using System;

using System.Collections;

using System.Collections.Generic;

using BenchmarkDotNet.Running;

using BenchmarkDotNet.Helpers;

using BenchmarkDotNet.Configs;

using BenchmarkDotNet.Attributes;

using BenchmarkDotNet.Jobs;

using BenchmarkDotNet.Toolchains.InProcess.Emit;

using BenchmarkDotNet.Loggers;

using Perfolizer.Horology;

​

[assembly: System.Diagnostics.Debuggable(isJITTrackingEnabled: false, isJITOptimizerDisabled: false)]

​

BenchmarkRunner.Run<Benchmark>(DefaultConfig.Instance

    .AddJob(Job.Default

        .WithToolchain(new InProcessEmitToolchain(

            timeout: TimeSpan.FromSeconds(30),

            logOutput: false))

        .WithIterationTime(TimeInterval.FromMilliseconds(20)))

    .AddLogger(new ConsoleLogger(unicodeSupport: true, ConsoleLogger.CreateGrayScheme()))

    .WithOptions(ConfigOptions.DisableLogFile));

​

[ReturnValueValidator]

[MemoryDiagnoser]

public class Benchmark

{   

    //[Params(0, long.MaxValue)]

    public long unixTimeStamp { get; set; }

    public string unixTimeStampHex { get; set; }

    [Params(1, 2, 3, 4, 5, 6, 7, 8, 9)]

    public int N;

    [GlobalSetup]

    public void Setup()

    {

        Random rnd = new Random();

        //unixTimeStamp = rnd.NextInt64(-62135596800L, 253402300799L);

        unixTimeStamp = rnd.Next(-6213559, 25340230);

        unixTimeStampHex = unixTimeStamp.ToString("X4");

        Console.WriteLine(unixTimeStampHex);

    }

​

    // ----

    /*

    [Benchmark]

    public DateTime Test1()

    {

         return DateTimeOffset.FromUnixTimeSeconds(unixTimeStamp).LocalDateTime;

    }

    private static readonly System.DateTime epochDateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc);

    [Benchmark]

    public DateTime Test2()

    {

        return epochDateTime.AddSeconds(unixTimeStamp).ToLocalTime();

    }

    */

    // ----

    [Benchmark]

    public int Test3()

    {

        return ParseHexFast(unixTimeStampHex);

    }

    [Benchmark]

    public int Test4()

    {

        return ParseHexFast2(unixTimeStampHex);

    }

    // ----

        // no exception when string is not a int

        public static int ParseHexFast2(in string s) { return ParseHexFast(s.AsSpan()); }

        public static int ParseHexFast2(in ReadOnlySpan<char> s)

        {

            int y = 0;

            for (int i = 0; i < s.Length; i++)

                y = (y * 16) + ((int)hexchar_hashtable[s[i]]);

            return y;

        }   

        // no exception when string is not a int

        public static int ParseHexFast(in string s) { return ParseHexFast(s.AsSpan()); }

        public static int ParseHexFast(in ReadOnlySpan<char> s)

        {

            int y = 0;

            for (int i = 0; i < s.Length; i++)

                y = (y * 16) + (hexchar_dict[s[i]]);

            return y;

        }

        // no exception when string is not a int

        public static long ParseHexLongFast(in string s) { return ParseHexFast(s.AsSpan()); }

        public static long ParseHexLongFast(in ReadOnlySpan<char> s)

        {

            long y = 0;

            for (int i = 0; i < s.Length; i++)

                y = (y * 16) + (hexchar_dict[s[i]]);

            return y;

        }

​

        private static System.Collections.Hashtable hexchar_hashtable = new System.Collections.Hashtable()

        {

            { '0', 0 }, { '1', 1 }, { '2', 2 }, { '3', 3 }, { '4', 4 }, { '5', 5 }, { '6', 6 }, { '7', 7 },

            { '8', 8 }, { '9', 9 }, { 'a', 10 }, { 'A', 10 }, { 'b', 11 }, { 'B', 11 }, { 'c', 12 },

            { 'C', 12 }, { 'd', 13 }, { 'D', 13 }, { 'e', 14 }, { 'E', 14 }, { 'f', 15 }, { 'F', 15 }

        };

        private static Dictionary<char, int> hexchar_dict = new Dictionary<char, int>()

        {

            { '0', 0 }, { '1', 1 }, { '2', 2 }, { '3', 3 }, { '4', 4 }, { '5', 5 }, { '6', 6 }, { '7', 7 },

            { '8', 8 }, { '9', 9 }, { 'a', 10 }, { 'A', 10 }, { 'b', 11 }, { 'B', 11 }, { 'c', 12 },

            { 'C', 12 }, { 'd', 13 }, { 'D', 13 }, { 'e', 14 }, { 'E', 14 }, { 'f', 15 }, { 'F', 15 }

        };

​

}