class.wsdlcache.php

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<?php



class wsdlcache {
        var $fplock;
        var $cache_lifetime;
        var $cache_dir;
        var $debug_str = '';

        function wsdlcache($cache_dir='.', $cache_lifetime=0) {
                $this->fplock = array();
                $this->cache_dir = $cache_dir != '' ? $cache_dir : '.';
                $this->cache_lifetime = $cache_lifetime;
        }

        function createFilename($wsdl) {
                return $this->cache_dir.'/wsdlcache-' . md5($wsdl);
        }

        function debug($string){
                $this->debug_str .= get_class($this).": $string\n";
        }

        function get($wsdl) {
                $filename = $this->createFilename($wsdl);
                if ($this->obtainMutex($filename, "r")) {
                        // check for expired WSDL that must be removed from the cache
                        if ($this->cache_lifetime > 0) {
                                if (file_exists($filename) && (time() - filemtime($filename) > $this->cache_lifetime)) {
                                        unlink($filename);
                                        $this->debug("Expired $wsdl ($filename) from cache");
                                        $this->releaseMutex($filename);
                                        return null;
                                }
                        }
                        // see what there is to return
                        $fp = @fopen($filename, "r");
                        if ($fp) {
                                $s = implode("", @file($filename));
                                fclose($fp);
                                $this->debug("Got $wsdl ($filename) from cache");
                        } else {
                                $s = null;
                                $this->debug("$wsdl ($filename) not in cache");
                        }
                        $this->releaseMutex($filename);
                        return (!is_null($s)) ? unserialize($s) : null;
                } else {
                        $this->debug("Unable to obtain mutex for $filename in get");
                }
                return null;
        }

        function obtainMutex($filename, $mode) {
                if (isset($this->fplock[md5($filename)])) {
                        $this->debug("Lock for $filename already exists");
                        return false;
                }
                $this->fplock[md5($filename)] = fopen($filename.".lock", "w");
                if ($mode == "r") {
                        return flock($this->fplock[md5($filename)], LOCK_SH);
                } else {
                        return flock($this->fplock[md5($filename)], LOCK_EX);
                }
        }

        function put($wsdl_instance) {
                $filename = $this->createFilename($wsdl_instance->wsdl);
                $s = serialize($wsdl_instance);
                if ($this->obtainMutex($filename, "w")) {
                        $fp = fopen($filename, "w");
                        fputs($fp, $s);
                        fclose($fp);
                        $this->debug("Put $wsdl_instance->wsdl ($filename) in cache");
                        $this->releaseMutex($filename);
                        return true;
                } else {
                        $this->debug("Unable to obtain mutex for $filename in put");
                }
                return false;
        }

        function releaseMutex($filename) {
                $ret = flock($this->fplock[md5($filename)], LOCK_UN);
                fclose($this->fplock[md5($filename)]);
                unset($this->fplock[md5($filename)]);
                if (! $ret) {
                        $this->debug("Not able to release lock for $filename");
                }
                return $ret;
        }

        function remove($wsdl) {
                $filename = $this->createFilename($wsdl);
                // ignore errors obtaining mutex
                $this->obtainMutex($filename, "w");
                $ret = unlink($filename);
                $this->debug("Removed ($ret) $wsdl ($filename) from cache");
                $this->releaseMutex($filename);
                return $ret;
        }
}
?>