/// <summary>
///
/// </summary>
/// <param name="fileName"></param>
/// <param name="size"></param>
/// <returns></returns>
public byte[] FileCheckSum(string fileName, int size)
{
var mdFour = new MdFour(_options);
using (var fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))
{
var buf = new MapFile(fileStream, size, Options.MaxMapSize, CsumChunk);
mdFour.Begin();
int i;
for (i = 0; i + CsumChunk <= size; i += CsumChunk)
{
var offset = buf.MapPtr(i, CsumChunk);
mdFour.Update(buf.P, offset, CsumChunk);
}
if (size - i > 0 || _options.ProtocolVersion >= 27)
{
var offset = buf.MapPtr(i, size - i);
mdFour.Update(buf.P, offset, (UInt32)(size - i));
}
fileStream.Close();
return(mdFour.Result());
}
}
/// <summary>
///
/// </summary>
/// <param name="buf"></param>
/// <param name="pos"></param>
/// <param name="len"></param>
/// <returns></returns>
public byte[] GetChecksum2(byte[] buf, int pos, int len)
{
var buf1 = new byte[len + 4];
for (var j = 0; j < len; j++)
{
buf1[j] = buf[pos + j];
}
var mdFour = new MdFour(_options);
mdFour.Begin();
if (_options.ChecksumSeed != 0)
{
Sival(ref buf1, len, (UInt32)_options.ChecksumSeed);
len += 4;
}
int i;
for (i = 0; i + CsumChunk <= len; i += CsumChunk)
{
mdFour.Update(buf1, i, CsumChunk);
}
if (len - i > 0 || _options.ProtocolVersion >= 27)
{
mdFour.Update(buf1, i, (UInt32)(len - i));
}
return(mdFour.Result());
}
public void Init(int seed)
{
var s = new byte[4];
Md.Begin();
SumResidue = 0;
CheckSum.Sival(ref s, 0, (UInt32)seed);
Update(s, 0, 4);
}