Question

我正在尝试编写一个Decorator类型类，它将结果缓存到任何内容（从memecache开始）。每种方法都需要检查缓存$ this-＆gt; cache-＆gt; get（$ key），如果没有找到，请调用真实方法$ this-＆gt; real-＆gt; getExpensiveInfo01（$ param1，$ param2，$ param3）然后设置$ this-＆gt; cache-＆gt; set（$ key，$ expensiveInfo）。所以现在每个方法都有这个样板代码;

class ExpensiveCache implements ExpensiveInterface
{
  public function getExpensiveInfo01($param1, $param2, $param3)
  {
     $key = __FUNCTION__ . $param1 . $param2 . $param3;
     $rtn = $this->cache->get($key);
     if ($rtn === false) {
        $rtn = $this->expensive->getExpensiveInfo01($param1, $param2, $param3);
        $cacheStatus = $this->cache->set($key, $rtn);
    }
    return $rtn;
  }
  public function getExpensiveInfo02($param1, $param2)
  {
     $key = __FUNCTION__ . $param1 . $param2;
     $rtn = $this->cache->get($key);
     if ($rtn === false) {
        $rtn = $this->expensive->getExpensiveInfo02($param1, $param2);
        $cacheStatus = $this->cache->set($key, $rtn);
    }
    return $rtn;
  }
  public function getExpensiveInfo03($param1, $param2)
  {
     $key = __FUNCTION__ . $param1 . $param2;
     $rtn = $this->cache->get($key);
     if ($rtn === false) {
        $rtn = $this->expensive->getExpensiveInfo03($param1, $param2);
        $cacheStatus = $this->cache->set($key, $rtn);
    }
    return $rtn;
  }
}

无论如何在PHP5.3（该死的CentOS）中将锅炉板代码减少为一个私有方法调用。

Answer 1

不公开，但公开__call

class ExpensiveCache implements ExpensiveInterface {
    public function __call($name, $arguments) {
        $key = $name.implode('', $arguments);
        $rtn = $this->cache->get($key);
        if ($rtn === false) {
            $rtn = call_user_func_array(array($this->expensive, $name), $arguments);
            $cacheStatus = $this->cache->set($key, $rtn);
        }
        return $rtn;
    }
}

（如果$ this-＆gt; expensive-＆gt; $ name可以调用，可以添加一些支票）

Answer 2

也许是这样的：

private function getCacheKey(array $args)
{
    return implode('', $args);
}

private function getExpensiveInfo()
{
    $args = func_get_args();
    $key = $this->getCacheKey($args);
    if (($value = $this->cache->get($key)) === false) {
        $value = call_user_func_array(array($this->expensive, __FUNCTION__), $args);
        $this->cache->set($key, $value);
    }

    return $value;
}

使用PHP 5.3中的Decorator模式进行DRY

2 个答案: