includes/ObjectCache.php

   1 <?php
   2 /**
   3  * Functions to get cache objects
   4  *
   5  * @file
   6  * @ingroup Cache
   7  */
   8
   9 /**
  10  * FakeMemCachedClient imitates the API of memcached-client v. 0.1.2.
  11  * It acts as a memcached server with no RAM, that is, all objects are
  12  * cleared the moment they are set. All set operations succeed and all
  13  * get operations return null.
  14  * @ingroup Cache
  15  */
  16 class FakeMemCachedClient {
  17         function add ($key, $val, $exp = 0) { return true; }
  18         function decr ($key, $amt=1) { return null; }
  19         function delete ($key, $time = 0) { return false; }
  20         function disconnect_all () { }
  21         function enable_compress ($enable) { }
  22         function forget_dead_hosts () { }
  23         function get ($key) { return null; }
  24         function get_multi ($keys) { return array_pad(array(), count($keys), null); }
  25         function incr ($key, $amt=1) { return null; }
  26         function replace ($key, $value, $exp=0) { return false; }
  27         function run_command ($sock, $cmd) { return null; }
  28         function set ($key, $value, $exp=0){ return true; }
  29         function set_compress_threshold ($thresh){ }
  30         function set_debug ($dbg) { }
  31         function set_servers ($list) { }
  32 }
  33
  34 global $wgCaches;
  35 $wgCaches = array();
  36
  37 /**
  38  * Get a cache object.
  39  * @param $inputType Integer: cache type, one the the CACHE_* constants.
  40  *
  41  * @return BagOStuff
  42  */
  43 function &wfGetCache( $inputType ) {
  44         global $wgCaches, $wgMemCachedServers, $wgMemCachedDebug, $wgMemCachedPersistent;
  45         $cache = false;
  46
  47         if ( $inputType == CACHE_ANYTHING ) {
  48                 reset( $wgCaches );
  49                 $type = key( $wgCaches );
  50                 if ( $type === false || $type === CACHE_NONE ) {
  51                         $type = CACHE_DB;
  52                 }
  53         } else {
  54                 $type = $inputType;
  55         }
  56
  57         if ( $type == CACHE_MEMCACHED ) {
  58                 if ( !array_key_exists( CACHE_MEMCACHED, $wgCaches ) ) {
  59                         $wgCaches[CACHE_MEMCACHED] = new MemCachedClientforWiki(
  60                                 array('persistant' => $wgMemCachedPersistent, 'compress_threshold' => 1500 ) );
  61                         $wgCaches[CACHE_MEMCACHED]->set_servers( $wgMemCachedServers );
  62                         $wgCaches[CACHE_MEMCACHED]->set_debug( $wgMemCachedDebug );
  63                 }
  64                 $cache =& $wgCaches[CACHE_MEMCACHED];
  65         } elseif ( $type == CACHE_ACCEL ) {
  66                 if ( !array_key_exists( CACHE_ACCEL, $wgCaches ) ) {
  67                         if ( function_exists( 'eaccelerator_get' ) ) {
  68                                 $wgCaches[CACHE_ACCEL] = new eAccelBagOStuff;
  69                         } elseif ( function_exists( 'apc_fetch') ) {
  70                                 $wgCaches[CACHE_ACCEL] = new APCBagOStuff;
  71                         } elseif( function_exists( 'xcache_get' ) ) {
  72                                 $wgCaches[CACHE_ACCEL] = new XCacheBagOStuff();
  73                         } elseif( function_exists( 'wincache_ucache_get' ) ) {
  74                                 $wgCaches[CACHE_ACCEL] = new WinCacheBagOStuff();
  75                         } else {
  76                                 $wgCaches[CACHE_ACCEL] = false;
  77                         }
  78                 }
  79                 if ( $wgCaches[CACHE_ACCEL] !== false ) {
  80                         $cache =& $wgCaches[CACHE_ACCEL];
  81                 }
  82         } elseif ( $type == CACHE_DBA ) {
  83                 if ( !array_key_exists( CACHE_DBA, $wgCaches ) ) {
  84                         $wgCaches[CACHE_DBA] = new DBABagOStuff;
  85                 }
  86                 $cache =& $wgCaches[CACHE_DBA];
  87         }
  88
  89         if ( $type == CACHE_DB || ( $inputType == CACHE_ANYTHING && $cache === false ) ) {
  90                 if ( !array_key_exists( CACHE_DB, $wgCaches ) ) {
  91                         $wgCaches[CACHE_DB] = new SqlBagOStuff('objectcache');
  92                 }
  93                 $cache =& $wgCaches[CACHE_DB];
  94         }
  95
  96         if ( $cache === false ) {
  97                 if ( !array_key_exists( CACHE_NONE, $wgCaches ) ) {
  98                         $wgCaches[CACHE_NONE] = new FakeMemCachedClient;
  99                 }
 100                 $cache =& $wgCaches[CACHE_NONE];
 101         }
 102
 103         return $cache;
 104 }
 105
 106 /** Get the main cache object */
 107 function &wfGetMainCache() {
 108         global $wgMainCacheType;
 109         $ret =& wfGetCache( $wgMainCacheType );
 110         return $ret;
 111 }
 112
 113 /** Get the cache object used by the message cache */
 114 function &wfGetMessageCacheStorage() {
 115         global $wgMessageCacheType;
 116         $ret =& wfGetCache( $wgMessageCacheType );
 117         return $ret;
 118 }
 119
 120 /** Get the cache object used by the parser cache */
 121 function &wfGetParserCacheStorage() {
 122         global $wgParserCacheType;
 123         $ret =& wfGetCache( $wgParserCacheType );
 124         return $ret;
 125 }