Enable all cache drivers, and add initial implementation of SQLite driver

common/framework/cache.php

@@ -34,7 +34,7 @@ class Cache
 		{
 			$class_name = '\\Rhymix\\Framework\\Drivers\\Cache\\' . $config['driver'];
 		}
-		elseif (preg_match('/^(apc|memcache|redis|wincache|file)/', strval(array_first($config)), $matches))
+		elseif (preg_match('/^(apc|dummy|file|memcache|redis|sqlite|wincache|xcache)/', strval(array_first($config)), $matches))
 		{
 			$class_name = '\\Rhymix\\Framework\\Drivers\\Cache\\' . $matches[1] . ($matches[1] === 'memcache' ? 'd' : '');
 		}

common/framework/drivers/cache/sqlite.php

@@ -0,0 +1,241 @@
+<?php
+
+namespace Rhymix\Framework\Drivers\Cache;
+
+use Rhymix\Framework\Storage;
+
+/**
+ * The SQLite cache driver.
+ */
+class SQLite implements \Rhymix\Framework\Drivers\CacheInterface
+{
+	/**
+	 * The database handle and prepared statements are stored here.
+	 */
+	protected $_dbh = null;
+	protected $_ps = array();
+	
+	/**
+	 * Create a new instance of the current cache driver, using the given settings.
+	 * 
+	 * @param array $config
+	 * @return void
+	 */
+	public function __construct(array $config)
+	{
+		$dir = \RX_BASEDIR . 'files/cache/store';
+		if (!Storage::isDirectory($dir))
+		{
+			Storage::createDirectory($dir);
+		}
+		
+		$key = substr(hash_hmac('sha256', $dir, config('crypto.authentication_key')), 0, 32);
+		$filename = "$dir/$key.db";
+		if (Storage::exists($filename))
+		{
+			$this->_connect($filename);
+		}
+		else
+		{
+			$this->_connect($filename);
+			for ($i = 0; $i < 32; $i++)
+			{
+				$this->_dbh->exec('CREATE TABLE cache_' . $i . ' (k TEXT PRIMARY KEY, v TEXT, exp INT)');
+			}
+		}
+	}
+	
+	/**
+	 * Connect to an SQLite3 database.
+	 * 
+	 * @param string $filename
+	 * @return void
+	 */
+	protected function _connect($filename)
+	{
+		$this->_dbh = new \SQLite3($filename);
+		$this->_dbh->exec('PRAGMA journal_mode = MEMORY');
+		$this->_dbh->exec('PRAGMA synchronous = OFF');
+	}
+	
+	/**
+	 * Check if the current cache driver is supported on this server.
+	 * 
+	 * This method returns true on success and false on failure.
+	 * 
+	 * @return bool
+	 */
+	public function isSupported()
+	{
+		return class_exists('\\SQLite3');
+	}
+	
+	/**
+	 * Validate cache settings.
+	 * 
+	 * This method returns true on success and false on failure.
+	 * 
+	 * @param mixed $config
+	 * @return bool
+	 */
+	public static function validateSettings($config)
+	{
+		return true;
+	}
+	
+	/**
+	 * Get the value of a key.
+	 * 
+	 * This method returns null if the key was not found.
+	 * 
+	 * @param string $key
+	 * @return mixed
+	 */
+	public function get($key)
+	{
+		$table = 'cache_' . (crc32($key) % 32);
+		$stmt = $this->_dbh->prepare('SELECT v, exp FROM ' . $table . ' WHERE k = :key');
+		$stmt->bindValue(':key', $key, \SQLITE3_TEXT);
+		$result = $stmt->execute();
+		$row = $result->fetchArray(\SQLITE3_NUM);
+		if ($row)
+		{
+			if ($row[1] == 0 || $row[1] >= time())
+			{
+				return unserialize($row[0]);
+			}
+			else
+			{
+				$this->delete($key);
+				return null;
+			}
+		}
+		else
+		{
+			return null;
+		}
+	}
+	
+	/**
+	 * Set the value to a key.
+	 * 
+	 * This method returns true on success and false on failure.
+	 * $ttl is measured in seconds. If it is zero, the key should not expire.
+	 * 
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl
+	 * @return bool
+	 */
+	public function set($key, $value, $ttl)
+	{
+		$table = 'cache_' . (crc32($key) % 32);
+		$stmt = $this->_dbh->prepare('INSERT OR REPLACE INTO ' . $table . ' (k, v, exp) VALUES (:key, :val, :exp)');
+		$stmt->bindValue(':key', $key, \SQLITE3_TEXT);
+		$stmt->bindValue(':val', serialize($value), \SQLITE3_TEXT);
+		$stmt->bindValue(':exp', $ttl ? (time() + $ttl) : 0, \SQLITE3_INTEGER);
+		return $stmt->execute() ? true : false;
+	}
+	
+	/**
+	 * Delete a key.
+	 * 
+	 * This method returns true on success and false on failure.
+	 * If the key does not exist, it should return false.
+	 * 
+	 * @param string $key
+	 * @return bool
+	 */
+	public function delete($key)
+	{
+		$table = 'cache_' . (crc32($key) % 32);
+		$stmt = $this->_dbh->prepare('DELETE FROM ' . $table . ' WHERE k = :key');
+		$stmt->bindValue(':key', $key, \SQLITE3_TEXT);
+		return $stmt->execute() ? true : false;
+	}
+	
+	/**
+	 * Check if a key exists.
+	 * 
+	 * This method returns true on success and false on failure.
+	 * 
+	 * @param string $key
+	 * @return bool
+	 */
+	public function exists($key)
+	{
+		$table = 'cache_' . (crc32($key) % 32);
+		$stmt = $this->_dbh->prepare('SELECT 1 FROM ' . $table . ' WHERE k = :key AND (exp = 0 OR exp >= :exp)');
+		$stmt->bindValue(':key', $key, \SQLITE3_TEXT);
+		$stmt->bindValue(':exp', time(), \SQLITE3_INTEGER);
+		$result = $stmt->execute();
+		$row = $result->fetchArray(\SQLITE3_NUM);
+		if ($row)
+		{
+			return true;
+		}
+		else
+		{
+			return false;
+		}
+	}
+	
+	/**
+	 * Increase the value of a key by $amount.
+	 * 
+	 * If the key does not exist, this method assumes that the current value is zero.
+	 * This method returns the new value.
+	 * 
+	 * @param string $key
+	 * @param int $amount
+	 * @return int
+	 */
+	public function incr($key, $amount)
+	{
+		$current_value = $this->get($key);
+		$new_value = intval($current_value) + $amount;
+		if ($this->set($key, $new_value))
+		{
+			return $new_value;
+		}
+		else
+		{
+			return false;
+		}
+	}
+	
+	/**
+	 * Decrease the value of a key by $amount.
+	 * 
+	 * If the key does not exist, this method assumes that the current value is zero.
+	 * This method returns the new value.
+	 * 
+	 * @param string $key
+	 * @param int $amount
+	 * @return int
+	 */
+	public function decr($key, $amount)
+	{
+		return $this->incr($key, 0 - $amount);
+	}
+	
+	/**
+	 * Clear all keys from the cache.
+	 * 
+	 * This method returns true on success and false on failure.
+	 * 
+	 * @return bool
+	 */
+	public function clear()
+	{
+		for ($i = 0; $i < 32; $i++)
+		{
+			$this->_dbh->exec('DROP TABLE cache_' . $i);
+		}
+		
+		for ($i = 0; $i < 32; $i++)
+		{
+			$this->_dbh->exec('CREATE TABLE cache_' . $i . ' (k TEXT PRIMARY KEY, v TEXT, exp INT)');
+		}
+	}
+}