class Program {
        static void Main(string[] args) {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            Test2();
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);
            sw.Restart();
            Console.WriteLine("=============");
            Test1();
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);
            Console.ReadKey();
        }
        public static void Test1() {
            using (FileStream fs = new FileStream("2020-05-24.log", FileMode.Open, FileAccess.Read, FileShare.ReadWrite)) {
                byte val = 0;
                long total = fs.Length;
                int read = 0;
                while (read < total) {
                    val = (byte)fs.ReadByte();
                    read++;
                }
            }
        }
        public static void Test2() {
            using (FileStream fs = new FileStream("2020-05-24.log", FileMode.Open, FileAccess.Read, FileShare.ReadWrite)) {
                byte[] buffer = new byte[1024 * 1024];
                int b = 1;
                while (b > 0) {
                    b = fs.Read(buffer, 0, buffer.Length);
                }
            }
        }
    }