namespace woo\base;

//基類
abstract class Registry {
  abstract protected function get($key);
  abstract protected function set($key,$val);
}

//請求級別,他的生存周期通常為從用戶發(fā)起一個請求到后臺程序回復(fù)這個請求為止
class RequestRegistry extends Registry{
  private $values = array();
  private static $instance;
  
  private function __construct (){}

  static function instance(){　　　　// 單例，即這個類只有一個唯一的實例
    if(!isset(self::$instance)){
      self::$instance = new self();
    }
    return self::$instance;
  }
  
  protected function get($key){
    if(isset($this->values[$key]){
      return $this->values[$key];
    }
    return null;
  }
  
  protected function set($key,$val){
    $this->values[$key] = $val;
  }
  
  static function getRequest(){
    return self::instance()->get('request');
  }
  
  static function setRequest(\woo\controller\Request $request){　　　　　　//\woo\controller\Request 主要功能是處理用戶請求信息的一個類
    return self::instance()->set('request',$request);
  }
}

//會話級別,此示例中類的生存周期主要還是看SESSION的生存時間
class SessionRegistry extends Registry{
  private static $instance;
  private function __construct (){
    session_start();
  }
  
  static function instance(){
    if(!isset(self::$instance)){
      self::$instance = new self();
    }
    return self::$instance;
  }
  
  protected function get($key){
    if(isset($_SESSION[__CLASS__][$key])){
      return $_SESSION[__CLASS__][$key];
    }
    return null;
  }
  
  protected function set($key,$val){
    $_SESSION[__CLASS__][$key] = $val;
  }
  
  function setComplex(Complex $complex){
    self::instance()->set('complex',$complex);
  }
  
  function getComplex(){
    return self::instance()->get('complex');
  }
}

//應(yīng)用程序級別,此示例中因相關(guān)的值是保存在文本文件中，所以只要文件存在，保存的值也就一直存在
 class ApplicationRegistry extends Registry{
  private Static $instance;
  private $freezedir = 'data';
  private $values = array();
  private $mtimes = array();

  private function __construct (){}
   
  static function instance(){
    if(!isset(self::$instance)){
      self::$instance = new self();    
    }
    return self::$instance;
  }
  
  protected function get($key){
    $path = $this->freezedir . DIRECTORY_SEPARATOR . $key; // 保存值的文件的路徑
    if(file_exists($path)){
      clearstatcache();   　　// 清除filemtime緩存的上次記錄的文件修改時間
      $mtime = filemtime($path);
      if(!isset($this->mtimes[$key])){
        $this->mtimes[$key] = 0;
      }
      if($mtime > $this->mtimes[$key]){　　　　// 文件內(nèi)容假如被修改過，那么就要重新獲取里面的值
        $data = file_get_contents($path);
        $this->mtimes[$key] = $mtime;
        return ($this->values[$key] = unserialize($data));
      }
    }
    if(isset($this->values[$key])){
      return $this->values[$key];
    }
    return null;
  }
  
  protected function set ($key,$val){
    $this->values[$key] = $val;
    $path = $this->freezedir . DIRECTORY_SEPARATOR . $key;
    file_put_contents($path,serialize($val));
    $this->mtimes[$key] = time();
  }
  
  static function getDSN(){
    return self::instance()->get('dsn');
  }
  
  static function setDSN($dsn){
    return self::instance()->set('dsn',$dsn);
  }
   
 }