/// <summary>Constructs a MetainfoFile</summary>
/// <param name="istream">Stream to read data from</param>
public MetainfoFile(IO.Stream istream)
{
BEncode.Dictionary mainDictionary = (BEncode.Dictionary)BEncode.NextElement(istream);
this.announceUrl = mainDictionary.GetString(new BEncode.String("announce"));
if (mainDictionary.Contains("comment"))
this.comment = mainDictionary.GetString("comment");
if (mainDictionary.Contains("created by"))
this.createdBy = mainDictionary.GetString("created by");
if (mainDictionary.Contains("creation date"))
{
int creation = mainDictionary.GetInteger("creation date");
this.creationDate = new System.DateTime(1970, 1, 1, 0, 0, 0);
this.creationDate = this.creationDate.AddSeconds(creation);
}
BEncode.Dictionary infoDictionary = mainDictionary.GetDictionary("info");
this.name = infoDictionary.GetString("name");
this.pieceLength = infoDictionary.GetInteger("piece length");
this.pieceFileName = this.name.ToLower().Replace(' ', '_');
// Get SHA digests
byte[] pieces = infoDictionary.GetBytes("pieces");
int numPieces = pieces.Length / 20;
this.shaDigestList.Capacity = numPieces;
for (int i=0; i<numPieces; ++i)
{
this.shaDigestList.Add( new ByteField20(pieces, i*20) );
}
// Get filenames and lengths
if (infoDictionary.Contains("length"))
{
// one file
this.fileList.Add(name);
int fileLength = infoDictionary.GetInteger("length");
this.fileLengthList.Add(fileLength);
this.totalSize = fileLength;
}
else
{
// multiple files - a list of dictionaries containing the filename and length
BEncode.List files = infoDictionary.GetList("files");
this.fileList.Capacity = this.fileLengthList.Capacity = files.Count;
this.totalSize = 0;
foreach (BEncode.Dictionary fileDic in files)
{
BEncode.List pathList = fileDic.GetList("path");
string path = this.name + IO.Path.DirectorySeparatorChar;
for (int i=0; i<pathList.Count-1; ++i)
{
path += pathList[i].ToString() + IO.Path.DirectorySeparatorChar;
}
path += pathList[ pathList.Count-1 ];
this.fileList.Add(path);
int fileLength = fileDic.GetInteger("length");
this.fileLengthList.Add(fileLength);
this.totalSize += fileLength;
}
}
// calculate the SHA-1 digest of the info dictionary - this is required for the tracker protocol
istream.Seek(infoDictionary.Position, IO.SeekOrigin.Begin);
byte[] infoData = new byte[ infoDictionary.Length ];
istream.Read(infoData, 0, infoData.Length);
this.infoDigest = ByteField20.ComputeSHAHash(infoData);
}
public BitField ReadBitfieldMessage(IO.Stream stream, int length)
{
byte[] bitfield = new byte[ length ];
stream.Read(bitfield, 0, bitfield.Length);
return new BitField(bitfield, 0, bitfield.Length);
}
public static void ReceiveHandshake(IO.Stream stream, ref ByteField20 infoDigest)
{
// read in protocol string
byte[] protocolVersionLength = new byte[1];
if ( stream.Read( protocolVersionLength, 0, protocolVersionLength.Length ) != protocolVersionLength.Length )
throw new System.Exception( "Invalid handshake protocol" );
if ( protocolVersionLength[0] != 19 )
throw new System.Exception( "Invalid handshake protocol" );
byte[] protocolBytes = new byte[ protocolVersionLength[ 0 ] ];
if ( stream.Read( protocolBytes, 0, protocolBytes.Length ) != protocolBytes.Length )
throw new System.Exception( "Invalid handshake protocol" );
string protocol = System.Text.ASCIIEncoding.ASCII.GetString(protocolBytes, 0, protocolBytes.Length);
if (protocol != protocolString)
throw new System.Exception( "Invalid handshake protocol" );
// 8 zeros
byte[] zeroes = new byte[ 8 ];
if ( stream.Read( zeroes, 0, zeroes.Length ) != zeroes.Length )
throw new System.Exception( "Invalid handshake protocol" );
// SHA digest
stream.Read(infoDigest.Data, 0, infoDigest.Data.Length);
}
public static bool ReceivePeerId(IO.Stream stream, ref ByteField20 peerId)
{
return stream.Read(peerId.Data, 0, peerId.Data.Length) > 0;
}
public void SendPiece(IO.Stream ostream, int pieceId, int begin, int length, IO.Stream istream, PeerFinishedPieceTransfer callback, object state)
{
SendMessageHeader(ostream, PeerMessage.Piece, 8 + length);
WriteInt(ostream, pieceId);
WriteInt(ostream, begin);
byte[] writeData = new byte[length];
istream.Read(writeData, 0, length);
object[] objs = new object[4];
objs[0] = ostream;
objs[1] = callback;
objs[2] = state;
objs[3] = length;
ostream.BeginWrite(writeData, 0, writeData.Length, new System.AsyncCallback(OnWriteFinished), (object)objs);
}
/// <summary>
/// Saves the stream to the torrent.
/// </summary>
/// <param name="pieceId">Piece index to save to</param>
/// <param name="istream">Stream to read data from</param>
/// <returns>True if the data saved checks out correctly with the SHA-1 digest, false otherwise. The bitfield
/// property is automatically updated if true</returns>
public bool SaveToFile(int pieceId, IO.Stream istream)
{
// it starts in this file, as it could be spread across several files keep looping till we finish
int dataWritten = 0;
int positionInFile = 0;
int fileNum = 0;
Crypto.SHA1 sha = new Crypto.SHA1CryptoServiceProvider();
WhichFileIsPieceIn(pieceId, out fileNum, out positionInFile);
while (dataWritten < this.infofile.GetPieceLength(pieceId) && fileNum < this.infofile.FileCount)
{
int fileLength = this.infofile.GetFileLength(fileNum);
int dataToWrite = System.Math.Min(fileLength - positionInFile, this.infofile.GetPieceLength(pieceId) - dataWritten);
IO.FileStream fstream = new IO.FileStream(this.infofile.GetFileName(fileNum), IO.FileMode.Open);
// write data to file
fstream.Seek(positionInFile, IO.SeekOrigin.Begin);
byte[] data = new byte[ dataToWrite ];
istream.Read(data, 0, data.Length);
fstream.Write(data, 0, data.Length);
dataWritten += dataToWrite;
if (dataWritten >= this.infofile.GetPieceLength(pieceId))
sha.TransformFinalBlock(data, 0, data.Length);
else
sha.TransformBlock(data, 0, data.Length, data, 0);
fstream.Close();
fileNum++; // move onto next file
positionInFile = 0;
}
if (this.infofile.GetSHADigest(pieceId).Equals(new ByteField20(sha.Hash)))
{
this.piecesDownloaded.Set(pieceId, true);
this.numBytesLeft -= dataWritten;
if (this.PercentChanged != null)
this.PercentChanged(this, this.PercentComplete);
if (this.piecesDownloaded.AllTrue)
Config.LogDebugMessage("Torrent finished!");
return true;
}
else
return false;
}
/// <summary>Constructs a string from the bEncoded stream</summary>
/// <param name="istream">Stream to construct string from</param>
public String(IO.Stream istream, int firstchar)
{
if (istream.CanSeek)
this.position = (int)istream.Position - 1;
string numstr = new string((char)firstchar, 1);
while (true)
{
int c = istream.ReadByte();
if (c != ':')
numstr += (char)c;
else
break;
}
int length = System.Int32.Parse(numstr);
if (length < 0)
throw new System.Exception("Invalid string length");
this.data = new byte[length];
istream.Read(this.data, 0, length);
if (istream.CanSeek)
this.length = (int)(istream.Position - this.position);
// System.Diagnostics.Debugger.Log(0, "BEncode", "String: " + this.ToString() + "\n");
}
private void Scan(IO.TextReader input)
{
while (input.Peek() != -1)
{
char ch = (char)input.Peek();
// Scan individual tokens
if (char.IsWhiteSpace(ch))
{
// eat the current char and skip ahead!
input.Read();
}
else if (char.IsLetter(ch) || ch == '_')
{
// keyword or identifier
Text.StringBuilder accum = new Text.StringBuilder();
while (char.IsLetter(ch) || ch == '_')
{
accum.Append(ch);
input.Read();
if (input.Peek() == -1)
{
break;
}
else
{
ch = (char)input.Peek();
}
}
this.result.Add(accum.ToString());
}
else if (ch == '"')
{
// string literal
Text.StringBuilder accum = new Text.StringBuilder();
input.Read(); // skip the '"'
if (input.Peek() == -1)
{
throw new System.Exception("unterminated string literal");
}
while ((ch = (char)input.Peek()) != '"')
{
accum.Append(ch);
input.Read();
if (input.Peek() == -1)
{
throw new System.Exception("unterminated string literal");
}
}
// skip the terminating "
input.Read();
this.result.Add(accum);
}
else if (char.IsDigit(ch))
{
// numeric literal
Text.StringBuilder accum = new Text.StringBuilder();
while (char.IsDigit(ch))
{
accum.Append(ch);
input.Read();
if (input.Peek() == -1)
{
break;
}
else
{
ch = (char)input.Peek();
}
}
this.result.Add(int.Parse(accum.ToString()));
}
else switch (ch)
{
case '+':
input.Read();
this.result.Add(Scanner.Add);
break;
case '-':
input.Read();
this.result.Add(Scanner.Sub);
break;
case '*':
input.Read();
this.result.Add(Scanner.Mul);
break;
case '/':
input.Read();
this.result.Add(Scanner.Div);
break;
case '=':
input.Read();
this.result.Add(Scanner.Equal);
break;
case ';':
input.Read();
this.result.Add(Scanner.Semi);
break;
default:
throw new System.Exception("Scanner encountered unrecognized character '" + ch + "'");
}
}
}
private void Scan(IO.TextReader input)
{
while (input.Peek() != -1)
{
char caracter = (char)input.Peek();
// Scan individual tokens
if (char.IsWhiteSpace(caracter))
{
// eat the current char and skip ahead!
input.Read();
}
else if (char.IsLetter(caracter) || caracter == '_')
{
// keyword or identifier
Text.StringBuilder accum = new Text.StringBuilder();
while (char.IsLetter(caracter) || caracter == '_')
{
accum.Append(caracter);
input.Read();
if (input.Peek() == -1)
{
break;
}
else
{
caracter = (char)input.Peek();
}
}
this.resultado.Add(accum.ToString());
}
else if (caracter == '"')
{
// string literal
Text.StringBuilder accum = new Text.StringBuilder();
input.Read(); // skip the '"'
if (input.Peek() == -1)
{
throw new System.Exception("Cadena sin terminar");
}
while ((caracter = (char)input.Peek()) != '"')
{
accum.Append(caracter);
input.Read();
if (input.Peek() == -1)
{
throw new System.Exception("Cadena sin terminar");
}
}
// skip the terminating "
input.Read();
this.resultado.Add(accum);
}
else if (char.IsDigit(caracter))
{
// numeric literal
Text.StringBuilder accum = new Text.StringBuilder();
while (char.IsDigit(caracter))
{
accum.Append(caracter);
input.Read();
if (input.Peek() == -1)
{
break;
}
else
{
caracter = (char)input.Peek();
}
}
this.resultado.Add(int.Parse(accum.ToString()));
}
else switch (caracter)
{
case '+':
input.Read();
this.resultado.Add(Scanner.Sum);
break;
case '-':
input.Read();
this.resultado.Add(Scanner.Res);
break;
case '*':
input.Read();
this.resultado.Add(Scanner.Mul);
break;
case '/':
input.Read();
this.resultado.Add(Scanner.Div);
break;
case '=':
input.Read();
if (input.Peek() == '=')
{
input.Read();
this.resultado.Add(Scanner.Eq);
}
else
this.resultado.Add(Scanner.Igual);
break;
case ';':
input.Read();
this.resultado.Add(Scanner.PyC);
break;
case '>':
input.Read();
if (input.Peek() == '=')
{
input.Read();
this.resultado.Add(Scanner.Gte);
}
else
this.resultado.Add(Scanner.Gt);
break;
case '<':
input.Read();
if (input.Peek() == '=')
{
input.Read();
this.resultado.Add(Scanner.Lte);
}
else
this.resultado.Add(Scanner.Lt);
break;
case '!':
input.Read();
if (input.Peek() == '=')
{
input.Read();
this.resultado.Add(Scanner.Neq);
}
else
throw new System.Exception("No se reconoce el siguiente caracter: '" + caracter + "'");
break;
default:
throw new System.Exception("No se reconoce el siguiente caracter: '" + caracter + "'");
}
}
}
/// <summary>Writes data to the piece</summary>
/// <param name="stream">Data to write</param>
/// <param name="length">Amount of data to write</param>
/// <param name="poffset">Offset within the piece to write data to</param>
public void Write(IO.Stream stream, int length, int poffset)
{
byte[] tdata = new byte[length];
stream.Read(tdata, 0, length);
this.Write(tdata, 0, length, poffset);
}
