Add SQLite3 database driver
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
new file mode 100644
index 0000000..b82ae1e
--- /dev/null
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -0,0 +1,591 @@
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.1.6 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst. It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package	CodeIgniter
+ * @author	EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license	http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link	http://codeigniter.com
+ * @since	Version 1.0
+ * @filesource
+ */
+
+/**
+ * SQLite3 Database Adapter Class
+ *
+ * Note: _DB is an extender class that the app controller
+ * creates dynamically based on whether the active record
+ * class is being used or not.
+ *
+ * @package	CodeIgniter
+ * @subpackage	Drivers
+ * @category	Database
+ * @author	Andrey Andreev
+ * @link	http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_sqlite3_driver extends CI_DB {
+
+	public $dbdriver = 'sqlite3';
+
+	// The character used for escaping
+	public $_escape_char = '"';
+
+	// clause and character used for LIKE escape sequences
+	public $_like_escape_str = ' ESCAPE \'%s\' ';
+	public $_like_escape_chr = '!';
+
+	/**
+	 * The syntax to count rows is slightly different across different
+	 * database engines, so this string appears in each driver and is
+	 * used for the count_all() and count_all_results() functions.
+	 */
+	public $_count_string = 'SELECT COUNT(*) AS ';
+	public $_random_keyword = ' RANDOM()';
+
+	/**
+	 * Non-persistent database connection
+	 *
+	 * @return	object	type SQLite3
+	 */
+	public function db_connect()
+	{
+		try
+		{
+			return ( ! $this->password)
+				? new SQLite3($this->database)
+				: new SQLite3($this->database, SQLITE3_OPEN_READWRITE | SQLITE3_OPEN_CREATE, $this->password);
+		}
+		catch (Exception $e)
+		{
+			return FALSE;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Persistent database connection
+	 *
+	 * @return  object	type SQLite3
+	 */
+	public function db_pconnect()
+	{
+		log_message('debug', 'SQLite3 doesn\'t support persistent connections');
+		return $this->db_pconnect();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Reconnect
+	 *
+	 * Keep / reestablish the db connection if no queries have been
+	 * sent for a length of time exceeding the server's idle timeout
+	 *
+	 * @return	void
+	 */
+	public function reconnect()
+	{
+		// Not supported
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Select the database
+	 *
+	 * @return	bool
+	 */
+	public function db_select()
+	{
+		// Not needed, in SQLite every pseudo-connection is a database
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set client character set
+	 *
+	 * @param	string
+	 * @param	string
+	 * @return	bool
+	 */
+	public function db_set_charset($charset, $collation)
+	{
+		// Not (natively) supported
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Version number query string
+	 *
+	 * @return	string
+	 */
+	protected function _version()
+	{
+		return implode(' (', $this->conn_id->version()).')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Execute the query
+	 *
+	 * @param	string	an SQL query
+	 * @return	mixed	SQLite3Result object or bool
+	 */
+	protected function _execute($sql)
+	{
+		if ( ! preg_match('/^(SELECT|EXPLAIN).+$/i', ltrim($sql)))
+		{
+			return $this->conn_id->exec($sql);
+		}
+
+		// TODO: Implement use of SQLite3::querySingle(), if needed
+		// TODO: Use $this->_prep_query(), if needed
+		return $this->conn_id->query($sql);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Prep the query
+	 *
+	 * If needed, each database adapter can prep the query string
+	 *
+	 * @param	string	an SQL query
+	 * @return	string
+	 */
+	private function _prep_query($sql)
+	{
+		return $this->conn_id->prepare($sql);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @return	bool
+	 */
+	public function trans_begin($test_mode = FALSE)
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		// Reset the transaction failure flag.
+		// If the $test_mode flag is set to TRUE transactions will be rolled back
+		// even if the queries produce a successful result.
+		$this->_trans_failure = ($test_mode === TRUE);
+
+		return $this->conn_id->exec('BEGIN TRANSACTION');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return	bool
+	 */
+	public function trans_commit()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		return $this->conn_id->exec('END TRANSACTION');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return	bool
+	 */
+	public function trans_rollback()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		return $this->conn_id->exec('ROLLBACK');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Escape String
+	 *
+	 * @param	string
+	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @return	string
+	 */
+	public function escape_str($str, $like = FALSE)
+	{
+		if (is_array($str))
+		{
+			foreach ($str as $key => $val)
+			{
+				$str[$key] = $this->escape_str($val, $like);
+			}
+
+			return $str;
+		}
+
+		$str = $this->conn_id->escapeString(remove_invisible_characters($str));
+
+		// escape LIKE condition wildcards
+		if ($like === TRUE)
+		{
+			return str_replace(array('%', '_', $this->_like_escape_chr),
+						array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
+						$str);
+		}
+
+		return $str;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Affected Rows
+	 *
+	 * @return	int
+	 */
+	public function affected_rows()
+	{
+		return $this->conn_id->changes();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert ID
+	 *
+	 * @return	int
+	 */
+	public function insert_id()
+	{
+		return $this->conn_id->lastInsertRowID();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * "Count All" query
+	 *
+	 * Generates a platform-specific query string that counts all records in
+	 * the specified database
+	 *
+	 * @param	string
+	 * @return	int
+	 */
+	public function count_all($table = '')
+	{
+		if ($table == '')
+		{
+			return 0;
+		}
+
+		$result = $this->conn_id->querySingle($this->_count_string.$this->_protect_identifiers('numrows')
+							.' FROM '.$this->_protect_identifiers($table, TRUE, NULL, FALSE));
+
+		return empty($result) ? 0 : (int) $result;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Show table query
+	 *
+	 * Generates a platform-specific query string so that the table names can be fetched
+	 *
+	 * @param	bool
+	 * @return	string
+	 */
+	protected function _list_tables($prefix_limit = FALSE)
+	{
+		return 'SELECT "NAME" FROM "SQLITE_MASTER" WHERE "TYPE" = \'table\''
+			.(($prefix_limit !== FALSE && $this->dbprefix != '')
+				? ' AND "NAME" LIKE \''.$this->escape_like_str($this->dbprefix).'%\' '.sprintf($this->_like_escape_str, $this->_like_escape_chr)
+				: '');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Show column query
+	 *
+	 * Generates a platform-specific query string so that the column names can be fetched
+	 *
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	protected function _list_columns($table = '')
+	{
+		// Not supported
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field data query
+	 *
+	 * Generates a platform-specific query so that the column data can be retrieved
+	 *
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	protected function _field_data($table)
+	{
+		return 'SELECT * FROM '.$table.' LIMIT 0,1';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * The error message string
+	 *
+	 * @return	string
+	 */
+	protected function _error_message()
+	{
+		return $this->conn_id->lastErrorMsg();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * The error message number
+	 *
+	 * @return	int
+	 */
+	protected function _error_number()
+	{
+		return $this->conn_id->lastErrorCode();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Escape the SQL Identifiers
+	 *
+	 * This function escapes column and table names
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _escape_identifiers($item)
+	{
+		if ($this->_escape_char == '')
+		{
+			return $item;
+		}
+
+		foreach ($this->_reserved_identifiers as $id)
+		{
+			if (strpos($item, '.'.$id) !== FALSE)
+			{
+				$item = str_replace('.', $this->_escape_char.'.', $item);
+
+				// remove duplicates if the user already included the escape
+				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
+			}
+		}
+
+		if (strpos($item, '.') !== FALSE)
+		{
+			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
+		}
+
+		// remove duplicates if the user already included the escape
+		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * From Tables
+	 *
+	 * This function implicitly groups FROM tables so there is no confusion
+	 * about operator precedence in harmony with SQL standards
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _from_tables($tables)
+	{
+		if ( ! is_array($tables))
+		{
+			$tables = array($tables);
+		}
+
+		return '('.implode(', ', $tables).')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the insert keys
+	 * @param	array	the insert values
+	 * @return	string
+	 */
+	protected function _insert($table, $keys, $values)
+	{
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Update statement
+	 *
+	 * Generates a platform-specific update string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the update data
+	 * @param	array	the where clause
+	 * @param	array	the orderby clause
+	 * @param	array	the limit clause
+	 * @return	string
+	 */
+	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	{
+		foreach ($values as $key => $val)
+		{
+			$valstr[] = $key.' = '.$val;
+		}
+
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
+			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
+			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
+			.( ! $limit ? '' : ' LIMIT '.$limit);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Truncate statement
+	 *
+	 * Generates a platform-specific truncate string from the supplied data
+	 * If the database does not support the truncate() command, then
+	 * this method maps to "DELETE FROM table"
+	 *
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	protected function _truncate($table)
+	{
+		return $this->_delete($table);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete statement
+	 *
+	 * Generates a platform-specific delete string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the where clause
+	 * @param	string	the limit clause
+	 * @return	string
+	 */
+	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	{
+		$conditions = '';
+		if (count($where) > 0 OR count($like) > 0)
+		{
+			$conditions .= "\nWHERE ".implode("\n", $this->ar_where);
+
+			if (count($where) > 0 && count($like) > 0)
+			{
+				$conditions .= ' AND ';
+			}
+			$conditions .= implode("\n", $like);
+		}
+
+		return 'DELETE FROM '.$table.$conditions.( ! $limit ? '' : ' LIMIT '.$limit);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Limit string
+	 *
+	 * Generates a platform-specific LIMIT clause
+	 *
+	 * @param	string	the sql query string
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
+	 * @return	string
+	 */
+	protected function _limit($sql, $limit, $offset)
+	{
+		return $sql.($offset ? $offset.',' : '').$limit;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Close DB Connection
+	 *
+	 * @return	void
+	 */
+	protected function _close()
+	{
+		$this->conn_id->close();
+	}
+
+}
+
+/* End of file sqlite3_driver.php */
+/* Location: ./system/database/drivers/sqlite3/sqlite3_driver.php */