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;
    }
}