/// <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);
}
