| <?php |
| /** |
| * File containing the ezcCacheMemcacheBackend class. |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| * @package Cache |
| * @version //autogentag// |
| * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0 |
| * @filesource |
| */ |
| |
| /** |
| * This backend stores data in a Memcache. |
| * |
| * @apichange This class will be deprecated in the next major version of the |
| * Cache component. Please do not use it directly, but use {@link |
| * ezcCacheStorageMemcache} instead. |
| * |
| * @package Cache |
| * @version //autogentag// |
| */ |
| class ezcCacheMemcacheBackend extends ezcCacheMemoryBackend |
| { |
| /** |
| * The compress threshold. |
| * |
| * Nearly 1MB (48,576B less). |
| */ |
| const COMPRESS_THRESHOLD = 1000000; |
| |
| /** |
| * Maximum length of a cache key for Memcached. |
| */ |
| const MAX_KEY_LENGTH = 249; |
| |
| /** |
| * Holds an instance to a Memcache object. |
| * |
| * @var resource |
| */ |
| protected $memcache; |
| |
| /** |
| * Holds the options for this class. |
| * |
| * @var ezcCacheStorageMemcacheOptions |
| */ |
| protected $options; |
| |
| /** |
| * Stores the connections to Memcached. |
| * |
| * @var array(string=>Memcache) |
| */ |
| protected static $connections = array(); |
| |
| /** |
| * Keeps track of the number of backends using the same connection. |
| * |
| * This is to avoid that the dtor of a backend accedentally closes a |
| * connection that is still in used by another backend. |
| * |
| * @var array(string=>int) |
| */ |
| protected static $connectionCounter = array(); |
| |
| /** |
| * Stores the connection identifier. |
| * |
| * This is generated in the ctor and used in the dtor. |
| * |
| * @var string |
| */ |
| protected $connectionIdentifier; |
| |
| /** |
| * Constructs a new ezcCacheMemcacheBackend object. |
| * |
| * For options for this backend see {@link ezcCacheStorageMemcacheOptions}. |
| * |
| * @throws ezcBaseExtensionNotFoundException |
| * If the PHP memcache and zlib extensions are not installed. |
| * @throws ezcCacheMemcacheException |
| * If the connection to the Memcache host did not succeed. |
| * |
| * @param array(string=>mixed) $options |
| */ |
| public function __construct( array $options = array() ) |
| { |
| if ( !ezcBaseFeatures::hasExtensionSupport( 'memcache' ) ) |
| { |
| throw new ezcBaseExtensionNotFoundException( 'memcache', null, "PHP does not have Memcache support." ); |
| } |
| |
| if ( !ezcBaseFeatures::hasExtensionSupport( 'zlib' ) ) |
| { |
| throw new ezcBaseExtensionNotFoundException( 'zlib', null, "PHP not configured with --with-zlib." ); |
| } |
| |
| $this->options = new ezcCacheStorageMemcacheOptions( $options ); |
| |
| $this->connectionIdentifier = $this->options->host . ':' . $this->options->port; |
| if ( !isset( self::$connections[$this->connectionIdentifier] ) ) |
| { |
| self::$connections[$this->connectionIdentifier] = new Memcache(); |
| // Currently 0 backends use the connection |
| self::$connectionCounter[$this->connectionIdentifier] = 0; |
| } |
| |
| $this->memcache = self::$connections[$this->connectionIdentifier]; |
| // Now 1 backend uses it |
| self::$connectionCounter[$this->connectionIdentifier]++; |
| if ( $this->options->persistent === true ) |
| { |
| if ( !@$this->memcache->pconnect( $this->options->host, $this->options->port, $this->options->ttl ) ) |
| { |
| throw new ezcCacheMemcacheException( 'Could not connect to Memcache using a persistent connection.' ); |
| } |
| } |
| else |
| { |
| if ( !@$this->memcache->connect( $this->options->host, $this->options->port, $this->options->ttl ) ) |
| { |
| throw new ezcCacheMemcacheException( 'Could not connect to Memcache.' ); |
| } |
| } |
| |
| $this->memcache->setCompressThreshold( self::COMPRESS_THRESHOLD ); |
| } |
| |
| /** |
| * Destructor for the Memcache backend. |
| */ |
| public function __destruct() |
| { |
| self::$connectionCounter[$this->connectionIdentifier]--; |
| // Save to ignore persistent connections, since close() does not affect them |
| if ( self::$connectionCounter[$this->connectionIdentifier] === 0 ) |
| { |
| $this->memcache->close(); |
| } |
| } |
| |
| /** |
| * Adds the $var data to the cache under the key $key. Returns true or |
| * false depending on the success of the operation. |
| * |
| * @param string $key |
| * @param mixed $var |
| * @param int $expire |
| * @return bool |
| */ |
| public function store( $key, $var, $expire = 0 ) |
| { |
| if ( strlen( $key ) > self::MAX_KEY_LENGTH ) |
| { |
| throw new ezcCacheInvalidKeyException( $key, 'Length > ' . self::MAX_KEY_LENGTH . '.' ); |
| } |
| |
| // protect our data by wrapping it in an object |
| $data = new ezcCacheMemoryVarStruct( $key, $var, $expire ); |
| $compressed = ( $this->options->compressed === true ) ? MEMCACHE_COMPRESSED : false; |
| return $this->memcache->set( $key, $data, $compressed, $expire ); |
| } |
| |
| /** |
| * Returns the data from the cache associated with key $key. |
| * |
| * @param mixed $key |
| * @return mixed |
| */ |
| public function fetch( $key ) |
| { |
| if ( strlen( $key ) > self::MAX_KEY_LENGTH ) |
| { |
| throw new ezcCacheInvalidKeyException( $key, 'Length > ' . self::MAX_KEY_LENGTH . '.' ); |
| } |
| |
| $data = $this->memcache->get( $key ); |
| return ( is_object( $data ) ) ? $data->var : false; |
| } |
| |
| /** |
| * Deletes the data from the cache associated with key $key. Returns true or |
| * false depending on the success of the operation. |
| * |
| * The value $timeout specifies the timeout period in seconds for the delete |
| * command. |
| * |
| * @param string $key |
| * @param int $timeout |
| * @return bool |
| */ |
| public function delete( $key, $timeout = 0 ) |
| { |
| if ( strlen( $key ) > self::MAX_KEY_LENGTH ) |
| { |
| throw new ezcCacheInvalidKeyException( $key, 'Length > ' . self::MAX_KEY_LENGTH . '.' ); |
| } |
| |
| return $this->memcache->delete( $key, $timeout ); |
| } |
| |
| /** |
| * Resets the complete backend. |
| * |
| * Marked private to not expose more of this interface to the user, since |
| * this will be removed in future versions. |
| * |
| * @return void |
| * @access private |
| */ |
| public function reset() |
| { |
| // Kills whole memcache content |
| $this->memcache->flush(); |
| } |
| |
| /** |
| * Acquires a lock on the given $key. |
| * |
| * @param string $key |
| * @param int $waitTime usleep() |
| * @param int $maxTime seconds |
| */ |
| public function acquireLock( $key, $waitTime, $maxTime ) |
| { |
| if ( strlen( $key ) > self::MAX_KEY_LENGTH ) |
| { |
| throw new ezcCacheInvalidKeyException( $key, 'Length > ' . self::MAX_KEY_LENGTH . '.' ); |
| } |
| |
| // add() does not replace and returns true on success. $maxTime is |
| // obeyed by Memcache expiry. |
| while ( $this->memcache->add( $key, $key, false, $maxTime ) === false ) |
| { |
| // Wait for next check |
| usleep( $waitTime ); |
| } |
| } |
| |
| /** |
| * Releases a lock on the given $key. |
| * |
| * @param string $key |
| * @return void |
| */ |
| public function releaseLock( $key ) |
| { |
| if ( strlen( $key ) > self::MAX_KEY_LENGTH ) |
| { |
| throw new ezcCacheInvalidKeyException( $key, 'Length > ' . self::MAX_KEY_LENGTH . '.' ); |
| } |
| |
| $this->memcache->delete( $key ); |
| } |
| |
| } |
| ?> |
