Tag: indexed

Mapping 256Bit Hash to 32Bit Indexed Hash

using System.Security.Cryptography;
public class Mapping256BitTo32BitHash : HashAlgorithm
{
    private readonly SHA256Managed                  hasher = new SHA256Managed();
    public readonly  TinyDictionary<byte[], byte[]> map    = new TinyDictionary<byte[], byte[]>(101, new ArrayComparer());
    private          byte[]                         h160;
    public override  int                            HashSize => 32;
    public override void Initialize()
    {
    }
    protected override void HashCore(byte[] bytes, int ibStart, int cbSize)
    {
        h160 = hasher.ComputeHash(bytes, ibStart, cbSize);
        map.Add(h160, bytes);
    }
    protected override byte[] HashFinal()
    {
        HashValue = (byte[])map.FindKeyIndex(h160).GetBytes().Clone();
        return HashValue;
    }
}