[Sommaire] [Imprimer]

   1  <?php
   2  /**
   3   * The Horde_Compress:: class provides an API for various compression
   4   * techniques that can be used by Horde applications.
   5   *
   6   * $Horde: framework/Compress/Compress.php,v 1.7.12.10 2006/01/01 21:28:11 jan Exp $
   7   *
   8   * Copyright 2003-2006 Michael Slusarz <slusarz@bigworm.colorado.edu>
   9   *
  10   * See the enclosed file COPYING for license information (LGPL). If you
  11   * did not receive this file, see http://www.fsf.org/copyleft/lgpl.html.
  12   *
  13   * @author  Michael Slusarz <slusarz@bigworm.colorado.edu>
  14   * @since   Horde 3.0
  15   * @package Horde_Compress
  16   */
  17  class Horde_Compress {
  18  
  19      /**
  20       * Attempts to return a concrete Horde_Compress instance based on $driver.
  21       *
  22       * @param mixed $driver  The type of concrete Horde_Compress subclass to
  23       *                       return. If $driver is an array, then we will look
  24       *                       in $driver[0]/lib/Compress/ for the subclass
  25       *                       implementation named $driver[1].php.
  26       * @param array $params  A hash containing any additional configuration or
  27       *                       parameters a subclass might need.
  28       *
  29       * @return Horde_Compress  The newly created concrete Horde_Compress
  30       *                         instance, or false on an error.
  31       */
  32      function &factory($driver, $params = array())
  33      {
  34          if (is_array($driver)) {
  35              list($app, $driver) = $driver;
  36          }
  37  
  38          $driver = basename($driver);
  39  
  40          if (!empty($app)) {
  41              require_once $app . '/lib/Compress/' . $driver . '.php';
  42          } elseif (@file_exists(dirname(__FILE__) . '/Compress/' . $driver . '.php')) {
  43              require_once dirname(__FILE__) . '/Compress/' . $driver . '.php';
  44          } else {
  45              @include_once 'Horde/Compress/' . $driver . '.php';
  46          }
  47  
  48          $class = 'Horde_Compress_' . $driver;
  49          if (class_exists($class)) {
  50              $compress = &new $class($params);
  51          } else {
  52              $compress = false;
  53          }
  54  
  55          return $compress;
  56      }
  57  
  58      /**
  59       * Attempts to return a reference to a concrete Horde_Compress instance
  60       * based on $driver. It will only create a new instance if no
  61       * Horde_Compress instance with the same parameters currently exists.
  62       *
  63       * This method must be invoked as:
  64       *   $var = &Horde_Compress::singleton();
  65       *
  66       * @param mixed $driver  See Horde_Compress::factory().
  67       * @param array $params  See Horde_Compress::factory().
  68       *
  69       * @return Horde_Compress  The concrete Horde_Compress reference, or false
  70       *                         on an error.
  71       */
  72      function &singleton($driver, $params = array())
  73      {
  74          static $instances = array();
  75  
  76          $signature = md5(serialize(array($driver, $params)));
  77          if (!isset($instances[$signature])) {
  78              $instances[$signature] = &Horde_Compress::factory($driver, $params);
  79          }
  80  
  81          return $instances[$signature];
  82      }
  83  
  84      /**
  85       * Constructor.
  86       *
  87       * @param array $params  Parameter array.
  88       */
  89      function Horde_Compress($params = array())
  90      {
  91      }
  92  
  93      /**
  94       * Compress the data.
  95       *
  96       * @param string $data   The data to compress.
  97       * @param array $params  An array of arguments needed to compress the data.
  98       *
  99       * @return mixed  The compressed data.
 100       *                Returns PEAR_Error object on error.
 101       */
 102      function compress($data, $params = array())
 103      {
 104          return PEAR::raiseError('Unsupported');
 105      }
 106  
 107      /**
 108       * Decompress the data.
 109       *
 110       * @param string $data   The data to decompress.
 111       * @param array $params  An array of arguments needed to decompress the
 112       *                       data.
 113       *
 114       * @return array  The decompressed data.
 115       *                Returns PEAR_Error object on error.
 116       */
 117      function decompress($data, $params = array())
 118      {
 119          return PEAR::raiseError('Unsupported');
 120      }
 121  
 122  }