基于哈希链表和时间链表的HTTP代理缓存机制的实现

随着互联网的快速发展，越来越多的用户需要访问Internet资源，局域网人的众多用户如何能够通过一条Internet连接进行快速的网络浏览？这涉及到WEB代理服务器的核心部分--HTTP缓存系统。HTTP代理服务器的缓存系统将用户浏览的网页保存在代理服务器中，一旦有用户浏览相同的网页并且该网页还没有更新，则代理服务器直接将网页传递给用户，无需重新下载。因此，缓存明显加快了浏览速度。本文首先介绍了代理服务器的缓存原理，然后对缓存机制的具体功能进行了划分，最后给出基于哈希链表和时间链表的缓存系统的实现方法。

Implement of Http Proxy′s Cache Mechanism Based on Hash Link-Table and Time Link-Table

With the rapid development of Internet and Intranet, proxy server, used as a bridge linking Internet with Intranet, plays a more and more important role in many applications. Thus it becomes particularly important to research its interior details, especially the cache algorithm, which is the core of proxy. Web pages browsed by users would be saved in the cache of HTTP proxy server. If a user browses the same page and the content are not refreshed, the proxy server delivers the cached pages to user rather than downloading them again. So the cache speeds up the visit to the same web site. This paper firstly introduces the cache mechanism and then brings up a module which is divided into serveral parts, including cached file management, client request accpetance and server response process. Finally the solution of the cache mechanism is given based on Hash link table and time link table.