Maintenance.php

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<?php
// Make sure we're on PHP5.3.2 or better
if ( !function_exists( 'version_compare' ) || version_compare( PHP_VERSION, '5.3.2' ) < 0 ) {
        // We need to use dirname( __FILE__ ) here cause __DIR__ is PHP5.3+
        require_once( dirname( __FILE__ ) . '/../includes/PHPVersionError.php' );
        wfPHPVersionError( 'cli' );
}

// Define this so scripts can easily find doMaintenance.php
define( 'RUN_MAINTENANCE_IF_MAIN', __DIR__ . '/doMaintenance.php' );
define( 'DO_MAINTENANCE', RUN_MAINTENANCE_IF_MAIN ); // original name, harmless

$maintClass = false;

abstract class Maintenance {

        const DB_NONE  = 0;
        const DB_STD   = 1;
        const DB_ADMIN = 2;

        // Const for getStdin()
        const STDIN_ALL = 'all';

        // This is the desired params
        protected $mParams = array();

        // Array of mapping short parameters to long ones
        protected $mShortParamsMap = array();

        // Array of desired args
        protected $mArgList = array();

        // This is the list of options that were actually passed
        protected $mOptions = array();

        // This is the list of arguments that were actually passed
        protected $mArgs = array();

        // Name of the script currently running
        protected $mSelf;

        // Special vars for params that are always used
        protected $mQuiet = false;
        protected $mDbUser, $mDbPass;

        // A description of the script, children should change this
        protected $mDescription = '';

        // Have we already loaded our user input?
        protected $mInputLoaded = false;

        protected $mBatchSize = null;

        // Generic options added by addDefaultParams()
        private $mGenericParameters = array();
        // Generic options which might or not be supported by the script
        private $mDependantParameters = array();

        private $mDb = null;

        public $fileHandle;

        protected static $mCoreScripts = null;

        public function __construct() {
                // Setup $IP, using MW_INSTALL_PATH if it exists
                global $IP;
                $IP = strval( getenv( 'MW_INSTALL_PATH' ) ) !== ''
                        ? getenv( 'MW_INSTALL_PATH' )
                        : realpath( __DIR__ . '/..' );

                $this->addDefaultParams();
                register_shutdown_function( array( $this, 'outputChanneled' ), false );
        }

        public static function shouldExecute() {
                $bt = debug_backtrace();
                $count = count( $bt );
                if ( $count < 2 ) {
                        return false; // sanity
                }
                if ( $bt[0]['class'] !== 'Maintenance' || $bt[0]['function'] !== 'shouldExecute' ) {
                        return false; // last call should be to this function
                }
                $includeFuncs = array( 'require_once', 'require', 'include', 'include_once' );
                for( $i=1; $i < $count; $i++ ) {
                        if ( !in_array( $bt[$i]['function'], $includeFuncs ) ) {
                                return false; // previous calls should all be "requires"
                        }
                }
                return true;
        }

        abstract public function execute();

        protected function addOption( $name, $description, $required = false, $withArg = false, $shortName = false ) {
                $this->mParams[$name] = array( 'desc' => $description, 'require' => $required, 'withArg' => $withArg, 'shortName' => $shortName );
                if ( $shortName !== false ) {
                        $this->mShortParamsMap[$shortName] = $name;
                }
        }

        protected function hasOption( $name ) {
                return isset( $this->mOptions[$name] );
        }

        protected function getOption( $name, $default = null ) {
                if ( $this->hasOption( $name ) ) {
                        return $this->mOptions[$name];
                } else {
                        // Set it so we don't have to provide the default again
                        $this->mOptions[$name] = $default;
                        return $this->mOptions[$name];
                }
        }

        protected function addArg( $arg, $description, $required = true ) {
                $this->mArgList[] = array(
                        'name' => $arg,
                        'desc' => $description,
                        'require' => $required
                );
        }

        protected function deleteOption( $name ) {
                unset( $this->mParams[$name] );
        }

        protected function addDescription( $text ) {
                $this->mDescription = $text;
        }

        protected function hasArg( $argId = 0 ) {
                return isset( $this->mArgs[$argId] );
        }

        protected function getArg( $argId = 0, $default = null ) {
                return $this->hasArg( $argId ) ? $this->mArgs[$argId] : $default;
        }

        protected function setBatchSize( $s = 0 ) {
                $this->mBatchSize = $s;

                // If we support $mBatchSize, show the option.
                // Used to be in addDefaultParams, but in order for that to
                // work, subclasses would have to call this function in the constructor
                // before they called parent::__construct which is just weird
                // (and really wasn't done).
                if ( $this->mBatchSize ) {
                        $this->addOption( 'batch-size', 'Run this many operations ' .
                                'per batch, default: ' . $this->mBatchSize, false, true );
                        if ( isset( $this->mParams['batch-size'] ) ) {
                                // This seems a little ugly...
                                $this->mDependantParameters['batch-size'] = $this->mParams['batch-size'];
                        }
                }
        }

        public function getName() {
                return $this->mSelf;
        }

        protected function getStdin( $len = null ) {
                if ( $len == Maintenance::STDIN_ALL ) {
                        return file_get_contents( 'php://stdin' );
                }
                $f = fopen( 'php://stdin', 'rt' );
                if ( !$len ) {
                        return $f;
                }
                $input = fgets( $f, $len );
                fclose( $f );
                return rtrim( $input );
        }

        public function isQuiet() {
                return $this->mQuiet;
        }

        protected function output( $out, $channel = null ) {
                if ( $this->mQuiet ) {
                        return;
                }
                if ( $channel === null ) {
                        $this->cleanupChanneled();
                        print( $out );
                } else {
                        $out = preg_replace( '/\n\z/', '', $out );
                        $this->outputChanneled( $out, $channel );
                }
        }

        protected function error( $err, $die = 0 ) {
                $this->outputChanneled( false );
                if ( php_sapi_name() == 'cli' ) {
                        fwrite( STDERR, $err . "\n" );
                } else {
                        print $err;
                }
                $die = intval( $die );
                if ( $die > 0 ) {
                        die( $die );
                }
        }

        private $atLineStart = true;
        private $lastChannel = null;

        public function cleanupChanneled() {
                if ( !$this->atLineStart ) {
                        print "\n";
                        $this->atLineStart = true;
                }
        }

        public function outputChanneled( $msg, $channel = null ) {
                if ( $msg === false ) {
                        $this->cleanupChanneled();
                        return;
                }

                // End the current line if necessary
                if ( !$this->atLineStart && $channel !== $this->lastChannel ) {
                        print "\n";
                }

                print $msg;

                $this->atLineStart = false;
                if ( $channel === null ) {
                        // For unchanneled messages, output trailing newline immediately
                        print "\n";
                        $this->atLineStart = true;
                }
                $this->lastChannel = $channel;
        }

        public function getDbType() {
                return Maintenance::DB_STD;
        }

        protected function addDefaultParams() {

                # Generic (non script dependant) options:

                $this->addOption( 'help', 'Display this help message', false, false, 'h' );
                $this->addOption( 'quiet', 'Whether to supress non-error output', false, false, 'q' );
                $this->addOption( 'conf', 'Location of LocalSettings.php, if not default', false, true );
                $this->addOption( 'wiki', 'For specifying the wiki ID', false, true );
                $this->addOption( 'globals', 'Output globals at the end of processing for debugging' );
                $this->addOption( 'memory-limit', 'Set a specific memory limit for the script, "max" for no limit or "default" to avoid changing it' );
                $this->addOption( 'server', "The protocol and server name to use in URLs, e.g. " .
                                "http://en.wikipedia.org. This is sometimes necessary because " .
                                "server name detection may fail in command line scripts.", false, true );

                # Save generic options to display them separately in help
                $this->mGenericParameters = $this->mParams ;

                # Script dependant options:

                // If we support a DB, show the options
                if ( $this->getDbType() > 0 ) {
                        $this->addOption( 'dbuser', 'The DB user to use for this script', false, true );
                        $this->addOption( 'dbpass', 'The password to use for this script', false, true );
                }

                # Save additional script dependant options to display
                # them separately in help
                $this->mDependantParameters = array_diff_key( $this->mParams, $this->mGenericParameters );
        }

        public function runChild( $maintClass, $classFile = null ) {
                // Make sure the class is loaded first
                if ( !MWInit::classExists( $maintClass ) ) {
                        if ( $classFile ) {
                                require_once( $classFile );
                        }
                        if ( !MWInit::classExists( $maintClass ) ) {
                                $this->error( "Cannot spawn child: $maintClass" );
                        }
                }

                $child = new $maintClass();
                $child->loadParamsAndArgs( $this->mSelf, $this->mOptions, $this->mArgs );
                if ( !is_null( $this->mDb ) ) {
                        $child->setDB( $this->mDb );
                }
                return $child;
        }

        public function setup() {
                global $wgCommandLineMode, $wgRequestTime;

                # Abort if called from a web server
                if ( isset( $_SERVER ) && isset( $_SERVER['REQUEST_METHOD'] ) ) {
                        $this->error( 'This script must be run from the command line', true );
                }

                # Make sure we can handle script parameters
                if ( !function_exists( 'hphp_thread_set_warmup_enabled' ) && !ini_get( 'register_argc_argv' ) ) {
                        $this->error( 'Cannot get command line arguments, register_argc_argv is set to false', true );
                }

                // Send PHP warnings and errors to stderr instead of stdout.
                // This aids in diagnosing problems, while keeping messages
                // out of redirected output.
                if ( ini_get( 'display_errors' ) ) {
                        ini_set( 'display_errors', 'stderr' );
                }

                $this->loadParamsAndArgs();
                $this->maybeHelp();

                # Set the memory limit
                # Note we need to set it again later in cache LocalSettings changed it
                $this->adjustMemoryLimit();

                # Set max execution time to 0 (no limit). PHP.net says that
                # "When running PHP from the command line the default setting is 0."
                # But sometimes this doesn't seem to be the case.
                ini_set( 'max_execution_time', 0 );

                $wgRequestTime = microtime( true );

                # Define us as being in MediaWiki
                define( 'MEDIAWIKI', true );

                $wgCommandLineMode = true;
                # Turn off output buffering if it's on
                @ob_end_flush();

                $this->validateParamsAndArgs();
        }

        public function memoryLimit() {
                $limit = $this->getOption( 'memory-limit', 'max' );
                $limit = trim( $limit, "\" '" ); // trim quotes in case someone misunderstood
                return $limit;
        }

        protected function adjustMemoryLimit() {
                $limit = $this->memoryLimit();
                if ( $limit == 'max' ) {
                        $limit = -1; // no memory limit
                }
                if ( $limit != 'default' ) {
                        ini_set( 'memory_limit', $limit );
                }
        }

        public function clearParamsAndArgs() {
                $this->mOptions = array();
                $this->mArgs = array();
                $this->mInputLoaded = false;
        }

        public function loadParamsAndArgs( $self = null, $opts = null, $args = null ) {
                # If we were given opts or args, set those and return early
                if ( $self ) {
                        $this->mSelf = $self;
                        $this->mInputLoaded = true;
                }
                if ( $opts ) {
                        $this->mOptions = $opts;
                        $this->mInputLoaded = true;
                }
                if ( $args ) {
                        $this->mArgs = $args;
                        $this->mInputLoaded = true;
                }

                # If we've already loaded input (either by user values or from $argv)
                # skip on loading it again. The array_shift() will corrupt values if
                # it's run again and again
                if ( $this->mInputLoaded ) {
                        $this->loadSpecialVars();
                        return;
                }

                global $argv;
                $this->mSelf = array_shift( $argv );

                $options = array();
                $args = array();

                # Parse arguments
                for ( $arg = reset( $argv ); $arg !== false; $arg = next( $argv ) ) {
                        if ( $arg == '--' ) {
                                # End of options, remainder should be considered arguments
                                $arg = next( $argv );
                                while ( $arg !== false ) {
                                        $args[] = $arg;
                                        $arg = next( $argv );
                                }
                                break;
                        } elseif ( substr( $arg, 0, 2 ) == '--' ) {
                                # Long options
                                $option = substr( $arg, 2 );
                                if ( array_key_exists( $option, $options ) ) {
                                        $this->error( "\nERROR: $option parameter given twice\n" );
                                        $this->maybeHelp( true );
                                }
                                if ( isset( $this->mParams[$option] ) && $this->mParams[$option]['withArg'] ) {
                                        $param = next( $argv );
                                        if ( $param === false ) {
                                                $this->error( "\nERROR: $option parameter needs a value after it\n" );
                                                $this->maybeHelp( true );
                                        }
                                        $options[$option] = $param;
                                } else {
                                        $bits = explode( '=', $option, 2 );
                                        if ( count( $bits ) > 1 ) {
                                                $option = $bits[0];
                                                $param = $bits[1];
                                        } else {
                                                $param = 1;
                                        }
                                        $options[$option] = $param;
                                }
                        } elseif ( substr( $arg, 0, 1 ) == '-' ) {
                                # Short options
                                for ( $p = 1; $p < strlen( $arg ); $p++ ) {
                                        $option = $arg { $p } ;
                                        if ( !isset( $this->mParams[$option] ) && isset( $this->mShortParamsMap[$option] ) ) {
                                                $option = $this->mShortParamsMap[$option];
                                        }
                                        if ( array_key_exists( $option, $options ) ) {
                                                $this->error( "\nERROR: $option parameter given twice\n" );
                                                $this->maybeHelp( true );
                                        }
                                        if ( isset( $this->mParams[$option]['withArg'] ) && $this->mParams[$option]['withArg'] ) {
                                                $param = next( $argv );
                                                if ( $param === false ) {
                                                        $this->error( "\nERROR: $option parameter needs a value after it\n" );
                                                        $this->maybeHelp( true );
                                                }
                                                $options[$option] = $param;
                                        } else {
                                                $options[$option] = 1;
                                        }
                                }
                        } else {
                                $args[] = $arg;
                        }
                }

                $this->mOptions = $options;
                $this->mArgs = $args;
                $this->loadSpecialVars();
                $this->mInputLoaded = true;
        }

        protected function validateParamsAndArgs() {
                $die = false;
                # Check to make sure we've got all the required options
                foreach ( $this->mParams as $opt => $info ) {
                        if ( $info['require'] && !$this->hasOption( $opt ) ) {
                                $this->error( "Param $opt required!" );
                                $die = true;
                        }
                }
                # Check arg list too
                foreach ( $this->mArgList as $k => $info ) {
                        if ( $info['require'] && !$this->hasArg( $k ) ) {
                                $this->error( 'Argument <' . $info['name'] . '> required!' );
                                $die = true;
                        }
                }

                if ( $die ) {
                        $this->maybeHelp( true );
                }
        }

        protected function loadSpecialVars() {
                if ( $this->hasOption( 'dbuser' ) ) {
                        $this->mDbUser = $this->getOption( 'dbuser' );
                }
                if ( $this->hasOption( 'dbpass' ) ) {
                        $this->mDbPass = $this->getOption( 'dbpass' );
                }
                if ( $this->hasOption( 'quiet' ) ) {
                        $this->mQuiet = true;
                }
                if ( $this->hasOption( 'batch-size' ) ) {
                        $this->mBatchSize = intval( $this->getOption( 'batch-size' ) );
                }
        }

        protected function maybeHelp( $force = false ) {
                if( !$force && !$this->hasOption( 'help' ) ) {
                        return;
                }

                $screenWidth = 80; // TODO: Caculate this!
                $tab = "    ";
                $descWidth = $screenWidth - ( 2 * strlen( $tab ) );

                ksort( $this->mParams );
                $this->mQuiet = false;

                // Description ...
                if ( $this->mDescription ) {
                        $this->output( "\n" . $this->mDescription . "\n" );
                }
                $output = "\nUsage: php " . basename( $this->mSelf );

                // ... append parameters ...
                if ( $this->mParams ) {
                        $output .= " [--" . implode( array_keys( $this->mParams ), "|--" ) . "]";
                }

                // ... and append arguments.
                if ( $this->mArgList ) {
                        $output .= ' ';
                        foreach ( $this->mArgList as $k => $arg ) {
                                if ( $arg['require'] ) {
                                        $output .= '<' . $arg['name'] . '>';
                                } else {
                                        $output .= '[' . $arg['name'] . ']';
                                }
                                if ( $k < count( $this->mArgList ) - 1 )
                                        $output .= ' ';
                        }
                }
                $this->output( "$output\n\n" );

                # TODO abstract some repetitive code below

                // Generic parameters
                $this->output( "Generic maintenance parameters:\n" );
                foreach ( $this->mGenericParameters as $par => $info ) {
                        if ( $info['shortName'] !== false ) {
                                $par .= " (-{$info['shortName']})";
                        }
                        $this->output(
                                wordwrap( "$tab--$par: " . $info['desc'], $descWidth,
                                                "\n$tab$tab" ) . "\n"
                        );
                }
                $this->output( "\n" );

                $scriptDependantParams = $this->mDependantParameters;
                if( count($scriptDependantParams) > 0 ) {
                        $this->output( "Script dependant parameters:\n" );
                        // Parameters description
                        foreach ( $scriptDependantParams as $par => $info ) {
                                if ( $info['shortName'] !== false ) {
                                        $par .= " (-{$info['shortName']})";
                                }
                                $this->output(
                                        wordwrap( "$tab--$par: " . $info['desc'], $descWidth,
                                                        "\n$tab$tab" ) . "\n"
                                );
                        }
                        $this->output( "\n" );
                }


                // Script specific parameters not defined on construction by
                // Maintenance::addDefaultParams()
                $scriptSpecificParams = array_diff_key(
                        # all script parameters:
                        $this->mParams,
                        # remove the Maintenance default parameters:
                        $this->mGenericParameters,
                        $this->mDependantParameters
                );
                if( count($scriptSpecificParams) > 0 ) {
                        $this->output( "Script specific parameters:\n" );
                        // Parameters description
                        foreach ( $scriptSpecificParams as $par => $info ) {
                                if ( $info['shortName'] !== false ) {
                                        $par .= " (-{$info['shortName']})";
                                }
                                $this->output(
                                        wordwrap( "$tab--$par: " . $info['desc'], $descWidth,
                                                        "\n$tab$tab" ) . "\n"
                                );
                        }
                        $this->output( "\n" );
                }

                // Print arguments
                if( count( $this->mArgList ) > 0 ) {
                        $this->output( "Arguments:\n" );
                        // Arguments description
                        foreach ( $this->mArgList as $info ) {
                                $openChar = $info['require'] ? '<' : '[';
                                $closeChar = $info['require'] ? '>' : ']';
                                $this->output(
                                        wordwrap( "$tab$openChar" . $info['name'] . "$closeChar: " .
                                                $info['desc'], $descWidth, "\n$tab$tab" ) . "\n"
                                );
                        }
                        $this->output( "\n" );
                }

                die( 1 );
        }

        public function finalSetup() {
                global $wgCommandLineMode, $wgShowSQLErrors, $wgServer;
                global $wgDBadminuser, $wgDBadminpassword;
                global $wgDBuser, $wgDBpassword, $wgDBservers, $wgLBFactoryConf;

                # Turn off output buffering again, it might have been turned on in the settings files
                if ( ob_get_level() ) {
                        ob_end_flush();
                }
                # Same with these
                $wgCommandLineMode = true;

                # Override $wgServer
                if( $this->hasOption( 'server') ) {
                        $wgServer = $this->getOption( 'server', $wgServer );
                }

                # If these were passed, use them
                if ( $this->mDbUser ) {
                        $wgDBadminuser = $this->mDbUser;
                }
                if ( $this->mDbPass ) {
                        $wgDBadminpassword = $this->mDbPass;
                }

                if ( $this->getDbType() == self::DB_ADMIN && isset( $wgDBadminuser ) ) {
                        $wgDBuser = $wgDBadminuser;
                        $wgDBpassword = $wgDBadminpassword;

                        if ( $wgDBservers ) {
                                foreach ( $wgDBservers as $i => $server ) {
                                        $wgDBservers[$i]['user'] = $wgDBuser;
                                        $wgDBservers[$i]['password'] = $wgDBpassword;
                                }
                        }
                        if ( isset( $wgLBFactoryConf['serverTemplate'] ) ) {
                                $wgLBFactoryConf['serverTemplate']['user'] = $wgDBuser;
                                $wgLBFactoryConf['serverTemplate']['password'] = $wgDBpassword;
                        }
                        LBFactory::destroyInstance();
                }

                $this->afterFinalSetup();

                $wgShowSQLErrors = true;
                @set_time_limit( 0 );
                $this->adjustMemoryLimit();
        }

        protected function afterFinalSetup() {
                if ( defined( 'MW_CMDLINE_CALLBACK' ) ) {
                        call_user_func( MW_CMDLINE_CALLBACK );
                }
        }

        public function globals() {
                if ( $this->hasOption( 'globals' ) ) {
                        print_r( $GLOBALS );
                }
        }

        public function loadSettings() {
                global $wgCommandLineMode, $IP;

                if ( isset( $this->mOptions['conf'] ) ) {
                        $settingsFile = $this->mOptions['conf'];
                } elseif ( defined("MW_CONFIG_FILE") ) {
                        $settingsFile = MW_CONFIG_FILE;
                } else {
                        $settingsFile = "$IP/LocalSettings.php";
                }
                if ( isset( $this->mOptions['wiki'] ) ) {
                        $bits = explode( '-', $this->mOptions['wiki'] );
                        if ( count( $bits ) == 1 ) {
                                $bits[] = '';
                        }
                        define( 'MW_DB', $bits[0] );
                        define( 'MW_PREFIX', $bits[1] );
                }

                if ( !is_readable( $settingsFile ) ) {
                        $this->error( "A copy of your installation's LocalSettings.php\n" .
                                                "must exist and be readable in the source directory.\n" .
                                                "Use --conf to specify it." , true );
                }
                $wgCommandLineMode = true;
                return $settingsFile;
        }

        public function purgeRedundantText( $delete = true ) {
                # Data should come off the master, wrapped in a transaction
                $dbw = $this->getDB( DB_MASTER );
                $dbw->begin( __METHOD__ );

                $tbl_arc = $dbw->tableName( 'archive' );
                $tbl_rev = $dbw->tableName( 'revision' );
                $tbl_txt = $dbw->tableName( 'text' );

                # Get "active" text records from the revisions table
                $this->output( 'Searching for active text records in revisions table...' );
                $res = $dbw->query( "SELECT DISTINCT rev_text_id FROM $tbl_rev" );
                foreach ( $res as $row ) {
                        $cur[] = $row->rev_text_id;
                }
                $this->output( "done.\n" );

                # Get "active" text records from the archive table
                $this->output( 'Searching for active text records in archive table...' );
                $res = $dbw->query( "SELECT DISTINCT ar_text_id FROM $tbl_arc" );
                foreach ( $res as $row ) {
                        $cur[] = $row->ar_text_id;
                }
                $this->output( "done.\n" );

                # Get the IDs of all text records not in these sets
                $this->output( 'Searching for inactive text records...' );
                $set = implode( ', ', $cur );
                $res = $dbw->query( "SELECT old_id FROM $tbl_txt WHERE old_id NOT IN ( $set )" );
                $old = array();
                foreach ( $res as $row ) {
                        $old[] = $row->old_id;
                }
                $this->output( "done.\n" );

                # Inform the user of what we're going to do
                $count = count( $old );
                $this->output( "$count inactive items found.\n" );

                # Delete as appropriate
                if ( $delete && $count ) {
                        $this->output( 'Deleting...' );
                        $set = implode( ', ', $old );
                        $dbw->query( "DELETE FROM $tbl_txt WHERE old_id IN ( $set )" );
                        $this->output( "done.\n" );
                }

                # Done
                $dbw->commit( __METHOD__ );
        }

        protected function getDir() {
                return __DIR__;
        }

        public static function getMaintenanceScripts() {
                global $wgMaintenanceScripts;
                return $wgMaintenanceScripts + self::getCoreScripts();
        }

        protected static function getCoreScripts() {
                if ( !self::$mCoreScripts ) {
                        $paths = array(
                                __DIR__,
                                __DIR__ . '/language',
                                __DIR__ . '/storage',
                        );
                        self::$mCoreScripts = array();
                        foreach ( $paths as $p ) {
                                $handle = opendir( $p );
                                while ( ( $file = readdir( $handle ) ) !== false ) {
                                        if ( $file == 'Maintenance.php' ) {
                                                continue;
                                        }
                                        $file = $p . '/' . $file;
                                        if ( is_dir( $file ) || !strpos( $file, '.php' ) ||
                                                ( strpos( file_get_contents( $file ), '$maintClass' ) === false ) ) {
                                                continue;
                                        }
                                        require( $file );
                                        $vars = get_defined_vars();
                                        if ( array_key_exists( 'maintClass', $vars ) ) {
                                                self::$mCoreScripts[$vars['maintClass']] = $file;
                                        }
                                }
                                closedir( $handle );
                        }
                }
                return self::$mCoreScripts;
        }

        protected function &getDB( $db, $groups = array(), $wiki = false ) {
                if ( is_null( $this->mDb ) ) {
                        return wfGetDB( $db, $groups, $wiki );
                } else {
                        return $this->mDb;
                }
        }

        public function setDB( &$db ) {
                $this->mDb = $db;
        }

        private function lockSearchindex( &$db ) {
                $write = array( 'searchindex' );
                $read = array( 'page', 'revision', 'text', 'interwiki', 'l10n_cache', 'user' );
                $db->lockTables( $read, $write, __CLASS__ . '::' . __METHOD__ );
        }

        private function unlockSearchindex( &$db ) {
                $db->unlockTables(  __CLASS__ . '::' . __METHOD__ );
        }

        private function relockSearchindex( &$db ) {
                $this->unlockSearchindex( $db );
                $this->lockSearchindex( $db );
        }

        public function updateSearchIndex( $maxLockTime, $callback, $dbw, $results ) {
                $lockTime = time();

                # Lock searchindex
                if ( $maxLockTime ) {
                        $this->output( "   --- Waiting for lock ---" );
                        $this->lockSearchindex( $dbw );
                        $lockTime = time();
                        $this->output( "\n" );
                }

                # Loop through the results and do a search update
                foreach ( $results as $row ) {
                        # Allow reads to be processed
                        if ( $maxLockTime && time() > $lockTime + $maxLockTime ) {
                                $this->output( "    --- Relocking ---" );
                                $this->relockSearchindex( $dbw );
                                $lockTime = time();
                                $this->output( "\n" );
                        }
                        call_user_func( $callback, $dbw, $row );
                }

                # Unlock searchindex
                if ( $maxLockTime ) {
                        $this->output( "    --- Unlocking --" );
                        $this->unlockSearchindex( $dbw );
                        $this->output( "\n" );
                }

        }

        public function updateSearchIndexForPage( $dbw, $pageId ) {
                // Get current revision
                $rev = Revision::loadFromPageId( $dbw, $pageId );
                $title = null;
                if ( $rev ) {
                        $titleObj = $rev->getTitle();
                        $title = $titleObj->getPrefixedDBkey();
                        $this->output( "$title..." );
                        # Update searchindex
                        # TODO: pass the Content object to SearchUpdate, let the search engine decide how to deal with it.
                        $u = new SearchUpdate( $pageId, $titleObj->getText(), $rev->getContent()->getTextForSearchIndex() );
                        $u->doUpdate();
                        $this->output( "\n" );
                }
                return $title;
        }

        public static function posix_isatty( $fd ) {
                if ( !MWInit::functionExists( 'posix_isatty' ) ) {
                        return !$fd;
                } else {
                        return posix_isatty( $fd );
                }
        }

        public static function readconsole( $prompt = '> ' ) {
                static $isatty = null;
                if ( is_null( $isatty ) ) {
                        $isatty = self::posix_isatty( 0 /*STDIN*/ );
                }

                if ( $isatty && function_exists( 'readline' ) ) {
                        return readline( $prompt );
                } else {
                        if ( $isatty ) {
                                $st = self::readlineEmulation( $prompt );
                        } else {
                                if ( feof( STDIN ) ) {
                                        $st = false;
                                } else {
                                        $st = fgets( STDIN, 1024 );
                                }
                        }
                        if ( $st === false ) return false;
                        $resp = trim( $st );
                        return $resp;
                }
        }

        private static function readlineEmulation( $prompt ) {
                $bash = Installer::locateExecutableInDefaultPaths( array( 'bash' ) );
                if ( !wfIsWindows() && $bash ) {
                        $retval = false;
                        $encPrompt = wfEscapeShellArg( $prompt );
                        $command = "read -er -p $encPrompt && echo \"\$REPLY\"";
                        $encCommand = wfEscapeShellArg( $command );
                        $line = wfShellExec( "$bash -c $encCommand", $retval );

                        if ( $retval == 0 ) {
                                return $line;
                        } elseif ( $retval == 127 ) {
                                // Couldn't execute bash even though we thought we saw it.
                                // Shell probably spit out an error message, sorry :(
                                // Fall through to fgets()...
                        } else {
                                // EOF/ctrl+D
                                return false;
                        }
                }

                // Fallback... we'll have no editing controls, EWWW
                if ( feof( STDIN ) ) {
                        return false;
                }
                print $prompt;
                return fgets( STDIN, 1024 );
        }
}

class FakeMaintenance extends Maintenance {
        protected $mSelf = "FakeMaintenanceScript";
        public function execute() {
                return;
        }
}

abstract class LoggedUpdateMaintenance extends Maintenance {
        public function __construct() {
                parent::__construct();
                $this->addOption( 'force', 'Run the update even if it was completed already' );
                $this->setBatchSize( 200 );
        }

        public function execute() {
                $db = $this->getDB( DB_MASTER );
                $key = $this->getUpdateKey();

                if ( !$this->hasOption( 'force' ) &&
                        $db->selectRow( 'updatelog', '1', array( 'ul_key' => $key ), __METHOD__ ) )
                {
                        $this->output( "..." . $this->updateSkippedMessage() . "\n" );
                        return true;
                }

                if ( !$this->doDBUpdates() ) {
                        return false;
                }

                if (
                        $db->insert( 'updatelog', array( 'ul_key' => $key ), __METHOD__, 'IGNORE' ) )
                {
                        return true;
                } else {
                        $this->output( $this->updatelogFailedMessage() . "\n" );
                        return false;
                }
        }

        protected function updateSkippedMessage() {
                $key = $this->getUpdateKey();
                return "Update '{$key}' already logged as completed.";
        }

        protected function updatelogFailedMessage() {
                $key = $this->getUpdateKey();
                return "Unable to log update '{$key}' as completed.";
        }

        abstract protected function doDBUpdates();

        abstract protected function getUpdateKey();
}