【作者】 万继光； 王继彬； 谢长生；

【Author】 Jiguang Wan, Jibin Wang, Changsheng Xie Dept. of Computer Science, Huazhong University of Science and Technology, China

【机构】 华中科技大学计算机学院；

【摘要】 多媒体应用对存储性能要求很高,由于磁盘系统性能发展比较慢,完全不能够满足多媒体共享的需要。Cache技术是目前提高存储性能的常用技术,针对多媒体请求访问地址可预测的特点,设计了一种FOPT(ForecastOPT)缓存替换算法。根据多媒体访问的地址连续性,来预测将来访问的地址顺序,并采用平衡二叉树的先序线索组织cache的数据块,从而快速实现基于预测的FOPT算法。仿真不同的客户端的情况下,对FOPT和LRU算法命中率进行了测试,从结果看,当请求块大小达到64KB时,FOPT算法的命中率比LRU命中率高50-70%,充分说明了FOPT算法的有效性。更多还原

【Abstract】 The multimedia applications require high storage performance, but because of the mechanical localization property of the disk, which completely cannot satisfy the demand of the multimedia sharing. The Cache technology is commonly used methods to resolve the problem at present, Classified by the predictable characters of request address for multimedia streams, a replacement algorithm called FOPT(Forecast OPT) is proposed, it may forecast access request address according to address continuities of the multimedia. The paper uses preorder traversal index of the balanced binary tree to organize cache the block data, thus can realize FOPT algorithm fast based on the forecast. The test to the hit probability of FOPT and LRU algorithm in the simulation different client situations has shown that when the request block size achieves 64KB, the FOPT algorithm’s hit probability has 50%-70% improvement over the LRU algorithm, which fully manifests the validity of FOPT algorithm in the multimedia applications.更多还原