pCache.inc in Visitors 8

File

pchart/pCache.inc

<?php

/*
    pCache - Faster renderding using data cache
    Copyright (C) 2008 Jean-Damien POGOLOTTI
    Version  1.1.2 last updated on 06/17/08

    http://pchart.sourceforge.net

    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 1,2,3 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, see <http://www.gnu.org/licenses/>.

    Class initialisation :
     pCache($CacheFolder="Cache/")
    Cache management :
     IsInCache($Data)
     GetFromCache($ID,$Data)
     WriteToCache($ID,$Data,$Picture)
     DeleteFromCache($ID,$Data)
     ClearCache()
    Inner functions :
     GetHash($ID,$Data)
*/

/* pCache class definition */
class pCache {
  var $HashKey = "";
  var $CacheFolder = "Cache/";

  /* Create the pCache object */
  function pCache($CacheFolder = "Cache/") {
    $this->CacheFolder = $CacheFolder;
  }

  /* This function is clearing the cache folder */
  function ClearCache() {
    if ($handle = opendir($this->CacheFolder)) {
      while (false !== ($file = readdir($handle))) {
        if ($file != "." && $file != "..") {
          unlink($this->CacheFolder . $file);
        }
      }
      closedir($handle);
    }
  }

  /* This function is checking if we have an offline version of this chart */
  function IsInCache($ID, $Data, $Hash = "") {
    if ($Hash == "") {
      $Hash = $this
        ->GetHash($ID, $Data);
    }
    if (file_exists($this->CacheFolder . $Hash)) {
      return TRUE;
    }
    else {
      return FALSE;
    }
  }

  /* This function is making a copy of drawn chart in the cache folder */
  function WriteToCache($ID, $Data, $Picture) {
    $Hash = $this
      ->GetHash($ID, $Data);
    $FileName = $this->CacheFolder . $Hash;
    imagepng($Picture->Picture, $FileName);
  }

  /* This function is removing any cached copy of this chart */
  function DeleteFromCache($ID, $Data) {
    $Hash = $this
      ->GetHash($ID, $Data);
    $FileName = $this->CacheFolder . $Hash;
    if (file_exists($FileName)) {
      unlink($FileName);
    }
  }

  /* This function is retrieving the cached picture if applicable */
  function GetFromCache($ID, $Data) {
    $Hash = $this
      ->GetHash($ID, $Data);
    if ($this
      ->IsInCache("", "", $Hash)) {
      $FileName = $this->CacheFolder . $Hash;
      header('Content-type: image/png');
      @readfile($FileName);
      exit;
    }
  }

  /* This function is building the graph unique hash key */
  function GetHash($ID, $Data) {
    $mKey = "{$ID}";
    foreach ($Data as $key => $Values) {
      $tKey = "";
      foreach ($Values as $Serie => $Value) {
        $tKey = $tKey . $Serie . $Value;
      }
      $mKey = $mKey . md5($tKey);
    }
    return md5($mKey);
  }

}

Classes

Name	Description
pCache