FileBackendGroup.php

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<?php
class FileBackendGroup {
        protected static $instance = null;

        protected $backends = array();

        protected function __construct() {}

        public static function singleton() {
                if ( self::$instance == null ) {
                        self::$instance = new self();
                        self::$instance->initFromGlobals();
                }
                return self::$instance;
        }

        public static function destroySingleton() {
                self::$instance = null;
        }

        protected function initFromGlobals() {
                global $wgLocalFileRepo, $wgForeignFileRepos, $wgFileBackends;

                // Register explicitly defined backends
                $this->register( $wgFileBackends );

                $autoBackends = array();
                // Automatically create b/c backends for file repos...
                $repos = array_merge( $wgForeignFileRepos, array( $wgLocalFileRepo ) );
                foreach ( $repos as $info ) {
                        $backendName = $info['backend'];
                        if ( is_object( $backendName ) || isset( $this->backends[$backendName] ) ) {
                                continue; // already defined (or set to the object for some reason)
                        }
                        $repoName = $info['name'];
                        // Local vars that used to be FSRepo members...
                        $directory = $info['directory'];
                        $deletedDir = isset( $info['deletedDir'] )
                                ? $info['deletedDir']
                                : false; // deletion disabled
                        $thumbDir = isset( $info['thumbDir'] )
                                ? $info['thumbDir']
                                : "{$directory}/thumb";
                        $transcodedDir = isset( $info['transcodedDir'] )
                                ? $info['transcodedDir']
                                : "{$directory}/transcoded";
                        $fileMode = isset( $info['fileMode'] )
                                ? $info['fileMode']
                                : 0644;
                        // Get the FS backend configuration
                        $autoBackends[] = array(
                                'name'           => $backendName,
                                'class'          => 'FSFileBackend',
                                'lockManager'    => 'fsLockManager',
                                'containerPaths' => array(
                                        "{$repoName}-public"  => "{$directory}",
                                        "{$repoName}-thumb"   => $thumbDir,
                                        "{$repoName}-transcoded"   => $transcodedDir,
                                        "{$repoName}-deleted" => $deletedDir,
                                        "{$repoName}-temp"    => "{$directory}/temp"
                                ),
                                'fileMode'       => $fileMode,
                        );
                }

                // Register implicitly defined backends
                $this->register( $autoBackends );
        }

        protected function register( array $configs ) {
                foreach ( $configs as $config ) {
                        if ( !isset( $config['name'] ) ) {
                                throw new MWException( "Cannot register a backend with no name." );
                        }
                        $name = $config['name'];
                        if ( isset( $this->backends[$name] ) ) {
                                throw new MWException( "Backend with name `{$name}` already registered." );
                        } elseif ( !isset( $config['class'] ) ) {
                                throw new MWException( "Cannot register backend `{$name}` with no class." );
                        }
                        $class = $config['class'];

                        unset( $config['class'] ); // backend won't need this
                        $this->backends[$name] = array(
                                'class'    => $class,
                                'config'   => $config,
                                'instance' => null
                        );
                }
        }

        public function get( $name ) {
                if ( !isset( $this->backends[$name] ) ) {
                        throw new MWException( "No backend defined with the name `$name`." );
                }
                // Lazy-load the actual backend instance
                if ( !isset( $this->backends[$name]['instance'] ) ) {
                        $class = $this->backends[$name]['class'];
                        $config = $this->backends[$name]['config'];
                        $this->backends[$name]['instance'] = new $class( $config );
                }
                return $this->backends[$name]['instance'];
        }

        public function config( $name ) {
                if ( !isset( $this->backends[$name] ) ) {
                        throw new MWException( "No backend defined with the name `$name`." );
                }
                $class = $this->backends[$name]['class'];
                return array( 'class' => $class ) + $this->backends[$name]['config'];
        }

        public function backendFromPath( $storagePath ) {
                list( $backend, , ) = FileBackend::splitStoragePath( $storagePath );
                if ( $backend !== null && isset( $this->backends[$backend] ) ) {
                        return $this->get( $backend );
                }
                return null;
        }
}