includes/objectcache/MemcachedPeclBagOStuff.php

   1 <?php
   2 /**
   3  * Object caching using memcached.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Cache
  22  */
  23
  24 /**
  25  * A wrapper class for the PECL memcached client
  26  *
  27  * @ingroup Cache
  28  */
  29 class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
  30
  31         /**
  32          * Constructor
  33          *
  34          * Available parameters are:
  35          *   - servers:             The list of IP:port combinations holding the memcached servers.
  36          *   - persistent:          Whether to use a persistent connection
  37          *   - compress_threshold:  The minimum size an object must be before it is compressed
  38          *   - timeout:             The read timeout in microseconds
  39          *   - connect_timeout:     The connect timeout in seconds
  40          *   - retry_timeout:       Time in seconds to wait before retrying a failed connect attempt
  41          *   - server_failure_limit:  Limit for server connect failures before it is removed
  42          *   - serializer:          May be either "php" or "igbinary". Igbinary produces more compact
  43          *                          values, but serialization is much slower unless the php.ini option
  44          *                          igbinary.compact_strings is off.
  45          * @param array $params
  46          * @throws InvalidArgumentException
  47          */
  48         function __construct( $params ) {
  49                 parent::__construct( $params );
  50                 $params = $this->applyDefaultParams( $params );
  51
  52                 if ( $params['persistent'] ) {
  53                         // The pool ID must be unique to the server/option combination.
  54                         // The Memcached object is essentially shared for each pool ID.
  55                         // We can only reuse a pool ID if we keep the config consistent.
  56                         $this->client = new Memcached( md5( serialize( $params ) ) );
  57                         if ( count( $this->client->getServerList() ) ) {
  58                                 $this->logger->debug( __METHOD__ . ": persistent Memcached object already loaded." );
  59                                 return; // already initialized; don't add duplicate servers
  60                         }
  61                 } else {
  62                         $this->client = new Memcached;
  63                 }
  64
  65                 if ( !isset( $params['serializer'] ) ) {
  66                         $params['serializer'] = 'php';
  67                 }
  68
  69                 if ( isset( $params['retry_timeout'] ) ) {
  70                         $this->client->setOption( Memcached::OPT_RETRY_TIMEOUT, $params['retry_timeout'] );
  71                 }
  72
  73                 if ( isset( $params['server_failure_limit'] ) ) {
  74                         $this->client->setOption( Memcached::OPT_SERVER_FAILURE_LIMIT, $params['server_failure_limit'] );
  75                 }
  76
  77                 // The compression threshold is an undocumented php.ini option for some
  78                 // reason. There's probably not much harm in setting it globally, for
  79                 // compatibility with the settings for the PHP client.
  80                 ini_set( 'memcached.compression_threshold', $params['compress_threshold'] );
  81
  82                 // Set timeouts
  83                 $this->client->setOption( Memcached::OPT_CONNECT_TIMEOUT, $params['connect_timeout'] * 1000 );
  84                 $this->client->setOption( Memcached::OPT_SEND_TIMEOUT, $params['timeout'] );
  85                 $this->client->setOption( Memcached::OPT_RECV_TIMEOUT, $params['timeout'] );
  86                 $this->client->setOption( Memcached::OPT_POLL_TIMEOUT, $params['timeout'] / 1000 );
  87
  88                 // Set libketama mode since it's recommended by the documentation and
  89                 // is as good as any. There's no way to configure libmemcached to use
  90                 // hashes identical to the ones currently in use by the PHP client, and
  91                 // even implementing one of the libmemcached hashes in pure PHP for
  92                 // forwards compatibility would require MemcachedClient::get_sock() to be
  93                 // rewritten.
  94                 $this->client->setOption( Memcached::OPT_LIBKETAMA_COMPATIBLE, true );
  95
  96                 // Set the serializer
  97                 switch ( $params['serializer'] ) {
  98                         case 'php':
  99                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_PHP );
 100                                 break;
 101                         case 'igbinary':
 102                                 if ( !Memcached::HAVE_IGBINARY ) {
 103                                         throw new InvalidArgumentException(
 104                                                 __CLASS__ . ': the igbinary extension is not available ' .
 105                                                 'but igbinary serialization was requested.'
 106                                         );
 107                                 }
 108                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY );
 109                                 break;
 110                         default:
 111                                 throw new InvalidArgumentException(
 112                                         __CLASS__ . ': invalid value for serializer parameter'
 113                                 );
 114                 }
 115                 $servers = array();
 116                 foreach ( $params['servers'] as $host ) {
 117                         $servers[] = IP::splitHostAndPort( $host ); // (ip, port)
 118                 }
 119                 $this->client->addServers( $servers );
 120         }
 121
 122         protected function getWithToken( $key, &$casToken, $flags = 0 ) {
 123                 $this->debugLog( "get($key)" );
 124                 $result = $this->client->get( $this->validateKeyEncoding( $key ), null, $casToken );
 125                 $result = $this->checkResult( $key, $result );
 126                 return $result;
 127         }
 128
 129         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
 130                 $this->debugLog( "set($key)" );
 131                 return $this->checkResult( $key, parent::set( $key, $value, $exptime ) );
 132         }
 133
 134         protected function cas( $casToken, $key, $value, $exptime = 0 ) {
 135                 $this->debugLog( "cas($key)" );
 136                 return $this->checkResult( $key, parent::cas( $casToken, $key, $value, $exptime ) );
 137         }
 138
 139         public function delete( $key ) {
 140                 $this->debugLog( "delete($key)" );
 141                 $result = parent::delete( $key );
 142                 if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTFOUND ) {
 143                         // "Not found" is counted as success in our interface
 144                         return true;
 145                 } else {
 146                         return $this->checkResult( $key, $result );
 147                 }
 148         }
 149
 150         public function add( $key, $value, $exptime = 0 ) {
 151                 $this->debugLog( "add($key)" );
 152                 return $this->checkResult( $key, parent::add( $key, $value, $exptime ) );
 153         }
 154
 155         public function incr( $key, $value = 1 ) {
 156                 $this->debugLog( "incr($key)" );
 157                 $result = $this->client->increment( $key, $value );
 158                 return $this->checkResult( $key, $result );
 159         }
 160
 161         public function decr( $key, $value = 1 ) {
 162                 $this->debugLog( "decr($key)" );
 163                 $result = $this->client->decrement( $key, $value );
 164                 return $this->checkResult( $key, $result );
 165         }
 166
 167         /**
 168          * Check the return value from a client method call and take any necessary
 169          * action. Returns the value that the wrapper function should return. At
 170          * present, the return value is always the same as the return value from
 171          * the client, but some day we might find a case where it should be
 172          * different.
 173          *
 174          * @param string $key The key used by the caller, or false if there wasn't one.
 175          * @param mixed $result The return value
 176          * @return mixed
 177          */
 178         protected function checkResult( $key, $result ) {
 179                 if ( $result !== false ) {
 180                         return $result;
 181                 }
 182                 switch ( $this->client->getResultCode() ) {
 183                         case Memcached::RES_SUCCESS:
 184                                 break;
 185                         case Memcached::RES_DATA_EXISTS:
 186                         case Memcached::RES_NOTSTORED:
 187                         case Memcached::RES_NOTFOUND:
 188                                 $this->debugLog( "result: " . $this->client->getResultMessage() );
 189                                 break;
 190                         default:
 191                                 $msg = $this->client->getResultMessage();
 192                                 $logCtx = array();
 193                                 if ( $key !== false ) {
 194                                         $server = $this->client->getServerByKey( $key );
 195                                         $logCtx['memcached-server'] = "{$server['host']}:{$server['port']}";
 196                                         $logCtx['memcached-key'] = $key;
 197                                         $msg = "Memcached error for key \"{memcached-key}\" on server \"{memcached-server}\": $msg";
 198                                 } else {
 199                                         $msg = "Memcached error: $msg";
 200                                 }
 201                                 $this->logger->error( $msg, $logCtx );
 202                                 $this->setLastError( BagOStuff::ERR_UNEXPECTED );
 203                 }
 204                 return $result;
 205         }
 206
 207         public function getMulti( array $keys, $flags = 0 ) {
 208                 $this->debugLog( 'getMulti(' . implode( ', ', $keys ) . ')' );
 209                 foreach ( $keys as $key ) {
 210                         $this->validateKeyEncoding( $key );
 211                 }
 212                 $result = $this->client->getMulti( $keys ) ?: array();
 213                 return $this->checkResult( false, $result );
 214         }
 215
 216         /**
 217          * @param array $data
 218          * @param int $exptime
 219          * @return bool
 220          */
 221         public function setMulti( array $data, $exptime = 0 ) {
 222                 $this->debugLog( 'setMulti(' . implode( ', ', array_keys( $data ) ) . ')' );
 223                 foreach ( array_keys( $data ) as $key ) {
 224                         $this->validateKeyEncoding( $key );
 225                 }
 226                 $result = $this->client->setMulti( $data, $this->fixExpiry( $exptime ) );
 227                 return $this->checkResult( false, $result );
 228         }
 229 }