includes/BlockCache.php

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