Location: PHPKode > projects > Cadence Guestbook Host > cadence/class/captcha/hn_captcha.class.x1.php
<?php
/**
  * PHP-Class hn_captcha_X1 Version 1.0, released 19-Apr-2004
  * is an extension for PHP-Class hn_captcha.
  * It adds a garbage-collector. (Useful, if you cannot use cronjobs.)
  * Author: Horst Nogajski, hide@address.com
  * 
  * License: GNU GPL (http://www.opensource.org/licenses/gpl-license.html)
  * Download: http://hn273.users.phpclasses.org/browse/package/1569.html
  *
  * If you find it useful, you might rate it on http://www.phpclasses.org/rate.html
  * If you use this class in a productional environment, you might drop me a note, so I can add a link to the page.
  *
  **/

/**
  * License: GNU GPL (http://www.opensource.org/licenses/gpl-license.html)
  * 
  * This program is free software;
  * 
  * you can redistribute it and/or modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2 of the License,
  * or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along with this program;
  * if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  **/

/**
  * Tabsize: 4
  * 
  **/



require_once(dirname(__file__).'/hn_captcha.class.php');



/**
  * This class is an extension for hn_captcha-class. It adds a garbage-collector!
  *
  * Normally all used images will be deleted automatically. But everytime a user
  * doesn't finish a request one image stays as garbage in tempfolder.
  * With this extension you can collect & trash this.
  *
  * You can specify:
  * - when the garbage-collector should run, (default = after 100 calls)
  * - the maxlifetime for images, (default is 600, = 10 minutes)
  * - a filename-prefix for the captcha-images (default = 'hn_captcha_')
  * - absolute filename for a textfile which stores the current counter-value
  *   (default is $tempfolder.'hn_captcha_counter.txt')
  * 
  * The classextension needs the filename-prefix to identify lost images
  * also if the tempfolder is shared with other scripts.
  *
  * If an error occures (with counting or trash-file-deleting), the class sets
  * the variable $classhandle->garbage_collector_error to TRUE.
  * You can check this in your scripts and if is TRUE, you might execute
  * an email-notification or something else.
  *
  * 
  * @shortdesc Class that adds a garbage-collector to the class hn_captcha
  * @public
  * @author Horst Nogajski, (mail: hide@address.com)
  * @version 1.0
  * @date 2004-April-19
  * 
  **/
class hn_captcha_X1 extends hn_captcha
{

	////////////////////////////////
	//
	//	PUBLIC PARAMS
	//

		/**
		  * @shortdesc You optionally can specify an absolute filename for the counter. If is not specified, the class use the tempfolder and the default_basename.
          * @public
          * @type string
          *
          **/
		var $counter_filename		= '';
		
		/**
		  * @shortdesc This is used as prefix for the picture filenames, so we can identify them also if we share the tempfolder with other programs.
          * @public
          * @type string
          *
          **/
		var $prefix					= 'hn_captcha_';
		
		/**
		  * @shortdesc The garbage-collector will started once when the class was called that number times.
          * @public
          * @type integer
          *
          **/
		var $collect_garbage_after	= 100;

		/**
		  * @shortdesc Only trash files which are older than this number of seconds.
          * @public
          * @type integer
          *
          **/
		var $maxlifetime			= 600;

		/**
		  * @shortdesc This becomes TRUE if the counter doesn't work or if trashfiles couldn't be deleted.
          * @public
          * @type boolean
          *
          **/
		var $garbage_collector_error	= FALSE;



	////////////////////////////////
	//
	//	PRIVATE PARAMS
	//

		/** @private **/
		var $counter_fn_default_basename = 'hn_captcha_counter.txt';




	////////////////////////////////
	//
	//	CONSTRUCTOR
	//

		/**
		  * @shortdesc This calls the constructor of main-class for extracting the config array and generating all needed params. Additionally it control the garbage-collector.
		  * @public
		  * @type void
		  * @return nothing
		  *
		  **/
		function hn_captcha_X1($config,$secure=TRUE)
		{
			// Call Constructor of main-class
			$this->hn_captcha($config,$secure);


			// specify counter-filename
			if($this->counter_filename == '') $this->counter_filename = $this->tempfolder.$this->counter_fn_default_basename;
			if($this->debug) echo "\n<br>-Captcha-Debug: The counterfilename is (".$this->counter_filename.")";


			// retrieve last counter-value
			$test = $this->txt_counter($this->counter_filename);

			// set and retrieve current counter-value
			$counter = $this->txt_counter($this->counter_filename,TRUE);


			// check if counter works correct
			if(($counter !== FALSE) && ($counter - $test == 1))
			{
				// Counter works perfect, =:)
				if($this->debug) echo "\n<br>-Captcha-Debug: Current counter-value is ($counter). Garbage-collector should start at (".$this->collect_garbage_after.")";

				// check if garbage-collector should run
				if($counter >= $this->collect_garbage_after)
				{
					// Reset counter
					if($this->debug) echo "\n<br>-Captcha-Debug: Reset the counter-value. (0)";
					$this->txt_counter($this->counter_filename,TRUE,0);

					// start garbage-collector
					$this->garbage_collector_error = $this->collect_garbage() ? FALSE : TRUE;
					if($this->debug && $this->garbage_collector_error) echo "\n<br>-Captcha-Debug: ERROR! SOME TRASHFILES COULD NOT BE DELETED! (Set the garbage_collector_error to TRUE)";
				}

			}
			else
			{
				// Counter-ERROR!
				if($this->debug) echo "\n<br>-Captcha-Debug: ERROR! NO COUNTER-VALUE AVAILABLE! (Set the garbage_collector_error to TRUE)";
				$this->garbage_collector_error = TRUE;
			}
		}


	////////////////////////////////
	//
	//	PRIVATE METHODS
	//


		/**
		  * @shortdesc Store/Retrieve a counter-value in/from a textfile. Optionally count it up or store a (as third param) specified value.
		  * @private
		  * @type integer
		  * @return counter-value
		  *
		  **/
		function txt_counter($filename,$add=FALSE,$fixvalue=FALSE)
		{
			if(is_file($filename) ? TRUE : touch($filename))
			{
				if(is_readable($filename) && is_writable($filename))
				{
					$fp = @fopen($filename, "r");
					if($fp)
					{
						$counter = (int)trim(fgets($fp));
						fclose($fp);

						if($add)
						{
							if($fixvalue !== FALSE)
							{
								$counter = (int)$fixvalue;
							}
							else
							{
								$counter++;
							}
							$fp = @fopen($filename, "w");
							if($fp)
							{
								fputs($fp,$counter);
								fclose($fp);
								return $counter;
							}
							else return FALSE;
						}
						else
						{
							return $counter;
						}
					}
					else return FALSE;
				}
				else return FALSE;
			}
			else return FALSE;
		}


		/**
		  * @shortdesc Scanns the tempfolder for jpeg-files with nameprefix used by the class and trash them if they are older than maxlifetime.
		  * @private
		  *
		  **/
		function collect_garbage()
		{
			$OK = FALSE;
			$captchas = 0;
			$trashed = 0;
			if($handle = @opendir($this->tempfolder))
			{
				$OK = TRUE;
				while(false !== ($file = readdir($handle)))
				{
					if(!is_file($this->tempfolder.$file)) continue;
					// check for name-prefix, extension and filetime
					if(substr($file,0,strlen($this->prefix)) == $this->prefix)
					{
						if(strrchr($file, ".") == ".jpg")
						{
							$captchas++;
							if((time() - filemtime($this->tempfolder.$file)) >= $this->maxlifetime)
							{
								$trashed++;
								$res = @unlink($this->tempfolder.$file);
								if(!$res) $OK = FALSE;
							}
						}
					}
				}
				closedir($handle);
			}
			if($this->debug) echo "\n<br>-Captcha-Debug: There are ($captchas) captcha-images in tempfolder, where ($trashed) are seems to be lost.";
			return $OK;
		}


		/** @private **/
		function get_filename($public="")
		{
			if($public=="") $public = $this->public_key;
			return $this->tempfolder.$this->prefix.$public.".jpg";
		}


		/** @private **/
		function get_filename_url($public="")
		{
			if($public=="") $public = $this->public_key;
			return str_replace($_SERVER['DOCUMENT_ROOT'],'',$this->tempfolder).$this->prefix.$public.".jpg";
		}


} // END CLASS hn_CAPTCHA_X1

?>
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