1: <?php
  2: 
  3: /**
  4:  * This file is part of the Nette Framework (https://nette.org)
  5:  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  6:  */
  7: 
  8: namespace Nette\Caching\Storages;
  9: 
 10: use Nette;
 11: use Nette\Caching\Cache;
 12: 
 13: 
 14: /**
 15:  * SQLite storage.
 16:  *
 17:  * @author     David Grudl
 18:  */
 19: class SQLiteStorage extends Nette\Object implements Nette\Caching\IStorage
 20: {
 21:     /** @var \PDO */
 22:     private $pdo;
 23: 
 24: 
 25:     public function __construct($path = ':memory:')
 26:     {
 27:         $this->pdo = new \PDO('sqlite:' . $path, NULL, NULL, array(\PDO::ATTR_PERSISTENT => TRUE));
 28:         $this->pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
 29:         $this->pdo->exec('
 30:             PRAGMA foreign_keys = ON;
 31:             CREATE TABLE IF NOT EXISTS cache (
 32:                 key BLOB NOT NULL PRIMARY KEY,
 33:                 data BLOB NOT NULL
 34:             );
 35:             CREATE TABLE IF NOT EXISTS tags (
 36:                 key BLOB NOT NULL REFERENCES cache ON DELETE CASCADE,
 37:                 tag BLOB NOT NULL
 38:             );
 39:             CREATE INDEX IF NOT EXISTS tags_key ON tags(key);
 40:             CREATE INDEX IF NOT EXISTS tags_tag ON tags(tag);
 41:         ');
 42:     }
 43: 
 44: 
 45:     /**
 46:      * Read from cache.
 47:      * @param  string key
 48:      * @return mixed|NULL
 49:      */
 50:     public function read($key)
 51:     {
 52:         $stmt = $this->pdo->prepare('SELECT data FROM cache WHERE key=?');
 53:         $stmt->execute(array($key));
 54:         if ($res = $stmt->fetchColumn()) {
 55:             return unserialize($res);
 56:         }
 57:     }
 58: 
 59: 
 60:     /**
 61:      * Prevents item reading and writing. Lock is released by write() or remove().
 62:      * @param  string key
 63:      * @return void
 64:      */
 65:     public function lock($key)
 66:     {
 67:     }
 68: 
 69: 
 70:     /**
 71:      * Writes item into the cache.
 72:      * @param  string key
 73:      * @param  mixed  data
 74:      * @param  array  dependencies
 75:      * @return void
 76:      */
 77:     public function write($key, $data, array $dependencies)
 78:     {
 79:         $this->pdo->exec('BEGIN TRANSACTION');
 80:         $this->pdo->prepare('REPLACE INTO cache (key, data) VALUES (?, ?)')
 81:             ->execute(array($key, serialize($data)));
 82: 
 83:         if (!empty($dependencies[Cache::TAGS])) {
 84:             foreach ((array) $dependencies[Cache::TAGS] as $tag) {
 85:                 $arr[] = $key;
 86:                 $arr[] = $tag;
 87:             }
 88:             $this->pdo->prepare('INSERT INTO tags (key, tag) SELECT ?, ?' . str_repeat('UNION SELECT ?, ?', count($arr) / 2 - 1))
 89:                 ->execute($arr);
 90:         }
 91:         $this->pdo->exec('COMMIT');
 92:     }
 93: 
 94: 
 95:     /**
 96:      * Removes item from the cache.
 97:      * @param  string key
 98:      * @return void
 99:      */
100:     public function remove($key)
101:     {
102:         $this->pdo->prepare('DELETE FROM cache WHERE key=?')
103:             ->execute(array($key));
104:     }
105: 
106: 
107:     /**
108:      * Removes items from the cache by conditions & garbage collector.
109:      * @param  array  conditions
110:      * @return void
111:      */
112:     public function clean(array $conditions)
113:     {
114:         if (!empty($conditions[Cache::ALL])) {
115:             $this->pdo->prepare('DELETE FROM cache')->execute();
116: 
117:         } elseif (!empty($conditions[Cache::TAGS])) {
118:             $tags = (array) $conditions[Cache::TAGS];
119:             $this->pdo->prepare('DELETE FROM cache WHERE key IN (SELECT key FROM tags WHERE tag IN (?'
120:                 . str_repeat(',?', count($tags) - 1) . '))')->execute($tags);
121:         }
122:     }
123: 
124: }
125: