首页 新闻 搜索 专区 学院

关于BufferedStream效率问题

0
[已关闭问题] 关闭于 2012-07-05 13:59
    class Program
    {
        const int dataArraySize = 200;
        const int streamBufferSize = 2000;
        const int numberOfLoops = 10000;
        static int totalSize = 0;
        static void Main(string[] args)
        {
            StringBuilder sbFS = new StringBuilder();
            StringBuilder sbBS = new StringBuilder();
            FileStream fs = new FileStream(@"E:\1.txt", FileMode.Open, FileAccess.Read);
            BufferedStream bs = new BufferedStream(fs, streamBufferSize);
            byte[] by = new byte[dataArraySize];
            int temp = 0;
            try
            {
                //FileStream Read
                DateTime startFS = DateTime.Now;
                while ((temp = fs.Read(by, 0, by.Length)) > 0)
                {
                    totalSize += temp;
                    //sbFS.Append(Encoding.GetEncoding("gb2312").GetString(by));
                }
                double endFS = (DateTime.Now - startFS).TotalMilliseconds;
                Console.WriteLine("FileStream Read TotalBit : {0}", totalSize);
                Console.WriteLine("FileStream Read Time : {0}", endFS.ToString("F5"));

                //Reset
                temp = 0;
                totalSize = 0;
                Array.Clear(by, 0, by.Length);
                fs.Seek(0, SeekOrigin.Begin);

                //BufferedStream
                DateTime startBS = DateTime.Now;
                while ((temp = bs.Read(by, 0, by.Length)) > 0)
                {
                    totalSize += temp;
                    //sbBS.Append(Encoding.GetEncoding("gb2312").GetString(by));
                }
                double endBS = (DateTime.Now - startBS).TotalMilliseconds;
                Console.WriteLine("BufferedStream Read TotalBit : {0}", totalSize);
                Console.WriteLine("BufferedStream Read Time : {0}", endBS.ToString("F5"));
            }
            finally
            {
                bs.Close();
                bs.Dispose();
                fs.Close();
                fs.Dispose();
            }
            Console.ReadLine();
        }
    }

本地准备了一个13M的txt文本.用FileStream直接Read.

和BufferedStream的Read进行对比

每次对比结果:

FileStream Read TotalBit : 13664376
FileStream Read Time : 31.25000
BufferedStream Read TotalBit : 13664376
BufferedStream Read Time : 31.25000

=============================================

FileStream Read TotalBit : 13664376
FileStream Read Time : 15.62500
BufferedStream Read TotalBit : 13664376
BufferedStream Read Time : 31.25000

=============================================

FileStream Read TotalBit : 13664376
FileStream Read Time : 31.25000
BufferedStream Read TotalBit : 13664376
BufferedStream Read Time : 15.62500

=============================================

几次对比结果都是这样!

为什么用了BufferedStream没有对效率提高多少呢?而且有时反而还比直接用FileStream读慢呢?

蓝丶 sky的主页 蓝丶 sky | 初学一级 | 园豆:6
提问于:2012-05-03 14:43
< >
分享
清除回答草稿
   您需要登录以后才能回答,未注册用户请先注册