FileBackend.php

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<?php
abstract class FileBackend {
        protected $name; // string; unique backend name
        protected $wikiId; // string; unique wiki name
        protected $readOnly; // string; read-only explanation message
        protected $parallelize; // string; when to do operations in parallel
        protected $concurrency; // integer; how many operations can be done in parallel

        protected $lockManager;
        protected $fileJournal;

        public function __construct( array $config ) {
                $this->name = $config['name'];
                if ( !preg_match( '!^[a-zA-Z0-9-_]{1,255}$!', $this->name ) ) {
                        throw new MWException( "Backend name `{$this->name}` is invalid." );
                }
                $this->wikiId = isset( $config['wikiId'] )
                        ? $config['wikiId']
                        : wfWikiID(); // e.g. "my_wiki-en_"
                $this->lockManager = ( $config['lockManager'] instanceof LockManager )
                        ? $config['lockManager']
                        : LockManagerGroup::singleton()->get( $config['lockManager'] );
                $this->fileJournal = isset( $config['fileJournal'] )
                        ? ( ( $config['fileJournal'] instanceof FileJournal )
                                ? $config['fileJournal']
                                : FileJournal::factory( $config['fileJournal'], $this->name ) )
                        : FileJournal::factory( array( 'class' => 'NullFileJournal' ), $this->name );
                $this->readOnly = isset( $config['readOnly'] )
                        ? (string)$config['readOnly']
                        : '';
                $this->parallelize = isset( $config['parallelize'] )
                        ? (string)$config['parallelize']
                        : 'off';
                $this->concurrency = isset( $config['concurrency'] )
                        ? (int)$config['concurrency']
                        : 50;
        }

        final public function getName() {
                return $this->name;
        }

        final public function getWikiId() {
                return $this->wikiId;
        }

        final public function isReadOnly() {
                return ( $this->readOnly != '' );
        }

        final public function getReadOnlyReason() {
                return ( $this->readOnly != '' ) ? $this->readOnly : false;
        }

        final public function doOperations( array $ops, array $opts = array() ) {
                if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
                if ( empty( $opts['force'] ) ) { // sanity
                        unset( $opts['nonLocking'] );
                        unset( $opts['allowStale'] );
                }
                $opts['concurrency'] = 1; // off
                if ( $this->parallelize === 'implicit' ) {
                        if ( !isset( $opts['parallelize'] ) || $opts['parallelize'] ) {
                                $opts['concurrency'] = $this->concurrency;
                        }
                } elseif ( $this->parallelize === 'explicit' ) {
                        if ( !empty( $opts['parallelize'] ) ) {
                                $opts['concurrency'] = $this->concurrency;
                        }
                }
                return $this->doOperationsInternal( $ops, $opts );
        }

        abstract protected function doOperationsInternal( array $ops, array $opts );

        final public function doOperation( array $op, array $opts = array() ) {
                return $this->doOperations( array( $op ), $opts );
        }

        final public function create( array $params, array $opts = array() ) {
                return $this->doOperation( array( 'op' => 'create' ) + $params, $opts );
        }

        final public function store( array $params, array $opts = array() ) {
                return $this->doOperation( array( 'op' => 'store' ) + $params, $opts );
        }

        final public function copy( array $params, array $opts = array() ) {
                return $this->doOperation( array( 'op' => 'copy' ) + $params, $opts );
        }

        final public function move( array $params, array $opts = array() ) {
                return $this->doOperation( array( 'op' => 'move' ) + $params, $opts );
        }

        final public function delete( array $params, array $opts = array() ) {
                return $this->doOperation( array( 'op' => 'delete' ) + $params, $opts );
        }

        final public function doQuickOperations( array $ops, array $opts = array() ) {
                if ( empty( $opts['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
                foreach ( $ops as &$op ) {
                        $op['overwrite'] = true; // avoids RTTs in key/value stores
                }
                return $this->doQuickOperationsInternal( $ops );
        }

        abstract protected function doQuickOperationsInternal( array $ops );

        final public function doQuickOperation( array $op ) {
                return $this->doQuickOperations( array( $op ) );
        }

        final public function quickCreate( array $params ) {
                return $this->doQuickOperation( array( 'op' => 'create' ) + $params );
        }

        final public function quickStore( array $params ) {
                return $this->doQuickOperation( array( 'op' => 'store' ) + $params );
        }

        final public function quickCopy( array $params ) {
                return $this->doQuickOperation( array( 'op' => 'copy' ) + $params );
        }

        final public function quickMove( array $params ) {
                return $this->doQuickOperation( array( 'op' => 'move' ) + $params );
        }

        final public function quickDelete( array $params ) {
                return $this->doQuickOperation( array( 'op' => 'delete' ) + $params );
        }

        abstract public function concatenate( array $params );

        final public function prepare( array $params ) {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
                return $this->doPrepare( $params );
        }

        abstract protected function doPrepare( array $params );

        final public function secure( array $params ) {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
                return $this->doSecure( $params );
        }

        abstract protected function doSecure( array $params );

        final public function publish( array $params ) {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
                return $this->doPublish( $params );
        }

        abstract protected function doPublish( array $params );

        final public function clean( array $params ) {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
                return $this->doClean( $params );
        }

        abstract protected function doClean( array $params );

        abstract public function fileExists( array $params );

        abstract public function getFileTimestamp( array $params );

        abstract public function getFileContents( array $params );

        abstract public function getFileSize( array $params );

        abstract public function getFileStat( array $params );

        abstract public function getFileSha1Base36( array $params );

        abstract public function getFileProps( array $params );

        abstract public function streamFile( array $params );

        abstract public function getLocalReference( array $params );

        abstract public function getLocalCopy( array $params );

        abstract public function directoryExists( array $params );

        abstract public function getDirectoryList( array $params );

        final public function getTopDirectoryList( array $params ) {
                return $this->getDirectoryList( array( 'topOnly' => true ) + $params );
        }

        abstract public function getFileList( array $params );

        final public function getTopFileList( array $params ) {
                return $this->getFileList( array( 'topOnly' => true ) + $params );
        }

        public function preloadCache( array $paths ) {}

        public function clearCache( array $paths = null ) {}

        final public function lockFiles( array $paths, $type ) {
                return $this->lockManager->lock( $paths, $type );
        }

        final public function unlockFiles( array $paths, $type ) {
                return $this->lockManager->unlock( $paths, $type );
        }

        final public function getScopedFileLocks( array $paths, $type, Status $status ) {
                return ScopedLock::factory( $this->lockManager, $paths, $type, $status );
        }

        abstract public function getScopedLocksForOps( array $ops, Status $status );

        final public function getRootStoragePath() {
                return "mwstore://{$this->name}";
        }

        final public function getJournal() {
                return $this->fileJournal;
        }

        final public static function isStoragePath( $path ) {
                return ( strpos( $path, 'mwstore://' ) === 0 );
        }

        final public static function splitStoragePath( $storagePath ) {
                if ( self::isStoragePath( $storagePath ) ) {
                        // Remove the "mwstore://" prefix and split the path
                        $parts = explode( '/', substr( $storagePath, 10 ), 3 );
                        if ( count( $parts ) >= 2 && $parts[0] != '' && $parts[1] != '' ) {
                                if ( count( $parts ) == 3 ) {
                                        return $parts; // e.g. "backend/container/path"
                                } else {
                                        return array( $parts[0], $parts[1], '' ); // e.g. "backend/container"
                                }
                        }
                }
                return array( null, null, null );
        }

        final public static function normalizeStoragePath( $storagePath ) {
                list( $backend, $container, $relPath ) = self::splitStoragePath( $storagePath );
                if ( $relPath !== null ) { // must be for this backend
                        $relPath = self::normalizeContainerPath( $relPath );
                        if ( $relPath !== null ) {
                                return ( $relPath != '' )
                                        ? "mwstore://{$backend}/{$container}/{$relPath}"
                                        : "mwstore://{$backend}/{$container}";
                        }
                }
                return null;
        }

        final public static function parentStoragePath( $storagePath ) {
                $storagePath = dirname( $storagePath );
                list( $b, $cont, $rel ) = self::splitStoragePath( $storagePath );
                return ( $rel === null ) ? null : $storagePath;
        }

        final public static function extensionFromPath( $path ) {
                $i = strrpos( $path, '.' );
                return strtolower( $i ? substr( $path, $i + 1 ) : '' );
        }

        final public static function isPathTraversalFree( $path ) {
                return ( self::normalizeContainerPath( $path ) !== null );
        }

        final public static function makeContentDisposition( $type, $filename = '' ) {
                $parts = array();

                $type = strtolower( $type );
                if ( !in_array( $type, array( 'inline', 'attachment' ) ) ) {
                        throw new MWException( "Invalid Content-Disposition type '$type'." );
                }
                $parts[] = $type;

                if ( strlen( $filename ) ) {
                        $parts[] = "filename*=UTF-8''" . rawurlencode( basename( $filename ) );
                }

                return implode( ';', $parts );
        }

        final protected static function normalizeContainerPath( $path ) {
                // Normalize directory separators
                $path = strtr( $path, '\\', '/' );
                // Collapse any consecutive directory separators
                $path = preg_replace( '![/]{2,}!', '/', $path );
                // Remove any leading directory separator
                $path = ltrim( $path, '/' );
                // Use the same traversal protection as Title::secureAndSplit()
                if ( strpos( $path, '.' ) !== false ) {
                        if (
                                $path === '.' ||
                                $path === '..' ||
                                strpos( $path, './' ) === 0 ||
                                strpos( $path, '../' ) === 0 ||
                                strpos( $path, '/./' ) !== false ||
                                strpos( $path, '/../' ) !== false
                        ) {
                                return null;
                        }
                }
                return $path;
        }
}