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Diffstat (limited to 'includes/deferred/SquidUpdate.php')
| -rw-r--r-- | includes/deferred/SquidUpdate.php | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/includes/deferred/SquidUpdate.php b/includes/deferred/SquidUpdate.php new file mode 100644 index 00000000..0dcff44a --- /dev/null +++ b/includes/deferred/SquidUpdate.php @@ -0,0 +1,311 @@ +<?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; + } +} |