/// <summary>
/// Generates parity streams from input streams. All streams should have the same length.
/// </summary>
/// <param name="iStreams">Input streams</param>
/// <param name="oStreams">Output streams</param>
public static void GenerateStreams(Stream[] iStreams, Stream[] oStreams)
{
int messageCount = iStreams.Length;
int parityCount = oStreams.Length;
var rs = new ECC.ReedSolomon(parityCount);
long streamLength = iStreams[0].Length;
Parallel.For(0, (int)Math.Ceiling((double)streamLength / (double)maxBufferSize), iii =>
{
int bufferSize = maxBufferSize;
if (streamLength - iii * maxBufferSize < bufferSize)
{
bufferSize = (int)(streamLength - iii * maxBufferSize);
}
byte[][] buffers = new byte[iStreams.Length][];
for (int i = 0; i < iStreams.Length; i++)
{
buffers[i] = new byte[bufferSize];
lock (iStreams[i])
{
iStreams[i].Position = iii * maxBufferSize;
iStreams[i].Read(buffers[i], 0, buffers[i].Length);
}
}
byte[][] outbuf = new byte[bufferSize][];
for (int i = 0; i < bufferSize; i++)
{
byte[] msg = new byte[messageCount];
for (int j = 0; j < messageCount; j++)
{
msg[j] = buffers[j][i];
}
outbuf[i] = rs.Encode(msg);
}
byte[][] outbuf2 = new byte[parityCount][];
for (int i = 0; i < parityCount; i++)
{
outbuf2[i] = new byte[bufferSize];
}
for (int i = 0; i < bufferSize; i++)
{
for (int j = 0; j < parityCount; j++)
{
outbuf2[j][i] = outbuf[i][messageCount + j];
}
}
for (int i = 0; i < parityCount; i++)
{
lock (oStreams[i])
{
oStreams[i].Position = iii * maxBufferSize;
oStreams[i].Write(outbuf2[i], 0, outbuf2[i].Length);
}
}
});
}
