-conflict" status if the current revision of the page changes after
 272          * hasEditConflict() (or grabParentRevision()) was called and before saveRevision() could insert
 273          * a new revision.
 274          *
 275          * @see grabParentRevision()
 276          *
 277          * @param int $expectedParentRevision The ID of the revision the client expects to be the
 278          *        current one. Use 0 to indicate that the page is expected to not yet exist.
 279          *
 280          * @return bool
 281          */
 282         public function hasEditConflict( $expectedParentRevision ) {
 283                 $parent = $this->grabParentRevision();
 284                 $parentId = $parent ? $parent->getId() : 0;
 285
 286                 return $parentId !== $expectedParentRevision;
 287         }
 288
 289         /**
 290          * Returns the revision that was the page's current revision when grabParentRevision()
 291          * was first called. This revision is the expected parent revision of the update, and will be
 292          * recorded as the new revision's parent revision (unless no new revision is created because
 293          * the content was not changed).
 294          *
 295          * This method MUST not be called after saveRevision() was called!
 296          *
 297          * The current revision determined by the first call to this methods effectively acts a
 298          * compare-and-swap (CAS) token which is checked by saveRevision(), which fails if any
 299          * concurrent updates created a new revision.
 300          *
 301          * Application code should call this method before applying transformations to the new
 302          * content that depend on the parent revision, e.g. adding/replacing sections, or resolving
 303          * conflicts via a 3-way merge. This protects against race conditions triggered by concurrent
 304          * updates.
 305          *
 306          * @see DerivedPageDataUpdater::grabCurrentRevision()
 307          *
 308          * @note The expected parent revision is not to be confused with the logical base revision.
 309          * The base revision is specified by the client, the parent revision is determined from the
 310          * database. If base revision and parent revision are not the same, the updates is considered
 311          * to require edit conflict resolution.
 312          *
 313          * @throws LogicException if called after saveRevision().
 314          * @return RevisionRecord|null the parent revision, or null of the page does not yet exist.
 315          */
 316         public function grabParentRevision() {
 317                 return $this->derivedDataUpdater->grabCurrentRevision();
 318         }
 319
 320         /**
 321          * @return string
 322          */
 323         private function getTimestampNow() {
 324                 // TODO: allow an override to be injected for testing
 325                 return wfTimestampNow();
 326         }
 327
 328         /**
 329          * Check flags and add EDIT_NEW or EDIT_UPDATE to them as needed.
 330          *
 331          * @param int $flags
 332          * @return int Updated $flags
 333          */
 334         private function checkFlags( $flags ) {
 335                 if ( !( $flags & EDIT_NEW ) && !( $flags & EDIT_UPDATE ) ) {
 336                         $flags |= ( $this->derivedDataUpdater->pageExisted() ) ? EDIT_UPDATE : EDIT_NEW;
 337                 }
 338
 339                 return $flags;
 340         }
 341
 342         /**
 343          * Set the new content for the given slot role
 344          *
 345          * @param string $role A slot role name (such as "main")
 346          * @param Content $content
 347          */
 348         public function setContent( $role, Content $content ) {
 349                 // TODO: MCR: check the role and the content's model against the list of supported
 350                 // roles, see T194046.
 351
 352                 $this->slotsUpdate->modifyContent( $role, $content );
 353         }
 354
 355         /**
 356          * Set the new slot for the given slot role
 357          *
 358          * @param SlotRecord $slot
 359          */
 360         public function setSlot( SlotRecord $slot ) {
 361                 $this->slotsUpdate->modifySlot( $slot );
 362         }
 363
 364         /**
 365          * Explicitly inherit a slot from some earlier revision.
 366          *
 367          * The primary use case for this is rollbacks, when slots are to be inherited from
 368          * the rollback target, overriding the content from the parent revision (which is the
 369          * revision being rolled back).
 370          *
 371          * This should typically not be used to inherit slots from the parent revision, which
 372          * happens implicitly. Using this method causes the given slot to be treated as "modified"
 373          * during revision creation, even if it has the same content as in the parent revision.
 374          *
 375          * @param SlotRecord $originalSlot A slot already existing in the database, to be inherited
 376          *        by the new revision.
 377          */
 378         public function inheritSlot( SlotRecord $originalSlot ) {
 379                 // NOTE: this slot is inherited from some other revision, but it's
 380                 // a "modified" slot for the RevisionSlotsUpdate and DerivedPageDataUpdater,
 381                 // since it's not implicitly inherited from the parent revision.
 382                 $inheritedSlot = SlotRecord::newInherited( $originalSlot );
 383                 $this->slotsUpdate->modifySlot( $inheritedSlot );
 384         }
 385
 386         /**
 387          * Removes the slot with the given role.
 388          *
 389          * This discontinues the "stream" of slots with this role on the page,
 390          * preventing the new revision, and any subsequent revisions, from
 391          * inheriting the slot with this role.
 392          *
 393          * @param string $role A slot role name (but not "main")
 394          */
 395         public function removeSlot( $role ) {
 396                 if ( $role === SlotRecord::MAIN ) {
 397                         throw new InvalidArgumentException( 'Cannot remove the main slot!' );
 398                 }
 399
 400                 $this->slotsUpdate->removeSlot( $role );
 401         }
 402
 403         /**
 404          * Returns the ID of an earlier revision that is being repeated or restored by this update.
 405          *
 406          * @return bool|int The original revision id, or false if no earlier revision is known to be
 407          * repeated or restored by this update.
 408          */
 409         public function getOriginalRevisionId() {
 410                 return $this->originalRevId;
 411         }
 412
 413         /**
 414          * Sets the ID of an earlier revision that is being repeated or restored by this update.
 415          * The new revision is expected to have the exact same content as the given original revision.
 416          * This is used with rollbacks and with dummy "null" revisions which are created to record
 417          * things like page moves.
 418          *
 419          * This value is passed to the PageContentSaveComplete and NewRevisionFromEditComplete hooks.
 420          *
 421          * @param int|bool $originalRevId The original revision id, or false if no earlier revision
 422          * is known to be repeated or restored by this update.
 423          */
 424         public function setOriginalRevisionId( $originalRevId ) {
 425                 Assert::parameterType( 'integer|boolean', $originalRevId, '$originalRevId' );
 426                 $this->originalRevId = $originalRevId;
 427         }
 428
 429         /**
 430          * Returns the revision ID set by setUndidRevisionId(), indicating what revision is being
 431          * undone by this edit.
 432          *
 433          * @return int
 434          */
 435         public function getUndidRevisionId() {
 436                 return $this->undidRevId;
 437         }
 438
 439         /**
 440          * Sets the ID of revision that was undone by the present update.
 441          * This is used with the "undo" action, and is expected to hold the oldest revision ID
 442          * in case more then one revision is being undone.
 443          *
 444          * @param int $undidRevId
 445          */
 446         public function setUndidRevisionId( $undidRevId ) {
 447                 Assert::parameterType( 'integer', $undidRevId, '$undidRevId' );
 448                 $this->undidRevId = $undidRevId;
 449         }
 450
 451         /**
 452          * Sets a tag to apply to this update.
 453          * Callers are responsible for permission checks,
 454          * using ChangeTags::canAddTagsAccompanyingChange.
 455          * @param string $tag
 456          */
 457         public function addTag( $tag ) {
 458                 Assert::parameterType( 'string', $tag, '$tag' );
 459                 $this->tags[] = trim( $tag );
 460         }
 461
 462         /**
 463          * Sets tags to apply to this update.
 464          * Callers are responsible for permission checks,
 465          * using ChangeTags::canAddTagsAccompanyingChange.
 466          * @param string[] $tags
 467          */
 468         public function addTags( array $tags ) {
 469                 Assert::parameterElementType( 'string', $tags, '$tags' );
 470                 foreach ( $tags as $tag ) {
 471                         $this->addTag( $tag );
 472                 }
 473         }
 474
 475         /**
 476          * Returns the list of tags set using the addTag() method.
 477          *
 478          * @return string[]
 479          */
 480         public function getExplicitTags() {
 481                 return $this->tags;
 482         }
 483
 484         /**
 485          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 486          * @return string[]
 487          */
 488         private function computeEffectiveTags( $flags ) {
 489                 $tags = $this->tags;
 490
 491                 foreach ( $this->slotsUpdate->getModifiedRoles() as $role ) {
 492                         $old_content = $this->getParentContent( $role );
 493
 494                         $handler = $this->getContentHandler( $role );
 495                         $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 496
 497                         // TODO: MCR: Do this for all slots. Also add tags for removing roles!
 498                         $tag = $handler->getChangeTag( $old_content, $content, $flags );
 499                         // If there is no applicable tag, null is returned, so we need to check
 500                         if ( $tag ) {
 501                                 $tags[] = $tag;
 502                         }
 503                 }
 504
 505                 // Check for undo tag
 506                 if ( $this->undidRevId !== 0 && in_array( 'mw-undo', ChangeTags::getSoftwareTags() ) ) {
 507                         $tags[] = 'mw-undo';
 508                 }
 509
 510                 return array_unique( $tags );
 511         }
 512
 513         /**
 514          * Returns the content of the given slot of the parent revision, with no audience checks applied.
 515          * If there is no parent revision or the slot is not defined, this returns null.
 516          *
 517          * @param string $role slot role name
 518          * @return Content|null
 519          */
 520         private function getParentContent( $role ) {
 521                 $parent = $this->grabParentRevision();
 522
 523                 if ( $parent && $parent->hasSlot( $role ) ) {
 524                         return $parent->getContent( $role, RevisionRecord::RAW );
 525                 }
 526
 527                 return null;
 528         }
 529
 530         /**
 531          * @param string $role slot role name
 532          * @return ContentHandler
 533          */
 534         private function getContentHandler( $role ) {
 535                 // TODO: inject something like a ContentHandlerRegistry
 536                 if ( $this->slotsUpdate->isModifiedSlot( $role ) ) {
 537                         $slot = $this->slotsUpdate->getModifiedSlot( $role );
 538                 } else {
 539                         $parent = $this->grabParentRevision();
 540
 541                         if ( $parent ) {
 542                                 $slot = $parent->getSlot( $role, RevisionRecord::RAW );
 543                         } else {
 544                                 throw new RevisionAccessException( 'No such slot: ' . $role );
 545                         }
 546                 }
 547
 548                 return ContentHandler::getForModelID( $slot->getModel() );
 549         }
 550
 551         /**
 552          * @param int $flags Bit mask: a bit mask of EDIT_XXX flags.
 553          *
 554          * @return CommentStoreComment
 555          */
 556         private function makeAutoSummary( $flags ) {
 557                 if ( !$this->useAutomaticEditSummaries || ( $flags & EDIT_AUTOSUMMARY ) === 0 ) {
 558                         return CommentStoreComment::newUnsavedComment( '' );
 559                 }
 560
 561                 // NOTE: this generates an auto-summary for SOME RANDOM changed slot!
 562                 // TODO: combine auto-summaries for multiple slots!
 563                 // XXX: this logic should not be in the storage layer!
 564                 $roles = $this->slotsUpdate->getModifiedRoles();
 565                 $role = reset( $roles );
 566
 567                 if ( $role === false ) {
 568                         return CommentStoreComment::newUnsavedComment( '' );
 569                 }
 570
 571                 $handler = $this->getContentHandler( $role );
 572                 $content = $this->slotsUpdate->getModifiedSlot( $role )->getContent();
 573                 $old_content = $this->getParentContent( $role );
 574                 $summary = $handler->getAutosummary( $old_content, $content, $flags );
 575
 576                 return CommentStoreComment::newUnsavedComment( $summary );
 577         }
 578
 579         /**
 580          * Change an existing article or create a new article. Updates RC and all necessary caches,
 581          * optionally via the deferred update array. This does not check user permissions.
 582          *
 583          * It is guaranteed that saveRevision() will fail if the current revision of the page
 584          * changes after grabParentRevision() was called and before saveRevision() can insert
 585          * a new revision, as per the CAS mechanism described above.
 586          *
 587          * The caller is however responsible for calling hasEditConflict() to detect a
 588          * user-level edit conflict, and to adjust the content of the new revision accordingly,
 589          * e.g. by using a 3-way-merge.
 590          *
 591          * MCR migration note: this replaces WikiPage::doEditContent. Callers that change to using
 592          * saveRevision() now need to check the "minoredit" themselves before using EDIT_MINOR.
 593          *
 594          * @param CommentStoreComment $summary Edit summary
 595          * @param int $flags Bitfield:
 596          *      EDIT_NEW
 597          *          Create a new page, or fail with "edit-already-exists" if the page exists.
 598          *      EDIT_UPDATE
 599          *          Create a new revision, or fail with "edit-gone-missing" if the page does not exist.
 600          *      EDIT_MINOR
 601          *          Mark this revision as minor
 602          *      EDIT_SUPPRESS_RC
 603          *          Do not log the change in recentchanges
 604          *      EDIT_FORCE_BOT
 605          *          Mark the revision as automated ("bot edit")
 606          *      EDIT_AUTOSUMMARY
 607          *          Fill in blank summaries with generated text where possible
 608          *      EDIT_INTERNAL
 609          *          Signal that the page retrieve/save cycle happened entirely in this request.
 610          *
 611          * If neither EDIT_NEW nor EDIT_UPDATE is specified, the expected state is detected
 612          * automatically via grabParentRevision(). In this case, the "edit-already-exists" or
 613          * "edit-gone-missing" errors may still be triggered due to race conditions, if the page
 614          * was unexpectedly created or deleted while revision creation is in progress. This can be
 615          * viewed as part of the CAS mechanism described above.
 616          *
 617          * @return RevisionRecord|null The new revision, or null if no new revision was created due
 618          *         to a failure or a null-edit. Use isUnchanged(), wasSuccessful() and getStatus()
 619          *         to determine the outcome of the revision creation.
 620          *
 621          * @throws MWException
 622          * @throws RuntimeException
 623          */
 624         public function saveRevision( CommentStoreComment $summary, $flags = 0 ) {
 625                 // Defend against mistakes caused by differences with the
 626                 // signature of WikiPage::doEditContent.
 627                 Assert::parameterType( 'integer', $flags, '$flags' );
 628
 629                 if ( $this->wasCommitted() ) {
 630                         throw new RuntimeException( 'saveRevision() has already been called on this PageUpdater!' );
 631                 }
 632
 633                 // Low-level sanity check
 634                 if ( $this->getLinkTarget()->getText() === '' ) {
 635                         throw new RuntimeException( 'Something is trying to edit an article with an empty title' );
 636                 }
 637
 638                 // TODO: MCR: check the role and the content's model against the list of supported
 639                 // and required roles, see T194046.
 640
 641                 // Make sure the given content type is allowed for this page
 642                 // TODO: decide: Extend check to other slots? Consider the role in check? [PageType]
 643                 $mainContentHandler = $this->getContentHandler( SlotRecord::MAIN );
 644                 if ( !$mainContentHandler->canBeUsedOn( $this->getTitle() ) ) {
 645                         $this->status = Status::newFatal( 'content-not-allowed-here',
 646                                 ContentHandler::getLocalizedName( $mainContentHandler->getModelID() ),
 647                                 $this->getTitle()->getPrefixedText()
 648                         );
 649                         return null;
 650                 }
 651
 652                 // Load the data from the master database if needed. Needed to check flags.
 653                 // NOTE: This grabs the parent revision as the CAS token, if grabParentRevision
 654                 // wasn't called yet. If the page is modified by another process before we are done with
 655                 // it, this method must fail (with status 'edit-conflict')!
 656                 // NOTE: The parent revision may be different from $this->originalRevisionId.
 657                 $this->grabParentRevision();
 658                 $flags = $this->checkFlags( $flags );
 659
 660                 // Avoid statsd noise and wasted cycles check the edit stash (T136678)
 661                 if ( ( $flags & EDIT_INTERNAL ) || ( $flags & EDIT_FORCE_BOT ) ) {
 662                         $useStashed = false;
 663                 } else {
 664                         $useStashed = $this->ajaxEditStash;
 665                 }
 666
 667                 // TODO: use this only for the legacy hook, and only if something uses the legacy hook
 668                 $wikiPage = $this->getWikiPage();
 669
 670                 $user = $this->user;
 671
 672                 // Prepare the update. This performs PST and generates the canonical ParserOutput.
 673                 $this->derivedDataUpdater->prepareContent(
 674                         $this->user,
 675                         $this->slotsUpdate,
 676                         $useStashed
 677                 );
 678
 679                 // TODO: don't force initialization here!
 680                 // This is a hack to work around the fact that late initialization of the ParserOutput
 681                 // causes ApiFlowEditHeaderTest::testCache to fail. Whether that failure indicates an
 682                 // actual problem, or is just an issue with the test setup, remains to be determined
 683                 // [dk, 2018-03].
 684                 // Anomie said in 2018-03:
 685                 /*
 686                         I suspect that what's breaking is this:
 687
 688                         The old version of WikiPage::doEditContent() called prepareContentForEdit() which
 689                         generated the ParserOutput right then, so when doEditUpdates() gets called from the
 690                         DeferredUpdate scheduled by WikiPage::doCreate() there's no need to parse. I note
 691                         there's a comment there that says "Get the pre-save transform content and final
 692                         parser output".
 693                         The new version of WikiPage::doEditContent() makes a PageUpdater and calls its
 694                         saveRevision(), which calls DerivedPageDataUpdater::prepareContent() and
 695                         PageUpdater::doCreate() without ever having to actually generate a ParserOutput.
 696                         Thus, when DerivedPageDataUpdater::doUpdates() is called from the DeferredUpdate
 697                         scheduled by PageUpdater::doCreate(), it does find that it needs to parse at that point.
 698
 699                         And the order of operations in that Flow test is presumably:
 700
 701                         - Create a page with a call to WikiPage::doEditContent(), in a way that somehow avoids
 702                         processing the DeferredUpdate.
 703                         - Set up the "no set!" mock cache in Flow\Tests\Api\ApiTestCase::expectCacheInvalidate()
 704                         - Then, during the course of doing that test, a $db->commit() results in the
 705                         DeferredUpdates being run.
 706                  */
 707                 $this->derivedDataUpdater->getCanonicalParserOutput();
 708
 709                 $mainContent = $this->derivedDataUpdater->getSlots()->getContent( SlotRecord::MAIN );
 710
 711                 // Trigger pre-save hook (using provided edit summary)
 712                 $hookStatus = Status::newGood( [] );
 713                 // TODO: replace legacy hook!
 714                 // TODO: avoid pass-by-reference, see T193950
 715                 $hook_args = [ &$wikiPage, &$user, &$mainContent, &$summary,
 716                         $flags & EDIT_MINOR, null, null, &$flags, &$hookStatus ];
 717                 // Check if the hook rejected the attempted save
 718                 if ( !Hooks::run( 'PageContentSave', $hook_args ) ) {
 719                         if ( $hookStatus->isOK() ) {
 720                                 // Hook returned false but didn't call fatal(); use generic message
 721                                 $hookStatus->fatal( 'edit-hook-aborted' );
 722                         }
 723
 724                         $this->status = $hookStatus;
 725                         return null;
 726                 }
 727
 728                 // Provide autosummaries if one is not provided and autosummaries are enabled
 729                 // XXX: $summary == null seems logical, but the empty string may actually come from the user
 730                 // XXX: Move this logic out of the storage layer! It does not belong here! Use a callback?
 731                 if ( $summary->text === '' && $summary->data === null ) {
 732                         $summary = $this->makeAutoSummary( $flags );
 733                 }
 734
 735                 // Actually create the revision and create/update the page.
 736                 // Do NOT yet set $this->status!
 737                 if ( $flags & EDIT_UPDATE ) {
 738                         $status = $this->doModify( $summary, $this->user, $flags );
 739                 } else {
 740                         $status = $this->doCreate( $summary, $this->user, $flags );
 741                 }
 742
 743                 // Promote user to any groups they meet the criteria for
 744                 DeferredUpdates::addCallableUpdate( function () use ( $user ) {
 745                         $user->addAutopromoteOnceGroups( 'onEdit' );
 746                         $user->addAutopromoteOnceGroups( 'onView' ); // b/c
 747                 } );
 748
 749                 // NOTE: set $this->status only after all hooks have been called,
 750                 // so wasCommitted doesn't return true wehn called indirectly from a hook handler!
 751                 $this->status = $status;
 752
 753                 // TODO: replace bad status with Exceptions!
 754                 return ( $this->status && $this->status->isOK() )
 755                         ? $this->status->value['revision-record']
 756                         : null;
 757         }
 758
 759         /**
 760          * Whether saveRevision() has been called on this instance
 761          *
 762          * @return bool
 763          */
 764         public function wasCommitted() {
 765                 return $this->status !== null;
 766         }
 767
 768         /**
 769          * The Status object indicating whether saveRevision() was successful, or null if
 770          * saveRevision() was not yet called on this instance.
 771          *
 772          * @note This is here for compatibility with WikiPage::doEditContent. It may be deprecated
 773          * soon.
 774          *
 775          * Possible status errors:
 776          *     edit-hook-aborted: The ArticleSave hook aborted the update but didn't
 777          *       set the fatal flag of $status.
 778          *     edit-gone-missing: In update mode, but the article didn't exist.
 779          *     edit-conflict: In update mode, the article changed unexpectedly.
 780          *     edit-no-change: Warning that the text was the same as before.
 781          *     edit-already-exists: In creation mode, but the article already exists.
 782          *
 783          *  Extensions may define additional errors.
 784          *
 785          *  $return->value will contain an associative array with members as follows:
 786          *     new: Boolean indicating if the function attempted to create a new article.
 787          *     revision: The revision object for the inserted revision, or null.
 788          *
 789          * @return null|Status
 790          */
 791         public function getStatus() {
 792                 return $this->status;
 793         }
 794
 795         /**
 796          * Whether saveRevision() completed successfully
 797          *
 798          * @return bool
 799          */
 800         public function wasSuccessful() {
 801                 return $this->status && $this->status->isOK();
 802         }
 803
 804         /**
 805          * Whether saveRevision() was called and created a new page.
 806          *
 807          * @return bool
 808          */
 809         public function isNew() {
 810                 return $this->status && $this->status->isOK() && $this->status->value['new'];
 811         }
 812
 813         /**
 814          * Whether saveRevision() did not create a revision because the content didn't change
 815          * (null-edit). Whether the content changed or not is determined by
 816          * DerivedPageDataUpdater::isChange().
 817          *
 818          * @return bool
 819          */
 820         public function isUnchanged() {
 821                 return $this->status
 822                         && $this->status->isOK()
 823                         && $this->status->value['revision-record'] === null;
 824         }
 825
 826         /**
 827          * The new revision created by saveRevision(), or null if saveRevision() has not yet been
 828          * called, failed, or did not create a new revision because the content did not change.
 829          *
 830          * @return RevisionRecord|null
 831          */
 832         public function getNewRevision() {
 833                 return ( $this->status && $this->status->isOK() )
 834                         ? $this->status->value['revision-record']
 835                         : null;
 836         }
 837
 838         /**
 839          * Constructs a MutableRevisionRecord based on the Content prepared by the
 840          * DerivedPageDataUpdater. This takes care of inheriting slots, updating slots
 841          * with PST applied, and removing discontinued slots.
 842          *
 843          * This calls Content::prepareSave() to verify that the slot content can be saved.
 844          * The $status parameter is updated with any errors or warnings found by Content::prepareSave().
 845          *
 846          * @param CommentStoreComment $comment
 847          * @param User $user
 848          * @param int $flags
 849          * @param Status $status
 850          *
 851          * @return MutableRevisionRecord
 852          */
 853         private function makeNewRevision(
 854                 CommentStoreComment $comment,
 855                 User $user,
 856                 $flags,
 857                 Status $status
 858         ) {
 859                 $wikiPage = $this->getWikiPage();
 860                 $title = $this->getTitle();
 861                 $parent = $this->grabParentRevision();
 862
 863                 // XXX: we expect to get a MutableRevisionRecord here, but that's a bit brittle!
 864                 // TODO: introduce something like an UnsavedRevisionFactory service instead!
 865                 /** @var MutableRevisionRecord $rev */
 866                 $rev = $this->derivedDataUpdater->getRevision();
 867
 868                 $rev->setPageId( $title->getArticleID() );
 869
 870                 if ( $parent ) {
 871                         $oldid = $parent->getId();
 872                         $rev->setParentId( $oldid );
 873                 } else {
 874                         $oldid = 0;
 875                 }
 876
 877                 $rev->setComment( $comment );
 878                 $rev->setUser( $user );
 879                 $rev->setMinorEdit( ( $flags & EDIT_MINOR ) > 0 );
 880
 881                 foreach ( $rev->getSlots()->getSlots() as $slot ) {
 882                         $content = $slot->getContent();
 883
 884                         // XXX: We may push this up to the "edit controller" level, see T192777.
 885                         // TODO: change the signature of PrepareSave to not take a WikiPage!
 886                         $prepStatus = $content->prepareSave( $wikiPage, $flags, $oldid, $user );
 887
 888                         // TODO: MCR: record which problem arose in which slot.
 889                         $status->merge( $prepStatus );
 890                 }
 891
 892                 return $rev;
 893         }
 894
 895         /**
 896          * @param CommentStoreComment $summary The edit summary
 897          * @param User $user The revision's author
 898          * @param int $flags EXIT_XXX constants
 899          *
 900          * @throws MWException
 901          * @return Status
 902          */
 903         private function doModify( CommentStoreComment $summary, User $user, $flags ) {
 904                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
 905
 906                 // Update article, but only if changed.
 907                 $status = Status::newGood( [ 'new' => false, 'revision' => null, 'revision-record' => null ] );
 908
 909                 $oldRev = $this->grabParentRevision();
 910                 $oldid = $oldRev ? $oldRev->getId() : 0;
 911
 912                 if ( !$oldRev ) {
 913                         // Article gone missing
 914                         $status->fatal( 'edit-gone-missing' );
 915
 916                         return $status;
 917                 }
 918
 919                 $newRevisionRecord = $this->makeNewRevision(
 920                         $summary,
 921                         $user,
 922                         $flags,
 923                         $status
 924                 );
 925
 926                 if ( !$status->isOK() ) {
 927                         return $status;
 928                 }
 929
 930                 $now = $newRevisionRecord->getTimestamp();
 931
 932                 // XXX: we may want a flag that allows a null revision to be forced!
 933                 $changed = $this->derivedDataUpdater->isChange();
 934
 935                 $dbw = $this->getDBConnectionRef( DB_MASTER );
 936
 937                 if ( $changed ) {
 938                         $dbw->startAtomic( __METHOD__ );
 939
 940                         // Get the latest page_latest value while locking it.
 941                         // Do a CAS style check to see if it's the same as when this method
 942                         // started. If it changed then bail out before touching the DB.
 943                         $latestNow = $wikiPage->lockAndGetLatest(); // TODO: move to storage service, pass DB
 944                         if ( $latestNow != $oldid ) {
 945                                 // We don't need to roll back, since we did not modify the database yet.
 946                                 // XXX: Or do we want to rollback, any transaction started by calling
 947                                 // code will fail? If we want that, we should probably throw an exception.
 948                                 $dbw->endAtomic( __METHOD__ );
 949                                 // Page updated or deleted in the mean time
 950                                 $status->fatal( 'edit-conflict' );
 951
 952                                 return $status;
 953                         }
 954
 955                         // At this point we are now comitted to returning an OK
 956                         // status unless some DB query error or other exception comes up.
 957                         // This way callers don't have to call rollback() if $status is bad
 958                         // unless they actually try to catch exceptions (which is rare).
 959
 960                         // Save revision content and meta-data
 961                         $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
 962                         $newLegacyRevision = new Revision( $newRevisionRecord );
 963
 964                         // Update page_latest and friends to reflect the new revision
 965                         // TODO: move to storage service
 966                         $wasRedirect = $this->derivedDataUpdater->wasRedirect();
 967                         if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, null, $wasRedirect ) ) {
 968                                 throw new PageUpdateException( "Failed to update page row to use new revision." );
 969                         }
 970
 971                         // TODO: replace legacy hook!
 972                         $tags = $this->computeEffectiveTags( $flags );
 973                         Hooks::run(
 974                                 'NewRevisionFromEditComplete',
 975                                 [ $wikiPage, $newLegacyRevision, $this->getOriginalRevisionId(), $user, &$tags ]
 976                         );
 977
 978                         // Update recentchanges
 979                         if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
 980                                 // Add RC row to the DB
 981                                 RecentChange::notifyEdit(
 982                                         $now,
 983                                         $this->getTitle(),
 984                                         $newRevisionRecord->isMinor(),
 985                                         $user,
 986                                         $summary->text, // TODO: pass object when that becomes possible
 987                                         $oldid,
 988                                         $newRevisionRecord->getTimestamp(),
 989                                         ( $flags & EDIT_FORCE_BOT ) > 0,
 990                                         '',
 991                                         $oldRev->getSize(),
 992                                         $newRevisionRecord->getSize(),
 993                                         $newRevisionRecord->getId(),
 994                                         $this->rcPatrolStatus,
 995                                         $tags
 996                                 );
 997                         }
 998
 999                         $user->incEditCount();
1000
1001                         $dbw->endAtomic( __METHOD__ );
1002
1003                         // Return the new revision to the caller
1004                         $status->value['revision-record'] = $newRevisionRecord;
1005
1006                         // TODO: globally replace usages of 'revision' with getNewRevision()
1007                         $status->value['revision'] = $newLegacyRevision;
1008                 } else {
1009                         // T34948: revision ID must be set to page {{REVISIONID}} and
1010                         // related variables correctly. Likewise for {{REVISIONUSER}} (T135261).
1011                         // Since we don't insert a new revision into the database, the least
1012                         // error-prone way is to reuse given old revision.
1013                         $newRevisionRecord = $oldRev;
1014
1015                         $status->warning( 'edit-no-change' );
1016                         // Update page_touched as updateRevisionOn() was not called.
1017                         // Other cache updates are managed in WikiPage::onArticleEdit()
1018                         // via WikiPage::doEditUpdates().
1019                         $this->getTitle()->invalidateCache( $now );
1020                 }
1021
1022                 // Do secondary updates once the main changes have been committed...
1023                 // NOTE: the updates have to be processed before sending the response to the client
1024                 // (DeferredUpdates::PRESEND), otherwise the client may already be following the
1025                 // HTTP redirect to the standard view before dervide data has been created - most
1026                 // importantly, before the parser cache has been updated. This would cause the
1027                 // content to be parsed a second time, or may cause stale content to be shown.
1028                 DeferredUpdates::addUpdate(
1029                         $this->getAtomicSectionUpdate(
1030                                 $dbw,
1031                                 $wikiPage,
1032                                 $newRevisionRecord,
1033                                 $user,
1034                                 $summary,
1035                                 $flags,
1036                                 $status,
1037                                 [ 'changed' => $changed, ]
1038                         ),
1039                         DeferredUpdates::PRESEND
1040                 );
1041
1042                 return $status;
1043         }
1044
1045         /**
1046          * @param CommentStoreComment $summary The edit summary
1047          * @param User $user The revision's author
1048          * @param int $flags EXIT_XXX constants
1049          *
1050          * @throws DBUnexpectedError
1051          * @throws MWException
1052          * @return Status
1053          */
1054         private function doCreate( CommentStoreComment $summary, User $user, $flags ) {
1055                 $wikiPage = $this->getWikiPage(); // TODO: use for legacy hooks only!
1056
1057                 if ( !$this->derivedDataUpdater->getSlots()->hasSlot( SlotRecord::MAIN ) ) {
1058                         throw new PageUpdateException( 'Must provide a main slot when creating a page!' );
1059                 }
1060
1061                 $status = Status::newGood( [ 'new' => true, 'revision' => null, 'revision-record' => null ] );
1062
1063                 $newRevisionRecord = $this->makeNewRevision(
1064                         $summary,
1065                         $user,
1066                         $flags,
1067                         $status
1068                 );
1069
1070                 if ( !$status->isOK() ) {
1071                         return $status;
1072                 }
1073
1074                 $now = $newRevisionRecord->getTimestamp();
1075
1076                 $dbw = $this->getDBConnectionRef( DB_MASTER );
1077                 $dbw->startAtomic( __METHOD__ );
1078
1079                 // Add the page record unless one already exists for the title
1080                 // TODO: move to storage service
1081                 $newid = $wikiPage->insertOn( $dbw );
1082                 if ( $newid === false ) {
1083                         $dbw->endAtomic( __METHOD__ ); // nothing inserted
1084                         $status->fatal( 'edit-already-exists' );
1085
1086                         return $status; // nothing done
1087                 }
1088
1089                 // At this point we are now comitted to returning an OK
1090                 // status unless some DB query error or other exception comes up.
1091                 // This way callers don't have to call rollback() if $status is bad
1092                 // unless they actually try to catch exceptions (which is rare).
1093                 $newRevisionRecord->setPageId( $newid );
1094
1095                 // Save the revision text...
1096                 $newRevisionRecord = $this->revisionStore->insertRevisionOn( $newRevisionRecord, $dbw );
1097                 $newLegacyRevision = new Revision( $newRevisionRecord );
1098
1099                 // Update the page record with revision data
1100                 // TODO: move to storage service
1101                 if ( !$wikiPage->updateRevisionOn( $dbw, $newLegacyRevision, 0 ) ) {
1102                         throw new PageUpdateException( "Failed to update page row to use new revision." );
1103                 }
1104
1105                 // TODO: replace legacy hook!
1106                 $tags = $this->computeEffectiveTags( $flags );
1107                 Hooks::run(
1108                         'NewRevisionFromEditComplete',
1109                         [ $wikiPage, $newLegacyRevision, false, $user, &$tags ]
1110                 );
1111
1112                 // Update recentchanges
1113                 if ( !( $flags & EDIT_SUPPRESS_RC ) ) {
1114                         // Add RC row to the DB
1115                         RecentChange::notifyNew(
1116                                 $now,
1117                                 $this->getTitle(),
1118                                 $newRevisionRecord->isMinor(),
1119                                 $user,
1120                                 $summary->text, // TODO: pass object when that becomes possible
1121                                 ( $flags & EDIT_FORCE_BOT ) > 0,
1122                                 '',
1123                                 $newRevisionRecord->getSize(),
1124                                 $newRevisionRecord->getId(),
1125                                 $this->rcPatrolStatus,
1126                                 $tags
1127                         );
1128                 }
1129
1130                 $user->incEditCount();
1131
1132                 if ( $this->usePageCreationLog ) {
1133                         // Log the page creation
1134                         // @TODO: Do we want a 'recreate' action?
1135                         $logEntry = new ManualLogEntry( 'create', 'create' );
1136                         $logEntry->setPerformer( $user );
1137                         $logEntry->setTarget( $this->getTitle() );
1138                         $logEntry->setComment( $summary->text );
1139                         $logEntry->setTimestamp( $now );
1140                         $logEntry->setAssociatedRevId( $newRevisionRecord->getId() );
1141                         $logEntry->insert();
1142                         // Note that we don't publish page creation events to recentchanges
1143                         // (i.e. $logEntry->publish()) since this would create duplicate entries,
1144                         // one for the edit and one for the page creation.
1145                 }
1146
1147                 $dbw->endAtomic( __METHOD__ );
1148
1149                 // Return the new revision to the caller
1150                 // TODO: globally replace usages of 'revision' with getNewRevision()
1151                 $status->value['revision'] = $newLegacyRevision;
1152                 $status->value['revision-record'] = $newRevisionRecord;
1153
1154                 // Do secondary updates once the main changes have been committed...
1155                 DeferredUpdates::addUpdate(
1156                         $this->getAtomicSectionUpdate(
1157                                 $dbw,
1158                                 $wikiPage,
1159                                 $newRevisionRecord,
1160                                 $user,
1161                                 $summary,
1162                                 $flags,
1163                                 $status,
1164                                 [ 'created' => true ]
1165                         ),
1166                         DeferredUpdates::PRESEND
1167                 );
1168
1169                 return $status;
1170         }
1171
1172         private function getAtomicSectionUpdate(
1173                 IDatabase $dbw,
1174                 WikiPage $wikiPage,
1175                 RevisionRecord $newRevisionRecord,
1176                 User $user,
1177                 CommentStoreComment $summary,
1178                 $flags,
1179                 Status $status,
1180                 $hints = []
1181         ) {
1182                 return new AtomicSectionUpdate(
1183                         $dbw,
1184                         __METHOD__,
1185                         function () use (
1186                                 $wikiPage, $newRevisionRecord, $user,
1187                                 $summary, $flags, $status, $hints
1188                         ) {
1189                                 // set debug data
1190                                 $hints['causeAction'] = 'edit-page';
1191                                 $hints['causeAgent'] = $user->getName();
1192
1193                                 $newLegacyRevision = new Revision( $newRevisionRecord );
1194                                 $mainContent = $newRevisionRecord->getContent( SlotRecord::MAIN, RevisionRecord::RAW );
1195
1196                                 // Update links tables, site stats, etc.
1197                                 $this->derivedDataUpdater->prepareUpdate( $newRevisionRecord, $hints );
1198                                 $this->derivedDataUpdater->doUpdates();
1199
1200                                 // TODO: replace legacy hook!
1201                                 // TODO: avoid pass-by-reference, see T193950
1202
1203                                 if ( $hints['created'] ?? false ) {
1204                                         // Trigger post-create hook
1205                                         $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1206                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision ];
1207                                         Hooks::run( 'PageContentInsertComplete', $params );
1208                                 }
1209
1210                                 // Trigger post-save hook
1211                                 $params = [ &$wikiPage, &$user, $mainContent, $summary->text,
1212                                                 $flags & EDIT_MINOR, null, null, &$flags, $newLegacyRevision,
1213                                                 &$status, $this->getOriginalRevisionId(), $this->undidRevId ];
1214                                 Hooks::run( 'PageContentSaveComplete', $params );
1215                         }
1216                 );
1217         }
1218
1219 }