public static void SendHandshake(IO.Stream stream, ByteField20 infoDigest)
{
stream.WriteByte((byte)protocolString.Length);
stream.Write(System.Text.ASCIIEncoding.ASCII.GetBytes(protocolString), 0, protocolString.Length);
// 8 zeros
stream.Write(new byte[] { 0, 0, 0, 0, 0, 0, 0, 0 }, 0, 8);
// SHA digest
stream.Write(infoDigest.Data, 0, infoDigest.Data.Length);
}
public static void SendPeerId(IO.Stream netStream, ByteField20 peerId)
{
netStream.Write(peerId.Data, 0, peerId.Data.Length);
}
public static void SendBitfieldMessage(IO.Stream stream, DownloadFile downloadFile)
{
int bitfieldLength = downloadFile.Bitfield.Count/8 + ((downloadFile.Bitfield.Count % 8) > 0 ? 1 : 0);
byte[] bitfield = new byte[bitfieldLength];
downloadFile.Bitfield.CopyTo(bitfield, 0);
SendMessageHeader(stream, PeerMessage.Bitfield, bitfieldLength);
stream.Write(bitfield, 0, bitfield.Length);
}
// i would use IO.BinaryWriter but that caused problems
private static void WriteInt(IO.Stream stream, int val)
{
byte[] b = new byte[4];
b[3] = (byte)(val & 0x000000FF);
b[2] = (byte)((val & 0x0000FF00) >> 8);
b[1] = (byte)((val & 0x00FF0000) >> 16);
b[0] = (byte)((val & 0xFF000000) >> 24);
stream.Write(b, 0, b.Length);
// stream.Write(System.BitConverter.GetBytes(val), 0, 4);
}
/// <summary>
/// Loads a piece from the torrent. The torrent piece must already have been downloaded (ie exists in the bitfield)
/// </summary>
/// <param name="pieceId">Piece index to load from</param>
/// <param name="ostream">Stream to save to</param>
/// <returns>True if the piece was loaded succesfully, false otherwise</returns>
public bool LoadFromFile(int pieceId, IO.Stream ostream)
{
if (!this.piecesDownloaded.Get(pieceId))
return false;
else
{
int dataRead = 0;
int positionInFile = 0;
int fileNum = 0;
WhichFileIsPieceIn(pieceId, out fileNum, out positionInFile);
while (dataRead < this.infofile.GetPieceLength(pieceId) && fileNum < this.infofile.FileCount)
{
int fileLength = this.infofile.GetFileLength(fileNum);
int dataToRead = System.Math.Min(fileLength - positionInFile, this.infofile.GetPieceLength(pieceId) - dataRead);
IO.FileStream fstream = new IO.FileStream(this.infofile.GetFileName(fileNum), IO.FileMode.Open);
// read data from the file
fstream.Seek(positionInFile, IO.SeekOrigin.Begin);
byte[] data = new byte[ dataToRead ];
fstream.Read(data, 0, data.Length);
ostream.Write(data, 0, data.Length);
dataRead += dataToRead;
fstream.Close();
fileNum++; // move onto next file
positionInFile = 0;
}
return true;
}
}
/// <summary>Reads data from the piece</summary>
/// <param name="stream">Data to read into</param>
/// <param name="length">Amount of data to read</param>
/// <param name="poffset">Offset within the piece to read data from</param>
public void Read(IO.Stream stream, int length, int poffset)
{
byte[] tdata = new byte[length];
this.Read(tdata, 0, length, poffset);
stream.Write(tdata, 0, length);
}
