LocalFile::restore(): roll back the DB transaction if the file is missing

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

<?php
/**
 */

/**
 * Bump this number when serialized cache records may be incompatible.
 */
define( 'MW_FILE_VERSION', 4 );

/**
 * Class to represent a local file in the wiki's own database
 *
 * Provides methods to retrieve paths (physical, logical, URL),
 * to generate image thumbnails or for uploading.
 *
 * 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.
 *
 * @addtogroup FileRepo
 */
class LocalFile extends File
{
        /**#@+
         * @private
         */
        var     $fileExists,    # does the file file exist on disk? (loadFromXxx)
                $historyLine,   # Number of line to return by nextHistoryLine() (constructor)
                $historyRes,    # result of the query for the file's history (nextHistoryLine)
                $width,         # \
                $height,        #  |
                $bits,          #   --- returned by getimagesize (loadFromXxx)
                $attr,          # /
                $media_type,    # MEDIATYPE_xxx (bitmap, drawing, audio...)
                $mime,          # MIME type, determined by MimeMagic::guessMimeType
                $major_mime,    # Major mime type
                $minor_mine,    # Minor mime type
                $size,          # Size in bytes (loadFromXxx)
                $metadata,      # Metadata
                $timestamp,     # Upload timestamp
                $dataLoaded,    # Whether or not all this has been loaded from the database (loadFromXxx)
                $upgraded;      # Whether the row was upgraded on load

        /**#@-*/

        /**
         * Create a LocalFile from a title
         * Do not call this except from inside a repo class.
         */
        function newFromTitle( $title, $repo ) {
                return new self( $title, $repo );
        }

        /**
         * Create a LocalFile from a title
         * Do not call this except from inside a repo class.
         */
        function newFromRow( $row, $repo ) {
                $title = Title::makeTitle( NS_IMAGE, $row->img_name );
                $file = new self( $title, $repo );
                $file->loadFromRow( $row );
                return $file;
        }

        /**
         * Constructor.
         * Do not call this except from inside a repo class.
         */
        function __construct( $title, $repo ) {
                if( !is_object( $title ) ) {
                        throw new MWException( __CLASS__.' constructor given bogus title.' );
                }
                parent::__construct( $title, $repo );
                $this->metadata = '';
                $this->historyLine = 0;
                $this->dataLoaded = false;
        }

        /**
         * Get the memcached key
         */
        function getCacheKey() {
                $hashedName = md5($this->getName());
                return wfMemcKey( 'file', $hashedName );
        }

        /**
         * Try to load file metadata from memcached. Returns true on success.
         */
        function loadFromCache() {
                global $wgMemc;
                wfProfileIn( __METHOD__ );
                $this->dataLoaded = false;
                $key = $this->getCacheKey();
                if ( !$key ) {
                        return false;
                }
                $cachedValues = $wgMemc->get( $key );

                // Check if the key existed and belongs to this version of MediaWiki
                if ( isset($cachedValues['version']) && ( $cachedValues['version'] == MW_FILE_VERSION ) ) {
                        wfDebug( "Pulling file metadata from cache key $key\n" );
                        $this->fileExists = $cachedValues['fileExists'];
                        if ( $this->fileExists ) {
                                unset( $cachedValues['version'] );
                                unset( $cachedValues['fileExists'] );
                                foreach ( $cachedValues as $name => $value ) {
                                        $this->$name = $value;
                                }
                        }
                }
                if ( $this->dataLoaded ) {
                        wfIncrStats( 'image_cache_hit' );
                } else {
                        wfIncrStats( 'image_cache_miss' );
                }

                wfProfileOut( __METHOD__ );
                return $this->dataLoaded;
        }

        /**
         * Save the file metadata to memcached
         */
        function saveToCache() {
                global $wgMemc;
                $this->load();
                $key = $this->getCacheKey();
                if ( !$key ) {
                        return;
                }
                $fields = $this->getCacheFields( '' );
                $cache = array( 'version' => MW_FILE_VERSION );
                $cache['fileExists'] = $this->fileExists;
                if ( $this->fileExists ) {
                        foreach ( $fields as $field ) {
                                $cache[$field] = $this->$field;
                        }
                }

                $wgMemc->set( $key, $cache, 60 * 60 * 24 * 7 ); // A week
        }

        /**
         * Load metadata from the file itself
         */
        function loadFromFile() {
                wfProfileIn( __METHOD__ );
                $path = $this->getPath();
                $this->fileExists = file_exists( $path );
                $gis = array();

                if ( $this->fileExists ) {
                        $magic=& MimeMagic::singleton();

                        $this->mime = $magic->guessMimeType($path,true);
                        list( $this->major_mime, $this->minor_mime ) = self::splitMime( $this->mime );
                        $this->media_type = $magic->getMediaType($path,$this->mime);
                        $handler = MediaHandler::getHandler( $this->mime );

                        # Get size in bytes
                        $this->size = filesize( $path );

                        # Height, width and metadata
                        if ( $handler ) {
                                $gis = $handler->getImageSize( $this, $path );
                                $this->metadata = $handler->getMetadata( $this, $path );
                        } else {
                                $gis = false;
                                $this->metadata = '';
                        }

                        wfDebug(__METHOD__.": $path loaded, {$this->size} bytes, {$this->mime}.\n");
                } else {
                        $this->mime = NULL;
                        $this->media_type = MEDIATYPE_UNKNOWN;
                        $this->metadata = '';
                        wfDebug(__METHOD__.": $path NOT FOUND!\n");
                }

                if( $gis ) {
                        $this->width = $gis[0];
                        $this->height = $gis[1];
                } else {
                        $this->width = 0;
                        $this->height = 0;
                }

                #NOTE: $gis[2] contains a code for the image type. This is no longer used.

                #NOTE: we have to set this flag early to avoid load() to be called
                # be some of the functions below. This may lead to recursion or other bad things!
                # as ther's only one thread of execution, this should be safe anyway.
                $this->dataLoaded = true;

                if ( isset( $gis['bits'] ) )  $this->bits = $gis['bits'];
                else $this->bits = 0;

                wfProfileOut( __METHOD__ );
        }

        function getCacheFields( $prefix = 'img_' ) {
                static $fields = array( 'size', 'width', 'height', 'bits', 'media_type', 
                        'major_mime', 'minor_mime', 'metadata', 'timestamp' );
                static $results = array();
                if ( $prefix == '' ) {
                        return $fields;
                }
                if ( !isset( $results[$prefix] ) ) {
                        $prefixedFields = array();
                        foreach ( $fields as $field ) {
                                $prefixedFields[] = $prefix . $field;
                        }
                        $results[$prefix] = $prefixedFields;
                }
                return $results[$prefix];
        }

        /**
         * Load file metadata from the DB
         */
        function loadFromDB() {
                wfProfileIn( __METHOD__ );

                # Unconditionally set loaded=true, we don't want the accessors constantly rechecking
                $this->dataLoaded = true;

                $dbr = $this->repo->getSlaveDB();

                $row = $dbr->selectRow( 'image', $this->getCacheFields( 'img_' ),
                        array( 'img_name' => $this->getName() ), __METHOD__ );
                if ( $row ) {
                        $this->loadFromRow( $row );
                } else {
                        $this->fileExists = false;
                }

                wfProfileOut( __METHOD__ );
        }

        /**
         * Decode a row from the database (either object or array) to an array 
         * with timestamps and MIME types decoded, and the field prefix removed.
         */
        function decodeRow( $row, $prefix = 'img_' ) {
                $array = (array)$row;
                $prefixLength = strlen( $prefix );
                // Sanity check prefix once
                if ( substr( key( $array ), 0, $prefixLength ) !== $prefix ) {
                        throw new MWException( __METHOD__. ': incorrect $prefix parameter' );
                }
                $decoded = array();
                foreach ( $array as $name => $value ) {
                        $deprefixedName = substr( $name, $prefixLength );
                        $decoded[substr( $name, $prefixLength )] = $value;
                }
                $decoded['timestamp'] = wfTimestamp( TS_MW, $decoded['timestamp'] );
                if ( empty( $decoded['major_mime'] ) ) {
                        $decoded['mime'] = "unknown/unknown";
                } else {
                        if (!$decoded['minor_mime']) {
                                $decoded['minor_mime'] = "unknown";
                        }
                        $decoded['mime'] = $decoded['major_mime'].'/'.$decoded['minor_mime'];
                }
                return $decoded;
        }

        /*
         * Load file metadata from a DB result row
         */
        function loadFromRow( $row, $prefix = 'img_' ) {
                $array = $this->decodeRow( $row, $prefix );
                foreach ( $array as $name => $value ) {
                        $this->$name = $value;
                }
                $this->fileExists = true;
                // Check for rows from a previous schema, quietly upgrade them
                $this->maybeUpgradeRow();
        }

        /**
         * Load file metadata from cache or DB, unless already loaded
         */
        function load() {
                if ( !$this->dataLoaded ) {
                        if ( !$this->loadFromCache() ) {
                                $this->loadFromDB();
                                $this->saveToCache();
                        }
                        $this->dataLoaded = true;
                }
        }

        /**
         * Upgrade a row if it needs it
         */
        function maybeUpgradeRow() {
                if ( wfReadOnly() ) {
                        return;
                }
                if ( is_null($this->media_type) || $this->mime == 'image/svg' ) {
                        $this->upgradeRow();
                        $this->upgraded = true;
                } else {
                        $handler = $this->getHandler();
                        if ( $handler && !$handler->isMetadataValid( $this, $this->metadata ) ) {
                                $this->upgradeRow();
                                $this->upgraded = true;
                        }
                }
        }

        function getUpgraded() {
                return $this->upgraded;
        }

        /**
         * Fix assorted version-related problems with the image row by reloading it from the file
         */
        function upgradeRow() {
                wfProfileIn( __METHOD__ );

                $this->loadFromFile();

                $dbw = $this->repo->getMasterDB();
                list( $major, $minor ) = self::splitMime( $this->mime );

                wfDebug(__METHOD__.': upgrading '.$this->getName()." to the current schema\n");

                $dbw->update( 'image',
                        array(
                                'img_width' => $this->width,
                                'img_height' => $this->height,
                                'img_bits' => $this->bits,
                                'img_media_type' => $this->media_type,
                                'img_major_mime' => $major,
                                'img_minor_mime' => $minor,
                                'img_metadata' => $this->metadata,
                        ), array( 'img_name' => $this->getName() ),
                        __METHOD__
                );
                $this->saveToCache();
                wfProfileOut( __METHOD__ );
        }

        /** splitMime inherited */
        /** getName inherited */
        /** getTitle inherited */
        /** getURL inherited */
        /** getViewURL inherited */
        /** getPath inherited */

        /**
         * Return the width of the image
         *
         * Returns false on error
         * @public
         */
        function getWidth( $page = 1 ) {
                $this->load();
                if ( $this->isMultipage() ) {
                        $dim = $this->getHandler()->getPageDimensions( $this, $page );
                        if ( $dim ) {
                                return $dim['width'];
                        } else {
                                return false;
                        }
                } else {
                        return $this->width;
                }
        }

        /**
         * Return the height of the image
         *
         * Returns false on error
         * @public
         */
        function getHeight( $page = 1 ) {
                $this->load();
                if ( $this->isMultipage() ) {
                        $dim = $this->getHandler()->getPageDimensions( $this, $page );
                        if ( $dim ) {
                                return $dim['height'];
                        } else {
                                return false;
                        }
                } else {
                        return $this->height;
                }
        }

        /**
         * Get handler-specific metadata
         */
        function getMetadata() {
                $this->load();
                return $this->metadata;
        }

        /**
         * Return the size of the image file, in bytes
         * @public
         */
        function getSize() {
                $this->load();
                return $this->size;
        }

        /**
         * Returns the mime type of the file.
         */
        function getMimeType() {
                $this->load();
                return $this->mime;
        }

        /**
         * Return the type of the media in the file.
         * Use the value returned by this function with the MEDIATYPE_xxx constants.
         */
        function getMediaType() {
                $this->load();
                return $this->media_type;
        }

        /** canRender inherited */
        /** mustRender inherited */
        /** allowInlineDisplay inherited */
        /** isSafeFile inherited */
        /** isTrustedFile inherited */

        /**
         * Returns true if the file file exists on disk.
         * @return boolean Whether file file exist on disk.
         * @public
         */
        function exists() {
                $this->load();
                return $this->fileExists;
        }

        /** getTransformScript inherited */
        /** getUnscaledThumb inherited */
        /** thumbName inherited */
        /** createThumb inherited */
        /** getThumbnail inherited */
        /** transform inherited */
        
        /**
         * Fix thumbnail files from 1.4 or before, with extreme prejudice
         */
        function migrateThumbFile( $thumbName ) {
                $thumbDir = $this->getThumbPath();
                $thumbPath = "$thumbDir/$thumbName";
                if ( is_dir( $thumbPath ) ) {
                        // Directory where file should be
                        // This happened occasionally due to broken migration code in 1.5
                        // Rename to broken-*
                        for ( $i = 0; $i < 100 ; $i++ ) {
                                $broken = $this->repo->getZonePath('public') . "/broken-$i-$thumbName";
                                if ( !file_exists( $broken ) ) {
                                        rename( $thumbPath, $broken );
                                        break;
                                }
                        }
                        // Doesn't exist anymore
                        clearstatcache();
                }
                if ( is_file( $thumbDir ) ) {
                        // File where directory should be
                        unlink( $thumbDir );
                        // Doesn't exist anymore
                        clearstatcache();
                }
        }

        /** getHandler inherited */
        /** iconThumb inherited */
        /** getLastError inherited */

        /**
         * Get all thumbnail names previously generated for this file
         */
        function getThumbnails() {
                if ( $this->isHashed() ) {
                        $this->load();
                        $files = array();
                        $dir = $this->getThumbPath();

                        if ( is_dir( $dir ) ) {
                                $handle = opendir( $dir );

                                if ( $handle ) {
                                        while ( false !== ( $file = readdir($handle) ) ) {
                                                if ( $file{0} != '.' ) {
                                                        $files[] = $file;
                                                }
                                        }
                                        closedir( $handle );
                                }
                        }
                } else {
                        $files = array();
                }

                return $files;
        }

        /**
         * Refresh metadata in memcached, but don't touch thumbnails or squid
         */
        function purgeMetadataCache() {
                clearstatcache();
                $this->loadFromFile();
                $this->saveToCache();
        }

        /**
         * Delete all previously generated thumbnails, refresh metadata in memcached and purge the squid
         */
        function purgeCache( $archiveFiles = array() ) {
                global $wgUseSquid;

                // Refresh metadata cache
                $this->purgeMetadataCache();

                // Delete thumbnails
                $files = $this->getThumbnails();
                $dir = $this->getThumbPath();
                $urls = array();
                foreach ( $files as $file ) {
                        $m = array();
                        # Check that the base file name is part of the thumb name
                        # This is a basic sanity check to avoid erasing unrelated directories
                        if ( strpos( $file, $this->getName() ) !== false ) {
                                $url = $this->getThumbUrl( $file );
                                $urls[] = $url;
                                @unlink( "$dir/$file" );
                        }
                }

                // Purge the squid
                if ( $wgUseSquid ) {
                        $urls[] = $this->getURL();
                        foreach ( $archiveFiles as $file ) {
                                $urls[] = $this->getArchiveUrl( $file );
                        }
                        wfPurgeSquidServers( $urls );
                }
        }

        /** purgeDescription inherited */
        /** purgeEverything inherited */

        /**
         * Return the history of this file, line by line.
         * starts with current version, then old versions.
         * uses $this->historyLine to check which line to return:
         *  0      return line for current version
         *  1      query for old versions, return first one
         *  2, ... return next old version from above query
         *
         * @public
         */
        function nextHistoryLine() {
                $dbr = $this->repo->getSlaveDB();

                if ( $this->historyLine == 0 ) {// called for the first time, return line from cur
                        $this->historyRes = $dbr->select( 'image',
                                array(
                                        'img_size',
                                        'img_description',
                                        'img_user','img_user_text',
                                        'img_timestamp',
                                        'img_width',
                                        'img_height',
                                        "'' AS oi_archive_name"
                                ),
                                array( 'img_name' => $this->title->getDBkey() ),
                                __METHOD__
                        );
                        if ( 0 == $dbr->numRows( $this->historyRes ) ) {
                                return FALSE;
                        }
                } else if ( $this->historyLine == 1 ) {
                        $this->historyRes = $dbr->select( 'oldimage',
                                array(
                                        'oi_size AS img_size',
                                        'oi_description AS img_description',
                                        'oi_user AS img_user',
                                        'oi_user_text AS img_user_text',
                                        'oi_timestamp AS img_timestamp',
                                        'oi_width as img_width',
                                        'oi_height as img_height',
                                        'oi_archive_name'
                                ),
                                array( 'oi_name' => $this->title->getDBkey() ),
                                __METHOD__,
                                array( 'ORDER BY' => 'oi_timestamp DESC' )
                        );
                }
                $this->historyLine ++;

                return $dbr->fetchObject( $this->historyRes );
        }

        /**
         * Reset the history pointer to the first element of the history
         * @public
         */
        function resetHistory() {
                $this->historyLine = 0;
        }

        /** getFullPath inherited */
        /** getHashPath inherited */
        /** getRel inherited */
        /** getUrlRel inherited */
        /** getArchivePath inherited */
        /** getThumbPath inherited */
        /** getArchiveUrl inherited */
        /** getThumbUrl inherited */
        /** getArchiveVirtualUrl inherited */
        /** getThumbVirtualUrl inherited */
        /** isHashed inherited */

        /**
         * Record a file upload in the upload log and the image table
         */
        function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', 
                $watch = false, $timestamp = false ) 
        {
                global $wgUser, $wgUseCopyrightUpload;

                $dbw = $this->repo->getMasterDB();

                // Delete thumbnails and refresh the metadata cache
                $this->purgeCache();

                // Fail now if the file isn't there
                if ( !$this->fileExists ) {
                        wfDebug( __METHOD__.": File ".$this->getPath()." went missing!\n" );
                        return false;
                }

                if ( $wgUseCopyrightUpload ) {
                        if ( $license != '' ) {
                                $licensetxt = '== ' . wfMsgForContent( 'license' ) . " ==\n" . '{{' . $license . '}}' . "\n";
                        }
                        $textdesc = '== ' . wfMsg ( 'filedesc' ) . " ==\n" . $desc . "\n" .
                          '== ' . wfMsgForContent ( 'filestatus' ) . " ==\n" . $copyStatus . "\n" .
                          "$licensetxt" .
                          '== ' . wfMsgForContent ( 'filesource' ) . " ==\n" . $source ;
                } else {
                        if ( $license != '' ) {
                                $filedesc = $desc == '' ? '' : '== ' . wfMsg ( 'filedesc' ) . " ==\n" . $desc . "\n";
                                 $textdesc = $filedesc .
                                         '== ' . wfMsgForContent ( 'license' ) . " ==\n" . '{{' . $license . '}}' . "\n";
                        } else {
                                $textdesc = $desc;
                        }
                }

                if ( $timestamp === false ) {
                        $timestamp = $dbw->timestamp();
                }

                #split mime type
                if (strpos($this->mime,'/')!==false) {
                        list($major,$minor)= explode('/',$this->mime,2);
                }
                else {
                        $major= $this->mime;
                        $minor= "unknown";
                }

                # Test to see if the row exists using INSERT IGNORE
                # This avoids race conditions by locking the row until the commit, and also
                # doesn't deadlock. SELECT FOR UPDATE causes a deadlock for every race condition.
                $dbw->insert( 'image',
                        array(
                                'img_name' => $this->getName(),
                                'img_size'=> $this->size,
                                'img_width' => intval( $this->width ),
                                'img_height' => intval( $this->height ),
                                'img_bits' => $this->bits,
                                'img_media_type' => $this->media_type,
                                'img_major_mime' => $major,
                                'img_minor_mime' => $minor,
                                'img_timestamp' => $timestamp,
                                'img_description' => $desc,
                                'img_user' => $wgUser->getID(),
                                'img_user_text' => $wgUser->getName(),
                                'img_metadata' => $this->metadata,
                        ),
                        __METHOD__,
                        'IGNORE'
                );

                if( $dbw->affectedRows() == 0 ) {
                        # Collision, this is an update of a file
                        # Insert previous contents into oldimage
                        $dbw->insertSelect( 'oldimage', 'image',
                                array(
                                        'oi_name' => 'img_name',
                                        'oi_archive_name' => $dbw->addQuotes( $oldver ),
                                        'oi_size' => 'img_size',
                                        'oi_width' => 'img_width',
                                        'oi_height' => 'img_height',
                                        'oi_bits' => 'img_bits',
                                        'oi_timestamp' => 'img_timestamp',
                                        'oi_description' => 'img_description',
                                        'oi_user' => 'img_user',
                                        'oi_user_text' => 'img_user_text',
                                ), array( 'img_name' => $this->getName() ), __METHOD__
                        );

                        # Update the current image row
                        $dbw->update( 'image',
                                array( /* SET */
                                        'img_size' => $this->size,
                                        'img_width' => intval( $this->width ),
                                        'img_height' => intval( $this->height ),
                                        'img_bits' => $this->bits,
                                        'img_media_type' => $this->media_type,
                                        'img_major_mime' => $major,
                                        'img_minor_mime' => $minor,
                                        'img_timestamp' => $timestamp,
                                        'img_description' => $desc,
                                        'img_user' => $wgUser->getID(),
                                        'img_user_text' => $wgUser->getName(),
                                        'img_metadata' => $this->metadata,
                                ), array( /* WHERE */
                                        'img_name' => $this->getName()
                                ), __METHOD__
                        );
                } else {
                        # This is a new file
                        # Update the image count
                        $site_stats = $dbw->tableName( 'site_stats' );
                        $dbw->query( "UPDATE $site_stats SET ss_images=ss_images+1", __METHOD__ );
                }

                $descTitle = $this->getTitle();
                $article = new Article( $descTitle );
                $minor = false;
                $watch = $watch || $wgUser->isWatched( $descTitle );
                $suppressRC = true; // There's already a log entry, so don't double the RC load

                if( $descTitle->exists() ) {
                        // TODO: insert a null revision into the page history for this update.
                        if( $watch ) {
                                $wgUser->addWatch( $descTitle );
                        }

                        # Invalidate the cache for the description page
                        $descTitle->invalidateCache();
                        $descTitle->purgeSquid();
                } else {
                        // New file; create the description page.
                        $article->insertNewArticle( $textdesc, $desc, $minor, $watch, $suppressRC );
                }

                # Hooks, hooks, the magic of hooks...
                wfRunHooks( 'FileUpload', array( $this ) );

                # Add the log entry
                $log = new LogPage( 'upload' );
                $log->addEntry( 'upload', $descTitle, $desc );

                # Commit the transaction now, in case something goes wrong later
                # The most important thing is that files don't get lost, especially archives
                $dbw->immediateCommit();

                # Invalidate cache for all pages using this file
                $update = new HTMLCacheUpdate( $this->getTitle(), 'imagelinks' );
                $update->doUpdate();

                return true;
        }

        /**
         * Move or copy a file to its public location. If a file exists at the  
         * destination, move it to an archive. Returns the archive name on success 
         * or an empty string if it was a new file, and a wikitext-formatted 
         * WikiError object on failure. 
         *
         * The archive name should be passed through to recordUpload for database
         * registration.
         *
         * @param string $sourcePath Local filesystem path to the source image
         * @param integer $flags A bitwise combination of:
         *     File::DELETE_SOURCE    Delete the source file, i.e. move 
         *         rather than copy
         * @return The archive name on success or an empty string if it was a new 
         *     file, and a wikitext-formatted WikiError object on failure. 
         */
        function publish( $srcPath, $flags = 0 ) {
                $dstPath = $this->getFullPath();
                $archiveName = gmdate( 'YmdHis' ) . '!'. $this->getName();
                $archivePath = $this->getArchivePath( $archiveName );
                $flags = $flags & File::DELETE_SOURCE ? LocalRepo::DELETE_SOURCE : 0;
                $status = $this->repo->publish( $srcPath, $dstPath, $archivePath, $flags );
                if ( WikiError::isError( $status ) ) {
                        return $status;
                } elseif ( $status == 'new' ) {
                        return '';
                } else {
                        return $archiveName;
                }
        }

        /** getLinksTo inherited */
        /** getExifData inherited */
        /** isLocal inherited */
        /** wasDeleted inherited */
        
        /**
         * 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
         * @return true on success, false on some kind of failure
         */
        function delete( $reason, $suppress=false ) {
                $transaction = new FSTransaction();
                $urlArr = array( $this->getURL() );

                if( !FileStore::lock() ) {
                        wfDebug( __METHOD__.": failed to acquire file store lock, aborting\n" );
                        return false;
                }

                try {
                        $dbw = $this->repo->getMasterDB();
                        $dbw->begin();

                        // Delete old versions
                        $result = $dbw->select( 'oldimage',
                                array( 'oi_archive_name' ),
                                array( 'oi_name' => $this->getName() ) );

                        while( $row = $dbw->fetchObject( $result ) ) {
                                $oldName = $row->oi_archive_name;

                                $transaction->add( $this->prepareDeleteOld( $oldName, $reason, $suppress ) );

                                // We'll need to purge this URL from caches...
                                $urlArr[] = $this->getArchiveUrl( $oldName );
                        }
                        $dbw->freeResult( $result );

                        // And the current version...
                        $transaction->add( $this->prepareDeleteCurrent( $reason, $suppress ) );

                        $dbw->immediateCommit();
                } catch( MWException $e ) {
                        wfDebug( __METHOD__.": db error, rolling back file transactions\n" );
                        $transaction->rollback();
                        FileStore::unlock();
                        throw $e;
                }

                wfDebug( __METHOD__.": deleted db items, applying file transactions\n" );
                $transaction->commit();
                FileStore::unlock();


                // Update site_stats
                $site_stats = $dbw->tableName( 'site_stats' );
                $dbw->query( "UPDATE $site_stats SET ss_images=ss_images-1", __METHOD__ );

                $this->purgeEverything( $urlArr );

                return true;
        }


        /**
         * Delete an old version of the file.
         *
         * Moves the file into an archive directory (or deletes it)
         * and removes the database row.
         *
         * Cache purging is done; logging is caller's responsibility.
         *
         * @param $reason
         * @throws MWException or FSException on database or filestore failure
         * @return true on success, false on some kind of failure
         */
        function deleteOld( $archiveName, $reason, $suppress=false ) {
                $transaction = new FSTransaction();
                $urlArr = array();

                if( !FileStore::lock() ) {
                        wfDebug( __METHOD__.": failed to acquire file store lock, aborting\n" );
                        return false;
                }

                $transaction = new FSTransaction();
                try {
                        $dbw = $this->repo->getMasterDB();
                        $dbw->begin();
                        $transaction->add( $this->prepareDeleteOld( $archiveName, $reason, $suppress ) );
                        $dbw->immediateCommit();
                } catch( MWException $e ) {
                        wfDebug( __METHOD__.": db error, rolling back file transaction\n" );
                        $transaction->rollback();
                        FileStore::unlock();
                        throw $e;
                }

                wfDebug( __METHOD__.": deleted db items, applying file transaction\n" );
                $transaction->commit();
                FileStore::unlock();

                $this->purgeDescription();

                // Squid purging
                global $wgUseSquid;
                if ( $wgUseSquid ) {
                        $urlArr = array(
                                $this->getArchiveUrl( $archiveName ),
                        );
                        wfPurgeSquidServers( $urlArr );
                }
                return true;
        }

        /**
         * Delete the current version of a file.
         * May throw a database error.
         * @return true on success, false on failure
         */
        private function prepareDeleteCurrent( $reason, $suppress=false ) {
                return $this->prepareDeleteVersion(
                        $this->getFullPath(),
                        $reason,
                        'image',
                        array(
                                'fa_name'         => 'img_name',
                                'fa_archive_name' => 'NULL',
                                'fa_size'         => 'img_size',
                                'fa_width'        => 'img_width',
                                'fa_height'       => 'img_height',
                                'fa_metadata'     => 'img_metadata',
                                'fa_bits'         => 'img_bits',
                                'fa_media_type'   => 'img_media_type',
                                'fa_major_mime'   => 'img_major_mime',
                                'fa_minor_mime'   => 'img_minor_mime',
                                'fa_description'  => 'img_description',
                                'fa_user'         => 'img_user',
                                'fa_user_text'    => 'img_user_text',
                                'fa_timestamp'    => 'img_timestamp' ),
                        array( 'img_name' => $this->getName() ),
                        $suppress,
                        __METHOD__ );
        }

        /**
         * Delete a given older version of a file.
         * May throw a database error.
         * @return true on success, false on failure
         */
        private function prepareDeleteOld( $archiveName, $reason, $suppress=false ) {
                $oldpath = $this->getArchivePath() .
                        DIRECTORY_SEPARATOR . $archiveName;
                return $this->prepareDeleteVersion(
                        $oldpath,
                        $reason,
                        'oldimage',
                        array(
                                'fa_name'         => 'oi_name',
                                'fa_archive_name' => 'oi_archive_name',
                                'fa_size'         => 'oi_size',
                                'fa_width'        => 'oi_width',
                                'fa_height'       => 'oi_height',
                                'fa_metadata'     => 'NULL',
                                'fa_bits'         => 'oi_bits',
                                'fa_media_type'   => 'NULL',
                                'fa_major_mime'   => 'NULL',
                                'fa_minor_mime'   => 'NULL',
                                'fa_description'  => 'oi_description',
                                'fa_user'         => 'oi_user',
                                'fa_user_text'    => 'oi_user_text',
                                'fa_timestamp'    => 'oi_timestamp' ),
                        array(
                                'oi_name' => $this->getName(),
                                'oi_archive_name' => $archiveName ),
                        $suppress,
                        __METHOD__ );
        }

        /**
         * Do the dirty work of backing up an image row and its file
         * (if $wgSaveDeletedFiles is on) and removing the originals.
         *
         * Must be run while the file store is locked and a database
         * transaction is open to avoid race conditions.
         *
         * @return FSTransaction
         */
        private function prepareDeleteVersion( $path, $reason, $table, $fieldMap, $where, $suppress=false, $fname ) {
                global $wgUser, $wgSaveDeletedFiles;

                // Dupe the file into the file store
                if( file_exists( $path ) ) {
                        if( $wgSaveDeletedFiles ) {
                                $group = 'deleted';

                                $store = FileStore::get( $group );
                                $key = FileStore::calculateKey( $path, $this->getExtension() );
                                $transaction = $store->insert( $key, $path,
                                        FileStore::DELETE_ORIGINAL );
                        } else {
                                $group = null;
                                $key = null;
                                $transaction = FileStore::deleteFile( $path );
                        }
                } else {
                        wfDebug( __METHOD__." deleting already-missing '$path'; moving on to database\n" );
                        $group = null;
                        $key = null;
                        $transaction = new FSTransaction(); // empty
                }

                if( $transaction === false ) {
                        // Fail to restore?
                        wfDebug( __METHOD__.": import to file store failed, aborting\n" );
                        throw new MWException( "Could not archive and delete file $path" );
                        return false;
                }
                
                // Bitfields to further supress the file content
                // Note that currently, live files are stored elsewhere
                // and cannot be partially deleted
                $bitfield = 0;
                if ( $suppress ) {
                        $bitfield |= self::DELETED_FILE;
                        $bitfield |= self::DELETED_COMMENT;
                        $bitfield |= self::DELETED_USER;
                        $bitfield |= self::DELETED_RESTRICTED;
                }

                $dbw = $this->repo->getMasterDB();
                $storageMap = array(
                        'fa_storage_group' => $dbw->addQuotes( $group ),
                        'fa_storage_key'   => $dbw->addQuotes( $key ),

                        'fa_deleted_user'      => $dbw->addQuotes( $wgUser->getId() ),
                        'fa_deleted_timestamp' => $dbw->timestamp(),
                        'fa_deleted_reason'    => $dbw->addQuotes( $reason ),
                        'fa_deleted'               => $bitfield);
                $allFields = array_merge( $storageMap, $fieldMap );

                try {
                        if( $wgSaveDeletedFiles ) {
                                $dbw->insertSelect( 'filearchive', $table, $allFields, $where, $fname );
                        }
                        $dbw->delete( $table, $where, $fname );
                } catch( DBQueryError $e ) {
                        // Something went horribly wrong!
                        // Leave the file as it was...
                        wfDebug( __METHOD__.": database error, rolling back file transaction\n" );
                        $transaction->rollback();
                        throw $e;
                }

                return $transaction;
        }

        /**
         * 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.
         * @return the number of file revisions restored if successful,
         *         or false on failure
         */
        function restore( $versions=array(), $Unsuppress=false ) {
                global $wgUser;
        
                if( !FileStore::lock() ) {
                        wfDebug( __METHOD__." could not acquire filestore lock\n" );
                        return false;
                }

                $transaction = new FSTransaction();
                try {
                        $dbw = $this->repo->getMasterDB();
                        $dbw->begin();

                        // Re-confirm whether this file presently exists;
                        // if no we'll need to create an file record for the
                        // first item we restore.
                        $exists = $dbw->selectField( 'image', '1',
                                array( 'img_name' => $this->getName() ),
                                __METHOD__ );

                        // Fetch all or selected archived revisions for the file,
                        // sorted from the most recent to the oldest.
                        $conditions = array( 'fa_name' => $this->getName() );
                        if( $versions ) {
                                $conditions['fa_id'] = $versions;
                        }

                        $result = $dbw->select( 'filearchive', '*',
                                $conditions,
                                __METHOD__,
                                array( 'ORDER BY' => 'fa_timestamp DESC' ) );

                        if( $dbw->numRows( $result ) < count( $versions ) ) {
                                // There's some kind of conflict or confusion;
                                // we can't restore everything we were asked to.
                                wfDebug( __METHOD__.": couldn't find requested items\n" );
                                $dbw->rollback();
                                FileStore::unlock();
                                return false;
                        }

                        if( $dbw->numRows( $result ) == 0 ) {
                                // Nothing to do.
                                wfDebug( __METHOD__.": nothing to do\n" );
                                $dbw->rollback();
                                FileStore::unlock();
                                return true;
                        }

                        $revisions = 0;
                        while( $row = $dbw->fetchObject( $result ) ) {
                                if ( $Unsuppress ) {
                                // Currently, fa_deleted flags fall off upon restore, lets be careful about this
                                } else if ( ($row->fa_deleted & Revision::DELETED_RESTRICTED) && !$wgUser->isAllowed('hiderevision') ) {
                                // Skip restoring file revisions that the user cannot restore
                                        continue;
                                }
                                $revisions++;
                                $store = FileStore::get( $row->fa_storage_group );
                                if( !$store ) {
                                        wfDebug( __METHOD__.": skipping row with no file.\n" );
                                        continue;
                                }

                                $restoredImage = new self( Title::makeTitle( NS_IMAGE, $row->fa_name ), $this->repo );

                                if( $revisions == 1 && !$exists ) {
                                        $destPath = $restoredImage->getFullPath();
                                        $destDir = dirname( $destPath );
                                        if ( !is_dir( $destDir ) ) {
                                                wfMkdirParents( $destDir );
                                        }

                                        // We may have to fill in data if this was originally
                                        // an archived file revision.
                                        if( is_null( $row->fa_metadata ) ) {
                                                $tempFile = $store->filePath( $row->fa_storage_key );

                                                $magic = MimeMagic::singleton();
                                                $mime = $magic->guessMimeType( $tempFile, true );
                                                $media_type = $magic->getMediaType( $tempFile, $mime );
                                                list( $major_mime, $minor_mime ) = self::splitMime( $mime );
                                                $handler = MediaHandler::getHandler( $mime );
                                                if ( $handler ) {
                                                        $metadata = $handler->getMetadata( false, $tempFile );
                                                } else {
                                                        $metadata = '';
                                                }
                                        } else {
                                                $metadata   = $row->fa_metadata;
                                                $major_mime = $row->fa_major_mime;
                                                $minor_mime = $row->fa_minor_mime;
                                                $media_type = $row->fa_media_type;
                                        }

                                        $table = 'image';
                                        $fields = array(
                                                'img_name'        => $row->fa_name,
                                                'img_size'        => $row->fa_size,
                                                'img_width'       => $row->fa_width,
                                                'img_height'      => $row->fa_height,
                                                'img_metadata'    => $metadata,
                                                'img_bits'        => $row->fa_bits,
                                                'img_media_type'  => $media_type,
                                                'img_major_mime'  => $major_mime,
                                                'img_minor_mime'  => $minor_mime,
                                                'img_description' => $row->fa_description,
                                                'img_user'        => $row->fa_user,
                                                'img_user_text'   => $row->fa_user_text,
                                                'img_timestamp'   => $row->fa_timestamp );
                                } else {
                                        $archiveName = $row->fa_archive_name;
                                        if( $archiveName == '' ) {
                                                // This was originally a current version; we
                                                // have to devise a new archive name for it.
                                                // Format is <timestamp of archiving>!<name>
                                                $archiveName =
                                                        wfTimestamp( TS_MW, $row->fa_deleted_timestamp ) .
                                                        '!' . $row->fa_name;
                                        }
                                        $destDir = $restoredImage->getArchivePath();
                                        if ( !is_dir( $destDir ) ) {
                                                wfMkdirParents( $destDir );
                                        }
                                        $destPath = $destDir . DIRECTORY_SEPARATOR . $archiveName;

                                        $table = 'oldimage';
                                        $fields = array(
                                                'oi_name'         => $row->fa_name,
                                                'oi_archive_name' => $archiveName,
                                                'oi_size'         => $row->fa_size,
                                                'oi_width'        => $row->fa_width,
                                                'oi_height'       => $row->fa_height,
                                                'oi_bits'         => $row->fa_bits,
                                                'oi_description'  => $row->fa_description,
                                                'oi_user'         => $row->fa_user,
                                                'oi_user_text'    => $row->fa_user_text,
                                                'oi_timestamp'    => $row->fa_timestamp );
                                }

                                $dbw->insert( $table, $fields, __METHOD__ );
                                // @todo this delete is not totally safe, potentially
                                $dbw->delete( 'filearchive',
                                        array( 'fa_id' => $row->fa_id ),
                                        __METHOD__ );

                                // Check if any other stored revisions use this file;
                                // if so, we shouldn't remove the file from the deletion
                                // archives so they will still work.
                                $useCount = $dbw->selectField( 'filearchive',
                                        'COUNT(*)',
                                        array(
                                                'fa_storage_group' => $row->fa_storage_group,
                                                'fa_storage_key'   => $row->fa_storage_key ),
                                        __METHOD__ );
                                if( $useCount == 0 ) {
                                        wfDebug( __METHOD__.": nothing else using {$row->fa_storage_key}, will deleting after\n" );
                                        $flags = FileStore::DELETE_ORIGINAL;
                                } else {
                                        $flags = 0;
                                }

                                $transaction->add( $store->export( $row->fa_storage_key,
                                        $destPath, $flags ) );
                        }

                        $dbw->immediateCommit();
                } catch( MWException $e ) {
                        wfDebug( __METHOD__." caught error, aborting\n" );
                        $transaction->rollback();
                        $dbw->rollback();
                        throw $e;
                }

                $transaction->commit();
                FileStore::unlock();

                if( $revisions > 0 ) {
                        if( !$exists ) {
                                wfDebug( __METHOD__." restored $revisions items, creating a new current\n" );

                                // Update site_stats
                                $site_stats = $dbw->tableName( 'site_stats' );
                                $dbw->query( "UPDATE $site_stats SET ss_images=ss_images+1", __METHOD__ );

                                $this->purgeEverything();
                        } else {
                                wfDebug( __METHOD__." restored $revisions as archived versions\n" );
                                $this->purgeDescription();
                        }
                }

                return $revisions;
        }

        /** isMultipage inherited */
        /** pageCount inherited */
        /** scaleHeight inherited */
        /** getImageSize inherited */
        
        /**
         * Get the URL of the file description page. 
         */
        function getDescriptionUrl() {
                return $this->title->getLocalUrl();
        }

        /**
         * Get the HTML text of the description page
         * This is not used by ImagePage for local files, since (among other things)
         * it skips the parser cache.
         */
        function getDescriptionText() {
                global $wgParser;
                $revision = Revision::newFromTitle( $this->title );
                if ( !$revision ) return false;
                $text = $revision->getText();
                if ( !$text ) return false;
                $html = $wgParser->parse( $text, new ParserOptions );
                return $html;
        }

        function getTimestamp() {
                $this->load();
                return $this->timestamp;
        }
} // LocalFile class

/**
 * Backwards compatibility class
 */
class Image extends LocalFile {
        function __construct( $title ) {
                $repo = RepoGroup::singleton()->getLocalRepo();
                parent::__construct( $title, $repo );
        }

        /**
         * Wrapper for wfFindFile(), for backwards-compatibility only
         * Do not use in core code.
         * @deprecated
         */
        function newFromTitle( $title, $time = false ) {
                $img = wfFindFile( $title, $time );
                if ( !$img ) {
                        $img = wfLocalFile( $title );
                }
                return $img;
        }
        
        /**
         * Return the URL of an image, provided its name.
         *
         * Backwards-compatibility for extensions.
         * Note that fromSharedDirectory will only use the shared path for files
         * that actually exist there now, and will return local paths otherwise.
         *
         * @param string $name  Name of the image, without the leading "Image:"
         * @param boolean $fromSharedDirectory  Should this be in $wgSharedUploadPath?
         * @return string URL of $name image
         * @deprecated
         */
        static function imageUrl( $name, $fromSharedDirectory = false ) {
                $image = null;
                if( $fromSharedDirectory ) {
                        $image = wfFindFile( $name );
                }
                if( !$image ) {
                        $image = wfLocalFile( $name );
                }
                return $image->getUrl();
        }
}

/**
 * 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 );

?>