将不确定变为确定~老赵写的CodeTimer是代码性能测试的利器

首先，非常感谢赵老大的CodeTimer，它让我们更好的了解到代码执行的性能，从而可以让我们从性能的角度来考虑问题，有些东西可能我们认为是这样的，但经理测试并非如何，这正应了我之前的那名话：“机器最能证明一切”！

费话就不说了，看代码吧：

  1     /// <summary>
  2     /// 执行代码规范
  3     /// </summary>
  4     public interface IAction
  5     {
  6         void Action();
  7     }
  8
  9     /// <summary>
 10     /// 老赵的性能测试工具
 11     /// </summary>
 12     public static class CodeTimer
 13     {
 14         [DllImport("kernel32.dll", SetLastError = true)]
 15         static extern bool GetThreadTimes(IntPtr hThread, out long lpCreationTime, out long lpExitTime, out long lpKernelTime, out long lpUserTime);
 16
 17         [DllImport("kernel32.dll")]
 18         static extern IntPtr GetCurrentThread();
 19         public delegate void ActionDelegate();
 20         private static long GetCurrentThreadTimes()
 21         {
 22             long l;
 23             long kernelTime, userTimer;
 24             GetThreadTimes(GetCurrentThread(), out l, out l, out kernelTime, out userTimer);
 25             return kernelTime + userTimer;
 26         }
 27         static CodeTimer()
 28         {
 29             Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
 30             Thread.CurrentThread.Priority = ThreadPriority.Highest;
 31         }
 32         public static void Time(string name, int iteration, ActionDelegate action)
 33         {
 34             if (String.IsNullOrEmpty(name))
 35             {
 36                 return;
 37             }
 38             if (action == null)
 39             {
 40                 return;
 41             }
 42
 43             //1. Print name
 44             ConsoleColor currentForeColor = Console.ForegroundColor;
 45             Console.ForegroundColor = ConsoleColor.Yellow;
 46             Console.WriteLine(name);
 47
 48             // 2. Record the latest GC counts
 49             //GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced);
 50             GC.Collect(GC.MaxGeneration);
 51             int[] gcCounts = new int[GC.MaxGeneration + 1];
 52             for (int i = 0; i <= GC.MaxGeneration; i++)
 53             {
 54                 gcCounts[i] = GC.CollectionCount(i);
 55             }
 56
 57             // 3. Run action
 58             Stopwatch watch = new Stopwatch();
 59             watch.Start();
 60             long ticksFst = GetCurrentThreadTimes(); //100 nanosecond one tick
 61             for (int i = 0; i < iteration; i++) action();
 62             long ticks = GetCurrentThreadTimes() - ticksFst;
 63             watch.Stop();
 64
 65             // 4. Print CPU
 66             Console.ForegroundColor = currentForeColor;
 67             Console.WriteLine("\tTime Elapsed:\t\t" +
 68                watch.ElapsedMilliseconds.ToString("N0") + "ms");
 69             Console.WriteLine("\tTime Elapsed (one time):" +
 70                (watch.ElapsedMilliseconds / iteration).ToString("N0") + "ms");
 71             Console.WriteLine("\tCPU time:\t\t" + (ticks * 100).ToString("N0")
 72                + "ns");
 73             Console.WriteLine("\tCPU time (one time):\t" + (ticks * 100 /
 74                iteration).ToString("N0") + "ns");
 75
 76             // 5. Print GC
 77             for (int i = 0; i <= GC.MaxGeneration; i++)
 78             {
 79                 int count = GC.CollectionCount(i) - gcCounts[i];
 80                 Console.WriteLine("\tGen " + i + ": \t\t\t" + count);
 81             }
 82             Console.WriteLine();
 83         }
 84
 85
 86
 87         public static void Time(string name, int iteration, IAction action)
 88         {
 89             if (String.IsNullOrEmpty(name))
 90             {
 91                 return;
 92             }
 93
 94             if (action == null)
 95             {
 96                 return;
 97             }
 98
 99             //1. Print name
100             ConsoleColor currentForeColor = Console.ForegroundColor;
101             Console.ForegroundColor = ConsoleColor.Yellow;
102             Console.WriteLine(name);
103
104             // 2. Record the latest GC counts
105             //GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced);
106             GC.Collect(GC.MaxGeneration);
107             int[] gcCounts = new int[GC.MaxGeneration + 1];
108             for (int i = 0; i <= GC.MaxGeneration; i++)
109             {
110                 gcCounts[i] = GC.CollectionCount(i);
111             }
112
113             // 3. Run action
114             Stopwatch watch = new Stopwatch();
115             watch.Start();
116             long ticksFst = GetCurrentThreadTimes(); //100 nanosecond one tick
117             for (int i = 0; i < iteration; i++) action.Action();
118             long ticks = GetCurrentThreadTimes() - ticksFst;
119             watch.Stop();
120
121             // 4. Print CPU
122             Console.ForegroundColor = currentForeColor;
123             Console.WriteLine("\tTime Elapsed:\t\t" +
124                watch.ElapsedMilliseconds.ToString("N0") + "ms");
125             Console.WriteLine("\tTime Elapsed (one time):" +
126                (watch.ElapsedMilliseconds / iteration).ToString("N0") + "ms");
127             Console.WriteLine("\tCPU time:\t\t" + (ticks * 100).ToString("N0")
128                 + "ns");
129             Console.WriteLine("\tCPU time (one time):\t" + (ticks * 100 /
130                 iteration).ToString("N0") + "ns");
131
132             // 5. Print GC
133             for (int i = 0; i <= GC.MaxGeneration; i++)
134             {
135                 int count = GC.CollectionCount(i) - gcCounts[i];
136                 Console.WriteLine("\tGen " + i + ": \t\t\t" + count);
137             }
138             Console.WriteLine();
139         }
140     }

有了上面的codeTimer我们就来测试一个吧，如字条串和并的问题，用+=还是用StringBuilder呢，有点经验的程序员肯定说是StringBuilder，是的，确实是后者，那我们就来看看这

两种方法测试的结果吧

 1      CodeTimer.Time("String  Concat", 100000,
 2                  () =>
 3                  {
 4                      var s = "1";
 5                      for (int i = 1; i < 10; i++)
 6                          s = s + "1";
 7                  });
 8
 9       CodeTimer.Time("StringBuilder Concat", 100000,
10                () =>
11                {
12                    var s = new StringBuilder();
13                    for (int i = 1; i < 10; i++)
14                        s.Append("1");
15                });

测试的结果如下：

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" alt="" />

从图中我们可以看到StringBuilder快的很明显，无论是执行时间，还是对CPU的消耗及GC回收都远低于String的拼结，所以，才有以下结论：

在字符串拼结时，请使用StringBuilder吧！