<?php
/***********************************************************************

  Copyright (C) 2002-2008  PunBB

  This file is part of PunBB.

  PunBB is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.

  PunBB is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  MA  02111-1307  USA

************************************************************************/


// Make sure we have built in support for MySQL
if (!function_exists('mysql_connect'))
	exit('This PHP environment doesn\'t have MySQL support built in. MySQL support is required if you want to use a MySQL database to run this forum. Consult the PHP documentation for further assistance.');


class DBLayer
{
	var $prefix;
	var $link_id;
	var $query_result;

	var $saved_queries = array();
	var $num_queries = 0;


	function DBLayer($db_host, $db_username, $db_password, $db_name, $db_prefix, $p_connect)
	{
		$this->prefix = $db_prefix;

		if ($p_connect)
			$this->link_id = @mysql_pconnect($db_host, $db_username, $db_password);
		else
			$this->link_id = @mysql_connect($db_host, $db_username, $db_password);

		if ($this->link_id)
		{
			if (@mysql_select_db($db_name, $this->link_id))
				return $this->link_id;
			else
				error('Unable to select database. MySQL reported: '.mysql_error(), __FILE__, __LINE__);
		}
		else
			error('Unable to connect to MySQL server. MySQL reported: '.mysql_error(), __FILE__, __LINE__);
	}


	function start_transaction()
	{
		return;
	}


	function end_transaction()
	{
		return;
	}


	function query($sql, $unbuffered = false)
	{
		if (defined('PUN_SHOW_QUERIES'))
			$q_start = get_microtime();

		if ($unbuffered)
			$this->query_result = @mysql_unbuffered_query($sql, $this->link_id);
		else
			$this->query_result = @mysql_query($sql, $this->link_id);

		if ($this->query_result)
		{
			if (defined('PUN_SHOW_QUERIES'))
				$this->saved_queries[] = array($sql, sprintf('%.5f', get_microtime() - $q_start));

			++$this->num_queries;

			return $this->query_result;
		}
		else
		{
			if (defined('PUN_SHOW_QUERIES'))
				$this->saved_queries[] = array($sql, 0);

			return false;
		}
	}


	function result($query_id = 0, $row = 0)
	{
		return ($query_id) ? @mysql_result($query_id, $row) : false;
	}


	function fetch_assoc($query_id = 0)
	{
		return ($query_id) ? @mysql_fetch_assoc($query_id) : false;
	}


	function fetch_row($query_id = 0)
	{
		return ($query_id) ? @mysql_fetch_row($query_id) : false;
	}


	function num_rows($query_id = 0)
	{
		return ($query_id) ? @mysql_num_rows($query_id) : false;
	}


	function affected_rows()
	{
		return ($this->link_id) ? @mysql_affected_rows($this->link_id) : false;
	}


	function insert_id()
	{
		return ($this->link_id) ? @mysql_insert_id($this->link_id) : false;
	}


	function get_num_queries()
	{
		return $this->num_queries;
	}


	function get_saved_queries()
	{
		return $this->saved_queries;
	}


	function free_result($query_id = false)
	{
		return ($query_id) ? @mysql_free_result($query_id) : false;
	}


	function escape($str)
	{
		if (is_array($str))
			return '';
		else if (function_exists('mysql_real_escape_string'))
			return mysql_real_escape_string($str, $this->link_id);
		else
			return mysql_escape_string($str);
	}


	function error()
	{
		$result['error_sql'] = @current(@end($this->saved_queries));
		$result['error_no'] = @mysql_errno($this->link_id);
		$result['error_msg'] = @mysql_error($this->link_id);

		return $result;
	}


	function close()
	{
		if ($this->link_id)
		{
			if ($this->query_result)
				@mysql_free_result($this->query_result);

			return @mysql_close($this->link_id);
		}
		else
			return false;
	}
}
