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<?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 */