includes/BlockCache.php

   1 <?php
   2 /**
   3  * Contain the blockcache class
   4  * @package MediaWiki
   5  */
   6
   7 /**
   8  * Object for fast lookup of IP blocks
   9  * Represents a memcached value, and in some sense, the entire ipblocks table
  10  * @package MediaWiki
  11  */
  12 class BlockCache
  13 {
  14         var $mData = false, $mMemcKey;
  15
  16         function BlockCache( $deferLoad = false, $dbName = '' ) {
  17                 global $wgDBname;
  18
  19                 if ( $dbName == '' ) {
  20                         $dbName = $wgDBname;
  21                 }
  22
  23                 $this->mMemcKey = $dbName.':ipblocks';
  24
  25                 if ( !$deferLoad ) {
  26                         $this->load();
  27                 }
  28         }
  29
  30         # Load the blocks from the database and save them to memcached
  31         function loadFromDB() {
  32                 global $wgUseMemCached, $wgMemc;
  33                 $this->mData = array();
  34                 # Selecting FOR UPDATE is a convenient way to serialise the memcached and DB operations,
  35                 # which is necessary even though we don't update the DB
  36                 if ( $wgUseMemCached ) {
  37                         Block::enumBlocks( 'wfBlockCacheInsert', '', EB_FOR_UPDATE );
  38                         $wgMemc->set( $this->mMemcKey, $this->mData, 0 );
  39                 } else {
  40                         Block::enumBlocks( 'wfBlockCacheInsert', '' );
  41                 }
  42         }
  43
  44         # Load the cache from memcached or, if that's not possible, from the DB
  45         function load() {
  46                 global $wgUseMemCached, $wgMemc;
  47
  48                 if ( $this->mData === false) {
  49                         # Try memcached
  50                         if ( $wgUseMemCached ) {
  51                                 $this->mData = $wgMemc->get( $this->mMemcKey );
  52                         }
  53
  54                         if ( !is_array( $this->mData ) ) {
  55                                 $this->loadFromDB();
  56                         }
  57                 }
  58         }
  59
  60         # Add a block to the cache
  61         function insert( &$block ) {
  62                 if ( $block->mUser == 0 ) {
  63                         $nb = $block->getNetworkBits();
  64                         $ipint = $block->getIntegerAddr();
  65                         $index = $ipint >> ( 32 - $nb );
  66
  67                         if ( !array_key_exists( $nb, $this->mData ) ) {
  68                                 $this->mData[$nb] = array();
  69                         }
  70
  71                         $this->mData[$nb][$index] = 1;
  72                 }
  73         }
  74
  75         # Find out if a given IP address is blocked
  76         function get( $ip ) {
  77                 $this->load();
  78                 $ipint = ip2long( $ip );
  79                 $blocked = false;
  80
  81                 foreach ( $this->mData as $networkBits => $blockInts ) {
  82                         if ( array_key_exists( $ipint >> ( 32 - $networkBits ), $blockInts ) ) {
  83                                 $blocked = true;
  84                                 break;
  85                         }
  86                 }
  87                 if ( $blocked ) {
  88                         # Clear low order bits
  89                         if ( $networkBits != 32 ) {
  90                                 $ip .= '/'.$networkBits;
  91                                 $ip = Block::normaliseRange( $ip );
  92                         }
  93                         $block = new Block();
  94                         $block->load( $ip );
  95                 } else {
  96                         $block = false;
  97                 }
  98
  99                 return $block;
 100         }
 101
 102         # Clear the local cache
 103         # There was once a clear() to clear memcached too, but I deleted it
 104         function clearLocal() {
 105                 $this->mData = false;
 106         }
 107 }
 108
 109 function wfBlockCacheInsert( $block, $tag ) {
 110         global $wgBlockCache;
 111         $wgBlockCache->insert( $block );
 112 }