Fixed undefined defines warnings introduced in change 5131

[mediawiki.git] / includes / filerepo / backend / FSFileBackend.php

<?php
/**
 * @file
 * @ingroup FileBackend
 * @author Aaron Schulz
 */

/**
 * @brief Class for a file system (FS) based file backend.
 * 
 * All "containers" each map to a directory under the backend's base directory.
 * For backwards-compatibility, some container paths can be set to custom paths.
 * The wiki ID will not be used in any custom paths, so this should be avoided.
 * 
 * Having directories with thousands of files will diminish performance.
 * Sharding can be accomplished by using FileRepo-style hash paths.
 *
 * Status messages should avoid mentioning the internal FS paths.
 * PHP warnings are assumed to be logged rather than output.
 *
 * @ingroup FileBackend
 * @since 1.19
 */
class FSFileBackend extends FileBackendStore {
        protected $basePath; // string; directory holding the container directories
        /** @var Array Map of container names to root paths */
        protected $containerPaths = array(); // for custom container paths
        protected $fileMode; // integer; file permission mode

        protected $hadWarningErrors = array();

        /**
         * @see FileBackendStore::__construct()
         * Additional $config params include:
         *    basePath       : File system directory that holds containers.
         *    containerPaths : Map of container names to custom file system directories.
         *                     This should only be used for backwards-compatibility.
         *    fileMode       : Octal UNIX file permissions to use on files stored.
         */
        public function __construct( array $config ) {
                parent::__construct( $config );

                // Remove any possible trailing slash from directories
                if ( isset( $config['basePath'] ) ) {
                        $this->basePath = rtrim( $config['basePath'], '/' ); // remove trailing slash
                } else {
                        $this->basePath = null; // none; containers must have explicit paths
                }

                if ( isset( $config['containerPaths'] ) ) {
                        $this->containerPaths = (array)$config['containerPaths'];
                        foreach ( $this->containerPaths as &$path ) {
                                $path = rtrim( $path, '/' );  // remove trailing slash
                        }
                }

                $this->fileMode = isset( $config['fileMode'] )
                        ? $config['fileMode']
                        : 0644;
        }

        /**
         * @see FileBackendStore::resolveContainerPath()
         * @return null|string
         */
        protected function resolveContainerPath( $container, $relStoragePath ) {
                // Check that container has a root directory
                if ( isset( $this->containerPaths[$container] ) || isset( $this->basePath ) ) {
                        // Check for sane relative paths (assume the base paths are OK)
                        if ( $this->isLegalRelPath( $relStoragePath ) ) {
                                return $relStoragePath;
                        }
                }
                return null;
        }

        /**
         * Sanity check a relative file system path for validity
         * 
         * @param $path string Normalized relative path
         * @return bool
         */
        protected function isLegalRelPath( $path ) {
                // Check for file names longer than 255 chars
                if ( preg_match( '![^/]{256}!', $path ) ) { // ext3/NTFS
                        return false;
                }
                if ( wfIsWindows() ) { // NTFS
                        return !preg_match( '![:*?"<>|]!', $path );
                } else {
                        return true;
                }
        }

        /**
         * Given the short (unresolved) and full (resolved) name of
         * a container, return the file system path of the container.
         * 
         * @param $shortCont string
         * @param $fullCont string
         * @return string|null 
         */
        protected function containerFSRoot( $shortCont, $fullCont ) {
                if ( isset( $this->containerPaths[$shortCont] ) ) {
                        return $this->containerPaths[$shortCont]; 
                } elseif ( isset( $this->basePath ) ) {
                        return "{$this->basePath}/{$fullCont}";
                }
                return null; // no container base path defined
        }

        /**
         * Get the absolute file system path for a storage path
         * 
         * @param $storagePath string Storage path
         * @return string|null
         */
        protected function resolveToFSPath( $storagePath ) {
                list( $fullCont, $relPath ) = $this->resolveStoragePathReal( $storagePath );
                if ( $relPath === null ) {
                        return null; // invalid
                }
                list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $storagePath );
                $fsPath = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                if ( $relPath != '' ) {
                        $fsPath .= "/{$relPath}";
                }
                return $fsPath;
        }

        /**
         * @see FileBackendStore::isPathUsableInternal()
         * @return bool
         */
        public function isPathUsableInternal( $storagePath ) {
                $fsPath = $this->resolveToFSPath( $storagePath );
                if ( $fsPath === null ) {
                        return false; // invalid
                }
                $parentDir = dirname( $fsPath );

                if ( file_exists( $fsPath ) ) {
                        $ok = is_file( $fsPath ) && is_writable( $fsPath );
                } else {
                        $ok = is_dir( $parentDir ) && is_writable( $parentDir );
                }

                return $ok;
        }

        /**
         * @see FileBackendStore::doStoreInternal()
         * @return Status
         */
        protected function doStoreInternal( array $params ) {
                $status = Status::newGood();

                $dest = $this->resolveToFSPath( $params['dst'] );
                if ( $dest === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
                        return $status;
                }

                if ( file_exists( $dest ) ) {
                        if ( !empty( $params['overwrite'] ) ) {
                                $ok = unlink( $dest );
                                if ( !$ok ) {
                                        $status->fatal( 'backend-fail-delete', $params['dst'] );
                                        return $status;
                                }
                        } else {
                                $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
                                return $status;
                        }
                }

                $ok = copy( $params['src'], $dest );
                if ( !$ok ) {
                        $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
                        return $status;
                }

                $this->chmod( $dest );

                return $status;
        }

        /**
         * @see FileBackendStore::doCopyInternal()
         * @return Status
         */
        protected function doCopyInternal( array $params ) {
                $status = Status::newGood();

                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['src'] );
                        return $status;
                }

                $dest = $this->resolveToFSPath( $params['dst'] );
                if ( $dest === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
                        return $status;
                }

                if ( file_exists( $dest ) ) {
                        if ( !empty( $params['overwrite'] ) ) {
                                $ok = unlink( $dest );
                                if ( !$ok ) {
                                        $status->fatal( 'backend-fail-delete', $params['dst'] );
                                        return $status;
                                }
                        } else {
                                $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
                                return $status;
                        }
                }

                $ok = copy( $source, $dest );
                if ( !$ok ) {
                        $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
                        return $status;
                }

                $this->chmod( $dest );

                return $status;
        }

        /**
         * @see FileBackendStore::doMoveInternal()
         * @return Status
         */
        protected function doMoveInternal( array $params ) {
                $status = Status::newGood();

                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['src'] );
                        return $status;
                }

                $dest = $this->resolveToFSPath( $params['dst'] );
                if ( $dest === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
                        return $status;
                }

                if ( file_exists( $dest ) ) {
                        if ( !empty( $params['overwrite'] ) ) {
                                // Windows does not support moving over existing files
                                if ( wfIsWindows() ) {
                                        $ok = unlink( $dest );
                                        if ( !$ok ) {
                                                $status->fatal( 'backend-fail-delete', $params['dst'] );
                                                return $status;
                                        }
                                }
                        } else {
                                $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
                                return $status;
                        }
                }

                $ok = rename( $source, $dest );
                clearstatcache(); // file no longer at source
                if ( !$ok ) {
                        $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
                        return $status;
                }

                return $status;
        }

        /**
         * @see FileBackendStore::doDeleteInternal()
         * @return Status
         */
        protected function doDeleteInternal( array $params ) {
                $status = Status::newGood();

                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['src'] );
                        return $status;
                }

                if ( !is_file( $source ) ) {
                        if ( empty( $params['ignoreMissingSource'] ) ) {
                                $status->fatal( 'backend-fail-delete', $params['src'] );
                        }
                        return $status; // do nothing; either OK or bad status
                }

                $ok = unlink( $source );
                if ( !$ok ) {
                        $status->fatal( 'backend-fail-delete', $params['src'] );
                        return $status;
                }

                return $status;
        }

        /**
         * @see FileBackendStore::doCreateInternal()
         * @return Status
         */
        protected function doCreateInternal( array $params ) {
                $status = Status::newGood();

                $dest = $this->resolveToFSPath( $params['dst'] );
                if ( $dest === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );
                        return $status;
                }

                if ( file_exists( $dest ) ) {
                        if ( !empty( $params['overwrite'] ) ) {
                                $ok = unlink( $dest );
                                if ( !$ok ) {
                                        $status->fatal( 'backend-fail-delete', $params['dst'] );
                                        return $status;
                                }
                        } else {
                                $status->fatal( 'backend-fail-alreadyexists', $params['dst'] );
                                return $status;
                        }
                }

                $bytes = file_put_contents( $dest, $params['content'] );
                if ( $bytes === false ) {
                        $status->fatal( 'backend-fail-create', $params['dst'] );
                        return $status;
                }

                $this->chmod( $dest );

                return $status;
        }

        /**
         * @see FileBackendStore::doPrepareInternal()
         * @return Status
         */
        protected function doPrepareInternal( $fullCont, $dirRel, array $params ) {
                $status = Status::newGood();
                list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                if ( !wfMkdirParents( $dir ) ) { // make directory and its parents
                        $status->fatal( 'directorycreateerror', $params['dir'] );
                } elseif ( !is_writable( $dir ) ) {
                        $status->fatal( 'directoryreadonlyerror', $params['dir'] );
                } elseif ( !is_readable( $dir ) ) {
                        $status->fatal( 'directorynotreadableerror', $params['dir'] );
                }
                return $status;
        }

        /**
         * @see FileBackendStore::doSecureInternal()
         * @return Status
         */
        protected function doSecureInternal( $fullCont, $dirRel, array $params ) {
                $status = Status::newGood();
                list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                // Seed new directories with a blank index.html, to prevent crawling...
                if ( !empty( $params['noListing'] ) && !file_exists( "{$dir}/index.html" ) ) {
                        $bytes = file_put_contents( "{$dir}/index.html", '' );
                        if ( !$bytes ) {
                                $status->fatal( 'backend-fail-create', $params['dir'] . '/index.html' );
                                return $status;
                        }
                }
                // Add a .htaccess file to the root of the container...
                if ( !empty( $params['noAccess'] ) ) {
                        if ( !file_exists( "{$contRoot}/.htaccess" ) ) {
                                $bytes = file_put_contents( "{$contRoot}/.htaccess", "Deny from all\n" );
                                if ( !$bytes ) {
                                        $storeDir = "mwstore://{$this->name}/{$shortCont}";
                                        $status->fatal( 'backend-fail-create', "{$storeDir}/.htaccess" );
                                        return $status;
                                }
                        }
                }
                return $status;
        }

        /**
         * @see FileBackendStore::doCleanInternal()
         * @return Status
         */
        protected function doCleanInternal( $fullCont, $dirRel, array $params ) {
                $status = Status::newGood();
                list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                wfSuppressWarnings();
                if ( is_dir( $dir ) ) {
                        rmdir( $dir ); // remove directory if empty
                }
                wfRestoreWarnings();
                return $status;
        }

        /**
         * @see FileBackendStore::doFileExists()
         * @return array|bool|null
         */
        protected function doGetFileStat( array $params ) {
                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
                        return false; // invalid storage path
                }

                $this->trapWarnings(); // don't trust 'false' if there were errors
                $stat = is_file( $source ) ? stat( $source ) : false; // regular files only
                $hadError = $this->untrapWarnings();

                if ( $stat ) {
                        return array(
                                'mtime' => wfTimestamp( TS_MW, $stat['mtime'] ),
                                'size'  => $stat['size']
                        );
                } elseif ( !$hadError ) {
                        return false; // file does not exist
                } else {
                        return null; // failure
                }
        }

        /**
         * @see FileBackendStore::doClearCache()
         */
        protected function doClearCache( array $paths = null ) {
                clearstatcache(); // clear the PHP file stat cache
        }

        /**
         * @see FileBackendStore::getFileListInternal()
         * @return array|FSFileBackendFileList|null
         */
        public function getFileListInternal( $fullCont, $dirRel, array $params ) {
                list( $b, $shortCont, $r ) = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $dir = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                $exists = is_dir( $dir );
                if ( !$exists ) {
                        wfDebug( __METHOD__ . "() given directory does not exist: '$dir'\n" );
                        return array(); // nothing under this dir
                }
                $readable = is_readable( $dir );
                if ( !$readable ) {
                        wfDebug( __METHOD__ . "() given directory is unreadable: '$dir'\n" );
                        return null; // bad permissions?
                }
                return new FSFileBackendFileList( $dir );
        }

        /**
         * @see FileBackendStore::getLocalReference()
         * @return FSFile|null
         */
        public function getLocalReference( array $params ) {
                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
                        return null;
                }
                return new FSFile( $source );
        }

        /**
         * @see FileBackendStore::getLocalCopy()
         * @return null|TempFSFile
         */
        public function getLocalCopy( array $params ) {
                $source = $this->resolveToFSPath( $params['src'] );
                if ( $source === null ) {
                        return null;
                }

                // Create a new temporary file with the same extension...
                $ext = FileBackend::extensionFromPath( $params['src'] );
                $tmpFile = TempFSFile::factory( wfBaseName( $source ) . '_', $ext );
                if ( !$tmpFile ) {
                        return null;
                }
                $tmpPath = $tmpFile->getPath();

                // Copy the source file over the temp file
                $ok = copy( $source, $tmpPath );
                if ( !$ok ) {
                        return null;
                }

                $this->chmod( $tmpPath );

                return $tmpFile;
        }

        /**
         * Chmod a file, suppressing the warnings
         *
         * @param $path string Absolute file system path
         * @return bool Success
         */
        protected function chmod( $path ) {
                wfSuppressWarnings();
                $ok = chmod( $path, $this->fileMode );
                wfRestoreWarnings();

                return $ok;
        }

        /**
         * Listen for E_WARNING errors and track whether any happen
         *
         * @return bool
         */
        protected function trapWarnings() {
                $this->hadWarningErrors[] = false; // push to stack
                set_error_handler( array( $this, 'handleWarning' ), E_WARNING );
                return false; // invoke normal PHP error handler
        }

        /**
         * Stop listening for E_WARNING errors and return true if any happened
         *
         * @return bool
         */
        protected function untrapWarnings() {
                restore_error_handler(); // restore previous handler
                return array_pop( $this->hadWarningErrors ); // pop from stack
        }

        private function handleWarning() {
                $this->hadWarningErrors[count( $this->hadWarningErrors ) - 1] = true;
                return true; // suppress from PHP handler
        }
}

/**
 * Wrapper around RecursiveDirectoryIterator that catches
 * exception or does any custom behavoir that we may want.
 * Do not use this class from places outside FSFileBackend.
 *
 * @ingroup FileBackend
 */
class FSFileBackendFileList implements Iterator {
        /** @var RecursiveIteratorIterator */
        protected $iter;
        protected $suffixStart; // integer
        protected $pos = 0; // integer

        /**
         * @param $dir string file system directory
         */
        public function __construct( $dir ) {
                $dir = realpath( $dir ); // normalize
                $this->suffixStart = strlen( $dir ) + 1; // size of "path/to/dir/"
                try {
                        # Get an iterator that will return leaf nodes (non-directories)
                        if ( MWInit::classExists( 'FilesystemIterator' ) ) { // PHP >= 5.3
                                # RecursiveDirectoryIterator extends FilesystemIterator.
                                # FilesystemIterator::SKIP_DOTS default is inconsistent in PHP 5.3.x.
                                $flags = FilesystemIterator::CURRENT_AS_FILEINFO | FilesystemIterator::SKIP_DOTS;
                                $this->iter = new RecursiveIteratorIterator( 
                                        new RecursiveDirectoryIterator( $dir, $flags ) );
                        } else { // PHP < 5.3
                                # RecursiveDirectoryIterator extends DirectoryIterator
                                $this->iter = new RecursiveIteratorIterator( 
                                        new RecursiveDirectoryIterator( $dir ) );
                        }
                } catch ( UnexpectedValueException $e ) {
                        $this->iter = null; // bad permissions? deleted?
                }
        }

        /**
         * @see Iterator::current()
         * @return string|bool String or false
         */
        public function current() {
                // Return only the relative path and normalize slashes to FileBackend-style
                // Make sure to use the realpath since the suffix is based upon that
                return str_replace( '\\', '/',
                        substr( realpath( $this->iter->current() ), $this->suffixStart ) );
        }

        /**
         * @see Iterator::key()
         * @return integer
         */
        public function key() {
                return $this->pos;
        }

        /**
         * @see Iterator::next()
         * @return void
         */
        public function next() {
                try {
                        $this->iter->next();
                } catch ( UnexpectedValueException $e ) {
                        $this->iter = null;
                }
                ++$this->pos;
        }

        /**
         * @see Iterator::rewind()
         * @return void
         */
        public function rewind() {
                $this->pos = 0;
                try {
                        $this->iter->rewind();
                } catch ( UnexpectedValueException $e ) {
                        $this->iter = null;
                }
        }

        /**
         * @see Iterator::valid()
         * @return bool
         */
        public function valid() {
                return $this->iter && $this->iter->valid();
        }
}