(bug 26895) in /include/db/LoadBalancer.php function "closeConnecton" should be calle...

[mediawiki.git] / includes / filerepo / File.php

<?php
/**
 * Base code for files.
 *
 * @file
 * @ingroup FileRepo
 */

/**
 * Implements some public methods and some protected utility functions which
 * are required by multiple child classes. Contains stub functionality for
 * unimplemented public methods.
 *
 * Stub functions which should be overridden are marked with STUB. Some more
 * concrete functions are also typically overridden by child classes.
 *
 * Note that only the repo object knows what its file class is called. You should
 * never name a file class explictly outside of the repo class. Instead use the
 * repo's factory functions to generate file objects, for example:
 *
 * RepoGroup::singleton()->getLocalRepo()->newFile($title);
 *
 * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
 * in most cases.
 *
 * @ingroup FileRepo
 */
abstract class File {
        const DELETED_FILE = 1;
        const DELETED_COMMENT = 2;
        const DELETED_USER = 4;
        const DELETED_RESTRICTED = 8;
        const RENDER_NOW = 1;

        const DELETE_SOURCE = 1;

        /**
         * Some member variables can be lazy-initialised using __get(). The
         * initialisation function for these variables is always a function named
         * like getVar(), where Var is the variable name with upper-case first
         * letter.
         *
         * The following variables are initialised in this way in this base class:
         *    name, extension, handler, path, canRender, isSafeFile,
         *    transformScript, hashPath, pageCount, url
         *
         * Code within this class should generally use the accessor function
         * directly, since __get() isn't re-entrant and therefore causes bugs that
         * depend on initialisation order.
         */

        /**
         * The following member variables are not lazy-initialised
         */
        var $repo, $title, $lastError, $redirected, $redirectedTitle;

        /**
         * Call this constructor from child classes
         */
        function __construct( $title, $repo ) {
                $this->title = $title;
                $this->repo = $repo;
        }

        function __get( $name ) {
                $function = array( $this, 'get' . ucfirst( $name ) );
                if ( !is_callable( $function ) ) {
                        return null;
                } else {
                        $this->$name = call_user_func( $function );
                        return $this->$name;
                }
        }

        /**
         * Normalize a file extension to the common form, and ensure it's clean.
         * Extensions with non-alphanumeric characters will be discarded.
         *
         * @param $ext string (without the .)
         * @return string
         */
        static function normalizeExtension( $ext ) {
                $lower = strtolower( $ext );
                $squish = array(
                        'htm' => 'html',
                        'jpeg' => 'jpg',
                        'mpeg' => 'mpg',
                        'tiff' => 'tif',
                        'ogv' => 'ogg' );
                if( isset( $squish[$lower] ) ) {
                        return $squish[$lower];
                } elseif( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
                        return $lower;
                } else {
                        return '';
                }
        }

        /**
         * Checks if file extensions are compatible
         *
         * @param $old File Old file
         * @param $new string New name
         */
        static function checkExtensionCompatibility( File $old, $new ) {
                $oldMime = $old->getMimeType();
                $n = strrpos( $new, '.' );
                $newExt = self::normalizeExtension(
                        $n ? substr( $new, $n + 1 ) : '' );
                $mimeMagic = MimeMagic::singleton();
                return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
        }

        /**
         * Upgrade the database row if there is one
         * Called by ImagePage
         * STUB
         */
        function upgradeRow() {}

        /**
         * Split an internet media type into its two components; if not
         * a two-part name, set the minor type to 'unknown'.
         *
         * @param $mime "text/html" etc
         * @return array ("text", "html") etc
         */
        static function splitMime( $mime ) {
                if( strpos( $mime, '/' ) !== false ) {
                        return explode( '/', $mime, 2 );
                } else {
                        return array( $mime, 'unknown' );
                }
        }

        /**
         * Return the name of this file
         */
        public function getName() {
                if ( !isset( $this->name ) ) {
                        $this->name = $this->repo->getNameFromTitle( $this->title );
                }
                return $this->name;
        }

        /**
         * Get the file extension, e.g. "svg"
         */
        function getExtension() {
                if ( !isset( $this->extension ) ) {
                        $n = strrpos( $this->getName(), '.' );
                        $this->extension = self::normalizeExtension(
                                $n ? substr( $this->getName(), $n + 1 ) : '' );
                }
                return $this->extension;
        }

        /**
         * Return the associated title object
         */
        public function getTitle() { return $this->title; }
        
        /**
         * Return the title used to find this file
         */
        public function getOriginalTitle() {
                if ( $this->redirected )
                        return $this->getRedirectedTitle();
                return $this->title;
        }

        /**
         * Return the URL of the file
         */
        public function getUrl() {
                if ( !isset( $this->url ) ) {
                        $this->url = $this->repo->getZoneUrl( 'public' ) . '/' . $this->getUrlRel();
                }
                return $this->url;
        }

        /**
         * Return a fully-qualified URL to the file.
         * Upload URL paths _may or may not_ be fully qualified, so
         * we check. Local paths are assumed to belong on $wgServer.
         *
         * @return String
         */
        public function getFullUrl() {
                return wfExpandUrl( $this->getUrl() );
        }

        function getViewURL() {
                if( $this->mustRender()) {
                        if( $this->canRender() ) {
                                return $this->createThumb( $this->getWidth() );
                        }
                        else {
                                wfDebug(__METHOD__.': supposed to render '.$this->getName().' ('.$this->getMimeType()."), but can't!\n");
                                return $this->getURL(); #hm... return NULL?
                        }
                } else {
                        return $this->getURL();
                }
        }

        /**
        * Return the full filesystem path to the file. Note that this does
        * not mean that a file actually exists under that location.
        *
        * This path depends on whether directory hashing is active or not,
        * i.e. whether the files are all found in the same directory,
        * or in hashed paths like /images/3/3c.
        *
        * May return false if the file is not locally accessible.
        */
        public function getPath() {
                if ( !isset( $this->path ) ) {
                        $this->path = $this->repo->getZonePath('public') . '/' . $this->getRel();
                }
                return $this->path;
        }

        /**
        * Alias for getPath()
        */
        public function getFullPath() {
                return $this->getPath();
        }

        /**
         * Return the width of the image. Returns false if the width is unknown
         * or undefined.
         *
         * STUB
         * Overridden by LocalFile, UnregisteredLocalFile
         */
        public function getWidth( $page = 1 ) { return false; }

        /**
         * Return the height of the image. Returns false if the height is unknown
         * or undefined
         *
         * STUB
         * Overridden by LocalFile, UnregisteredLocalFile
         */
        public function getHeight( $page = 1 ) { return false; }

        /**
         * Returns ID or name of user who uploaded the file
         * STUB
         *
         * @param $type string 'text' or 'id'
         */
        public function getUser( $type='text' ) { return null; }

        /**
         * Get the duration of a media file in seconds
         */
        public function getLength() {
                $handler = $this->getHandler();
                if ( $handler ) {
                        return $handler->getLength( $this );
                } else {
                        return 0;
                }
        }

        /**
         *  Return true if the file is vectorized
         */
        public function isVectorized() {
                $handler = $this->getHandler();
                if ( $handler ) {
                        return $handler->isVectorized( $this );
                } else {
                        return false;
                }
        }


        /**
         * Get handler-specific metadata
         * Overridden by LocalFile, UnregisteredLocalFile
         * STUB
         */
        public function getMetadata() { return false; }

        /**
         * Return the bit depth of the file
         * Overridden by LocalFile
         * STUB
         */
        public function getBitDepth() { return 0; }

        /**
         * Return the size of the image file, in bytes
         * Overridden by LocalFile, UnregisteredLocalFile
         * STUB
         */
        public function getSize() { return false; }

        /**
         * Returns the mime type of the file.
         * Overridden by LocalFile, UnregisteredLocalFile
         * STUB
         */
        function getMimeType() { return 'unknown/unknown'; }

        /**
         * Return the type of the media in the file.
         * Use the value returned by this function with the MEDIATYPE_xxx constants.
         * Overridden by LocalFile,
         * STUB
         */
        function getMediaType() { return MEDIATYPE_UNKNOWN; }

        /**
         * Checks if the output of transform() for this file is likely
         * to be valid. If this is false, various user elements will
         * display a placeholder instead.
         *
         * Currently, this checks if the file is an image format
         * that can be converted to a format
         * supported by all browsers (namely GIF, PNG and JPEG),
         * or if it is an SVG image and SVG conversion is enabled.
         */
        function canRender() {
                if ( !isset( $this->canRender ) ) {
                        $this->canRender = $this->getHandler() && $this->handler->canRender( $this );
                }
                return $this->canRender;
        }

        /**
         * Accessor for __get()
         */
        protected function getCanRender() {
                return $this->canRender();
        }

        /**
         * Return true if the file is of a type that can't be directly
         * rendered by typical browsers and needs to be re-rasterized.
         *
         * This returns true for everything but the bitmap types
         * supported by all browsers, i.e. JPEG; GIF and PNG. It will
         * also return true for any non-image formats.
         *
         * @return bool
         */
        function mustRender() {
                return $this->getHandler() && $this->handler->mustRender( $this );
        }

        /**
         * Alias for canRender()
         */
        function allowInlineDisplay() {
                return $this->canRender();
        }

        /**
         * Determines if this media file is in a format that is unlikely to
         * contain viruses or malicious content. It uses the global
         * $wgTrustedMediaFormats list to determine if the file is safe.
         *
         * This is used to show a warning on the description page of non-safe files.
         * It may also be used to disallow direct [[media:...]] links to such files.
         *
         * Note that this function will always return true if allowInlineDisplay()
         * or isTrustedFile() is true for this file.
         */
        function isSafeFile() {
                if ( !isset( $this->isSafeFile ) ) {
                        $this->isSafeFile = $this->_getIsSafeFile();
                }
                return $this->isSafeFile;
        }

        /** Accessor for __get() */
        protected function getIsSafeFile() {
                return $this->isSafeFile();
        }

        /** Uncached accessor */
        protected function _getIsSafeFile() {
                if ($this->allowInlineDisplay()) return true;
                if ($this->isTrustedFile()) return true;

                global $wgTrustedMediaFormats;

                $type= $this->getMediaType();
                $mime= $this->getMimeType();
                #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");

                if (!$type || $type===MEDIATYPE_UNKNOWN) return false; #unknown type, not trusted
                if ( in_array( $type, $wgTrustedMediaFormats) ) return true;

                if ($mime==="unknown/unknown") return false; #unknown type, not trusted
                if ( in_array( $mime, $wgTrustedMediaFormats) ) return true;

                return false;
        }

        /** Returns true if the file is flagged as trusted. Files flagged that way
        * can be linked to directly, even if that is not allowed for this type of
        * file normally.
        *
        * This is a dummy function right now and always returns false. It could be
        * implemented to extract a flag from the database. The trusted flag could be
        * set on upload, if the user has sufficient privileges, to bypass script-
        * and html-filters. It may even be coupled with cryptographics signatures
        * or such.
        */
        function isTrustedFile() {
                #this could be implemented to check a flag in the databas,
                #look for signatures, etc
                return false;
        }

        /**
         * Returns true if file exists in the repository.
         *
         * Overridden by LocalFile to avoid unnecessary stat calls.
         *
         * @return boolean Whether file exists in the repository.
         */
        public function exists() {
                return $this->getPath() && file_exists( $this->path );
        }

        /**
         * Returns true if file exists in the repository and can be included in a page.
         * It would be unsafe to include private images, making public thumbnails inadvertently
         *
         * @return boolean Whether file exists in the repository and is includable.
         * @public
         */
        function isVisible() {
                return $this->exists();
        }

        function getTransformScript() {
                if ( !isset( $this->transformScript ) ) {
                        $this->transformScript = false;
                        if ( $this->repo ) {
                                $script = $this->repo->getThumbScriptUrl();
                                if ( $script ) {
                                        $this->transformScript = "$script?f=" . urlencode( $this->getName() );
                                }
                        }
                }
                return $this->transformScript;
        }

        /**
         * Get a ThumbnailImage which is the same size as the source
         */
        function getUnscaledThumb( $handlerParams = array() ) {
                $hp =& $handlerParams;
                $page = isset( $hp['page'] ) ? $hp['page'] : false;
                $width = $this->getWidth( $page );
                if ( !$width ) {
                        return $this->iconThumb();
                }
                $hp['width'] = $width;
                return $this->transform( $hp );
        }

        /**
         * Return the file name of a thumbnail with the specified parameters
         *
         * @param $params Array: handler-specific parameters
         * @private -ish
         */
        function thumbName( $params ) {
                if ( !$this->getHandler() ) {
                        return null;
                }
                $extension = $this->getExtension();
                list( $thumbExt, $thumbMime ) = $this->handler->getThumbType( $extension, $this->getMimeType(), $params );
                $thumbName = $this->handler->makeParamString( $params ) . '-' . $this->getName();
                if ( $thumbExt != $extension ) {
                        $thumbName .= ".$thumbExt";
                }
                return $thumbName;
        }

        /**
         * Create a thumbnail of the image having the specified width/height.
         * The thumbnail will not be created if the width is larger than the
         * image's width. Let the browser do the scaling in this case.
         * The thumbnail is stored on disk and is only computed if the thumbnail
         * file does not exist OR if it is older than the image.
         * Returns the URL.
         *
         * Keeps aspect ratio of original image. If both width and height are
         * specified, the generated image will be no bigger than width x height,
         * and will also have correct aspect ratio.
         *
         * @param $width Integer: maximum width of the generated thumbnail
         * @param $height Integer: maximum height of the image (optional)
         */
        public function createThumb( $width, $height = -1 ) {
                $params = array( 'width' => $width );
                if ( $height != -1 ) {
                        $params['height'] = $height;
                }
                $thumb = $this->transform( $params );
                if( is_null( $thumb ) || $thumb->isError() ) return '';
                return $thumb->getUrl();
        }

        /**
         * As createThumb, but returns a ThumbnailImage object. This can
         * provide access to the actual file, the real size of the thumb,
         * and can produce a convenient \<img\> tag for you.
         *
         * For non-image formats, this may return a filetype-specific icon.
         *
         * @param $width Integer: maximum width of the generated thumbnail
         * @param $height Integer: maximum height of the image (optional)
         * @param $render Integer: Deprecated
         *
         * @return ThumbnailImage or null on failure
         *
         * @deprecated use transform()
         */
        public function getThumbnail( $width, $height=-1, $render = true ) {
                wfDeprecated( __METHOD__ );
                $params = array( 'width' => $width );
                if ( $height != -1 ) {
                        $params['height'] = $height;
                }
                return $this->transform( $params, 0 );
        }

        /**
         * Transform a media file
         *
         * @param $params Array: an associative array of handler-specific parameters.
         *                Typical keys are width, height and page.
         * @param $flags Integer: a bitfield, may contain self::RENDER_NOW to force rendering
         * @return MediaTransformOutput | false
         */
        function transform( $params, $flags = 0 ) {
                global $wgUseSquid, $wgIgnoreImageErrors, $wgThumbnailEpoch, $wgServer;

                wfProfileIn( __METHOD__ );
                do {
                        if ( !$this->canRender() ) {
                                // not a bitmap or renderable image, don't try.
                                $thumb = $this->iconThumb();
                                break;
                        }

                        // Get the descriptionUrl to embed it as comment into the thumbnail. Bug 19791.
                        $descriptionUrl =  $this->getDescriptionUrl();
                        if ( $descriptionUrl ) {
                                $params['descriptionUrl'] = $wgServer . $descriptionUrl;
                        }

                        $script = $this->getTransformScript();
                        if ( $script && !($flags & self::RENDER_NOW) ) {
                                // Use a script to transform on client request, if possible
                                $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
                                if( $thumb ) {
                                        break;
                                }
                        }

                        $normalisedParams = $params;
                        $this->handler->normaliseParams( $this, $normalisedParams );
                        $thumbName = $this->thumbName( $normalisedParams );
                        $thumbPath = $this->getThumbPath( $thumbName );
                        $thumbUrl = $this->getThumbUrl( $thumbName );

                        if ( $this->repo && $this->repo->canTransformVia404() && !($flags & self::RENDER_NOW ) ) {
                                $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
                                break;
                        }

                        wfDebug( __METHOD__.": Doing stat for $thumbPath\n" );
                        $this->migrateThumbFile( $thumbName );
                        if ( file_exists( $thumbPath )) {
                                $thumbTime = filemtime( $thumbPath );
                                if ( $thumbTime !== FALSE &&
                                     gmdate( 'YmdHis', $thumbTime ) >= $wgThumbnailEpoch ) { 
        
                                        $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
                                        break;
                                }
                        }
                        $thumb = $this->handler->doTransform( $this, $thumbPath, $thumbUrl, $params );

                        // Ignore errors if requested
                        if ( !$thumb ) {
                                $thumb = null;
                        } elseif ( $thumb->isError() ) {
                                $this->lastError = $thumb->toText();
                                if ( $wgIgnoreImageErrors && !($flags & self::RENDER_NOW) ) {
                                        $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
                                }
                        }
                        
                        // Purge. Useful in the event of Core -> Squid connection failure or squid 
                        // purge collisions from elsewhere during failure. Don't keep triggering for 
                        // "thumbs" which have the main image URL though (bug 13776)
                        if ( $wgUseSquid && ( !$thumb || $thumb->isError() || $thumb->getUrl() != $this->getURL()) ) {
                                SquidUpdate::purge( array( $thumbUrl ) );
                        }
                } while (false);

                wfProfileOut( __METHOD__ );
                return is_object( $thumb ) ? $thumb : false;
        }

        /**
         * Hook into transform() to allow migration of thumbnail files
         * STUB
         * Overridden by LocalFile
         */
        function migrateThumbFile( $thumbName ) {}

        /**
         * Get a MediaHandler instance for this file
         */
        function getHandler() {
                if ( !isset( $this->handler ) ) {
                        $this->handler = MediaHandler::getHandler( $this->getMimeType() );
                }
                return $this->handler;
        }

        /**
         * Get a ThumbnailImage representing a file type icon
         * @return ThumbnailImage
         */
        function iconThumb() {
                global $wgStylePath, $wgStyleDirectory;

                $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
                foreach( $try as $icon ) {
                        $path = '/common/images/icons/' . $icon;
                        $filepath = $wgStyleDirectory . $path;
                        if( file_exists( $filepath ) ) {
                                return new ThumbnailImage( $this, $wgStylePath . $path, 120, 120 );
                        }
                }
                return null;
        }

        /**
         * Get last thumbnailing error.
         * Largely obsolete.
         */
        function getLastError() {
                return $this->lastError;
        }

        /**
         * Get all thumbnail names previously generated for this file
         * STUB
         * Overridden by LocalFile
         */
        function getThumbnails() { return array(); }

        /**
         * Purge shared caches such as thumbnails and DB data caching
         * STUB
         * Overridden by LocalFile
         */
        function purgeCache() {}

        /**
         * Purge the file description page, but don't go after
         * pages using the file. Use when modifying file history
         * but not the current data.
         */
        function purgeDescription() {
                $title = $this->getTitle();
                if ( $title ) {
                        $title->invalidateCache();
                        $title->purgeSquid();
                }
        }

        /**
         * Purge metadata and all affected pages when the file is created,
         * deleted, or majorly updated.
         */
        function purgeEverything() {
                // Delete thumbnails and refresh file metadata cache
                $this->purgeCache();
                $this->purgeDescription();

                // Purge cache of all pages using this file
                $title = $this->getTitle();
                if ( $title ) {
                        $update = new HTMLCacheUpdate( $title, 'imagelinks' );
                        $update->doUpdate();
                }
        }

        /**
         * Return a fragment of the history of file.
         *
         * STUB
         * @param $limit integer Limit of rows to return
         * @param $start timestamp Only revisions older than $start will be returned
         * @param $end timestamp Only revisions newer than $end will be returned
         * @param $inc bool Include the endpoints of the time range
         */
        function getHistory($limit = null, $start = null, $end = null, $inc=true) {
                return array();
        }

        /**
         * Return the history of this file, line by line. Starts with current version,
         * then old versions. Should return an object similar to an image/oldimage
         * database row.
         *
         * STUB
         * Overridden in LocalFile
         */
        public function nextHistoryLine() {
                return false;
        }

        /**
         * Reset the history pointer to the first element of the history.
         * Always call this function after using nextHistoryLine() to free db resources
         * STUB
         * Overridden in LocalFile.
         */
        public function resetHistory() {}

        /**
         * Get the filename hash component of the directory including trailing slash,
         * e.g. f/fa/
         * If the repository is not hashed, returns an empty string.
         */
        function getHashPath() {
                if ( !isset( $this->hashPath ) ) {
                        $this->hashPath = $this->repo->getHashPath( $this->getName() );
                }
                return $this->hashPath;
        }

        /**
         * Get the path of the file relative to the public zone root
         */
        function getRel() {
                return $this->getHashPath() . $this->getName();
        }

        /**
         * Get urlencoded relative path of the file
         */
        function getUrlRel() {
                return $this->getHashPath() . rawurlencode( $this->getName() );
        }

        /** Get the relative path for an archive file */
        function getArchiveRel( $suffix = false ) {
                $path = 'archive/' . $this->getHashPath();
                if ( $suffix === false ) {
                        $path = substr( $path, 0, -1 );
                } else {
                        $path .= $suffix;
                }
                return $path;
        }

        /** Get the path of the archive directory, or a particular file if $suffix is specified */
        function getArchivePath( $suffix = false ) {
                return $this->repo->getZonePath('public') . '/' . $this->getArchiveRel( $suffix );
        }

        /** Get the path of the thumbnail directory, or a particular file if $suffix is specified */
        function getThumbPath( $suffix = false ) {
                $path = $this->repo->getZonePath('thumb') . '/' . $this->getRel();
                if ( $suffix !== false ) {
                        $path .= '/' . $suffix;
                }
                return $path;
        }

        /** Get the URL of the archive directory, or a particular file if $suffix is specified */
        function getArchiveUrl( $suffix = false ) {
                $path = $this->repo->getZoneUrl('public') . '/archive/' . $this->getHashPath();
                if ( $suffix === false ) {
                        $path = substr( $path, 0, -1 );
                } else {
                        $path .= rawurlencode( $suffix );
                }
                return $path;
        }

        /** Get the URL of the thumbnail directory, or a particular file if $suffix is specified */
        function getThumbUrl( $suffix = false ) {
                $path = $this->repo->getZoneUrl('thumb') . '/' . $this->getUrlRel();
                if ( $suffix !== false ) {
                        $path .= '/' . rawurlencode( $suffix );
                }
                return $path;
        }

        /** Get the virtual URL for an archive file or directory */
        function getArchiveVirtualUrl( $suffix = false ) {
                $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
                if ( $suffix === false ) {
                        $path = substr( $path, 0, -1 );
                } else {
                        $path .= rawurlencode( $suffix );
                }
                return $path;
        }

        /** Get the virtual URL for a thumbnail file or directory */
        function getThumbVirtualUrl( $suffix = false ) {
                $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
                if ( $suffix !== false ) {
                        $path .= '/' . rawurlencode( $suffix );
                }
                return $path;
        }

        /** Get the virtual URL for the file itself */
        function getVirtualUrl( $suffix = false ) {
                $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
                if ( $suffix !== false ) {
                        $path .= '/' . rawurlencode( $suffix );
                }
                return $path;
        }

        /**
         * @return bool
         */
        function isHashed() {
                return $this->repo->isHashed();
        }

        function readOnlyError() {
                throw new MWException( get_class($this) . ': write operations are not supported' );
        }

        /**
         * Record a file upload in the upload log and the image table
         * STUB
         * Overridden by LocalFile
         */
        function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
                $this->readOnlyError();
        }

        /**
         * Move or copy a file to its public location. If a file exists at the
         * destination, move it to an archive. Returns a FileRepoStatus object with
         * the archive name in the "value" member on success.
         *
         * The archive name should be passed through to recordUpload for database
         * registration.
         *
         * @param $srcPath String: local filesystem path to the source image
         * @param $flags Integer: a bitwise combination of:
         *     File::DELETE_SOURCE    Delete the source file, i.e. move
         *         rather than copy
         * @return FileRepoStatus object. On success, the value member contains the
         *     archive name, or an empty string if it was a new file.
         *
         * STUB
         * Overridden by LocalFile
         */
        function publish( $srcPath, $flags = 0 ) {
                $this->readOnlyError();
        }

        /**
         * Get an array of Title objects which are articles which use this file
         * Also adds their IDs to the link cache
         *
         * This is mostly copied from Title::getLinksTo()
         *
         * @deprecated Use HTMLCacheUpdate, this function uses too much memory
         */
        function getLinksTo( $options = array() ) {
                wfDeprecated( __METHOD__ );
                wfProfileIn( __METHOD__ );

                // Note: use local DB not repo DB, we want to know local links
                if ( count( $options ) > 0 ) {
                        $db = wfGetDB( DB_MASTER );
                } else {
                        $db = wfGetDB( DB_SLAVE );
                }
                $linkCache = LinkCache::singleton();

                $encName = $db->addQuotes( $this->getName() );
                $res = $db->select( array( 'page', 'imagelinks'), 
                                                        array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
                                                        array( 'page_id=il_from', 'il_to' => $encName ),
                                                        __METHOD__,
                                                        $options );

                $retVal = array();
                if ( $db->numRows( $res ) ) {
                        foreach ( $res as $row ) {
                                $titleObj = Title::newFromRow( $row );
                                if ( $titleObj ) {
                                        $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
                                        $retVal[] = $titleObj;
                                }
                        }
                }
                wfProfileOut( __METHOD__ );
                return $retVal;
        }

        function formatMetadata() {
                if ( !$this->getHandler() ) {
                        return false;
                }
                return $this->getHandler()->formatMetadata( $this, $this->getMetadata() );
        }

        /**
         * Returns true if the file comes from the local file repository.
         *
         * @return bool
         */
        function isLocal() {
                $repo = $this->getRepo();
                return $repo && $repo->isLocal();
        }

        /**
         * Returns the name of the repository.
         *
         * @return string
         */
        function getRepoName() {
                return $this->repo ? $this->repo->getName() : 'unknown';
        }
        /*
         * Returns the repository
         */
        function getRepo() {
                return $this->repo;
        }

        /**
         * Returns true if the image is an old version
         * STUB
         */
        function isOld() {
                return false;
        }

        /**
         * Is this file a "deleted" file in a private archive?
         * STUB
         */
        function isDeleted( $field ) {
                return false;
        }
        
        /**
         * Return the deletion bitfield
         * STUB
         */     
        function getVisibility() {
                return 0;
        }

        /**
         * Was this file ever deleted from the wiki?
         *
         * @return bool
         */
        function wasDeleted() {
                $title = $this->getTitle();
                return $title && $title->isDeletedQuick();
        }

        /**
         * Move file to the new title
         *
         * Move current, old version and all thumbnails
         * to the new filename. Old file is deleted.
         *
         * Cache purging is done; checks for validity
         * and logging are caller's responsibility
         *
         * @param $target Title New file name
         * @return FileRepoStatus object.
         */
         function move( $target ) {
                $this->readOnlyError();
         }

        /**
         * Delete all versions of the file.
         *
         * Moves the files into an archive directory (or deletes them)
         * and removes the database rows.
         *
         * Cache purging is done; logging is caller's responsibility.
         *
         * @param $reason String
         * @param $suppress Boolean: hide content from sysops?
         * @return true on success, false on some kind of failure
         * STUB
         * Overridden by LocalFile
         */
        function delete( $reason, $suppress = false ) {
                $this->readOnlyError();
        }

        /**
         * Restore all or specified deleted revisions to the given file.
         * Permissions and logging are left to the caller.
         *
         * May throw database exceptions on error.
         *
         * @param $versions set of record ids of deleted items to restore,
         *                    or empty to restore all revisions.
         * @param $unsuppress remove restrictions on content upon restoration?
         * @return the number of file revisions restored if successful,
         *         or false on failure
         * STUB
         * Overridden by LocalFile
         */
        function restore( $versions=array(), $unsuppress=false ) {
                $this->readOnlyError();
        }

        /**
         * Returns 'true' if this file is a type which supports multiple pages, 
         * e.g. DJVU or PDF. Note that this may be true even if the file in 
         * question only has a single page.
         *
         * @return Bool
         */
        function isMultipage() {
                return $this->getHandler() && $this->handler->isMultiPage( $this );
        }

        /**
         * Returns the number of pages of a multipage document, or false for
         * documents which aren't multipage documents
         */
        function pageCount() {
                if ( !isset( $this->pageCount ) ) {
                        if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
                                $this->pageCount = $this->handler->pageCount( $this );
                        } else {
                                $this->pageCount = false;
                        }
                }
                return $this->pageCount;
        }

        /**
         * Calculate the height of a thumbnail using the source and destination width
         */
        static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
                // Exact integer multiply followed by division
                if ( $srcWidth == 0 ) {
                        return 0;
                } else {
                        return round( $srcHeight * $dstWidth / $srcWidth );
                }
        }

        /**
         * Get an image size array like that returned by getImageSize(), or false if it
         * can't be determined.
         *
         * @param $fileName String: The filename
         * @return Array
         */
        function getImageSize( $fileName ) {
                if ( !$this->getHandler() ) {
                        return false;
                }
                return $this->handler->getImageSize( $this, $fileName );
        }

        /**
         * Get the URL of the image description page. May return false if it is
         * unknown or not applicable.
         */
        function getDescriptionUrl() {
                return $this->repo->getDescriptionUrl( $this->getName() );
        }

        /**
         * Get the HTML text of the description page, if available
         * For local files ImagePage does not use it, because it skips the parser cache.
         */
        function getDescriptionText() {
                if( $this->isLocal() ) {
                        global $wgParser;
                        $revision = Revision::newFromTitle( $this->title );
                        if ( !$revision ) return false;
                        $text = $revision->getText();
                        if ( !$text ) return false;
                        $pout = $wgParser->parse( $text, $this->title, new ParserOptions() );
                        return $pout->getText();
                }

                global $wgMemc, $wgLang;
                if ( !$this->repo->fetchDescription ) {
                        return false;
                }
                $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $wgLang->getCode() );
                if ( $renderUrl ) {
                        if ( $this->repo->descriptionCacheExpiry > 0 ) {
                                wfDebug("Attempting to get the description from cache...");
                                $key = $this->repo->getLocalCacheKey( 'RemoteFileDescription', 'url', $wgLang->getCode(), 
                                                                        $this->getName() );
                                $obj = $wgMemc->get($key);
                                if ($obj) {
                                        wfDebug("success!\n");
                                        return $obj;
                                }
                                wfDebug("miss\n");
                        }
                        wfDebug( "Fetching shared description from $renderUrl\n" );
                        $res = Http::get( $renderUrl );
                        if ( $res && $this->repo->descriptionCacheExpiry > 0 ) {
                                $wgMemc->set( $key, $res, $this->repo->descriptionCacheExpiry );
                        }
                        return $res;
                } else {
                        return false;
                }
        }

        /**
         * Get discription of file revision
         * STUB
         */
        function getDescription() {
                return null;
        }

        /**
         * Get the 14-character timestamp of the file upload, or false if
         * it doesn't exist
         */
        function getTimestamp() {
                $path = $this->getPath();
                if ( !file_exists( $path ) ) {
                        return false;
                }
                return wfTimestamp( TS_MW, filemtime( $path ) );
        }

        /**
         * Get the SHA-1 base 36 hash of the file
         */
        function getSha1() {
                return self::sha1Base36( $this->getPath() );
        }

        /**
         * Get the deletion archive key, <sha1>.<ext>
         */
        function getStorageKey() {
                $hash = $this->getSha1();
                if ( !$hash ) {
                        return false;
                }
                $ext = $this->getExtension();
                $dotExt = $ext === '' ? '' : ".$ext";
                return $hash . $dotExt;                         
        }

        /**
         * Determine if the current user is allowed to view a particular
         * field of this file, if it's marked as deleted.
         * STUB
         * @param $field Integer
         * @return Boolean
         */
        function userCan( $field ) {
                return true;
        }

        /**
         * Get an associative array containing information about a file in the local filesystem.
         *
         * @param $path String: absolute local filesystem path
         * @param $ext Mixed: the file extension, or true to extract it from the filename.
         *             Set it to false to ignore the extension.
         */
        static function getPropsFromPath( $path, $ext = true ) {
                wfProfileIn( __METHOD__ );
                wfDebug( __METHOD__.": Getting file info for $path\n" );
                $info = array(
                        'fileExists' => file_exists( $path ) && !is_dir( $path )
                );
                $gis = false;
                if ( $info['fileExists'] ) {
                        $magic = MimeMagic::singleton();

                        if ( $ext === true ) {
                                $i = strrpos( $path, '.' );
                                $ext = strtolower( $i ? substr( $path, $i + 1 ) : '' );
                        }

                        # mime type according to file contents
                        $info['file-mime'] = $magic->guessMimeType( $path, false );
                        # logical mime type
                        $info['mime'] = $magic->improveTypeFromExtension( $info['file-mime'], $ext );

                        list( $info['major_mime'], $info['minor_mime'] ) = self::splitMime( $info['mime'] );
                        $info['media_type'] = $magic->getMediaType( $path, $info['mime'] );

                        # Get size in bytes
                        $info['size'] = filesize( $path );

                        # Height, width and metadata
                        $handler = MediaHandler::getHandler( $info['mime'] );
                        if ( $handler ) {
                                $tempImage = (object)array();
                                $info['metadata'] = $handler->getMetadata( $tempImage, $path );
                                $gis = $handler->getImageSize( $tempImage, $path, $info['metadata'] );
                        } else {
                                $gis = false;
                                $info['metadata'] = '';
                        }
                        $info['sha1'] = self::sha1Base36( $path );

                        wfDebug(__METHOD__.": $path loaded, {$info['size']} bytes, {$info['mime']}.\n");
                } else {
                        $info['mime'] = null;
                        $info['media_type'] = MEDIATYPE_UNKNOWN;
                        $info['metadata'] = '';
                        $info['sha1'] = '';
                        wfDebug(__METHOD__.": $path NOT FOUND!\n");
                }
                if( $gis ) {
                        # NOTE: $gis[2] contains a code for the image type. This is no longer used.
                        $info['width'] = $gis[0];
                        $info['height'] = $gis[1];
                        if ( isset( $gis['bits'] ) ) {
                                $info['bits'] = $gis['bits'];
                        } else {
                                $info['bits'] = 0;
                        }
                } else {
                        $info['width'] = 0;
                        $info['height'] = 0;
                        $info['bits'] = 0;
                }
                wfProfileOut( __METHOD__ );
                return $info;
        }

        /**
         * Get a SHA-1 hash of a file in the local filesystem, in base-36 lower case
         * encoding, zero padded to 31 digits.
         *
         * 160 log 2 / log 36 = 30.95, so the 160-bit hash fills 31 digits in base 36
         * fairly neatly.
         *
         * Returns false on failure
         */
        static function sha1Base36( $path ) {
                wfSuppressWarnings();
                $hash = sha1_file( $path );
                wfRestoreWarnings();
                if ( $hash === false ) {
                        return false;
                } else {
                        return wfBaseConvert( $hash, 16, 36, 31 );
                }
        }

        function getLongDesc() {
                $handler = $this->getHandler();
                if ( $handler ) {
                        return $handler->getLongDesc( $this );
                } else {
                        return MediaHandler::getGeneralLongDesc( $this );
                }
        }

        function getShortDesc() {
                $handler = $this->getHandler();
                if ( $handler ) {
                        return $handler->getShortDesc( $this );
                } else {
                        return MediaHandler::getGeneralShortDesc( $this );
                }
        }

        function getDimensionsString() {
                $handler = $this->getHandler();
                if ( $handler ) {
                        return $handler->getDimensionsString( $this );
                } else {
                        return '';
                }
        }

        function getRedirected() {
                return $this->redirected;
        }
        
        function getRedirectedTitle() {
                if ( $this->redirected ) {
                        if ( !$this->redirectTitle )
                                $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
                        return $this->redirectTitle;
                }
        }

        function redirectedFrom( $from ) {
                $this->redirected = $from;
        }

        function isMissing() {
                return false;
        }
}
/**
 * Aliases for backwards compatibility with 1.6
 */
define( 'MW_IMG_DELETED_FILE', File::DELETED_FILE );
define( 'MW_IMG_DELETED_COMMENT', File::DELETED_COMMENT );
define( 'MW_IMG_DELETED_USER', File::DELETED_USER );
define( 'MW_IMG_DELETED_RESTRICTED', File::DELETED_RESTRICTED );