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 ( !Memcached::HAVE_IGBINARY ) {
  62                                         throw new MWException( __CLASS__.': the igbinary extension is not available ' .
  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                 $result = parent::delete( $key, $time );
 104                 if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTFOUND ) {
 105                         // "Not found" is counted as success in our interface
 106                         return true;
 107                 } else {
 108                         return $this->checkResult( $key, $result );
 109                 }
 110         }
 111
 112         /**
 113          * @param $key string
 114          * @param $value int
 115          * @return Mixed
 116          */
 117         public function add( $key, $value, $exptime = 0 ) {
 118                 $this->debugLog( "add($key)" );
 119                 return $this->checkResult( $key, parent::add( $key, $value, $exptime ) );
 120         }
 121
 122         /**
 123          * @param $key string
 124          * @param $value int
 125          * @param $exptime
 126          * @return Mixed
 127          */
 128         public function replace( $key, $value, $exptime = 0 ) {
 129                 $this->debugLog( "replace($key)" );
 130                 return $this->checkResult( $key, parent::replace( $key, $value, $exptime ) );
 131         }
 132
 133         /**
 134          * @param $key string
 135          * @param $value int
 136          * @return Mixed
 137          */
 138         public function incr( $key, $value = 1 ) {
 139                 $this->debugLog( "incr($key)" );
 140                 $result = $this->client->increment( $key, $value );
 141                 return $this->checkResult( $key, $result );
 142         }
 143
 144         /**
 145          * @param $key string
 146          * @param $value int
 147          * @return Mixed
 148          */
 149         public function decr( $key, $value = 1 ) {
 150                 $this->debugLog( "decr($key)" );
 151                 $result = $this->client->decrement( $key, $value );
 152                 return $this->checkResult( $key, $result );
 153         }
 154
 155         /**
 156          * Check the return value from a client method call and take any necessary
 157          * action. Returns the value that the wrapper function should return. At
 158          * present, the return value is always the same as the return value from
 159          * the client, but some day we might find a case where it should be
 160          * different.
 161          *
 162          * @param $key The key used by the caller, or false if there wasn't one.
 163          * @param $result The return value
 164          */
 165         protected function checkResult( $key, $result ) {
 166                 if ( $result !== false ) {
 167                         return $result;
 168                 }
 169                 switch ( $this->client->getResultCode() ) {
 170                         case Memcached::RES_SUCCESS:
 171                                 break;
 172                         case Memcached::RES_DATA_EXISTS:
 173                         case Memcached::RES_NOTSTORED:
 174                         case Memcached::RES_NOTFOUND:
 175                                 $this->debugLog( "result: " . $this->client->getResultMessage() );
 176                                 break;
 177                         default:
 178                                 $msg = $this->client->getResultMessage();
 179                                 if ( $key !== false ) {
 180                                         $server = $this->client->getServerByKey( $key );
 181                                         $serverName = "{$server['host']}:{$server['port']}";
 182                                         $msg = "Memcached error for key \"$key\" on server \"$serverName\": $msg";
 183                                 } else {
 184                                         $msg = "Memcached error: $msg";
 185                                 }
 186                                 wfDebugLog( 'memcached-serious', $msg );
 187                 }
 188                 return $result;
 189         }
 190
 191         /**
 192          * @param $keys Array
 193          * @return Array
 194          */
 195         public function getMulti( array $keys ) {
 196                 $this->debugLog( 'getMulti(' . implode( ', ', $keys ) . ')' );
 197                 $callback = array( $this, 'encodeKey' );
 198                 $result = $this->client->getMulti( array_map( $callback, $keys ) );
 199                 return $this->checkResult( false, $result );
 200         }
 201
 202         /* NOTE: there is no cas() method here because it is currently not supported
 203          * by the BagOStuff interface and other BagOStuff subclasses, such as
 204          * SqlBagOStuff.
 205          */
 206 }