system/core/Output.php

   1 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 5.1.6 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008 - 2011, EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 1.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * Output Class
  20  *
  21  * Responsible for sending final output to browser
  22  *
  23  * @package             CodeIgniter
  24  * @subpackage  Libraries
  25  * @category    Output
  26  * @author              ExpressionEngine Dev Team
  27  * @link                http://codeigniter.com/user_guide/libraries/output.html
  28  */
  29 class CI_Output {
  30
  31         protected $final_output;
  32         protected $cache_expiration     = 0;
  33         protected $headers                      = array();
  34         protected $mime_types                   = array();
  35         protected $enable_profiler      = FALSE;
  36         protected $_zlib_oc                     = FALSE;
  37         protected $_profiler_sections = array();
  38         protected $parse_exec_vars      = TRUE; // whether or not to parse variables like {elapsed_time} and {memory_usage}
  39
  40         function __construct()
  41         {
  42                 $this->_zlib_oc = @ini_get('zlib.output_compression');
  43
  44                 // Get mime types for later
  45                 if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT))
  46                 {
  47                     include APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT;
  48                 }
  49                 else
  50                 {
  51                         include APPPATH.'config/mimes'.EXT;
  52                 }
  53
  54
  55                 $this->mime_types = $mimes;
  56
  57                 log_message('debug', "Output Class Initialized");
  58         }
  59
  60         // --------------------------------------------------------------------
  61
  62         /**
  63          * Get Output
  64          *
  65          * Returns the current output string
  66          *
  67          * @access      public
  68          * @return      string
  69          */
  70         function get_output()
  71         {
  72                 return $this->final_output;
  73         }
  74
  75         // --------------------------------------------------------------------
  76
  77         /**
  78          * Set Output
  79          *
  80          * Sets the output string
  81          *
  82          * @access      public
  83          * @param       string
  84          * @return      void
  85          */
  86         function set_output($output)
  87         {
  88                 $this->final_output = $output;
  89
  90                 return $this;
  91         }
  92
  93         // --------------------------------------------------------------------
  94
  95         /**
  96          * Append Output
  97          *
  98          * Appends data onto the output string
  99          *
 100          * @access      public
 101          * @param       string
 102          * @return      void
 103          */
 104         function append_output($output)
 105         {
 106                 if ($this->final_output == '')
 107                 {
 108                         $this->final_output = $output;
 109                 }
 110                 else
 111                 {
 112                         $this->final_output .= $output;
 113                 }
 114
 115                 return $this;
 116         }
 117
 118         // --------------------------------------------------------------------
 119
 120         /**
 121          * Set Header
 122          *
 123          * Lets you set a server header which will be outputted with the final display.
 124          *
 125          * Note:  If a file is cached, headers will not be sent.  We need to figure out
 126          * how to permit header data to be saved with the cache data...
 127          *
 128          * @access      public
 129          * @param       string
 130          * @return      void
 131          */
 132         function set_header($header, $replace = TRUE)
 133         {
 134                 // If zlib.output_compression is enabled it will compress the output,
 135                 // but it will not modify the content-length header to compensate for
 136                 // the reduction, causing the browser to hang waiting for more data.
 137                 // We'll just skip content-length in those cases.
 138
 139                 if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) == 0)
 140                 {
 141                         return;
 142                 }
 143
 144                 $this->headers[] = array($header, $replace);
 145
 146                 return $this;
 147         }
 148
 149         // --------------------------------------------------------------------
 150
 151         /**
 152          * Set Content Type Header
 153          *
 154          * @access      public
 155          * @param       string  extension of the file we're outputting
 156          * @return      void
 157          */
 158         function set_content_type($mime_type)
 159         {
 160                 if (strpos($mime_type, '/') === FALSE)
 161                 {
 162                         $extension = ltrim($mime_type, '.');
 163
 164                         // Is this extension supported?
 165                         if (isset($this->mime_types[$extension]))
 166                         {
 167                                 $mime_type =& $this->mime_types[$extension];
 168
 169                                 if (is_array($mime_type))
 170                                 {
 171                                         $mime_type = current($mime_type);
 172                                 }
 173                         }
 174                 }
 175
 176                 $header = 'Content-Type: '.$mime_type;
 177
 178                 $this->headers[] = array($header, TRUE);
 179
 180                 return $this;
 181         }
 182
 183         // --------------------------------------------------------------------
 184
 185         /**
 186          * Set HTTP Status Header
 187          * moved to Common procedural functions in 1.7.2
 188          *
 189          * @access      public
 190          * @param       int             the status code
 191          * @param       string
 192          * @return      void
 193          */
 194         function set_status_header($code = 200, $text = '')
 195         {
 196                 set_status_header($code, $text);
 197
 198                 return $this;
 199         }
 200
 201         // --------------------------------------------------------------------
 202
 203         /**
 204          * Enable/disable Profiler
 205          *
 206          * @access      public
 207          * @param       bool
 208          * @return      void
 209          */
 210         function enable_profiler($val = TRUE)
 211         {
 212                 $this->enable_profiler = (is_bool($val)) ? $val : TRUE;
 213
 214                 return $this;
 215         }
 216
 217         // --------------------------------------------------------------------
 218
 219         /**
 220          * Set Profiler Sections
 221          *
 222          * Allows override of default / config settings for Profiler section display
 223          *
 224          * @access      public
 225          * @param       array
 226          * @return      void
 227          */
 228         function set_profiler_sections($sections)
 229         {
 230                 foreach ($sections as $section => $enable)
 231                 {
 232                         $this->_profiler_sections[$section] = ($enable !== FALSE) ? TRUE : FALSE;
 233                 }
 234
 235                 return $this;
 236         }
 237
 238         // --------------------------------------------------------------------
 239
 240         /**
 241          * Set Cache
 242          *
 243          * @access      public
 244          * @param       integer
 245          * @return      void
 246          */
 247         function cache($time)
 248         {
 249                 $this->cache_expiration = ( ! is_numeric($time)) ? 0 : $time;
 250
 251                 return $this;
 252         }
 253
 254         // --------------------------------------------------------------------
 255
 256         /**
 257          * Display Output
 258          *
 259          * All "view" data is automatically put into this variable by the controller class:
 260          *
 261          * $this->final_output
 262          *
 263          * This function sends the finalized output data to the browser along
 264          * with any server headers and profile data.  It also stops the
 265          * benchmark timer so the page rendering speed and memory usage can be shown.
 266          *
 267          * @access      public
 268          * @return      mixed
 269          */
 270         function _display($output = '')
 271         {
 272                 // Note:  We use globals because we can't use $CI =& get_instance()
 273                 // since this function is sometimes called by the caching mechanism,
 274                 // which happens before the CI super object is available.
 275                 global $BM, $CFG;
 276
 277                 // Grab the super object if we can.
 278                 if (class_exists('CI_Controller'))
 279                 {
 280                         $CI =& get_instance();
 281                 }
 282
 283                 // --------------------------------------------------------------------
 284
 285                 // Set the output data
 286                 if ($output == '')
 287                 {
 288                         $output =& $this->final_output;
 289                 }
 290
 291                 // --------------------------------------------------------------------
 292
 293                 // Do we need to write a cache file?  Only if the controller does not have its
 294                 // own _output() method and we are not dealing with a cache file, which we
 295                 // can determine by the existence of the $CI object above
 296                 if ($this->cache_expiration > 0 && isset($CI) && ! method_exists($CI, '_output'))
 297                 {
 298                         $this->_write_cache($output);
 299                 }
 300
 301                 // --------------------------------------------------------------------
 302
 303                 // Parse out the elapsed time and memory usage,
 304                 // then swap the pseudo-variables with the data
 305
 306                 $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');
 307
 308                 if ($this->parse_exec_vars === TRUE)
 309                 {
 310                         $memory  = ( ! function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2).'MB';
 311
 312                         $output = str_replace('{elapsed_time}', $elapsed, $output);
 313                         $output = str_replace('{memory_usage}', $memory, $output);
 314                 }
 315
 316                 // --------------------------------------------------------------------
 317
 318                 // Is compression requested?
 319                 if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc == FALSE)
 320                 {
 321                         if (extension_loaded('zlib'))
 322                         {
 323                                 if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)
 324                                 {
 325                                         ob_start('ob_gzhandler');
 326                                 }
 327                         }
 328                 }
 329
 330                 // --------------------------------------------------------------------
 331
 332                 // Are there any server headers to send?
 333                 if (count($this->headers) > 0)
 334                 {
 335                         foreach ($this->headers as $header)
 336                         {
 337                                 @header($header[0], $header[1]);
 338                         }
 339                 }
 340
 341                 // --------------------------------------------------------------------
 342
 343                 // Does the $CI object exist?
 344                 // If not we know we are dealing with a cache file so we'll
 345                 // simply echo out the data and exit.
 346                 if ( ! isset($CI))
 347                 {
 348                         echo $output;
 349                         log_message('debug', "Final output sent to browser");
 350                         log_message('debug', "Total execution time: ".$elapsed);
 351                         return TRUE;
 352                 }
 353
 354                 // --------------------------------------------------------------------
 355
 356                 // Do we need to generate profile data?
 357                 // If so, load the Profile class and run it.
 358                 if ($this->enable_profiler == TRUE)
 359                 {
 360                         $CI->load->library('profiler');
 361
 362                         if ( ! empty($this->_profiler_sections))
 363                         {
 364                                 $CI->profiler->set_sections($this->_profiler_sections);
 365                         }
 366
 367                         // If the output data contains closing </body> and </html> tags
 368                         // we will remove them and add them back after we insert the profile data
 369                         if (preg_match("|</body>.*?</html>|is", $output))
 370                         {
 371                                 $output  = preg_replace("|</body>.*?</html>|is", '', $output);
 372                                 $output .= $CI->profiler->run();
 373                                 $output .= '</body></html>';
 374                         }
 375                         else
 376                         {
 377                                 $output .= $CI->profiler->run();
 378                         }
 379                 }
 380
 381                 // --------------------------------------------------------------------
 382
 383                 // Does the controller contain a function named _output()?
 384                 // If so send the output there.  Otherwise, echo it.
 385                 if (method_exists($CI, '_output'))
 386                 {
 387                         $CI->_output($output);
 388                 }
 389                 else
 390                 {
 391                         echo $output;  // Send it to the browser!
 392                 }
 393
 394                 log_message('debug', "Final output sent to browser");
 395                 log_message('debug', "Total execution time: ".$elapsed);
 396         }
 397
 398         // --------------------------------------------------------------------
 399
 400         /**
 401          * Write a Cache File
 402          *
 403          * @access      public
 404          * @return      void
 405          */
 406         function _write_cache($output)
 407         {
 408                 $CI =& get_instance();
 409                 $path = $CI->config->item('cache_path');
 410
 411                 $cache_path = ($path == '') ? APPPATH.'cache/' : $path;
 412
 413                 if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 414                 {
 415                         log_message('error', "Unable to write cache file: ".$cache_path);
 416                         return;
 417                 }
 418
 419                 $uri =  $CI->config->item('base_url').
 420                                 $CI->config->item('index_page').
 421                                 $CI->uri->uri_string();
 422
 423                 $cache_path .= md5($uri);
 424
 425                 if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE))
 426                 {
 427                         log_message('error', "Unable to write cache file: ".$cache_path);
 428                         return;
 429                 }
 430
 431                 $expire = time() + ($this->cache_expiration * 60);
 432
 433                 if (flock($fp, LOCK_EX))
 434                 {
 435                         fwrite($fp, $expire.'TS--->'.$output);
 436                         flock($fp, LOCK_UN);
 437                 }
 438                 else
 439                 {
 440                         log_message('error', "Unable to secure a file lock for file at: ".$cache_path);
 441                         return;
 442                 }
 443                 fclose($fp);
 444                 @chmod($cache_path, FILE_WRITE_MODE);
 445
 446                 log_message('debug', "Cache file written: ".$cache_path);
 447         }
 448
 449         // --------------------------------------------------------------------
 450
 451         /**
 452          * Update/serve a cached file
 453          *
 454          * @access      public
 455          * @return      void
 456          */
 457         function _display_cache(&$CFG, &$URI)
 458         {
 459                 $cache_path = ($CFG->item('cache_path') == '') ? APPPATH.'cache/' : $CFG->item('cache_path');
 460
 461                 // Build the file path.  The file name is an MD5 hash of the full URI
 462                 $uri =  $CFG->item('base_url').
 463                                 $CFG->item('index_page').
 464                                 $URI->uri_string;
 465
 466                 $filepath = $cache_path.md5($uri);
 467
 468                 if ( ! @file_exists($filepath))
 469                 {
 470                         return FALSE;
 471                 }
 472
 473                 if ( ! $fp = @fopen($filepath, FOPEN_READ))
 474                 {
 475                         return FALSE;
 476                 }
 477
 478                 flock($fp, LOCK_SH);
 479
 480                 $cache = '';
 481                 if (filesize($filepath) > 0)
 482                 {
 483                         $cache = fread($fp, filesize($filepath));
 484                 }
 485
 486                 flock($fp, LOCK_UN);
 487                 fclose($fp);
 488
 489                 // Strip out the embedded timestamp
 490                 if ( ! preg_match("/(\d+TS--->)/", $cache, $match))
 491                 {
 492                         return FALSE;
 493                 }
 494
 495                 // Has the file expired? If so we'll delete it.
 496                 if (time() >= trim(str_replace('TS--->', '', $match['1'])))
 497                 {
 498                         if (is_really_writable($cache_path))
 499                         {
 500                                 @unlink($filepath);
 501                                 log_message('debug', "Cache file has expired. File deleted");
 502                                 return FALSE;
 503                         }
 504                 }
 505
 506                 // Display the cache
 507                 $this->_display(str_replace($match['0'], '', $cache));
 508                 log_message('debug', "Cache file is current. Sending it to browser.");
 509                 return TRUE;
 510         }
 511
 512
 513 }
 514 // END Output Class
 515
 516 /* End of file Output.php */
 517 /* Location: ./system/core/Output.php */