libraries/OutputBuffering.class.php

   1 <?php /* vim: set expandtab sw=4 ts=4 sts=4: */
   2 /**
   3  * Output buffering wrapper
   4  *
   5  * @package PhpMyAdmin
   6  */
   7 if (! defined('PHPMYADMIN')) {
   8     exit;
   9 }
  10
  11 /**
  12  * Output buffering wrapper class
  13  *
  14  * @package PhpMyAdmin
  15  */
  16 class PMA_OutputBuffering
  17 {
  18     private static $_instance;
  19     private $_mode;
  20     private $_content;
  21     private $_on;
  22
  23     /**
  24      * Initializes class
  25      *
  26      * @return void
  27      */
  28     private function __construct()
  29     {
  30         $this->_mode = $this->_getMode();
  31         $this->_on = false;
  32     }
  33
  34     /**
  35      * This function could be used eventually to support more modes.
  36      *
  37      * @return integer  the output buffer mode
  38      */
  39     private function _getMode()
  40     {
  41         $mode = 0;
  42         if ($GLOBALS['cfg']['OBGzip'] && function_exists('ob_start')) {
  43             if (ini_get('output_handler') == 'ob_gzhandler') {
  44                 // If a user sets the output_handler in php.ini to ob_gzhandler, then
  45                 // any right frame file in phpMyAdmin will not be handled properly by
  46                 // the browser. My fix was to check the ini file within the
  47                 // PMA_outBufferModeGet() function.
  48                 $mode = 0;
  49             } elseif (function_exists('ob_get_level') && ob_get_level() > 0) {
  50                 // If output buffering is enabled in php.ini it's not possible to
  51                 // add the ob_gzhandler without a warning message from php 4.3.0.
  52                 // Being better safe than sorry, check for any existing output
  53                 // handler instead of just checking the 'output_buffering' setting.
  54                 $mode = 0;
  55             } else {
  56                 $mode = 1;
  57             }
  58         }
  59         // Zero (0) is no mode or in other words output buffering is OFF.
  60         // Follow 2^0, 2^1, 2^2, 2^3 type values for the modes.
  61         // Usefull if we ever decide to combine modes.  Then a bitmask field of
  62         // the sum of all modes will be the natural choice.
  63         return $mode;
  64     }
  65
  66     /**
  67      * Returns the singleton PMA_OutputBuffering object
  68      *
  69      * @return PMA_OutputBuffering object
  70      */
  71     public static function getInstance()
  72     {
  73         if (empty(self::$_instance)) {
  74             self::$_instance = new PMA_OutputBuffering();
  75         }
  76         return self::$_instance;
  77     }
  78
  79     /**
  80      * This function will need to run at the top of all pages if output
  81      * output buffering is turned on.  It also needs to be passed $mode from
  82      * the PMA_outBufferModeGet() function or it will be useless.
  83      *
  84      * @return void
  85      */
  86     public function start()
  87     {
  88         if (! $this->_on) {
  89             if ($this->_mode) {
  90                 ob_start('ob_gzhandler');
  91             }
  92             ob_start();
  93             if (! defined('TESTSUITE')) {
  94                 header('X-ob_mode: ' . $this->_mode);
  95             }
  96             register_shutdown_function('PMA_OutputBuffering::stop');
  97             $this->_on = true;
  98         }
  99     }
 100
 101     /**
 102      * This function will need to run at the bottom of all pages if output
 103      * buffering is turned on.  It also needs to be passed $mode from the
 104      * PMA_outBufferModeGet() function or it will be useless.
 105      *
 106      * @return void
 107      */
 108     public static function stop()
 109     {
 110         $buffer = PMA_OutputBuffering::getInstance();
 111         if ($buffer->_on) {
 112             $buffer->_on = false;
 113             $buffer->_content = ob_get_contents();
 114             ob_end_clean();
 115         }
 116         PMA_Response::response();
 117     }
 118
 119     /**
 120      * Gets buffer content
 121      *
 122      * @return buffer content
 123      */
 124     public function getContents()
 125     {
 126         return $this->_content;
 127     }
 128
 129     /**
 130      * Flushes output buffer
 131      *
 132      * @return void
 133      */
 134     public function flush()
 135     {
 136         if (ob_get_status() && $this->_mode) {
 137             ob_flush();
 138         } else {
 139             flush();
 140         }
 141     }
 142 }
 143
 144 ?>