Properly deprecate srprop=score|hasrelated

[mediawiki.git] / includes / deferred / SquidUpdate.php

<?php
/**
 * Squid cache purging.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Cache
 */

/**
 * Handles purging appropriate Squid URLs given a title (or titles)
 * @ingroup Cache
 */
class SquidUpdate {
        /**
         * Collection of URLs to purge.
         * @var array
         */
        protected $urlArr;

        /**
         * @param array $urlArr Collection of URLs to purge
         * @param bool|int $maxTitles Maximum number of unique URLs to purge
         */
        public function __construct( $urlArr = array(), $maxTitles = false ) {
                global $wgMaxSquidPurgeTitles;
                if ( $maxTitles === false ) {
                        $maxTitles = $wgMaxSquidPurgeTitles;
                }

                // Remove duplicate URLs from list
                $urlArr = array_unique( $urlArr );
                if ( count( $urlArr ) > $maxTitles ) {
                        // Truncate to desired maximum URL count
                        $urlArr = array_slice( $urlArr, 0, $maxTitles );
                }
                $this->urlArr = $urlArr;
        }

        /**
         * Create a SquidUpdate from the given Title object.
         *
         * The resulting SquidUpdate will purge the given Title's URLs as well as
         * the pages that link to it. Capped at $wgMaxSquidPurgeTitles total URLs.
         *
         * @param Title $title
         * @return SquidUpdate
         */
        public static function newFromLinksTo( Title $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 ( $res->numRows() <= $wgMaxSquidPurgeTitles ) {
                        foreach ( $res as $BL ) {
                                $tobj = Title::makeTitle( $BL->page_namespace, $BL->page_title );
                                $blurlArr[] = $tobj->getInternalURL();
                        }
                }

                wfProfileOut( __METHOD__ );

                return new SquidUpdate( $blurlArr );
        }

        /**
         * Create a SquidUpdate from an array of Title objects, or a TitleArray object
         *
         * @param array $titles
         * @param array $urlArr
         * @return SquidUpdate
         */
        public static function newFromTitles( $titles, $urlArr = array() ) {
                global $wgMaxSquidPurgeTitles;
                $i = 0;
                /** @var Title $title */
                foreach ( $titles as $title ) {
                        $urlArr[] = $title->getInternalURL();
                        if ( $i++ > $wgMaxSquidPurgeTitles ) {
                                break;
                        }
                }

                return new SquidUpdate( $urlArr );
        }

        /**
         * @param Title $title
         * @return SquidUpdate
         */
        public static function newSimplePurge( Title $title ) {
                $urlArr = $title->getSquidURLs();

                return new SquidUpdate( $urlArr );
        }

        /**
         * Purges the list of URLs passed to the constructor.
         */
        public function doUpdate() {
                self::purge( $this->urlArr );
        }

        /**
         * Purges a list of Squids defined in $wgSquidServers.
         * $urlArr should contain the full URLs to purge as values
         * (example: $urlArr[] = 'http://my.host/something')
         * XXX report broken Squids per mail or log
         *
         * @param array $urlArr List of full URLs to purge
         */
        public static function purge( $urlArr ) {
                global $wgSquidServers, $wgHTCPRouting;

                if ( !$urlArr ) {
                        return;
                }

                wfDebugLog( 'squid', __METHOD__ . ': ' . implode( ' ', $urlArr ) );

                if ( $wgHTCPRouting ) {
                        self::HTCPPurge( $urlArr );
                }

                wfProfileIn( __METHOD__ );

                // Remove duplicate URLs
                $urlArr = array_unique( $urlArr );
                // Maximum number of parallel connections per squid
                $maxSocketsPerSquid = 8;
                // Number of requests to send per socket
                // 400 seems to be a good tradeoff, opening a socket takes a while
                $urlsPerSocket = 400;
                $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__ );
        }

        /**
         * Send Hyper Text Caching Protocol (HTCP) CLR requests.
         *
         * @throws MWException
         * @param array $urlArr Collection of URLs to purge
         */
        public static function HTCPPurge( $urlArr ) {
                global $wgHTCPRouting, $wgHTCPMulticastTTL;
                wfProfileIn( __METHOD__ );

                // HTCP CLR operation
                $htcpOpCLR = 4;

                // @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 ) {
                        $errstr = socket_strerror( socket_last_error() );
                        wfDebugLog( 'squid', __METHOD__ .
                                ": Error opening UDP socket: $errstr" );
                        wfProfileOut( __METHOD__ );

                        return;
                }

                // Set socket options
                socket_set_option( $conn, IPPROTO_IP, IP_MULTICAST_LOOP, 0 );
                if ( $wgHTCPMulticastTTL != 1 ) {
                        // Set multicast time to live (hop count) option on socket
                        socket_set_option( $conn, IPPROTO_IP, IP_MULTICAST_TTL,
                                $wgHTCPMulticastTTL );
                }

                // Remove duplicate URLs from collection
                $urlArr = array_unique( $urlArr );
                // Get sequential trx IDs for packet loss counting
                $ids = UIDGenerator::newSequentialPerNodeIDs(
                        'squidhtcppurge', 32, count( $urlArr ), UIDGenerator::QUICK_VOLATILE
                );

                foreach ( $urlArr as $url ) {
                        if ( !is_string( $url ) ) {
                                wfProfileOut( __METHOD__ );
                                throw new MWException( 'Bad purge URL' );
                        }
                        $url = self::expand( $url );
                        $conf = self::getRuleForURL( $url, $wgHTCPRouting );
                        if ( !$conf ) {
                                wfDebugLog( 'squid', __METHOD__ .
                                        "No HTCP rule configured for URL {$url} , skipping" );
                                continue;
                        }

                        if ( isset( $conf['host'] ) && isset( $conf['port'] ) ) {
                                // Normalize single entries
                                $conf = array( $conf );
                        }
                        foreach ( $conf as $subconf ) {
                                if ( !isset( $subconf['host'] ) || !isset( $subconf['port'] ) ) {
                                        wfProfileOut( __METHOD__ );
                                        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 = current( $ids );
                        next( $ids );

                        $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 );

                        wfDebugLog( 'squid', __METHOD__ .
                                "Purging URL $url via HTCP" );
                        foreach ( $conf as $subconf ) {
                                socket_sendto( $conn, $htcpPacket, $htcpLen, 0,
                                        $subconf['host'], $subconf['port'] );
                        }
                }
                wfProfileOut( __METHOD__ );
        }

        /**
         * Expand local URLs to fully-qualified URLs using the internal protocol
         * and host defined in $wgInternalServer. Input that's already fully-
         * qualified will be passed through unchanged.
         *
         * This is used to generate purge URLs that may be either local to the
         * main wiki or include a non-native host, such as images hosted on a
         * second internal server.
         *
         * Client functions should not need to call this.
         *
         * @param string $url
         * @return string
         */
        public static function expand( $url ) {
                return wfExpandUrl( $url, PROTO_INTERNAL );
        }

        /**
         * Find the HTCP routing rule to use for a given URL.
         * @param string $url URL to match
         * @param array $rules Array of rules, see $wgHTCPRouting for format and behavior
         * @return mixed Element of $rules that matched, or false if nothing matched
         */
        private static function getRuleForURL( $url, $rules ) {
                foreach ( $rules as $regex => $routing ) {
                        if ( $regex === '' || preg_match( $regex, $url ) ) {
                                return $routing;
                        }
                }

                return false;
        }
}