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			332 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
			
		
		
	
	
			332 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
| <?php
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| /**
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|  * @link http://www.yiiframework.com/
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|  * @copyright Copyright (c) 2008 Yii Software LLC
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|  * @license http://www.yiiframework.com/license/
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|  */
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| 
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| namespace yii\caching;
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| 
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| use Yii;
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| use yii\base\InvalidConfigException;
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| use yii\db\Connection;
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| use yii\db\PdoValue;
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| use yii\db\Query;
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| use yii\di\Instance;
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| 
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| /**
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|  * DbCache implements a cache application component by storing cached data in a database.
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|  *
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|  * By default, DbCache stores session data in a DB table named 'cache'. This table
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|  * must be pre-created. The table name can be changed by setting [[cacheTable]].
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|  *
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|  * Please refer to [[Cache]] for common cache operations that are supported by DbCache.
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|  *
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|  * The following example shows how you can configure the application to use DbCache:
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|  *
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|  * ```php
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|  * 'cache' => [
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|  *     'class' => 'yii\caching\DbCache',
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|  *     // 'db' => 'mydb',
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|  *     // 'cacheTable' => 'my_cache',
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|  * ]
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|  * ```
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|  *
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|  * For more details and usage information on Cache, see the [guide article on caching](guide:caching-overview).
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|  *
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|  * @author Qiang Xue <qiang.xue@gmail.com>
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|  * @since 2.0
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|  */
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| class DbCache extends Cache
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| {
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|     /**
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|      * @var Connection|array|string the DB connection object or the application component ID of the DB connection.
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|      * After the DbCache object is created, if you want to change this property, you should only assign it
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|      * with a DB connection object.
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|      * Starting from version 2.0.2, this can also be a configuration array for creating the object.
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|      */
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|     public $db = 'db';
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|     /**
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|      * @var string name of the DB table to store cache content.
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|      * The table should be pre-created as follows:
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|      *
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|      * ```php
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|      * CREATE TABLE cache (
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|      *     id char(128) NOT NULL PRIMARY KEY,
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|      *     expire int(11),
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|      *     data BLOB
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|      * );
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|      * ```
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|      *
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|      * For MSSQL:
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|      * ```php
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|      * CREATE TABLE cache (
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|      *     id VARCHAR(128) NOT NULL PRIMARY KEY,
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|      *     expire INT(11),
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|      *     data VARBINARY(MAX)
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|      * );
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|      * ```
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|      *
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|      * where 'BLOB' refers to the BLOB-type of your preferred DBMS. Below are the BLOB type
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|      * that can be used for some popular DBMS:
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|      *
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|      * - MySQL: LONGBLOB
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|      * - PostgreSQL: BYTEA
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|      *
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|      * When using DbCache in a production server, we recommend you create a DB index for the 'expire'
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|      * column in the cache table to improve the performance.
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|      */
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|     public $cacheTable = '{{%cache}}';
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|     /**
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|      * @var int the probability (parts per million) that garbage collection (GC) should be performed
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|      * when storing a piece of data in the cache. Defaults to 100, meaning 0.01% chance.
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|      * This number should be between 0 and 1000000. A value 0 meaning no GC will be performed at all.
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|      */
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|     public $gcProbability = 100;
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| 
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|     protected $isVarbinaryDataField;
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| 
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| 
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|     /**
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|      * Initializes the DbCache component.
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|      * This method will initialize the [[db]] property to make sure it refers to a valid DB connection.
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|      * @throws InvalidConfigException if [[db]] is invalid.
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|      */
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|     public function init()
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|     {
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|         parent::init();
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|         $this->db = Instance::ensure($this->db, Connection::className());
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|     }
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| 
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|     /**
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|      * Checks whether a specified key exists in the cache.
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|      * This can be faster than getting the value from the cache if the data is big.
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|      * Note that this method does not check whether the dependency associated
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|      * with the cached data, if there is any, has changed. So a call to [[get]]
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|      * may return false while exists returns true.
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|      * @param mixed $key a key identifying the cached value. This can be a simple string or
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|      * a complex data structure consisting of factors representing the key.
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|      * @return bool true if a value exists in cache, false if the value is not in the cache or expired.
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|      */
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|     public function exists($key)
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|     {
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|         $key = $this->buildKey($key);
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| 
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|         $query = new Query();
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|         $query->select(['COUNT(*)'])
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|             ->from($this->cacheTable)
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|             ->where('[[id]] = :id AND ([[expire]] = 0 OR [[expire]] >' . time() . ')', [':id' => $key]);
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|         if ($this->db->enableQueryCache) {
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|             // temporarily disable and re-enable query caching
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|             $this->db->enableQueryCache = false;
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|             $result = $query->createCommand($this->db)->queryScalar();
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|             $this->db->enableQueryCache = true;
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|         } else {
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|             $result = $query->createCommand($this->db)->queryScalar();
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|         }
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| 
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|         return $result > 0;
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|     }
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| 
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|     /**
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|      * Retrieves a value from cache with a specified key.
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|      * This is the implementation of the method declared in the parent class.
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|      * @param string $key a unique key identifying the cached value
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|      * @return string|false the value stored in cache, false if the value is not in the cache or expired.
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|      */
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|     protected function getValue($key)
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|     {
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|         $query = new Query();
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|         $query->select([$this->getDataFieldName()])
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|             ->from($this->cacheTable)
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|             ->where('[[id]] = :id AND ([[expire]] = 0 OR [[expire]] >' . time() . ')', [':id' => $key]);
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|         if ($this->db->enableQueryCache) {
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|             // temporarily disable and re-enable query caching
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|             $this->db->enableQueryCache = false;
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|             $result = $query->createCommand($this->db)->queryScalar();
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|             $this->db->enableQueryCache = true;
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| 
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|             return $result;
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|         }
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| 
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|         return $query->createCommand($this->db)->queryScalar();
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|     }
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| 
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|     /**
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|      * Retrieves multiple values from cache with the specified keys.
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|      * @param array $keys a list of keys identifying the cached values
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|      * @return array a list of cached values indexed by the keys
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|      */
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|     protected function getValues($keys)
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|     {
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|         if (empty($keys)) {
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|             return [];
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|         }
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|         $query = new Query();
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|         $query->select(['id', $this->getDataFieldName()])
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|             ->from($this->cacheTable)
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|             ->where(['id' => $keys])
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|             ->andWhere('([[expire]] = 0 OR [[expire]] > ' . time() . ')');
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| 
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|         if ($this->db->enableQueryCache) {
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|             $this->db->enableQueryCache = false;
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|             $rows = $query->createCommand($this->db)->queryAll();
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|             $this->db->enableQueryCache = true;
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|         } else {
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|             $rows = $query->createCommand($this->db)->queryAll();
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|         }
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| 
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|         $results = [];
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|         foreach ($keys as $key) {
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|             $results[$key] = false;
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|         }
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|         foreach ($rows as $row) {
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|             if (is_resource($row['data']) && get_resource_type($row['data']) === 'stream') {
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|                 $results[$row['id']] = stream_get_contents($row['data']);
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|             } else {
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|                 $results[$row['id']] = $row['data'];
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|             }
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|         }
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| 
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|         return $results;
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|     }
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| 
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|     /**
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|      * Stores a value identified by a key in cache.
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|      * This is the implementation of the method declared in the parent class.
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|      *
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|      * @param string $key the key identifying the value to be cached
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|      * @param string $value the value to be cached. Other types (if you have disabled [[serializer]]) cannot be saved.
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|      * @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
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|      * @return bool true if the value is successfully stored into cache, false otherwise
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|      */
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|     protected function setValue($key, $value, $duration)
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|     {
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|         try {
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|             $this->db->noCache(function (Connection $db) use ($key, $value, $duration) {
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|                 $db->createCommand()->upsert($this->cacheTable, [
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|                     'id' => $key,
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|                     'expire' => $duration > 0 ? $duration + time() : 0,
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|                     'data' => $this->getDataFieldValue($value),
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|                 ])->execute();
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|             });
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| 
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|             $this->gc();
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| 
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|             return true;
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|         } catch (\Exception $e) {
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|             Yii::warning("Unable to update or insert cache data: {$e->getMessage()}", __METHOD__);
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| 
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|             return false;
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|         }
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|     }
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| 
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|     /**
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|      * Stores a value identified by a key into cache if the cache does not contain this key.
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|      * This is the implementation of the method declared in the parent class.
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|      *
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|      * @param string $key the key identifying the value to be cached
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|      * @param string $value the value to be cached. Other types (if you have disabled [[serializer]]) cannot be saved.
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|      * @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
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|      * @return bool true if the value is successfully stored into cache, false otherwise
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|      */
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|     protected function addValue($key, $value, $duration)
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|     {
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|         $this->gc();
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| 
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|         try {
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|             $this->db->noCache(function (Connection $db) use ($key, $value, $duration) {
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|                 $db->createCommand()
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|                     ->insert($this->cacheTable, [
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|                         'id' => $key,
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|                         'expire' => $duration > 0 ? $duration + time() : 0,
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|                         'data' => $this->getDataFieldValue($value),
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|                     ])->execute();
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|             });
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| 
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|             return true;
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|         } catch (\Exception $e) {
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|             Yii::warning("Unable to insert cache data: {$e->getMessage()}", __METHOD__);
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| 
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|             return false;
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|         }
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|     }
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| 
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|     /**
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|      * Deletes a value with the specified key from cache
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|      * This is the implementation of the method declared in the parent class.
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|      * @param string $key the key of the value to be deleted
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|      * @return bool if no error happens during deletion
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|      */
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|     protected function deleteValue($key)
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|     {
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|         $this->db->noCache(function (Connection $db) use ($key) {
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|             $db->createCommand()
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|                 ->delete($this->cacheTable, ['id' => $key])
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|                 ->execute();
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|         });
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| 
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|         return true;
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|     }
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| 
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|     /**
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|      * Removes the expired data values.
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|      * @param bool $force whether to enforce the garbage collection regardless of [[gcProbability]].
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|      * Defaults to false, meaning the actual deletion happens with the probability as specified by [[gcProbability]].
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|      */
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|     public function gc($force = false)
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|     {
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| 
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|         if ($force || random_int(0, 1000000) < $this->gcProbability) {
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|             $this->db->createCommand()
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|                 ->delete($this->cacheTable, '[[expire]] > 0 AND [[expire]] < ' . time())
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|                 ->execute();
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|         }
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|     }
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| 
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|     /**
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|      * Deletes all values from cache.
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|      * This is the implementation of the method declared in the parent class.
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|      * @return bool whether the flush operation was successful.
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|      */
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|     protected function flushValues()
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|     {
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|         $this->db->createCommand()
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|             ->delete($this->cacheTable)
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|             ->execute();
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| 
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|         return true;
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|     }
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| 
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|     /**
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|      * @return bool whether field is MSSQL varbinary
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|      * @since 2.0.42
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|      */
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|     protected function isVarbinaryDataField()
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|     {
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|         if ($this->isVarbinaryDataField === null) {
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|             $this->isVarbinaryDataField = in_array($this->db->getDriverName(), ['sqlsrv', 'dblib']) &&
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|                 $this->db->getTableSchema($this->cacheTable)->columns['data']->dbType === 'varbinary';
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|         }
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|         return $this->isVarbinaryDataField;
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|     }
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| 
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|     /**
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|      * @return string `data` field name converted for usage in MSSQL (if needed)
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|      * @since 2.0.42
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|      */
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|     protected function getDataFieldName()
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|     {
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|         return $this->isVarbinaryDataField() ? 'convert(nvarchar(max),[data]) data' : 'data';
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|     }
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| 
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|     /**
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|      * @return PdoValue PdoValue or direct $value for usage in MSSQL
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|      * @since 2.0.42
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|      */
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|     protected function getDataFieldValue($value)
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|     {
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|         return $this->isVarbinaryDataField() ? $value : new PdoValue($value, \PDO::PARAM_LOB);
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|     }
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| }
 | 
