includes/objectcache/MemcachedPeclBagOStuff.php

   1 <?php
   2
   3 /**
   4  * A wrapper class for the PECL memcached client
   5  *
   6  * @ingroup Cache
   7  */
   8 class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
   9
  10         /**
  11          * Constructor
  12          *
  13          * Available parameters are:
  14          *   - servers:             The list of IP:port combinations holding the memcached servers.
  15          *   - persistent:          Whether to use a persistent connection
  16          *   - compress_threshold:  The minimum size an object must be before it is compressed
  17          *   - timeout:             The read timeout in microseconds
  18          *   - connect_timeout:     The connect timeout in seconds
  19          *   - serializer:          May be either "php" or "igbinary". Igbinary produces more compact
  20          *                          values, but serialization is much slower unless the php.ini option
  21          *                          igbinary.compact_strings is off.
  22          */
  23         function __construct( $params ) {
  24                 $params = $this->applyDefaultParams( $params );
  25
  26                 if ( $params['persistent'] ) {
  27                         $this->client = new Memcached( __CLASS__ );
  28                 } else {
  29                         $this->client = new Memcached;
  30                 }
  31
  32                 if ( !isset( $params['serializer'] ) ) {
  33                         $params['serializer'] = 'php';
  34                 }
  35
  36                 // The compression threshold is an undocumented php.ini option for some
  37                 // reason. There's probably not much harm in setting it globally, for
  38                 // compatibility with the settings for the PHP client.
  39                 ini_set( 'memcached.compression_threshold', $params['compress_threshold'] );
  40
  41                 // Set timeouts
  42                 $this->client->setOption( Memcached::OPT_CONNECT_TIMEOUT, $params['connect_timeout'] * 1000 );
  43                 $this->client->setOption( Memcached::OPT_SEND_TIMEOUT, $params['timeout'] );
  44                 $this->client->setOption( Memcached::OPT_RECV_TIMEOUT, $params['timeout'] );
  45                 $this->client->setOption( Memcached::OPT_POLL_TIMEOUT, $params['timeout'] / 1000 );
  46
  47                 // Set libketama mode since it's recommended by the documentation and
  48                 // is as good as any. There's no way to configure libmemcached to use
  49                 // hashes identical to the ones currently in use by the PHP client, and
  50                 // even implementing one of the libmemcached hashes in pure PHP for
  51                 // forwards compatibility would require MWMemcached::get_sock() to be
  52                 // rewritten.
  53                 $this->client->setOption( Memcached::OPT_LIBKETAMA_COMPATIBLE, true );
  54
  55                 // Set the serializer
  56                 switch ( $params['serializer'] ) {
  57                         case 'php':
  58                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_PHP );
  59                                 break;
  60                         case 'igbinary':
  61                                 if ( !extension_loaded( 'igbinary' ) ) {
  62                                         throw new MWException( __CLASS__.': the igbinary extension is not loaded ' .
  63                                                 'but igbinary serialization was requested.' );
  64                                 }
  65                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY );
  66                                 break;
  67                         default:
  68                                 throw new MWException( __CLASS__.': invalid value for serializer parameter' );
  69                 }
  70                 foreach ( $params['servers'] as $host ) {
  71                         list( $ip, $port ) = IP::splitHostAndPort( $host );
  72                         $this->client->addServer( $ip, $port );
  73                 }
  74         }
  75
  76         /**
  77          * @param $key string
  78          * @return Mixed
  79          */
  80         public function get( $key ) {
  81                 $this->debugLog( "get($key)" );
  82                 return $this->checkResult( $key, parent::get( $key ) );
  83         }
  84
  85         /**
  86          * @param $key string
  87          * @param $value
  88          * @param $exptime int
  89          * @return bool
  90          */
  91         public function set( $key, $value, $exptime = 0 ) {
  92                 $this->debugLog( "set($key)" );
  93                 return $this->checkResult( $key, parent::set( $key, $value, $exptime ) );
  94         }
  95
  96         /**
  97          * @param $key string
  98          * @param $time int
  99          * @return bool
 100          */
 101         public function delete( $key, $time = 0 ) {
 102                 $this->debugLog( "delete($key)" );
 103                 return $this->checkResult( $key, parent::delete( $key, $time ) );
 104         }
 105
 106         /**
 107          * @param $key string
 108          * @param $value int
 109          * @return Mixed
 110          */
 111         public function add( $key, $value, $exptime = 0 ) {
 112                 $this->debugLog( "add($key)" );
 113                 return $this->checkResult( $key, parent::add( $key, $value, $exptime ) );
 114         }
 115
 116         /**
 117          * @param $key string
 118          * @param $value int
 119          * @param $exptime
 120          * @return Mixed
 121          */
 122         public function replace( $key, $value, $exptime = 0 ) {
 123                 $this->debugLog( "replace($key)" );
 124                 return $this->checkResult( $key, parent::replace( $key, $value, $exptime ) );
 125         }
 126
 127         /**
 128          * @param $key string
 129          * @param $value int
 130          * @return Mixed
 131          */
 132         public function incr( $key, $value = 1 ) {
 133                 $this->debugLog( "incr($key)" );
 134                 $result = $this->client->increment( $key, $value );
 135                 return $this->checkResult( $key, $result );
 136         }
 137
 138         /**
 139          * @param $key string
 140          * @param $value int
 141          * @return Mixed
 142          */
 143         public function decr( $key, $value = 1 ) {
 144                 $this->debugLog( "decr($key)" );
 145                 $result = $this->client->decrement( $key, $value );
 146                 return $this->checkResult( $key, $result );
 147         }
 148
 149         /**
 150          * Check the return value from a client method call and take any necessary
 151          * action. Returns the value that the wrapper function should return. At
 152          * present, the return value is always the same as the return value from
 153          * the client, but some day we might find a case where it should be
 154          * different.
 155          *
 156          * @param $key The key used by the caller, or false if there wasn't one.
 157          * @param $result The return value
 158          */
 159         protected function checkResult( $key, $result ) {
 160                 if ( $result !== false ) {
 161                         return $result;
 162                 }
 163                 switch ( $this->client->getResultCode() ) {
 164                         case Memcached::RES_SUCCESS:
 165                                 break;
 166                         case Memcached::RES_DATA_EXISTS:
 167                         case Memcached::RES_NOTSTORED:
 168                         case Memcached::RES_NOTFOUND:
 169                                 $this->debugLog( "result: " . $this->client->getResultMessage() );
 170                                 break;
 171                         default:
 172                                 $msg = $this->client->getResultMessage();
 173                                 if ( $key !== false ) {
 174                                         $server = $this->client->getServerByKey( $key );
 175                                         $serverName = "{$server['host']}:{$server['port']}";
 176                                         $msg = "Memcached error for key \"$key\" on server \"$serverName\": $msg";
 177                                 } else {
 178                                         $msg = "Memcached error: $msg";
 179                                 }
 180                                 wfDebugLog( 'memcached-serious', $msg );
 181                 }
 182                 return $result;
 183         }
 184
 185         /**
 186          * @param $keys Array
 187          * @return Array
 188          */
 189         public function getBatch( array $keys ) {
 190                 $this->debugLog( 'getBatch(' . implode( ', ', $keys ) . ')' );
 191                 $callback = array( $this, 'encodeKey' );
 192                 $result = $this->client->getMulti( array_map( $callback, $keys ) );
 193                 return $this->checkResult( false, $result );
 194         }
 195
 196         /* NOTE: there is no cas() method here because it is currently not supported
 197          * by the BagOStuff interface and other BagOStuff subclasses, such as
 198          * SqlBagOStuff.
 199          */
 200 }