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          *   - use_binary_protocol  Whether to enable the binary protocol (default is ASCII) (boolean)
  46          * @param array $params
  47          * @throws InvalidArgumentException
  48          */
  49         function __construct( $params ) {
  50                 parent::__construct( $params );
  51                 $params = $this->applyDefaultParams( $params );
  52
  53                 if ( $params['persistent'] ) {
  54                         // The pool ID must be unique to the server/option combination.
  55                         // The Memcached object is essentially shared for each pool ID.
  56                         // We can only reuse a pool ID if we keep the config consistent.
  57                         $this->client = new Memcached( md5( serialize( $params ) ) );
  58                         if ( count( $this->client->getServerList() ) ) {
  59                                 $this->logger->debug( __METHOD__ . ": persistent Memcached object already loaded." );
  60                                 return; // already initialized; don't add duplicate servers
  61                         }
  62                 } else {
  63                         $this->client = new Memcached;
  64                 }
  65
  66                 if ( $params['use_binary_protocol'] ) {
  67                         $this->client->setOption( Memcached::OPT_BINARY_PROTOCOL, true );
  68                 }
  69
  70                 if ( isset( $params['retry_timeout'] ) ) {
  71                         $this->client->setOption( Memcached::OPT_RETRY_TIMEOUT, $params['retry_timeout'] );
  72                 }
  73
  74                 if ( isset( $params['server_failure_limit'] ) ) {
  75                         $this->client->setOption( Memcached::OPT_SERVER_FAILURE_LIMIT, $params['server_failure_limit'] );
  76                 }
  77
  78                 // The compression threshold is an undocumented php.ini option for some
  79                 // reason. There's probably not much harm in setting it globally, for
  80                 // compatibility with the settings for the PHP client.
  81                 ini_set( 'memcached.compression_threshold', $params['compress_threshold'] );
  82
  83                 // Set timeouts
  84                 $this->client->setOption( Memcached::OPT_CONNECT_TIMEOUT, $params['connect_timeout'] * 1000 );
  85                 $this->client->setOption( Memcached::OPT_SEND_TIMEOUT, $params['timeout'] );
  86                 $this->client->setOption( Memcached::OPT_RECV_TIMEOUT, $params['timeout'] );
  87                 $this->client->setOption( Memcached::OPT_POLL_TIMEOUT, $params['timeout'] / 1000 );
  88
  89                 // Set libketama mode since it's recommended by the documentation and
  90                 // is as good as any. There's no way to configure libmemcached to use
  91                 // hashes identical to the ones currently in use by the PHP client, and
  92                 // even implementing one of the libmemcached hashes in pure PHP for
  93                 // forwards compatibility would require MemcachedClient::get_sock() to be
  94                 // rewritten.
  95                 $this->client->setOption( Memcached::OPT_LIBKETAMA_COMPATIBLE, true );
  96
  97                 // Set the serializer
  98                 switch ( $params['serializer'] ) {
  99                         case 'php':
 100                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_PHP );
 101                                 break;
 102                         case 'igbinary':
 103                                 if ( !Memcached::HAVE_IGBINARY ) {
 104                                         throw new InvalidArgumentException(
 105                                                 __CLASS__ . ': the igbinary extension is not available ' .
 106                                                 'but igbinary serialization was requested.'
 107                                         );
 108                                 }
 109                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY );
 110                                 break;
 111                         default:
 112                                 throw new InvalidArgumentException(
 113                                         __CLASS__ . ': invalid value for serializer parameter'
 114                                 );
 115                 }
 116                 $servers = [];
 117                 foreach ( $params['servers'] as $host ) {
 118                         $servers[] = IP::splitHostAndPort( $host ); // (ip, port)
 119                 }
 120                 $this->client->addServers( $servers );
 121         }
 122
 123         protected function applyDefaultParams( $params ) {
 124                 $params = parent::applyDefaultParams( $params );
 125
 126                 if ( !isset( $params['use_binary_protocol'] ) ) {
 127                         $params['use_binary_protocol'] = false;
 128                 }
 129
 130                 if ( !isset( $params['serializer'] ) ) {
 131                         $params['serializer'] = 'php';
 132                 }
 133
 134                 return $params;
 135         }
 136
 137         protected function getWithToken( $key, &$casToken, $flags = 0 ) {
 138                 $this->debugLog( "get($key)" );
 139                 $result = $this->client->get( $this->validateKeyEncoding( $key ), null, $casToken );
 140                 $result = $this->checkResult( $key, $result );
 141                 return $result;
 142         }
 143
 144         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
 145                 $this->debugLog( "set($key)" );
 146                 return $this->checkResult( $key, parent::set( $key, $value, $exptime ) );
 147         }
 148
 149         protected function cas( $casToken, $key, $value, $exptime = 0 ) {
 150                 $this->debugLog( "cas($key)" );
 151                 return $this->checkResult( $key, parent::cas( $casToken, $key, $value, $exptime ) );
 152         }
 153
 154         public function delete( $key ) {
 155                 $this->debugLog( "delete($key)" );
 156                 $result = parent::delete( $key );
 157                 if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTFOUND ) {
 158                         // "Not found" is counted as success in our interface
 159                         return true;
 160                 } else {
 161                         return $this->checkResult( $key, $result );
 162                 }
 163         }
 164
 165         public function add( $key, $value, $exptime = 0 ) {
 166                 $this->debugLog( "add($key)" );
 167                 return $this->checkResult( $key, parent::add( $key, $value, $exptime ) );
 168         }
 169
 170         public function incr( $key, $value = 1 ) {
 171                 $this->debugLog( "incr($key)" );
 172                 $result = $this->client->increment( $key, $value );
 173                 return $this->checkResult( $key, $result );
 174         }
 175
 176         public function decr( $key, $value = 1 ) {
 177                 $this->debugLog( "decr($key)" );
 178                 $result = $this->client->decrement( $key, $value );
 179                 return $this->checkResult( $key, $result );
 180         }
 181
 182         /**
 183          * Check the return value from a client method call and take any necessary
 184          * action. Returns the value that the wrapper function should return. At
 185          * present, the return value is always the same as the return value from
 186          * the client, but some day we might find a case where it should be
 187          * different.
 188          *
 189          * @param string $key The key used by the caller, or false if there wasn't one.
 190          * @param mixed $result The return value
 191          * @return mixed
 192          */
 193         protected function checkResult( $key, $result ) {
 194                 if ( $result !== false ) {
 195                         return $result;
 196                 }
 197                 switch ( $this->client->getResultCode() ) {
 198                         case Memcached::RES_SUCCESS:
 199                                 break;
 200                         case Memcached::RES_DATA_EXISTS:
 201                         case Memcached::RES_NOTSTORED:
 202                         case Memcached::RES_NOTFOUND:
 203                                 $this->debugLog( "result: " . $this->client->getResultMessage() );
 204                                 break;
 205                         default:
 206                                 $msg = $this->client->getResultMessage();
 207                                 $logCtx = [];
 208                                 if ( $key !== false ) {
 209                                         $server = $this->client->getServerByKey( $key );
 210                                         $logCtx['memcached-server'] = "{$server['host']}:{$server['port']}";
 211                                         $logCtx['memcached-key'] = $key;
 212                                         $msg = "Memcached error for key \"{memcached-key}\" on server \"{memcached-server}\": $msg";
 213                                 } else {
 214                                         $msg = "Memcached error: $msg";
 215                                 }
 216                                 $this->logger->error( $msg, $logCtx );
 217                                 $this->setLastError( BagOStuff::ERR_UNEXPECTED );
 218                 }
 219                 return $result;
 220         }
 221
 222         public function getMulti( array $keys, $flags = 0 ) {
 223                 $this->debugLog( 'getMulti(' . implode( ', ', $keys ) . ')' );
 224                 foreach ( $keys as $key ) {
 225                         $this->validateKeyEncoding( $key );
 226                 }
 227                 $result = $this->client->getMulti( $keys ) ?: [];
 228                 return $this->checkResult( false, $result );
 229         }
 230
 231         /**
 232          * @param array $data
 233          * @param int $exptime
 234          * @return bool
 235          */
 236         public function setMulti( array $data, $exptime = 0 ) {
 237                 $this->debugLog( 'setMulti(' . implode( ', ', array_keys( $data ) ) . ')' );
 238                 foreach ( array_keys( $data ) as $key ) {
 239                         $this->validateKeyEncoding( $key );
 240                 }
 241                 $result = $this->client->setMulti( $data, $this->fixExpiry( $exptime ) );
 242                 return $this->checkResult( false, $result );
 243         }
 244
 245         public function changeTTL( $key, $expiry = 0 ) {
 246                 $this->debugLog( "touch($key)" );
 247                 $result = $this->client->touch( $key, $expiry );
 248                 return $this->checkResult( $key, $result );
 249         }
 250 }