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@ahydrax
Last active Apr 29, 2017
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Performance comparison between existing and proposed implementation of method ToHexString
using System;
using System.Linq;
using System.Text;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
namespace ToHexStringPerf
{
public class Tests
{
public static readonly byte[] testBytes = Enumerable.Repeat(Enumerable.Range(-127, 127), 4).SelectMany(x => x).Select(x => (byte)x).ToArray();
[Benchmark]
public void MongoDbImplementation()
{
ToHexStringMongoDB(testBytes);
}
public static string ToHexStringMongoDB(byte[] bytes)
{
if (bytes == null)
{
throw new ArgumentNullException("bytes");
}
var sb = new StringBuilder(bytes.Length * 2);
foreach (var b in bytes)
{
sb.AppendFormat("{0:x2}", b);
}
return sb.ToString();
}
[Benchmark]
public void HandCoded()
{
ToHexStringHandCoded(testBytes);
}
public static string ToHexStringHandCoded(byte[] bytes)
{
if (bytes == null)
{
throw new ArgumentNullException(nameof(bytes));
}
var c = new char[bytes.Length * 2];
byte b;
for (int bx = 0, cx = 0; bx < bytes.Length; ++bx, ++cx)
{
b = ((byte)(bytes[bx] >> 4));
c[cx] = (char)(b > 9 ? b + 0x37 + 0x20 : b + 0x30);
b = ((byte)(bytes[bx] & 0x0F));
c[++cx] = (char)(b > 9 ? b + 0x37 + 0x20 : b + 0x30);
}
return new string(c);
}
}
class Program
{
static void Main(string[] args)
{
var summary = BenchmarkRunner.Run<Tests>();
}
}
}
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ahydrax commented Apr 29, 2017

Local run

BenchmarkDotNet=v0.10.5, OS=Windows 10.0.15063
Processor=Intel Core i5-2400 CPU 3.10GHz (Sandy Bridge), ProcessorCount=4
Frequency=3037251 Hz, Resolution=329.2451 ns, Timer=TSC
  [Host]     : Clr 4.0.30319.42000, 32bit LegacyJIT-v4.7.2046.0
  DefaultJob : Clr 4.0.30319.42000, 32bit LegacyJIT-v4.7.2046.0

Method Mean Error StdDev
MongoDbImplementation 97.146 us 1.1451 us 1.0711 us
HandCoded 1.932 us 0.0216 us 0.0202 us

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