[Sommaire] [Imprimer]

   1  <?php
   2  
   3  
   4  
   5  /**
   6  * caches instances of the wsdl class
   7  * 
   8  * @author   Scott Nichol <snichol@computer.org>
   9  * @author    Ingo Fischer <ingo@apollon.de>
  10  * @version  $Id: class.wsdlcache.php,v 1.5 2005/05/20 17:58:17 snichol Exp $
  11  * @access public 
  12  */
  13  class wsdlcache {
  14      /**
  15       *    @var resource
  16       *    @access private
  17       */
  18      var $fplock;
  19      /**
  20       *    @var integer
  21       *    @access private
  22       */
  23      var $cache_lifetime;
  24      /**
  25       *    @var string
  26       *    @access private
  27       */
  28      var $cache_dir;
  29      /**
  30       *    @var string
  31       *    @access public
  32       */
  33      var $debug_str = '';
  34  
  35      /**
  36      * constructor
  37      *
  38      * @param string $cache_dir directory for cache-files
  39      * @param integer $cache_lifetime lifetime for caching-files in seconds or 0 for unlimited
  40      * @access public
  41      */
  42  	function wsdlcache($cache_dir='.', $cache_lifetime=0) {
  43          $this->fplock = array();
  44          $this->cache_dir = $cache_dir != '' ? $cache_dir : '.';
  45          $this->cache_lifetime = $cache_lifetime;
  46      }
  47  
  48      /**
  49      * creates the filename used to cache a wsdl instance
  50      *
  51      * @param string $wsdl The URL of the wsdl instance
  52      * @return string The filename used to cache the instance
  53      * @access private
  54      */
  55  	function createFilename($wsdl) {
  56          return $this->cache_dir.'/wsdlcache-' . md5($wsdl);
  57      }
  58  
  59      /**
  60      * adds debug data to the class level debug string
  61      *
  62      * @param    string $string debug data
  63      * @access   private
  64      */
  65  	function debug($string){
  66          $this->debug_str .= get_class($this).": $string\n";
  67      }
  68  
  69      /**
  70      * gets a wsdl instance from the cache
  71      *
  72      * @param string $wsdl The URL of the wsdl instance
  73      * @return object wsdl The cached wsdl instance, null if the instance is not in the cache
  74      * @access public
  75      */
  76  	function get($wsdl) {
  77          $filename = $this->createFilename($wsdl);
  78          if ($this->obtainMutex($filename, "r")) {
  79              // check for expired WSDL that must be removed from the cache
  80               if ($this->cache_lifetime > 0) {
  81                  if (file_exists($filename) && (time() - filemtime($filename) > $this->cache_lifetime)) {
  82                      unlink($filename);
  83                      $this->debug("Expired $wsdl ($filename) from cache");
  84                      $this->releaseMutex($filename);
  85                      return null;
  86                    }
  87              }
  88              // see what there is to return
  89              $fp = @fopen($filename, "r");
  90              if ($fp) {
  91                  $s = implode("", @file($filename));
  92                  fclose($fp);
  93                  $this->debug("Got $wsdl ($filename) from cache");
  94              } else {
  95                  $s = null;
  96                  $this->debug("$wsdl ($filename) not in cache");
  97              }
  98              $this->releaseMutex($filename);
  99              return (!is_null($s)) ? unserialize($s) : null;
 100          } else {
 101              $this->debug("Unable to obtain mutex for $filename in get");
 102          }
 103          return null;
 104      }
 105  
 106      /**
 107      * obtains the local mutex
 108      *
 109      * @param string $filename The Filename of the Cache to lock
 110      * @param string $mode The open-mode ("r" or "w") or the file - affects lock-mode
 111      * @return boolean Lock successfully obtained ?!
 112      * @access private
 113      */
 114  	function obtainMutex($filename, $mode) {
 115          if (isset($this->fplock[md5($filename)])) {
 116              $this->debug("Lock for $filename already exists");
 117              return false;
 118          }
 119          $this->fplock[md5($filename)] = fopen($filename.".lock", "w");
 120          if ($mode == "r") {
 121              return flock($this->fplock[md5($filename)], LOCK_SH);
 122          } else {
 123              return flock($this->fplock[md5($filename)], LOCK_EX);
 124          }
 125      }
 126  
 127      /**
 128      * adds a wsdl instance to the cache
 129      *
 130      * @param object wsdl $wsdl_instance The wsdl instance to add
 131      * @return boolean WSDL successfully cached
 132      * @access public
 133      */
 134  	function put($wsdl_instance) {
 135          $filename = $this->createFilename($wsdl_instance->wsdl);
 136          $s = serialize($wsdl_instance);
 137          if ($this->obtainMutex($filename, "w")) {
 138              $fp = fopen($filename, "w");
 139              fputs($fp, $s);
 140              fclose($fp);
 141              $this->debug("Put $wsdl_instance->wsdl ($filename) in cache");
 142              $this->releaseMutex($filename);
 143              return true;
 144          } else {
 145              $this->debug("Unable to obtain mutex for $filename in put");
 146          }
 147          return false;
 148      }
 149  
 150      /**
 151      * releases the local mutex
 152      *
 153      * @param string $filename The Filename of the Cache to lock
 154      * @return boolean Lock successfully released
 155      * @access private
 156      */
 157  	function releaseMutex($filename) {
 158          $ret = flock($this->fplock[md5($filename)], LOCK_UN);
 159          fclose($this->fplock[md5($filename)]);
 160          unset($this->fplock[md5($filename)]);
 161          if (! $ret) {
 162              $this->debug("Not able to release lock for $filename");
 163          }
 164          return $ret;
 165      }
 166  
 167      /**
 168      * removes a wsdl instance from the cache
 169      *
 170      * @param string $wsdl The URL of the wsdl instance
 171      * @return boolean Whether there was an instance to remove
 172      * @access public
 173      */
 174  	function remove($wsdl) {
 175          $filename = $this->createFilename($wsdl);
 176          // ignore errors obtaining mutex
 177          $this->obtainMutex($filename, "w");
 178          $ret = unlink($filename);
 179          $this->debug("Removed ($ret) $wsdl ($filename) from cache");
 180          $this->releaseMutex($filename);
 181          return $ret;
 182      }
 183  }
 184  ?>