/modules/shop/includes/functions/cache.php

<?php

//

// +----------------------------------------------------------------------+

// |zen-cart Open Source E-commerce                                       |

// +----------------------------------------------------------------------+

// | Copyright (c) 2003 The zen-cart developers                           |

// |                                                                      |

// | http://www.zen-cart.com/index.php                                    |

// |                                                                      |

// | Portions Copyright (c) 2003 osCommerce                               |

// +----------------------------------------------------------------------+

// | This source file is subject to version 2.0 of the GPL license,       |

// | that is bundled with this package in the file LICENSE, and is        |

// | available through the world-wide-web at the following url:           |

// | http://www.zen-cart.com/license/2_0.txt.                             |

// | If you did not receive a copy of the zen-cart license and are unable |

// | to obtain it through the world-wide-web, please send a note to       |

// | license@zen-cart.com so we can mail you a copy immediately.          |

// +----------------------------------------------------------------------+

// $Id: cache.php 290 2004-09-15 19:48:26Z wilt $

//

/**

 * @package ZenCart_Functions

*/



////

//! Write out serialized data.

//  write_cache uses serialize() to store $var in $filename.

//  $var      -  The variable to be written out.

//  $filename -  The name of the file to write to.

  function write_cache(&$var, $filename) {

    $filename = DIR_FS_CACHE . $filename;

    $success = false;



// try to open the file

    if ($fp = @fopen($filename, 'w')) {

// obtain a file lock to stop corruptions occuring

      flock($fp, 2); // LOCK_EX

// write serialized data

      fputs($fp, serialize($var));

// release the file lock

      flock($fp, 3); // LOCK_UN

      fclose($fp);

      $success = true;

    }



    return $success;

  }



////

//! Read in seralized data.

//  read_cache reads the serialized data in $filename and

//  fills $var using unserialize().

//  $var      -  The variable to be filled.

//  $filename -  The name of the file to read.

  function read_cache(&$var, $filename, $auto_expire = false){

    $filename = DIR_FS_CACHE . $filename;

    $success = false;



    if (($auto_expire == true) && file_exists($filename)) {

      $now = time();

      $filetime = filemtime($filename);

      $difference = $now - $filetime;



      if ($difference >= $auto_expire) {

        return false;

      }

    }



// try to open file

    if ($fp = @fopen($filename, 'r')) {

// read in serialized data

      $szdata = fread($fp, filesize($filename));

      fclose($fp);

// unserialze the data

      $var = unserialize($szdata);



      $success = true;

    }



    return $success;

  }



////

//! Get data from the cache or the database.

//  get_db_cache checks the cache for cached SQL data in $filename

//  or retreives it from the database is the cache is not present.

//  $SQL      -  The SQL query to exectue if needed.

//  $filename -  The name of the cache file.

//  $var      -  The variable to be filled.

//  $refresh  -  Optional.  If true, do not read from the cache.

//  function get_db_cache($sql, &$var, $filename, $refresh = false){

//    $var = array();



// check for the refresh flag and try to the data

//    if (($refresh == true)|| !read_cache($var, $filename)) {

// Didn' get cache so go to the database.

//      $conn = mysql_connect("localhost", "apachecon", "apachecon");

//      $res = $db->Execute($sql);

//      if ($err = mysql_error()) trigger_error($err, E_USER_ERROR);

// loop through the results and add them to an array

//      while ($rec = zen_db_fetch_array($res)) {

//        $var[] = $rec;

//      }

// write the data to the file

//      write_cache($var, $filename);

//    }

//  }



////

//! Cache the categories box

// Cache the categories box

  function zen_cache_categories_box($auto_expire = false, $refresh = false) {

    global $cPath, $foo, $id, $categories_string;



    if (($refresh == true) || !read_cache($cache_output, 'categories_box-' . $_SESSION['language'] . '.cache' . $cPath, $auto_expire)) {

      ob_start();

      include(DIR_WS_BOXES . 'categories.php');

      $cache_output = ob_get_contents();

      ob_end_clean();

      write_cache($cache_output, 'categories_box-' . $_SESSION['language'] . '.cache' . $cPath);

    }



    return $cache_output;

  }



////

//! Cache the manufacturers box

// Cache the manufacturers box

  function zen_cache_manufacturers_box($auto_expire = false, $refresh = false) {



    if (($refresh == true) || !read_cache($cache_output, 'manufacturers_box-' . $_SESSION['language'] . '.cache' . $_GET['manufacturers_id'], $auto_expire)) {

      ob_start();

      include(DIR_WS_BOXES . 'manufacturers.php');

      $cache_output = ob_get_contents();

      ob_end_clean();

      write_cache($cache_output, 'manufacturers_box-' . $_SESSION['language'] . '.cache' . $_GET['manufacturers_id']);

    }



    return $cache_output;

  }



////

//! Cache the also purchased module

// Cache the also purchased module

  function zen_cache_also_purchased($auto_expire = false, $refresh = false) {



    if (($refresh == true) || !read_cache($cache_output, 'also_purchased-' . $_SESSION['language'] . '.cache' . $_GET['products_id'], $auto_expire)) {

      ob_start();

      include(DIR_WS_MODULES . zen_get_module_directory(FILENAME_ALSO_PURCHASED_PRODUCTS));

      $cache_output = ob_get_contents();

      ob_end_clean();

      write_cache($cache_output, 'also_purchased-' . $_SESSION['language'] . '.cache' . $_GET['products_id']);

    }



    return $cache_output;

  }

?>