private void ReceiveFile(IPEndPoint remoteEP, Message meta)
{
int continueId = LoadMetaFile(meta);
UdpSend(remoteEP, new Message {
PackID = continueId
});
TcpAcceptStream(ns =>
{
using (FileStream metafs = new FileStream(meta.Filename + ".meta", FileMode.Open))
using (FileStream fs = new FileStream(meta.Filename, FileMode.OpenOrCreate))
using (SHA256 sha = SHA256.Create())
{
Message data;
byte[] bs = new byte[meta.PackSize + 9];
for (int i = continueId - 1; i < meta.PackCount - 1; i++)
{
ns.Read(bs, 0, meta.PackSize + 9);
data = Message.Parse(bs);
fs.Seek(0, SeekOrigin.End);
fs.Write(data.Data, 0, meta.PackSize);
metafs.Seek(-8, SeekOrigin.End);
metafs.Write(Utils.GetBytes(data.PackID + 1), 0, 8);
fs.Flush(); metafs.Flush();
OnPackTransfered?.Invoke((i / meta.PackCount));
}
ns.Read(bs, 0, meta.PackSize + 9);
data = Message.Parse(bs);
fs.Write(data.Data, 0, (int)(meta.Size - meta.PackSize * (meta.PackCount - 1)));
fs.Flush();
fs.Seek(0, SeekOrigin.Begin);
metafs.Seek(0, SeekOrigin.Begin);
byte[] metahs = new byte[256];
metafs.Read(metahs, 0, 256);
byte[] hash = new byte[256];
byte[] t = sha.ComputeHash(fs);
Array.Copy(t, 0, hash, 0, t.Length);
if (!hash.SequenceEqual(metahs))
{
throw new ChecksumMismatchException("Checksum not match, file may be collapsed.");
}
}
File.Delete(meta.Filename + ".meta");
});
}
private int LoadMetaFile(Message meta)
{
if (!File.Exists(meta.Filename + ".meta"))
{
byte[] bs = new byte[256 + 8];
Array.Copy(meta.Hash, 0, bs, 0, 256);
Array.Copy(Utils.GetBytes((long)1), 0, bs, 256, 8);
File.WriteAllBytes(meta.Filename + ".meta", bs);
return(1);
}
using FileStream fs = new FileStream(meta.Filename + ".meta", FileMode.Open);
byte[] hash = new byte[256];
byte[] id = new byte[8];
fs.Read(hash, 0, 256);
if (hash.SequenceEqual(meta.Hash))
{
fs.Read(id, 0, 8);
return((int)Utils.BtoLong(id));
}
else
{
throw new ChecksumMismatchException("Two files with same name have differed hash, please check your file or rename it.");
}
}
