libraries/OutputBuffering.php

   1 <?php /* vim: set expandtab sw=4 ts=4 sts=4: */
   2 /**
   3  * Output buffering wrapper
   4  *
   5  * @package PhpMyAdmin
   6  */
   7 namespace PMA\libraries;
   8
   9 /**
  10  * Output buffering wrapper class
  11  *
  12  * @package PhpMyAdmin
  13  */
  14 class OutputBuffering
  15 {
  16     private static $_instance;
  17     private $_mode;
  18     private $_content;
  19     private $_on;
  20
  21     /**
  22      * Initializes class
  23      */
  24     private function __construct()
  25     {
  26         $this->_mode = $this->_getMode();
  27         $this->_on = false;
  28     }
  29
  30     /**
  31      * This function could be used eventually to support more modes.
  32      *
  33      * @return integer  the output buffer mode
  34      */
  35     private function _getMode()
  36     {
  37         $mode = 0;
  38         if ($GLOBALS['cfg']['OBGzip'] && function_exists('ob_start')) {
  39             if (ini_get('output_handler') == 'ob_gzhandler') {
  40                 // If a user sets the output_handler in php.ini to ob_gzhandler, then
  41                 // any right frame file in phpMyAdmin will not be handled properly by
  42                 // the browser. My fix was to check the ini file within the
  43                 // PMA_outBufferModeGet() function.
  44                 $mode = 0;
  45             } elseif (function_exists('ob_get_level') && ob_get_level() > 0) {
  46                 // happens when php.ini's output_buffering is not Off
  47                 ob_end_clean();
  48                 $mode = 1;
  49             } else {
  50                 $mode = 1;
  51             }
  52         }
  53         // Zero (0) is no mode or in other words output buffering is OFF.
  54         // Follow 2^0, 2^1, 2^2, 2^3 type values for the modes.
  55         // Useful if we ever decide to combine modes.  Then a bitmask field of
  56         // the sum of all modes will be the natural choice.
  57         return $mode;
  58     }
  59
  60     /**
  61      * Returns the singleton OutputBuffering object
  62      *
  63      * @return OutputBuffering object
  64      */
  65     public static function getInstance()
  66     {
  67         if (empty(self::$_instance)) {
  68             self::$_instance = new OutputBuffering();
  69         }
  70         return self::$_instance;
  71     }
  72
  73     /**
  74      * This function will need to run at the top of all pages if output
  75      * output buffering is turned on.  It also needs to be passed $mode from
  76      * the PMA_outBufferModeGet() function or it will be useless.
  77      *
  78      * @return void
  79      */
  80     public function start()
  81     {
  82         if (! $this->_on) {
  83             if ($this->_mode && function_exists('ob_gzhandler')) {
  84                 ob_start('ob_gzhandler');
  85             }
  86             ob_start();
  87             if (! defined('TESTSUITE')) {
  88                 header('X-ob_mode: ' . $this->_mode);
  89             }
  90             register_shutdown_function(
  91                 array('PMA\libraries\OutputBuffering', 'stop')
  92             );
  93             $this->_on = true;
  94         }
  95     }
  96
  97     /**
  98      * This function will need to run at the bottom of all pages if output
  99      * buffering is turned on.  It also needs to be passed $mode from the
 100      * PMA_outBufferModeGet() function or it will be useless.
 101      *
 102      * @return void
 103      */
 104     public static function stop()
 105     {
 106         $buffer = OutputBuffering::getInstance();
 107         if ($buffer->_on) {
 108             $buffer->_on = false;
 109             $buffer->_content = ob_get_contents();
 110             ob_end_clean();
 111         }
 112     }
 113
 114     /**
 115      * Gets buffer content
 116      *
 117      * @return string buffer content
 118      */
 119     public function getContents()
 120     {
 121         return $this->_content;
 122     }
 123
 124     /**
 125      * Flushes output buffer
 126      *
 127      * @return void
 128      */
 129     public function flush()
 130     {
 131         if (ob_get_status() && $this->_mode) {
 132             ob_flush();
 133         } else {
 134             flush();
 135         }
 136     }
 137 }
 138