SquidUpdate.php

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<?php
class SquidUpdate {
        var $urlArr, $mMaxTitles;

        function __construct( $urlArr = array(), $maxTitles = false ) {
                global $wgMaxSquidPurgeTitles;
                if ( $maxTitles === false ) {
                        $this->mMaxTitles = $wgMaxSquidPurgeTitles;
                } else {
                        $this->mMaxTitles = $maxTitles;
                }
                $urlArr = array_unique( $urlArr ); // Remove duplicates
                if ( count( $urlArr ) > $this->mMaxTitles ) {
                        $urlArr = array_slice( $urlArr, 0, $this->mMaxTitles );
                }
                $this->urlArr = $urlArr;
        }

        static function newFromLinksTo( &$title ) {
                global $wgMaxSquidPurgeTitles;
                wfProfileIn( __METHOD__ );

                # Get a list of URLs linking to this page
                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( array( 'links', 'page' ),
                        array( 'page_namespace', 'page_title' ),
                        array(
                                'pl_namespace' => $title->getNamespace(),
                                'pl_title'     => $title->getDBkey(),
                                'pl_from=page_id' ),
                        __METHOD__ );
                $blurlArr = $title->getSquidURLs();
                if ( $dbr->numRows( $res ) <= $wgMaxSquidPurgeTitles ) {
                        foreach ( $res as $BL ) {
                                $tobj = Title::makeTitle( $BL->page_namespace, $BL->page_title ) ;
                                $blurlArr[] = $tobj->getInternalURL();
                        }
                }

                wfProfileOut( __METHOD__ );
                return new SquidUpdate( $blurlArr );
        }

        static function newFromTitles( $titles, $urlArr = array() ) {
                global $wgMaxSquidPurgeTitles;
                $i = 0;
                foreach ( $titles as $title ) {
                        $urlArr[] = $title->getInternalURL();
                        if ( $i++ > $wgMaxSquidPurgeTitles ) {
                                break;
                        }
                }
                return new SquidUpdate( $urlArr );
        }

        static function newSimplePurge( &$title ) {
                $urlArr = $title->getSquidURLs();
                return new SquidUpdate( $urlArr );
        }

        function doUpdate() {
                SquidUpdate::purge( $this->urlArr );
        }

        static function purge( $urlArr ) {
                global $wgSquidServers, $wgHTCPMulticastRouting;

                if( !$urlArr ) {
                        return;
                }

                if ( $wgHTCPMulticastRouting ) {
                        SquidUpdate::HTCPPurge( $urlArr );
                }

                wfProfileIn( __METHOD__ );

                $urlArr = array_unique( $urlArr ); // Remove duplicates
                $maxSocketsPerSquid = 8; //  socket cap per Squid
                $urlsPerSocket = 400; // 400 seems to be a good tradeoff, opening a socket takes a while
                $socketsPerSquid = ceil( count( $urlArr ) / $urlsPerSocket );
                if ( $socketsPerSquid > $maxSocketsPerSquid ) {
                        $socketsPerSquid = $maxSocketsPerSquid;
                }

                $pool = new SquidPurgeClientPool;
                $chunks = array_chunk( $urlArr, ceil( count( $urlArr ) / $socketsPerSquid ) );
                foreach ( $wgSquidServers as $server ) {
                        foreach ( $chunks as $chunk ) {
                                $client = new SquidPurgeClient( $server );
                                foreach ( $chunk as $url ) {
                                        $client->queuePurge( $url );
                                }
                                $pool->addClient( $client );
                        }
                }
                $pool->run();

                wfProfileOut( __METHOD__ );
        }

        static function HTCPPurge( $urlArr ) {
                global $wgHTCPMulticastRouting, $wgHTCPMulticastTTL;
                wfProfileIn( __METHOD__ );

                $htcpOpCLR = 4; // HTCP CLR

                // @todo FIXME: PHP doesn't support these socket constants (include/linux/in.h)
                if( !defined( "IPPROTO_IP" ) ) {
                        define( "IPPROTO_IP", 0 );
                        define( "IP_MULTICAST_LOOP", 34 );
                        define( "IP_MULTICAST_TTL", 33 );
                }

                // pfsockopen doesn't work because we need set_sock_opt
                $conn = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
                if ( $conn ) {
                        // Set socket options
                        socket_set_option( $conn, IPPROTO_IP, IP_MULTICAST_LOOP, 0 );
                        if ( $wgHTCPMulticastTTL != 1 )
                                socket_set_option( $conn, IPPROTO_IP, IP_MULTICAST_TTL,
                                        $wgHTCPMulticastTTL );

                        $urlArr = array_unique( $urlArr ); // Remove duplicates
                        foreach ( $urlArr as $url ) {
                                if( !is_string( $url ) ) {
                                        throw new MWException( 'Bad purge URL' );
                                }
                                $url = SquidUpdate::expand( $url );
                                $conf = self::getRuleForURL( $url, $wgHTCPMulticastRouting );
                                if ( !$conf ) {
                                        wfDebug( "No HTCP rule configured for URL $url , skipping\n" );
                                        continue;
                                }
                                if ( !isset( $conf['host'] ) || !isset( $conf['port'] ) ) {
                                        throw new MWException( "Invalid HTCP rule for URL $url\n" );
                                }

                                // Construct a minimal HTCP request diagram
                                // as per RFC 2756
                                // Opcode 'CLR', no response desired, no auth
                                $htcpTransID = rand();

                                $htcpSpecifier = pack( 'na4na*na8n',
                                        4, 'HEAD', strlen( $url ), $url,
                                        8, 'HTTP/1.0', 0 );

                                $htcpDataLen = 8 + 2 + strlen( $htcpSpecifier );
                                $htcpLen = 4 + $htcpDataLen + 2;

                                // Note! Squid gets the bit order of the first
                                // word wrong, wrt the RFC. Apparently no other
                                // implementation exists, so adapt to Squid
                                $htcpPacket = pack( 'nxxnCxNxxa*n',
                                        $htcpLen, $htcpDataLen, $htcpOpCLR,
                                        $htcpTransID, $htcpSpecifier, 2);

                                // Send out
                                wfDebug( "Purging URL $url via HTCP\n" );
                                socket_sendto( $conn, $htcpPacket, $htcpLen, 0,
                                        $conf['host'], $conf['port'] );
                        }
                } else {
                        $errstr = socket_strerror( socket_last_error() );
                        wfDebug( __METHOD__ . "(): Error opening UDP socket: $errstr\n" );
                }
                wfProfileOut( __METHOD__ );
        }

        static function expand( $url ) {
                return wfExpandUrl( $url, PROTO_INTERNAL );
        }
        
        static function getRuleForURL( $url, $rules ) {
                foreach ( $rules as $regex => $routing ) {
                        if ( $regex === '' || preg_match( $regex, $url ) ) {
                                return $routing;
                        }
                }
                return false;
        }
        
}