PageArchive.php

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<?php
use MediaWiki\MediaWikiServices;
use Wikimedia\Rdbms\ResultWrapper;
use Wikimedia\Rdbms\IDatabase;
 
class PageArchive {
    protected $title;
 
    protected $fileStatus;
 
    protected $revisionStatus;
 
    protected $config;
 
    public function __construct( $title, Config $config = null ) {
        if ( is_null( $title ) ) {
            throw new MWException( __METHOD__ . ' given a null title.' );
        }
        $this->title = $title;
        if ( $config === null ) {
            wfDebug( __METHOD__ . ' did not have a Config object passed to it' );
            $config = MediaWikiServices::getInstance()->getMainConfig();
        }
        $this->config = $config;
    }
 
    public function doesWrites() {
        return true;
    }
 
    public static function listAllPages() {
        $dbr = wfGetDB( DB_REPLICA );
 
        return self::listPages( $dbr, '' );
    }
 
    public static function listPagesBySearch( $term ) {
        $title = Title::newFromText( $term );
        if ( $title ) {
            $ns = $title->getNamespace();
            $termMain = $title->getText();
            $termDb = $title->getDBkey();
        } else {
            // Prolly won't work too good
            // @todo handle bare namespace names cleanly?
            $ns = 0;
            $termMain = $termDb = $term;
        }
 
        // Try search engine first
        $engine = MediaWikiServices::getInstance()->newSearchEngine();
        $engine->setLimitOffset( 100 );
        $engine->setNamespaces( [ $ns ] );
        $results = $engine->searchArchiveTitle( $termMain );
        if ( !$results->isOK() ) {
            $results = [];
        } else {
            $results = $results->getValue();
        }
 
        if ( !$results ) {
            // Fall back to regular prefix search
            return self::listPagesByPrefix( $term );
        }
 
        $dbr = wfGetDB( DB_REPLICA );
        $condTitles = array_unique( array_map( function ( Title $t ) {
            return $t->getDBkey();
        }, $results ) );
        $conds = [
            'ar_namespace' => $ns,
            $dbr->makeList( [ 'ar_title' => $condTitles ], LIST_OR ) . " OR ar_title " .
            $dbr->buildLike( $termDb, $dbr->anyString() )
        ];
 
        return self::listPages( $dbr, $conds );
    }
 
    public static function listPagesByPrefix( $prefix ) {
        $dbr = wfGetDB( DB_REPLICA );
 
        $title = Title::newFromText( $prefix );
        if ( $title ) {
            $ns = $title->getNamespace();
            $prefix = $title->getDBkey();
        } else {
            // Prolly won't work too good
            // @todo handle bare namespace names cleanly?
            $ns = 0;
        }
 
        $conds = [
            'ar_namespace' => $ns,
            'ar_title' . $dbr->buildLike( $prefix, $dbr->anyString() ),
        ];
 
        return self::listPages( $dbr, $conds );
    }
 
    protected static function listPages( $dbr, $condition ) {
        return $dbr->select(
            [ 'archive' ],
            [
                'ar_namespace',
                'ar_title',
                'count' => 'COUNT(*)'
            ],
            $condition,
            __METHOD__,
            [
                'GROUP BY' => [ 'ar_namespace', 'ar_title' ],
                'ORDER BY' => [ 'ar_namespace', 'ar_title' ],
                'LIMIT' => 100,
            ]
        );
    }
 
    public function listRevisions() {
        $dbr = wfGetDB( DB_REPLICA );
        $commentQuery = CommentStore::newKey( 'ar_comment' )->getJoin();
 
        $tables = [ 'archive' ] + $commentQuery['tables'];
 
        $fields = [
            'ar_minor_edit', 'ar_timestamp', 'ar_user', 'ar_user_text',
            'ar_len', 'ar_deleted', 'ar_rev_id', 'ar_sha1',
            'ar_page_id'
        ] + $commentQuery['fields'];
 
        if ( $this->config->get( 'ContentHandlerUseDB' ) ) {
            $fields[] = 'ar_content_format';
            $fields[] = 'ar_content_model';
        }
 
        $conds = [ 'ar_namespace' => $this->title->getNamespace(),
            'ar_title' => $this->title->getDBkey() ];
 
        $options = [ 'ORDER BY' => 'ar_timestamp DESC' ];
 
        $join_conds = [] + $commentQuery['joins'];
 
        ChangeTags::modifyDisplayQuery(
            $tables,
            $fields,
            $conds,
            $join_conds,
            $options,
            ''
        );
 
        return $dbr->select( $tables,
            $fields,
            $conds,
            __METHOD__,
            $options,
            $join_conds
        );
    }
 
    public function listFiles() {
        if ( $this->title->getNamespace() != NS_FILE ) {
            return null;
        }
 
        $dbr = wfGetDB( DB_REPLICA );
        return $dbr->select(
            'filearchive',
            ArchivedFile::selectFields(),
            [ 'fa_name' => $this->title->getDBkey() ],
            __METHOD__,
            [ 'ORDER BY' => 'fa_timestamp DESC' ]
        );
    }
 
    public function getRevision( $timestamp ) {
        $dbr = wfGetDB( DB_REPLICA );
        $commentQuery = CommentStore::newKey( 'ar_comment' )->getJoin();
 
        $tables = [ 'archive' ] + $commentQuery['tables'];
 
        $fields = [
            'ar_rev_id',
            'ar_text',
            'ar_user',
            'ar_user_text',
            'ar_timestamp',
            'ar_minor_edit',
            'ar_flags',
            'ar_text_id',
            'ar_deleted',
            'ar_len',
            'ar_sha1',
        ] + $commentQuery['fields'];
 
        if ( $this->config->get( 'ContentHandlerUseDB' ) ) {
            $fields[] = 'ar_content_format';
            $fields[] = 'ar_content_model';
        }
 
        $join_conds = [] + $commentQuery['joins'];
 
        $row = $dbr->selectRow(
            $tables,
            $fields,
            [
                'ar_namespace' => $this->title->getNamespace(),
                'ar_title' => $this->title->getDBkey(),
                'ar_timestamp' => $dbr->timestamp( $timestamp )
            ],
            __METHOD__,
            [],
            $join_conds
        );
 
        if ( $row ) {
            return Revision::newFromArchiveRow( $row, [ 'title' => $this->title ] );
        }
 
        return null;
    }
 
    public function getPreviousRevision( $timestamp ) {
        $dbr = wfGetDB( DB_REPLICA );
 
        // Check the previous deleted revision...
        $row = $dbr->selectRow( 'archive',
            'ar_timestamp',
            [ 'ar_namespace' => $this->title->getNamespace(),
                'ar_title' => $this->title->getDBkey(),
                'ar_timestamp < ' .
                $dbr->addQuotes( $dbr->timestamp( $timestamp ) ) ],
            __METHOD__,
            [
                'ORDER BY' => 'ar_timestamp DESC',
                'LIMIT' => 1 ] );
        $prevDeleted = $row ? wfTimestamp( TS_MW, $row->ar_timestamp ) : false;
 
        $row = $dbr->selectRow( [ 'page', 'revision' ],
            [ 'rev_id', 'rev_timestamp' ],
            [
                'page_namespace' => $this->title->getNamespace(),
                'page_title' => $this->title->getDBkey(),
                'page_id = rev_page',
                'rev_timestamp < ' .
                $dbr->addQuotes( $dbr->timestamp( $timestamp ) ) ],
            __METHOD__,
            [
                'ORDER BY' => 'rev_timestamp DESC',
                'LIMIT' => 1 ] );
        $prevLive = $row ? wfTimestamp( TS_MW, $row->rev_timestamp ) : false;
        $prevLiveId = $row ? intval( $row->rev_id ) : null;
 
        if ( $prevLive && $prevLive > $prevDeleted ) {
            // Most prior revision was live
            return Revision::newFromId( $prevLiveId );
        } elseif ( $prevDeleted ) {
            // Most prior revision was deleted
            return $this->getRevision( $prevDeleted );
        }
 
        // No prior revision on this page.
        return null;
    }
 
    public function getTextFromRow( $row ) {
        if ( is_null( $row->ar_text_id ) ) {
            // An old row from MediaWiki 1.4 or previous.
            // Text is embedded in this row in classic compression format.
            return Revision::getRevisionText( $row, 'ar_' );
        }
 
        // New-style: keyed to the text storage backend.
        $dbr = wfGetDB( DB_REPLICA );
        $text = $dbr->selectRow( 'text',
            [ 'old_text', 'old_flags' ],
            [ 'old_id' => $row->ar_text_id ],
            __METHOD__ );
 
        return Revision::getRevisionText( $text );
    }
 
    public function getLastRevisionText() {
        $dbr = wfGetDB( DB_REPLICA );
        $row = $dbr->selectRow( 'archive',
            [ 'ar_text', 'ar_flags', 'ar_text_id' ],
            [ 'ar_namespace' => $this->title->getNamespace(),
                'ar_title' => $this->title->getDBkey() ],
            __METHOD__,
            [ 'ORDER BY' => 'ar_timestamp DESC' ] );
 
        if ( $row ) {
            return $this->getTextFromRow( $row );
        }
 
        return null;
    }
 
    public function isDeleted() {
        $dbr = wfGetDB( DB_REPLICA );
        $n = $dbr->selectField( 'archive', 'COUNT(ar_title)',
            [ 'ar_namespace' => $this->title->getNamespace(),
                'ar_title' => $this->title->getDBkey() ],
            __METHOD__
        );
 
        return ( $n > 0 );
    }
 
    public function undelete( $timestamps, $comment = '', $fileVersions = [],
        $unsuppress = false, User $user = null, $tags = null
    ) {
        // If both the set of text revisions and file revisions are empty,
        // restore everything. Otherwise, just restore the requested items.
        $restoreAll = empty( $timestamps ) && empty( $fileVersions );
 
        $restoreText = $restoreAll || !empty( $timestamps );
        $restoreFiles = $restoreAll || !empty( $fileVersions );
 
        if ( $restoreFiles && $this->title->getNamespace() == NS_FILE ) {
            $img = wfLocalFile( $this->title );
            $img->load( File::READ_LATEST );
            $this->fileStatus = $img->restore( $fileVersions, $unsuppress );
            if ( !$this->fileStatus->isOK() ) {
                return false;
            }
            $filesRestored = $this->fileStatus->successCount;
        } else {
            $filesRestored = 0;
        }
 
        if ( $restoreText ) {
            $this->revisionStatus = $this->undeleteRevisions( $timestamps, $unsuppress, $comment );
            if ( !$this->revisionStatus->isOK() ) {
                return false;
            }
 
            $textRestored = $this->revisionStatus->getValue();
        } else {
            $textRestored = 0;
        }
 
        // Touch the log!
 
        if ( !$textRestored && !$filesRestored ) {
            wfDebug( "Undelete: nothing undeleted...\n" );
 
            return false;
        }
 
        if ( $user === null ) {
            global $wgUser;
            $user = $wgUser;
        }
 
        $logEntry = new ManualLogEntry( 'delete', 'restore' );
        $logEntry->setPerformer( $user );
        $logEntry->setTarget( $this->title );
        $logEntry->setComment( $comment );
        $logEntry->setTags( $tags );
        $logEntry->setParameters( [
            ':assoc:count' => [
                'revisions' => $textRestored,
                'files' => $filesRestored,
            ],
        ] );
 
        Hooks::run( 'ArticleUndeleteLogEntry', [ $this, &$logEntry, $user ] );
 
        $logid = $logEntry->insert();
        $logEntry->publish( $logid );
 
        return [ $textRestored, $filesRestored, $comment ];
    }
 
    private function undeleteRevisions( $timestamps, $unsuppress = false, $comment = '' ) {
        if ( wfReadOnly() ) {
            throw new ReadOnlyError();
        }
 
        $dbw = wfGetDB( DB_MASTER );
        $dbw->startAtomic( __METHOD__ );
 
        $restoreAll = empty( $timestamps );
 
        # Does this page already exist? We'll have to update it...
        $article = WikiPage::factory( $this->title );
        # Load latest data for the current page (T33179)
        $article->loadPageData( 'fromdbmaster' );
        $oldcountable = $article->isCountable();
 
        $page = $dbw->selectRow( 'page',
            [ 'page_id', 'page_latest' ],
            [ 'page_namespace' => $this->title->getNamespace(),
                'page_title' => $this->title->getDBkey() ],
            __METHOD__,
            [ 'FOR UPDATE' ] // lock page
        );
 
        if ( $page ) {
            $makepage = false;
            # Page already exists. Import the history, and if necessary
            # we'll update the latest revision field in the record.
 
            # Get the time span of this page
            $previousTimestamp = $dbw->selectField( 'revision', 'rev_timestamp',
                [ 'rev_id' => $page->page_latest ],
                __METHOD__ );
 
            if ( $previousTimestamp === false ) {
                wfDebug( __METHOD__ . ": existing page refers to a page_latest that does not exist\n" );
 
                $status = Status::newGood( 0 );
                $status->warning( 'undeleterevision-missing' );
                $dbw->endAtomic( __METHOD__ );
 
                return $status;
            }
        } else {
            # Have to create a new article...
            $makepage = true;
            $previousTimestamp = 0;
        }
 
        $oldWhere = [
            'ar_namespace' => $this->title->getNamespace(),
            'ar_title' => $this->title->getDBkey(),
        ];
        if ( !$restoreAll ) {
            $oldWhere['ar_timestamp'] = array_map( [ &$dbw, 'timestamp' ], $timestamps );
        }
 
        $commentQuery = CommentStore::newKey( 'ar_comment' )->getJoin();
 
        $tables = [ 'archive', 'revision' ] + $commentQuery['tables'];
 
        $fields = [
            'ar_id',
            'ar_rev_id',
            'rev_id',
            'ar_text',
            'ar_user',
            'ar_user_text',
            'ar_timestamp',
            'ar_minor_edit',
            'ar_flags',
            'ar_text_id',
            'ar_deleted',
            'ar_page_id',
            'ar_len',
            'ar_sha1'
        ] + $commentQuery['fields'];
 
        if ( $this->config->get( 'ContentHandlerUseDB' ) ) {
            $fields[] = 'ar_content_format';
            $fields[] = 'ar_content_model';
        }
 
        $join_conds = [
            'revision' => [ 'LEFT JOIN', 'ar_rev_id=rev_id' ],
        ] + $commentQuery['joins'];
 
        $result = $dbw->select(
            $tables,
            $fields,
            $oldWhere,
            __METHOD__,
            /* options */
            [ 'ORDER BY' => 'ar_timestamp' ],
            $join_conds
        );
 
        $rev_count = $result->numRows();
        if ( !$rev_count ) {
            wfDebug( __METHOD__ . ": no revisions to restore\n" );
 
            $status = Status::newGood( 0 );
            $status->warning( "undelete-no-results" );
            $dbw->endAtomic( __METHOD__ );
 
            return $status;
        }
 
        // We use ar_id because there can be duplicate ar_rev_id even for the same
        // page.  In this case, we may be able to restore the first one.
        $restoreFailedArIds = [];
 
        // Map rev_id to the ar_id that is allowed to use it.  When checking later,
        // if it doesn't match, the current ar_id can not be restored.
 
        // Value can be an ar_id or -1 (-1 means no ar_id can use it, since the
        // rev_id is taken before we even start the restore).
        $allowedRevIdToArIdMap = [];
 
        $latestRestorableRow = null;
 
        foreach ( $result as $row ) {
            if ( $row->ar_rev_id ) {
                // rev_id is taken even before we start restoring.
                if ( $row->ar_rev_id === $row->rev_id ) {
                    $restoreFailedArIds[] = $row->ar_id;
                    $allowedRevIdToArIdMap[$row->ar_rev_id] = -1;
                } else {
                    // rev_id is not taken yet in the DB, but it might be taken
                    // by a prior revision in the same restore operation. If
                    // not, we need to reserve it.
                    if ( isset( $allowedRevIdToArIdMap[$row->ar_rev_id] ) ) {
                        $restoreFailedArIds[] = $row->ar_id;
                    } else {
                        $allowedRevIdToArIdMap[$row->ar_rev_id] = $row->ar_id;
                        $latestRestorableRow = $row;
                    }
                }
            } else {
                // If ar_rev_id is null, there can't be a collision, and a
                // rev_id will be chosen automatically.
                $latestRestorableRow = $row;
            }
        }
 
        $result->seek( 0 ); // move back
 
        $oldPageId = 0;
        if ( $latestRestorableRow !== null ) {
            $oldPageId = (int)$latestRestorableRow->ar_page_id; // pass this to ArticleUndelete hook
 
            // grab the content to check consistency with global state before restoring the page.
            $revision = Revision::newFromArchiveRow( $latestRestorableRow,
                [
                    'title' => $article->getTitle(), // used to derive default content model
                ]
            );
            $user = User::newFromName( $revision->getUserText( Revision::RAW ), false );
            $content = $revision->getContent( Revision::RAW );
 
            // NOTE: article ID may not be known yet. prepareSave() should not modify the database.
            $status = $content->prepareSave( $article, 0, -1, $user );
            if ( !$status->isOK() ) {
                $dbw->endAtomic( __METHOD__ );
 
                return $status;
            }
        }
 
        $newid = false; // newly created page ID
        $restored = 0; // number of revisions restored
        $revision = null;
        $restoredPages = [];
        // If there are no restorable revisions, we can skip most of the steps.
        if ( $latestRestorableRow === null ) {
            $failedRevisionCount = $rev_count;
        } else {
            if ( $makepage ) {
                // Check the state of the newest to-be version...
                if ( !$unsuppress
                    && ( $latestRestorableRow->ar_deleted & Revision::DELETED_TEXT )
                ) {
                    $dbw->endAtomic( __METHOD__ );
 
                    return Status::newFatal( "undeleterevdel" );
                }
                // Safe to insert now...
                $newid = $article->insertOn( $dbw, $latestRestorableRow->ar_page_id );
                if ( $newid === false ) {
                    // The old ID is reserved; let's pick another
                    $newid = $article->insertOn( $dbw );
                }
                $pageId = $newid;
            } else {
                // Check if a deleted revision will become the current revision...
                if ( $latestRestorableRow->ar_timestamp > $previousTimestamp ) {
                    // Check the state of the newest to-be version...
                    if ( !$unsuppress
                        && ( $latestRestorableRow->ar_deleted & Revision::DELETED_TEXT )
                    ) {
                        $dbw->endAtomic( __METHOD__ );
 
                        return Status::newFatal( "undeleterevdel" );
                    }
                }
 
                $newid = false;
                $pageId = $article->getId();
            }
 
            foreach ( $result as $row ) {
                // Check for key dupes due to needed archive integrity.
                if ( $row->ar_rev_id && $allowedRevIdToArIdMap[$row->ar_rev_id] !== $row->ar_id ) {
                    continue;
                }
                // Insert one revision at a time...maintaining deletion status
                // unless we are specifically removing all restrictions...
                $revision = Revision::newFromArchiveRow( $row,
                    [
                        'page' => $pageId,
                        'title' => $this->title,
                        'deleted' => $unsuppress ? 0 : $row->ar_deleted
                    ] );
 
                // This will also copy the revision to ip_changes if it was an IP edit.
                $revision->insertOn( $dbw );
 
                $restored++;
 
                Hooks::run( 'ArticleRevisionUndeleted',
                    [ &$this->title, $revision, $row->ar_page_id ] );
                $restoredPages[$row->ar_page_id] = true;
            }
 
            // Now that it's safely stored, take it out of the archive
            // Don't delete rows that we failed to restore
            $toDeleteConds = $oldWhere;
            $failedRevisionCount = count( $restoreFailedArIds );
            if ( $failedRevisionCount > 0 ) {
                $toDeleteConds[] = 'ar_id NOT IN ( ' . $dbw->makeList( $restoreFailedArIds ) . ' )';
            }
 
            $dbw->delete( 'archive',
                $toDeleteConds,
                __METHOD__ );
        }
 
        $status = Status::newGood( $restored );
 
        if ( $failedRevisionCount > 0 ) {
            $status->warning(
                wfMessage( 'undeleterevision-duplicate-revid', $failedRevisionCount ) );
        }
 
        // Was anything restored at all?
        if ( $restored ) {
            $created = (bool)$newid;
            // Attach the latest revision to the page...
            $wasnew = $article->updateIfNewerOn( $dbw, $revision );
            if ( $created || $wasnew ) {
                // Update site stats, link tables, etc
                $article->doEditUpdates(
                    $revision,
                    User::newFromName( $revision->getUserText( Revision::RAW ), false ),
                    [
                        'created' => $created,
                        'oldcountable' => $oldcountable,
                        'restored' => true
                    ]
                );
            }
 
            Hooks::run( 'ArticleUndelete',
                [ &$this->title, $created, $comment, $oldPageId, $restoredPages ] );
            if ( $this->title->getNamespace() == NS_FILE ) {
                DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this->title, 'imagelinks' ) );
            }
        }
 
        $dbw->endAtomic( __METHOD__ );
 
        return $status;
    }
 
    public function getFileStatus() {
        return $this->fileStatus;
    }
 
    public function getRevisionStatus() {
        return $this->revisionStatus;
    }
}