struct node
  {
    string url;
    std::string* data;
    struct node* next;
    struct node* prev;
  };


  void RandomCache::cachePage(string* page_data, string url)
  {
    datanode *page_node= (datanode*)malloc(sizeof(datanode));
    page_node->url = url;
    page_node->data = page_data;
    page_node->next=NULL;
    page_node->prev=NULL;

    insertNode(page_node);

  }

datanode *page_node= new datanode();