<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP 5.1.6 or newer

 *

 * @package		CodeIgniter

 * @author		ExpressionEngine Dev Team

 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.

 * @license		http://codeigniter.com/user_guide/license.html

 * @link		http://codeigniter.com

 * @since		Version 1.0

 * @filesource

 */



// ------------------------------------------------------------------------



/**

 * Output Class

 *

 * Responsible for sending final output to browser

 *

 * @package		CodeIgniter

 * @subpackage	Libraries

 * @category	Output

 * @author		ExpressionEngine Dev Team

 * @link		http://codeigniter.com/user_guide/libraries/output.html

 */

class CI_Output {



	/**

	 * Current output string

	 *

	 * @var string

	 * @access 	protected

	 */

	protected $final_output;

	/**

	 * Cache expiration time

	 *

	 * @var int

	 * @access 	protected

	 */

	protected $cache_expiration	= 0;

	/**

	 * List of server headers

	 *

	 * @var array

	 * @access 	protected

	 */

	protected $headers			= array();

	/**

	 * List of mime types

	 *

	 * @var array

	 * @access 	protected

	 */

	protected $mime_types		= array();

	/**

	 * Determines wether profiler is enabled

	 *

	 * @var book

	 * @access 	protected

	 */

	protected $enable_profiler	= FALSE;

	/**

	 * Determines if output compression is enabled

	 *

	 * @var bool

	 * @access 	protected

	 */

	protected $_zlib_oc			= FALSE;

	/**

	 * List of profiler sections

	 *

	 * @var array

	 * @access 	protected

	 */

	protected $_profiler_sections = array();

	/**

	 * Whether or not to parse variables like {elapsed_time} and {memory_usage}

	 *

	 * @var bool

	 * @access 	protected

	 */

	protected $parse_exec_vars	= TRUE;



	/**

	 * Constructor

	 *

	 */

	function __construct()

	{

		$this->_zlib_oc = @ini_get('zlib.output_compression');



		// Get mime types for later

		if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))

		{

		    include APPPATH.'config/'.ENVIRONMENT.'/mimes.php';

		}

		else

		{

			include APPPATH.'config/mimes.php';

		}





		$this->mime_types = $mimes;



		log_message('debug', "Output Class Initialized");

	}



	// --------------------------------------------------------------------



	/**

	 * Get Output

	 *

	 * Returns the current output string

	 *

	 * @access	public

	 * @return	string

	 */

	function get_output()

	{

		return $this->final_output;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Output

	 *

	 * Sets the output string

	 *

	 * @access	public

	 * @param	string

	 * @return	void

	 */

	function set_output($output)

	{

		$this->final_output = $output;



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Append Output

	 *

	 * Appends data onto the output string

	 *

	 * @access	public

	 * @param	string

	 * @return	void

	 */

	function append_output($output)

	{

		if ($this->final_output == '')

		{

			$this->final_output = $output;

		}

		else

		{

			$this->final_output .= $output;

		}



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Header

	 *

	 * Lets you set a server header which will be outputted with the final display.

	 *

	 * Note:  If a file is cached, headers will not be sent.  We need to figure out

	 * how to permit header data to be saved with the cache data...

	 *

	 * @access	public

	 * @param	string

	 * @param 	bool

	 * @return	void

	 */

	function set_header($header, $replace = TRUE)

	{

		// If zlib.output_compression is enabled it will compress the output,

		// but it will not modify the content-length header to compensate for

		// the reduction, causing the browser to hang waiting for more data.

		// We'll just skip content-length in those cases.



		if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) == 0)

		{

			return;

		}



		$this->headers[] = array($header, $replace);



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Content Type Header

	 *

	 * @access	public

	 * @param	string	extension of the file we're outputting

	 * @return	void

	 */

	function set_content_type($mime_type)

	{

		if (strpos($mime_type, '/') === FALSE)

		{

			$extension = ltrim($mime_type, '.');



			// Is this extension supported?

			if (isset($this->mime_types[$extension]))

			{

				$mime_type =& $this->mime_types[$extension];



				if (is_array($mime_type))

				{

					$mime_type = current($mime_type);

				}

			}

		}



		$header = 'Content-Type: '.$mime_type;



		$this->headers[] = array($header, TRUE);



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Set HTTP Status Header

	 * moved to Common procedural functions in 1.7.2

	 *

	 * @access	public

	 * @param	int		the status code

	 * @param	string

	 * @return	void

	 */

	function set_status_header($code = 200, $text = '')

	{

		set_status_header($code, $text);



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Enable/disable Profiler

	 *

	 * @access	public

	 * @param	bool

	 * @return	void

	 */

	function enable_profiler($val = TRUE)

	{

		$this->enable_profiler = (is_bool($val)) ? $val : TRUE;



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Profiler Sections

	 *

	 * Allows override of default / config settings for Profiler section display

	 *

	 * @access	public

	 * @param	array

	 * @return	void

	 */

	function set_profiler_sections($sections)

	{

		foreach ($sections as $section => $enable)

		{

			$this->_profiler_sections[$section] = ($enable !== FALSE) ? TRUE : FALSE;

		}



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Cache

	 *

	 * @access	public

	 * @param	integer

	 * @return	void

	 */

	function cache($time)

	{

		$this->cache_expiration = ( ! is_numeric($time)) ? 0 : $time;



		return $this;

	}



	// --------------------------------------------------------------------



	/**

	 * Display Output

	 *

	 * All "view" data is automatically put into this variable by the controller class:

	 *

	 * $this->final_output

	 *

	 * This function sends the finalized output data to the browser along

	 * with any server headers and profile data.  It also stops the

	 * benchmark timer so the page rendering speed and memory usage can be shown.

	 *

	 * @access	public

	 * @param 	string

	 * @return	mixed

	 */

	function _display($output = '')

	{

		// Note:  We use globals because we can't use $CI =& get_instance()

		// since this function is sometimes called by the caching mechanism,

		// which happens before the CI super object is available.

		global $BM, $CFG;



		// Grab the super object if we can.

		if (class_exists('CI_Controller'))

		{

			$CI =& get_instance();

		}



		// --------------------------------------------------------------------



		// Set the output data

		if ($output == '')

		{

			$output =& $this->final_output;

		}



		// --------------------------------------------------------------------



		// Do we need to write a cache file?  Only if the controller does not have its

		// own _output() method and we are not dealing with a cache file, which we

		// can determine by the existence of the $CI object above

		if ($this->cache_expiration > 0 && isset($CI) && ! method_exists($CI, '_output'))

		{

			$this->_write_cache($output);

		}



		// --------------------------------------------------------------------



		// Parse out the elapsed time and memory usage,

		// then swap the pseudo-variables with the data



		$elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');



		if ($this->parse_exec_vars === TRUE)

		{

			$memory	 = ( ! function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2).'MB';



			$output = str_replace('{elapsed_time}', $elapsed, $output);

			$output = str_replace('{memory_usage}', $memory, $output);

		}



		// --------------------------------------------------------------------



		// Is compression requested?

		if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc == FALSE)

		{

			if (extension_loaded('zlib'))

			{

				if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)

				{

					ob_start('ob_gzhandler');

				}

			}

		}



		// --------------------------------------------------------------------



		// Are there any server headers to send?

		if (count($this->headers) > 0)

		{

			foreach ($this->headers as $header)

			{

				@header($header[0], $header[1]);

			}

		}



		// --------------------------------------------------------------------



		// Does the $CI object exist?

		// If not we know we are dealing with a cache file so we'll

		// simply echo out the data and exit.

		if ( ! isset($CI))

		{

			echo $output;

			log_message('debug', "Final output sent to browser");

			log_message('debug', "Total execution time: ".$elapsed);

			return TRUE;

		}



		// --------------------------------------------------------------------



		// Do we need to generate profile data?

		// If so, load the Profile class and run it.

		if ($this->enable_profiler == TRUE)

		{

			$CI->load->library('profiler');



			if ( ! empty($this->_profiler_sections))

			{

				$CI->profiler->set_sections($this->_profiler_sections);

			}



			// If the output data contains closing </body> and </html> tags

			// we will remove them and add them back after we insert the profile data

			if (preg_match("|</body>.*?</html>|is", $output))

			{

				$output  = preg_replace("|</body>.*?</html>|is", '', $output);

				$output .= $CI->profiler->run();

				$output .= '</body></html>';

			}

			else

			{

				$output .= $CI->profiler->run();

			}

		}



		// --------------------------------------------------------------------



		// Does the controller contain a function named _output()?

		// If so send the output there.  Otherwise, echo it.

		if (method_exists($CI, '_output'))

		{

			$CI->_output($output);

		}

		else

		{

			echo $output;  // Send it to the browser!

		}



		log_message('debug', "Final output sent to browser");

		log_message('debug', "Total execution time: ".$elapsed);

	}



	// --------------------------------------------------------------------



	/**

	 * Write a Cache File

	 *

	 * @access	public

	 * @param 	string

	 * @return	void

	 */

	function _write_cache($output)

	{

		$CI =& get_instance();

		$path = $CI->config->item('cache_path');



		$cache_path = ($path == '') ? APPPATH.'cache/' : $path;



		if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))

		{

			log_message('error', "Unable to write cache file: ".$cache_path);

			return;

		}



		$uri =	$CI->config->item('base_url').

				$CI->config->item('index_page').

				$CI->uri->uri_string();



		$cache_path .= md5($uri);



		if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE))

		{

			log_message('error', "Unable to write cache file: ".$cache_path);

			return;

		}



		$expire = time() + ($this->cache_expiration * 60);



		if (flock($fp, LOCK_EX))

		{

			fwrite($fp, $expire.'TS--->'.$output);

			flock($fp, LOCK_UN);

		}

		else

		{

			log_message('error', "Unable to secure a file lock for file at: ".$cache_path);

			return;

		}

		fclose($fp);

		@chmod($cache_path, FILE_WRITE_MODE);



		log_message('debug', "Cache file written: ".$cache_path);

	}



	// --------------------------------------------------------------------



	/**

	 * Update/serve a cached file

	 *

	 * @access	public

	 * @param 	object	config class

	 * @param 	object	uri class

	 * @return	void

	 */

	function _display_cache(&$CFG, &$URI)

	{

		$cache_path = ($CFG->item('cache_path') == '') ? APPPATH.'cache/' : $CFG->item('cache_path');



		// Build the file path.  The file name is an MD5 hash of the full URI

		$uri =	$CFG->item('base_url').

				$CFG->item('index_page').

				$URI->uri_string;



		$filepath = $cache_path.md5($uri);



		if ( ! @file_exists($filepath))

		{

			return FALSE;

		}



		if ( ! $fp = @fopen($filepath, FOPEN_READ))

		{

			return FALSE;

		}



		flock($fp, LOCK_SH);



		$cache = '';

		if (filesize($filepath) > 0)

		{

			$cache = fread($fp, filesize($filepath));

		}



		flock($fp, LOCK_UN);

		fclose($fp);



		// Strip out the embedded timestamp

		if ( ! preg_match("/(\d+TS--->)/", $cache, $match))

		{

			return FALSE;

		}



		// Has the file expired? If so we'll delete it.

		if (time() >= trim(str_replace('TS--->', '', $match['1'])))

		{

			if (is_really_writable($cache_path))

			{

				@unlink($filepath);

				log_message('debug', "Cache file has expired. File deleted");

				return FALSE;

			}

		}



		// Display the cache

		$this->_display(str_replace($match['0'], '', $cache));

		log_message('debug', "Cache file is current. Sending it to browser.");

		return TRUE;

	}





}

// END Output Class



/* End of file Output.php */

/* Location: ./system/core/Output.php */