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         /**
  32          * Current output string
  33          *
  34          * @var string
  35          * @access      protected
  36          */
  37         protected $final_output;
  38         /**
  39          * Cache expiration time
  40          *
  41          * @var int
  42          * @access      protected
  43          */
  44         protected $cache_expiration     = 0;
  45         /**
  46          * List of server headers
  47          *
  48          * @var array
  49          * @access      protected
  50          */
  51         protected $headers                      = array();
  52         /**
  53          * List of mime types
  54          *
  55          * @var array
  56          * @access      protected
  57          */
  58         protected $mime_types           = array();
  59         /**
  60          * Determines wether profiler is enabled
  61          *
  62          * @var book
  63          * @access      protected
  64          */
  65         protected $enable_profiler      = FALSE;
  66         /**
  67          * Determines if output compression is enabled
  68          *
  69          * @var bool
  70          * @access      protected
  71          */
  72         protected $_zlib_oc                     = FALSE;
  73         /**
  74          * List of profiler sections
  75          *
  76          * @var array
  77          * @access      protected
  78          */
  79         protected $_profiler_sections = array();
  80         /**
  81          * Whether or not to parse variables like {elapsed_time} and {memory_usage}
  82          *
  83          * @var bool
  84          * @access      protected
  85          */
  86         protected $parse_exec_vars      = TRUE;
  87
  88         /**
  89          * Constructor
  90          *
  91          */
  92         function __construct()
  93         {
  94                 $this->_zlib_oc = @ini_get('zlib.output_compression');
  95
  96                 // Get mime types for later
  97                 if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
  98                 {
  99                     include APPPATH.'config/'.ENVIRONMENT.'/mimes.php';
 100                 }
 101                 else
 102                 {
 103                         include APPPATH.'config/mimes.php';
 104                 }
 105
 106
 107                 $this->mime_types = $mimes;
 108
 109                 log_message('debug', "Output Class Initialized");
 110         }
 111
 112         // --------------------------------------------------------------------
 113
 114         /**
 115          * Get Output
 116          *
 117          * Returns the current output string
 118          *
 119          * @access      public
 120          * @return      string
 121          */
 122         function get_output()
 123         {
 124                 return $this->final_output;
 125         }
 126
 127         // --------------------------------------------------------------------
 128
 129         /**
 130          * Set Output
 131          *
 132          * Sets the output string
 133          *
 134          * @access      public
 135          * @param       string
 136          * @return      void
 137          */
 138         function set_output($output)
 139         {
 140                 $this->final_output = $output;
 141
 142                 return $this;
 143         }
 144
 145         // --------------------------------------------------------------------
 146
 147         /**
 148          * Append Output
 149          *
 150          * Appends data onto the output string
 151          *
 152          * @access      public
 153          * @param       string
 154          * @return      void
 155          */
 156         function append_output($output)
 157         {
 158                 if ($this->final_output == '')
 159                 {
 160                         $this->final_output = $output;
 161                 }
 162                 else
 163                 {
 164                         $this->final_output .= $output;
 165                 }
 166
 167                 return $this;
 168         }
 169
 170         // --------------------------------------------------------------------
 171
 172         /**
 173          * Set Header
 174          *
 175          * Lets you set a server header which will be outputted with the final display.
 176          *
 177          * Note:  If a file is cached, headers will not be sent.  We need to figure out
 178          * how to permit header data to be saved with the cache data...
 179          *
 180          * @access      public
 181          * @param       string
 182          * @param       bool
 183          * @return      void
 184          */
 185         function set_header($header, $replace = TRUE)
 186         {
 187                 // If zlib.output_compression is enabled it will compress the output,
 188                 // but it will not modify the content-length header to compensate for
 189                 // the reduction, causing the browser to hang waiting for more data.
 190                 // We'll just skip content-length in those cases.
 191
 192                 if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) == 0)
 193                 {
 194                         return;
 195                 }
 196
 197                 $this->headers[] = array($header, $replace);
 198
 199                 return $this;
 200         }
 201
 202         // --------------------------------------------------------------------
 203
 204         /**
 205          * Set Content Type Header
 206          *
 207          * @access      public
 208          * @param       string  extension of the file we're outputting
 209          * @return      void
 210          */
 211         function set_content_type($mime_type)
 212         {
 213                 if (strpos($mime_type, '/') === FALSE)
 214                 {
 215                         $extension = ltrim($mime_type, '.');
 216
 217                         // Is this extension supported?
 218                         if (isset($this->mime_types[$extension]))
 219                         {
 220                                 $mime_type =& $this->mime_types[$extension];
 221
 222                                 if (is_array($mime_type))
 223                                 {
 224                                         $mime_type = current($mime_type);
 225                                 }
 226                         }
 227                 }
 228
 229                 $header = 'Content-Type: '.$mime_type;
 230
 231                 $this->headers[] = array($header, TRUE);
 232
 233                 return $this;
 234         }
 235
 236         // --------------------------------------------------------------------
 237
 238         /**
 239          * Set HTTP Status Header
 240          * moved to Common procedural functions in 1.7.2
 241          *
 242          * @access      public
 243          * @param       int             the status code
 244          * @param       string
 245          * @return      void
 246          */
 247         function set_status_header($code = 200, $text = '')
 248         {
 249                 set_status_header($code, $text);
 250
 251                 return $this;
 252         }
 253
 254         // --------------------------------------------------------------------
 255
 256         /**
 257          * Enable/disable Profiler
 258          *
 259          * @access      public
 260          * @param       bool
 261          * @return      void
 262          */
 263         function enable_profiler($val = TRUE)
 264         {
 265                 $this->enable_profiler = (is_bool($val)) ? $val : TRUE;
 266
 267                 return $this;
 268         }
 269
 270         // --------------------------------------------------------------------
 271
 272         /**
 273          * Set Profiler Sections
 274          *
 275          * Allows override of default / config settings for Profiler section display
 276          *
 277          * @access      public
 278          * @param       array
 279          * @return      void
 280          */
 281         function set_profiler_sections($sections)
 282         {
 283                 foreach ($sections as $section => $enable)
 284                 {
 285                         $this->_profiler_sections[$section] = ($enable !== FALSE) ? TRUE : FALSE;
 286                 }
 287
 288                 return $this;
 289         }
 290
 291         // --------------------------------------------------------------------
 292
 293         /**
 294          * Set Cache
 295          *
 296          * @access      public
 297          * @param       integer
 298          * @return      void
 299          */
 300         function cache($time)
 301         {
 302                 $this->cache_expiration = ( ! is_numeric($time)) ? 0 : $time;
 303
 304                 return $this;
 305         }
 306
 307         // --------------------------------------------------------------------
 308
 309         /**
 310          * Display Output
 311          *
 312          * All "view" data is automatically put into this variable by the controller class:
 313          *
 314          * $this->final_output
 315          *
 316          * This function sends the finalized output data to the browser along
 317          * with any server headers and profile data.  It also stops the
 318          * benchmark timer so the page rendering speed and memory usage can be shown.
 319          *
 320          * @access      public
 321          * @param       string
 322          * @return      mixed
 323          */
 324         function _display($output = '')
 325         {
 326                 // Note:  We use globals because we can't use $CI =& get_instance()
 327                 // since this function is sometimes called by the caching mechanism,
 328                 // which happens before the CI super object is available.
 329                 global $BM, $CFG;
 330
 331                 // Grab the super object if we can.
 332                 if (class_exists('CI_Controller'))
 333                 {
 334                         $CI =& get_instance();
 335                 }
 336
 337                 // --------------------------------------------------------------------
 338
 339                 // Set the output data
 340                 if ($output == '')
 341                 {
 342                         $output =& $this->final_output;
 343                 }
 344
 345                 // --------------------------------------------------------------------
 346
 347                 // Do we need to write a cache file?  Only if the controller does not have its
 348                 // own _output() method and we are not dealing with a cache file, which we
 349                 // can determine by the existence of the $CI object above
 350                 if ($this->cache_expiration > 0 && isset($CI) && ! method_exists($CI, '_output'))
 351                 {
 352                         $this->_write_cache($output);
 353                 }
 354
 355                 // --------------------------------------------------------------------
 356
 357                 // Parse out the elapsed time and memory usage,
 358                 // then swap the pseudo-variables with the data
 359
 360                 $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');
 361
 362                 if ($this->parse_exec_vars === TRUE)
 363                 {
 364                         $memory  = ( ! function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2).'MB';
 365
 366                         $output = str_replace('{elapsed_time}', $elapsed, $output);
 367                         $output = str_replace('{memory_usage}', $memory, $output);
 368                 }
 369
 370                 // --------------------------------------------------------------------
 371
 372                 // Is compression requested?
 373                 if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc == FALSE)
 374                 {
 375                         if (extension_loaded('zlib'))
 376                         {
 377                                 if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)
 378                                 {
 379                                         ob_start('ob_gzhandler');
 380                                 }
 381                         }
 382                 }
 383
 384                 // --------------------------------------------------------------------
 385
 386                 // Are there any server headers to send?
 387                 if (count($this->headers) > 0)
 388                 {
 389                         foreach ($this->headers as $header)
 390                         {
 391                                 @header($header[0], $header[1]);
 392                         }
 393                 }
 394
 395                 // --------------------------------------------------------------------
 396
 397                 // Does the $CI object exist?
 398                 // If not we know we are dealing with a cache file so we'll
 399                 // simply echo out the data and exit.
 400                 if ( ! isset($CI))
 401                 {
 402                         echo $output;
 403                         log_message('debug', "Final output sent to browser");
 404                         log_message('debug', "Total execution time: ".$elapsed);
 405                         return TRUE;
 406                 }
 407
 408                 // --------------------------------------------------------------------
 409
 410                 // Do we need to generate profile data?
 411                 // If so, load the Profile class and run it.
 412                 if ($this->enable_profiler == TRUE)
 413                 {
 414                         $CI->load->library('profiler');
 415
 416                         if ( ! empty($this->_profiler_sections))
 417                         {
 418                                 $CI->profiler->set_sections($this->_profiler_sections);
 419                         }
 420
 421                         // If the output data contains closing </body> and </html> tags
 422                         // we will remove them and add them back after we insert the profile data
 423                         if (preg_match("|</body>.*?</html>|is", $output))
 424                         {
 425                                 $output  = preg_replace("|</body>.*?</html>|is", '', $output);
 426                                 $output .= $CI->profiler->run();
 427                                 $output .= '</body></html>';
 428                         }
 429                         else
 430                         {
 431                                 $output .= $CI->profiler->run();
 432                         }
 433                 }
 434
 435                 // --------------------------------------------------------------------
 436
 437                 // Does the controller contain a function named _output()?
 438                 // If so send the output there.  Otherwise, echo it.
 439                 if (method_exists($CI, '_output'))
 440                 {
 441                         $CI->_output($output);
 442                 }
 443                 else
 444                 {
 445                         echo $output;  // Send it to the browser!
 446                 }
 447
 448                 log_message('debug', "Final output sent to browser");
 449                 log_message('debug', "Total execution time: ".$elapsed);
 450         }
 451
 452         // --------------------------------------------------------------------
 453
 454         /**
 455          * Write a Cache File
 456          *
 457          * @access      public
 458          * @param       string
 459          * @return      void
 460          */
 461         function _write_cache($output)
 462         {
 463                 $CI =& get_instance();
 464                 $path = $CI->config->item('cache_path');
 465
 466                 $cache_path = ($path == '') ? APPPATH.'cache/' : $path;
 467
 468                 if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 469                 {
 470                         log_message('error', "Unable to write cache file: ".$cache_path);
 471                         return;
 472                 }
 473
 474                 $uri =  $CI->config->item('base_url').
 475                                 $CI->config->item('index_page').
 476                                 $CI->uri->uri_string();
 477
 478                 $cache_path .= md5($uri);
 479
 480                 if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE))
 481                 {
 482                         log_message('error', "Unable to write cache file: ".$cache_path);
 483                         return;
 484                 }
 485
 486                 $expire = time() + ($this->cache_expiration * 60);
 487
 488                 if (flock($fp, LOCK_EX))
 489                 {
 490                         fwrite($fp, $expire.'TS--->'.$output);
 491                         flock($fp, LOCK_UN);
 492                 }
 493                 else
 494                 {
 495                         log_message('error', "Unable to secure a file lock for file at: ".$cache_path);
 496                         return;
 497                 }
 498                 fclose($fp);
 499                 @chmod($cache_path, FILE_WRITE_MODE);
 500
 501                 log_message('debug', "Cache file written: ".$cache_path);
 502         }
 503
 504         // --------------------------------------------------------------------
 505
 506         /**
 507          * Update/serve a cached file
 508          *
 509          * @access      public
 510          * @param       object  config class
 511          * @param       object  uri class
 512          * @return      void
 513          */
 514         function _display_cache(&$CFG, &$URI)
 515         {
 516                 $cache_path = ($CFG->item('cache_path') == '') ? APPPATH.'cache/' : $CFG->item('cache_path');
 517
 518                 // Build the file path.  The file name is an MD5 hash of the full URI
 519                 $uri =  $CFG->item('base_url').
 520                                 $CFG->item('index_page').
 521                                 $URI->uri_string;
 522
 523                 $filepath = $cache_path.md5($uri);
 524
 525                 if ( ! @file_exists($filepath))
 526                 {
 527                         return FALSE;
 528                 }
 529
 530                 if ( ! $fp = @fopen($filepath, FOPEN_READ))
 531                 {
 532                         return FALSE;
 533                 }
 534
 535                 flock($fp, LOCK_SH);
 536
 537                 $cache = '';
 538                 if (filesize($filepath) > 0)
 539                 {
 540                         $cache = fread($fp, filesize($filepath));
 541                 }
 542
 543                 flock($fp, LOCK_UN);
 544                 fclose($fp);
 545
 546                 // Strip out the embedded timestamp
 547                 if ( ! preg_match("/(\d+TS--->)/", $cache, $match))
 548                 {
 549                         return FALSE;
 550                 }
 551
 552                 // Has the file expired? If so we'll delete it.
 553                 if (time() >= trim(str_replace('TS--->', '', $match['1'])))
 554                 {
 555                         if (is_really_writable($cache_path))
 556                         {
 557                                 @unlink($filepath);
 558                                 log_message('debug', "Cache file has expired. File deleted");
 559                                 return FALSE;
 560                         }
 561                 }
 562
 563                 // Display the cache
 564                 $this->_display(str_replace($match['0'], '', $cache));
 565                 log_message('debug', "Cache file is current. Sending it to browser.");
 566                 return TRUE;
 567         }
 568
 569
 570 }
 571 // END Output Class
 572
 573 /* End of file Output.php */
 574 /* Location: ./system/core/Output.php */