ArchivedFile.php

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<?php
use MediaWiki\FileRepo\File\FileSelectQueryBuilder;
use MediaWiki\MediaWikiServices;
use MediaWiki\Permissions\Authority;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\Title\Title;
use MediaWiki\User\UserIdentity;
use Wikimedia\Rdbms\Blob;
use Wikimedia\Rdbms\IDatabase;
use Wikimedia\Rdbms\IReadableDatabase;
use Wikimedia\Rdbms\SelectQueryBuilder;
 
class ArchivedFile {
 
    // Audience options for ::getDescription() and ::getUploader()
    public const FOR_PUBLIC = 1;
    public const FOR_THIS_USER = 2;
    public const RAW = 3;
 
    private const MDS_EMPTY = 'empty';
 
    private const MDS_LEGACY = 'legacy';
 
    private const MDS_PHP = 'php';
 
    private const MDS_JSON = 'json';
 
    private $id;
 
    private $name;
 
    private $group;
 
    private $key;
 
    private $size;
 
    private $bits;
 
    private $width;
 
    private $height;
 
    protected $metadataArray = [];
 
    protected $extraDataLoaded = false;
 
    protected $metadataSerializationFormat;
 
    protected $metadataBlobs = [];
 
    protected $unloadedMetadataBlobs = [];
 
    private $mime;
 
    private $media_type;
 
    private $description;
 
    private $user;
 
    private $timestamp;
 
    private $dataLoaded;
 
    private $deleted;
 
    private $sha1;
 
    private $pageCount;
 
    private $archive_name;
 
    protected $handler;
 
    protected $title; # image title
 
    protected $exists;
 
    private $repo;
 
    private $metadataStorageHelper;
 
    public function __construct( $title, $id = 0, $key = '', $sha1 = '' ) {
        $this->id = -1;
        $this->title = null;
        $this->name = false;
        $this->group = 'deleted'; // needed for direct use of constructor
        $this->key = '';
        $this->size = 0;
        $this->bits = 0;
        $this->width = 0;
        $this->height = 0;
        $this->mime = "unknown/unknown";
        $this->media_type = '';
        $this->description = '';
        $this->user = null;
        $this->timestamp = null;
        $this->deleted = 0;
        $this->dataLoaded = false;
        $this->exists = false;
        $this->sha1 = '';
 
        if ( $title instanceof Title ) {
            $this->title = File::normalizeTitle( $title, 'exception' );
            $this->name = $title->getDBkey();
        }
 
        if ( $id ) {
            $this->id = $id;
        }
 
        if ( $key ) {
            $this->key = $key;
        }
 
        if ( $sha1 ) {
            $this->sha1 = $sha1;
        }
 
        if ( !$id && !$key && !( $title instanceof Title ) && !$sha1 ) {
            throw new MWException( "No specifications provided to ArchivedFile constructor." );
        }
 
        $this->repo = MediaWikiServices::getInstance()->getRepoGroup()->getLocalRepo();
        $this->metadataStorageHelper = new MetadataStorageHelper( $this->repo );
    }
 
    public function load() {
        if ( $this->dataLoaded ) {
            return true;
        }
        $conds = [];
 
        if ( $this->id > 0 ) {
            $conds['fa_id'] = $this->id;
        }
        if ( $this->key ) {
            $conds['fa_storage_group'] = $this->group;
            $conds['fa_storage_key'] = $this->key;
        }
        if ( $this->title ) {
            $conds['fa_name'] = $this->title->getDBkey();
        }
        if ( $this->sha1 ) {
            $conds['fa_sha1'] = $this->sha1;
        }
 
        if ( $conds === [] ) {
            throw new MWException( "No specific information for retrieving archived file" );
        }
 
        if ( !$this->title || $this->title->getNamespace() === NS_FILE ) {
            $this->dataLoaded = true; // set it here, to have also true on miss
            $dbr = $this->repo->getReplicaDB();
            $queryBuilder = FileSelectQueryBuilder::newForArchivedFile( $dbr );
            $row = $queryBuilder->where( $conds )
                ->orderBy( 'fa_timestamp', SelectQueryBuilder::SORT_DESC )
                ->caller( __METHOD__ )->fetchRow();
            if ( !$row ) {
                // this revision does not exist?
                return null;
            }
 
            // initialize fields for filestore image object
            $this->loadFromRow( $row );
        } else {
            throw new MWException( 'This title does not correspond to an image page.' );
        }
 
        return true;
    }
 
    public static function newFromRow( $row ) {
        $file = new ArchivedFile( Title::makeTitle( NS_FILE, $row->fa_name ) );
        $file->loadFromRow( $row );
 
        return $file;
    }
 
    public static function getQueryInfo() {
        $dbr = MediaWikiServices::getInstance()->getDBLoadBalancerFactory()->getReplicaDatabase();
        $queryInfo = ( FileSelectQueryBuilder::newForArchivedFile( $dbr ) )->getQueryInfo();
        return [
            'tables' => $queryInfo['tables'],
            'fields' => $queryInfo['fields'],
            'joins' => $queryInfo['join_conds'],
        ];
    }
 
    public function loadFromRow( $row ) {
        $this->id = intval( $row->fa_id );
        $this->name = $row->fa_name;
        $this->archive_name = $row->fa_archive_name;
        $this->group = $row->fa_storage_group;
        $this->key = $row->fa_storage_key;
        $this->size = $row->fa_size;
        $this->bits = $row->fa_bits;
        $this->width = $row->fa_width;
        $this->height = $row->fa_height;
        $this->loadMetadataFromDbFieldValue(
            $this->repo->getReplicaDB(), $row->fa_metadata );
        $this->mime = "$row->fa_major_mime/$row->fa_minor_mime";
        $this->media_type = $row->fa_media_type;
        $services = MediaWikiServices::getInstance();
        $this->description = $services->getCommentStore()
            // Legacy because $row may have come from self::selectFields()
            ->getCommentLegacy( $this->repo->getReplicaDB(), 'fa_description', $row )->text;
        $this->user = $services->getUserFactory()
            ->newFromAnyId( $row->fa_user, $row->fa_user_text, $row->fa_actor );
        $this->timestamp = $row->fa_timestamp;
        $this->deleted = $row->fa_deleted;
        if ( isset( $row->fa_sha1 ) ) {
            $this->sha1 = $row->fa_sha1;
        } else {
            // old row, populate from key
            $this->sha1 = LocalRepo::getHashFromKey( $this->key );
        }
        if ( !$this->title ) {
            $this->title = Title::makeTitleSafe( NS_FILE, $row->fa_name );
        }
        $this->exists = $row->fa_archive_name !== '';
    }
 
    public function getTitle() {
        if ( !$this->title ) {
            $this->load();
        }
        return $this->title;
    }
 
    public function getName() {
        if ( $this->name === false ) {
            $this->load();
        }
 
        return $this->name;
    }
 
    public function getID() {
        $this->load();
 
        return $this->id;
    }
 
    public function exists() {
        $this->load();
 
        return $this->exists;
    }
 
    public function getKey() {
        $this->load();
 
        return $this->key;
    }
 
    public function getStorageKey() {
        return $this->getKey();
    }
 
    public function getGroup() {
        return $this->group;
    }
 
    public function getWidth() {
        $this->load();
 
        return $this->width;
    }
 
    public function getHeight() {
        $this->load();
 
        return $this->height;
    }
 
    public function getMetadata() {
        $data = $this->getMetadataArray();
        if ( !$data ) {
            return '';
        } elseif ( array_keys( $data ) === [ '_error' ] ) {
            // Legacy error encoding
            return $data['_error'];
        } else {
            return serialize( $this->getMetadataArray() );
        }
    }
 
    public function getMetadataArray(): array {
        $this->load();
        if ( $this->unloadedMetadataBlobs ) {
            return $this->getMetadataItems(
                array_unique( array_merge(
                    array_keys( $this->metadataArray ),
                    array_keys( $this->unloadedMetadataBlobs )
                ) )
            );
        }
        return $this->metadataArray;
    }
 
    public function getMetadataItems( array $itemNames ): array {
        $this->load();
        $result = [];
        $addresses = [];
        foreach ( $itemNames as $itemName ) {
            if ( array_key_exists( $itemName, $this->metadataArray ) ) {
                $result[$itemName] = $this->metadataArray[$itemName];
            } elseif ( isset( $this->unloadedMetadataBlobs[$itemName] ) ) {
                $addresses[$itemName] = $this->unloadedMetadataBlobs[$itemName];
            }
        }
 
        if ( $addresses ) {
            $resultFromBlob = $this->metadataStorageHelper->getMetadataFromBlobStore( $addresses );
            foreach ( $addresses as $itemName => $address ) {
                unset( $this->unloadedMetadataBlobs[$itemName] );
                $value = $resultFromBlob[$itemName] ?? null;
                if ( $value !== null ) {
                    $result[$itemName] = $value;
                    $this->metadataArray[$itemName] = $value;
                }
            }
        }
        return $result;
    }
 
    public function getMetadataForDb( IDatabase $db ) {
        $this->load();
        if ( !$this->metadataArray && !$this->metadataBlobs ) {
            $s = '';
        } elseif ( $this->repo->isJsonMetadataEnabled() ) {
            $s = $this->getJsonMetadata();
        } else {
            $s = serialize( $this->getMetadataArray() );
        }
        if ( !is_string( $s ) ) {
            throw new MWException( 'Could not serialize image metadata value for DB' );
        }
        return $db->encodeBlob( $s );
    }
 
    private function getJsonMetadata() {
        // Directly store data that is not already in BlobStore
        $envelope = [
            'data' => array_diff_key( $this->metadataArray, $this->metadataBlobs )
        ];
 
        // Also store the blob addresses
        if ( $this->metadataBlobs ) {
            $envelope['blobs'] = $this->metadataBlobs;
        }
 
        [ $s, $blobAddresses ] = $this->metadataStorageHelper->getJsonMetadata( $this, $envelope );
 
        // Repeated calls to this function should not keep inserting more blobs
        $this->metadataBlobs += $blobAddresses;
 
        return $s;
    }
 
    protected function loadMetadataFromDbFieldValue( IReadableDatabase $db, $metadataBlob ) {
        $this->loadMetadataFromString( $db->decodeBlob( $metadataBlob ) );
    }
 
    protected function loadMetadataFromString( $metadataString ) {
        $this->extraDataLoaded = true;
        $this->metadataArray = [];
        $this->metadataBlobs = [];
        $this->unloadedMetadataBlobs = [];
        $metadataString = (string)$metadataString;
        if ( $metadataString === '' ) {
            $this->metadataSerializationFormat = self::MDS_EMPTY;
            return;
        }
        if ( $metadataString[0] === '{' ) {
            $envelope = $this->metadataStorageHelper->jsonDecode( $metadataString );
            if ( !$envelope ) {
                // Legacy error encoding
                $this->metadataArray = [ '_error' => $metadataString ];
                $this->metadataSerializationFormat = self::MDS_LEGACY;
            } else {
                $this->metadataSerializationFormat = self::MDS_JSON;
                if ( isset( $envelope['data'] ) ) {
                    $this->metadataArray = $envelope['data'];
                }
                if ( isset( $envelope['blobs'] ) ) {
                    $this->metadataBlobs = $this->unloadedMetadataBlobs = $envelope['blobs'];
                }
            }
        } else {
            // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
            $data = @unserialize( $metadataString );
            if ( !is_array( $data ) ) {
                // Legacy error encoding
                $data = [ '_error' => $metadataString ];
                $this->metadataSerializationFormat = self::MDS_LEGACY;
            } else {
                $this->metadataSerializationFormat = self::MDS_PHP;
            }
            $this->metadataArray = $data;
        }
    }
 
    public function getSize() {
        $this->load();
 
        return $this->size;
    }
 
    public function getBits() {
        $this->load();
 
        return $this->bits;
    }
 
    public function getMimeType() {
        $this->load();
 
        return $this->mime;
    }
 
    private function getHandler() {
        if ( !isset( $this->handler ) ) {
            $this->handler = MediaHandler::getHandler( $this->getMimeType() );
        }
 
        return $this->handler;
    }
 
    public function pageCount() {
        if ( !isset( $this->pageCount ) ) {
            // @FIXME: callers expect File objects
            // @phan-suppress-next-line PhanTypeMismatchArgument
            if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
                // @phan-suppress-next-line PhanTypeMismatchArgument
                $this->pageCount = $this->handler->pageCount( $this );
            } else {
                $this->pageCount = false;
            }
        }
 
        return $this->pageCount;
    }
 
    public function getMediaType() {
        $this->load();
 
        return $this->media_type;
    }
 
    public function getTimestamp() {
        $this->load();
 
        return wfTimestamp( TS_MW, $this->timestamp );
    }
 
    public function getSha1() {
        $this->load();
 
        return $this->sha1;
    }
 
    public function getUploader( int $audience = self::FOR_PUBLIC, Authority $performer = null ): ?UserIdentity {
        $this->load();
        if ( $audience === self::FOR_PUBLIC && $this->isDeleted( File::DELETED_USER ) ) {
            return null;
        } elseif ( $audience === self::FOR_THIS_USER && !$this->userCan( File::DELETED_USER, $performer ) ) {
            return null;
        } else {
            return $this->user;
        }
    }
 
    public function getDescription( int $audience = self::FOR_PUBLIC, Authority $performer = null ): string {
        $this->load();
        if ( $audience === self::FOR_PUBLIC && $this->isDeleted( File::DELETED_COMMENT ) ) {
            return '';
        } elseif ( $audience === self::FOR_THIS_USER && !$this->userCan( File::DELETED_COMMENT, $performer ) ) {
            return '';
        } else {
            return $this->description;
        }
    }
 
    public function getVisibility() {
        $this->load();
 
        return $this->deleted;
    }
 
    public function isDeleted( $field ) {
        $this->load();
 
        return ( $this->deleted & $field ) == $field;
    }
 
    public function userCan( $field, Authority $performer ) {
        $this->load();
        $title = $this->getTitle();
 
        return RevisionRecord::userCanBitfield(
            $this->deleted,
            $field,
            $performer,
            $title ?: null
        );
    }
}