benchmark.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;

namespace ConsoleApp3
{
    class Program
    {
        static List<string> Words = SampleSet().ToList();
        static readonly string[] KeywordArray = new string[] { "AS", "SELECT", "WHERE", "LOAD", "GROUP", "ORDER", "INCLUDE", "UPDATE" };
        static readonly List<string> KeywordList = KeywordArray.ToList();
        static readonly HashSet<string> KeywordSet = new HashSet<string>(KeywordArray, StringComparer.OrdinalIgnoreCase);

        static void Main(string[] args)
        {
            (string, Action)[] benchmarks = new[]
            {
                ("Fast Array", new Action(FastArray)),
                ("Set", new Action(SetCheck)),
                ("Normal Array", new Action(NormalArray)),
            };

            foreach (var benchmark in benchmarks)
                RunBenchmark(benchmark);

            Console.Read();
        }

        private static void RunBenchmark((string name, Action invoke) benchmark)
        {

            GC.Collect(3);

            // warmup
            for (var i = 0; i < 500; i++)
                benchmark.invoke();

            var timer = Stopwatch.StartNew();
            for (var i = 0; i < 100000; i++)
                benchmark.invoke();

            timer.Stop();

            Console.WriteLine($"{benchmark.name}: {timer.Elapsed}");
        }

        static void NormalArray()
        {
            foreach (var word in Words)
            {
                string alias = string.Empty;
                if (KeywordList.Contains(word))
                    alias = "'" + word + "'";
            }
        }

        static void FastArray()
        {
            foreach (var word in Words)
            {
                string alias = string.Empty;
                foreach (var keyword in KeywordArray)
                    if (string.Equals(keyword, word))
                    {
                        alias = "'" + word + "'";
                        break;
                    }
            }
        }

        static void SetCheck()
        {
            foreach (var word in Words)
            {
                string alias = string.Empty;
                if (KeywordSet.Contains(word))
                    alias = "'" + word + "'";
            }
        }

        private static IEnumerable<string> SampleSet()
        {
            var random = new Random();
            var buffer = new StringBuilder(8);

            return Enumerable.Range(0, 1000)
                .Select(x => random.Next(2, 7))
                .Select(x => CreateString(x, buffer, random));
        }

        static string CreateString(int length, StringBuilder buffer, Random random)
        {
            buffer.Clear();
            for (var i = 0; i < length; i++)
                buffer.Append(random.Next((char)random.Next(65, 90)));

            return buffer.ToString();
        }
    }
}