Fan.Sys.FileBuf.toDigest C# (CSharp) Method

        public override Buf toDigest(string algorithm)
        {
            string alg = algorithm;
              if (alg == "SHA-1") alg = "SHA1";  // to make .NET happy
              HashAlgorithm ha = HashAlgorithm.Create(alg);
              if (ha == null)
            throw ArgErr.make("Unknown digest algorthm: " + algorithm).val;

              try
              {
            long oldPos = getPos();
            long size = getSize();
            byte[] temp = this.temp();

            setPos(0);
            long total = 0;
            while (total < size)
            {
              int n = m_stream.Read(temp, (int)total, (int)(size-total));
              total += n;
            }

            setPos(oldPos);
            return new MemBuf(ha.ComputeHash(temp, 0, (int)size));
              }
              catch (IOException e)
              {
            throw IOErr.make(e).val;
              }
        }