Gapotchenko.FX.Data.Integrity.Checksum.Crc16 2022.2.7

Overview

The module provides the implementation of checksum algorithms belonging to CRC-16 family.

Quick Start

Use the following code to calculate a CRC-16 checksum for the specified data, be it System.Byte[], System.ReadOnlySpan<Byte> or System.IO.Stream:

using Gapotchenko.FX.Data.Integrity.Checksum;

var checksum = Crc16.Standard.ComputeChecksum(data);

If you need to calculate a CRC-16 checksum iteratively then the following approach becomes handy:

var iterator = Crc16.Standard.CreateIterator();

iterator.ComputeBlock(...); // block 1
// ...
iterator.ComputeBlock(...); // block N

// Compute the final checksum:
var checksum = iterator.ComputeFinal();

Available CRC-16 Algorithms

CRC-16 family of cyclic redundancy checks consists of several attested checksum algorithms with predefined parameters:

The check parameter shows what checksum value an algorithm should produce for "123456789" input string interpreted as an ASCII data:

// Get the byte representation of the ASCII string.
var data = Encoding.ASCII.GetBytes("123456789");

// Compute the checksum.
var checksum = Crc16.Standard.ComputeChecksum(data);

// Print out the result ("Checksum = 0xbb3d" for standard CRC-16).
Console.WriteLine("Checksum = 0x{0:x}", checksum);

Recommended CRC-16 Algorithm

Among all other posibilities, it is recommended to use the standard CRC-16 algorithm which comes under CRC-16, CRC-16/ARC, CRC-IBM, CRC-16/LHA aliases and is available via Crc16.Standard property.

All other predefined algorithms are available via the corresponding properties of Crc16.Attested class.

Custom CRC-16 Algorithms

Once in a while, you may encounter a custom CRC-16 algorithm that is neither widely known nor characterized. In that case, you can instantiate a custom checksum algorithm with the desired parameters by hand:

var checksumAlgorithm = new CustomCrc16(poly, init, refin, refout, xorout);

If you want to formalize a custom algorithm even further, you may opt-in to creating a separate class for it with a convenient accessor property:

/// <summary>
/// Defines a custom CRC-16 algorithm.
/// </summary>
sealed class FooCrc16 : CustomCrc16
{
    FooCrc16() :
        base(poly, init, refin, refout, xorout)
    {
    }

    public static FooCrc16 Instance { get; } = new FooCrc16();
}

That will allow you to use the algorithm effortlessly from several places in the codebase later:

var checksum = FooCrc16.Instance.ComputeChecksum(...);

Commonly Used Types

• Gapotchenko.FX.Data.Integrity.Checksum.Crc16

Other Modules

Let's continue with a look at some other modules provided by Gapotchenko.FX:

• Gapotchenko.FX
• Gapotchenko.FX.AppModel.Information
• Gapotchenko.FX.Collections
• Gapotchenko.FX.Console
• Gapotchenko.FX.Data
  • Gapotchenko.FX.Data.Encoding
  • Gapotchenko.FX.Data.Integrity.Checksum
    • Gapotchenko.FX.Data.Integrity.Checksum.Crc8
    • ➴ Gapotchenko.FX.Data.Integrity.Checksum.Crc16
    • Gapotchenko.FX.Data.Integrity.Checksum.Crc32
• Gapotchenko.FX.Diagnostics
• Gapotchenko.FX.IO
• Gapotchenko.FX.Linq
• Gapotchenko.FX.Math
• Gapotchenko.FX.Memory
• Gapotchenko.FX.Security.Cryptography
• Gapotchenko.FX.Text
• Gapotchenko.FX.Threading

Or look at the full list of modules.