/// <summary>
/// Handles the deletion of a chunk of the file
/// </summary>
/// <param name="currentFileChunk">The P2PChunk to be deleted</param>
/// <param name="currentFile">The P2PFile to wich the chunk belongs</param>
/// <returns></returns>
public bool ChunkDeleter(P2PChunk currentFileChunk, P2PFile currentFile){
Listener listener = new Listener(this._port);
int lastIndex = currentFileChunk.peers.Count - 1;
//Sends a delete message to every peer with the chunk
for (int i = lastIndex; i >= 0; i--) {
if (_peers.TryGetValue(currentFileChunk.peers[i], out Peer currentReceiver)) {
if (!currentReceiver.IsOnline()){
return false;
}
var deletionMessage = new FileDeletionMessage(currentReceiver) {
type = TypeCode.REQUEST,
statusCode = StatusCode.OK,
port = _port,
fileHash = currentFileChunk.hash,
fullFileHash = currentFile.hash
};
//Sends the message and waits for a response,
//which will then overwrite the original sent message
if (listener.SendAndAwaitResponse(ref deletionMessage, 2000)) {
if (deletionMessage.type.Equals(TypeCode.RESPONSE)) {
currentFileChunk.RemovePeer(deletionMessage.fromUuid);
if (currentFileChunk.peers.Count == 0) {
currentFile.RemoveChunk(currentFileChunk.hash);
}
if (deletionMessage.statusCode.Equals(StatusCode.FILE_NOT_FOUND)) {
DiskHelper.ConsoleWrite("File not found at peer");
}
}
}
}
}
return true;
}
/// <summary>
/// Pushes the inputted chunk to the network, sending it the required amount of peers.
/// </summary>
/// <param name="chunk">The chunk to push to the network</param>
/// <param name="chunkPath">String path to the chunks</param>
/// <param name="numberOfRecevingPeers">The number of peers to send the file to,
/// this will be the amount of receivers, unless the network is smaller than the given input.</param>
/// <param name="receiverOffset">The offset for whom to send the files to, this determines the spacing of the chunks on the peerlist.</param>
/// <returns>Boolean of whether the push was a success.</returns>
public bool Push(P2PChunk chunk, string chunkPath, int numberOfRecevingPeers = 10, int receiverOffset = 0)
{
this._port = _ports.GetAvailablePort();
List <Peer> peers = this.GetPeers();
FileInfo fileInfo = new FileInfo(chunkPath);
Listener listener = new Listener(this._port);
bool sendToAll = true;
int listLength = peers.Count;
int peerCount;
int numberOfReceivers = Math.Min(numberOfRecevingPeers, listLength);
for (peerCount = 0; peerCount < numberOfReceivers; peerCount++)
{
Peer currentPeer = peers[(peerCount + receiverOffset) % listLength];
var upload = new UploadMessage(currentPeer)
{
filesize = fileInfo.Length,
fullFilename = chunk.originalHash,
chunkHash = chunk.hash,
path = chunkPath,
port = this._port
};
if (listener.SendAndAwaitResponse(ref upload, 2000))
{
if (upload.statusCode == StatusCode.ACCEPTED)
{
ChunkSender sender = new ChunkSender(currentPeer.StringIp, upload.port);
if (sender.Send(chunkPath))
{
DiskHelper.ConsoleWrite($"The chunk {chunk.hash} was sent to {currentPeer.GetUuid()}");
chunk.AddPeer(currentPeer.GetUuid());
}
else
{
sendToAll = false;
}
_ports.Release(upload.port);
}
}
}
_ports.Release(this._port);
return(sendToAll);
}
/// <summary>
/// Fetching function, this fetches the given chunk from the network, returns true if the chunk is fetched.
/// </summary>
/// <param name="chunk">The chunk wanted to download.</param>
/// <param name="fullFileName">The name of the full file.</param>
/// <returns>Rather the chunk has been fetched.</returns>
public bool Fetch(P2PChunk chunk, string fullFileName)
{
_port = _ports.GetAvailablePort();
_hash = chunk.hash;
_peersToAsk = chunk.peers;
Listener listener = new Listener(this._port);
foreach (var peer in _peersToAsk)
{
if (!_peers.TryGetValue(peer, out Peer currentPeer))
{
break;
}
if (currentPeer.IsOnline())
{
var download = new DownloadMessage(currentPeer)
{
port = this._port,
fullFileName = chunk.originalHash,
filehash = _hash
};
// Sends the download message and waits for a
// "response" download message to be received.
// Then changed 'download' to this message and
// returns true. If a response is not received
// within time, it returns false.
if (listener.SendAndAwaitResponse(ref download, 3000))
{
// If the download is accepted, a receiver is
// started and the port of the receiver is
// sent to the peer.
if (download.statusCode == StatusCode.ACCEPTED)
{
int receiverPort = _ports.GetAvailablePort();
download.CreateReply();
download.type = Messages.TypeCode.REQUEST;
download.statusCode = StatusCode.ACCEPTED;
download.port = receiverPort;
if (!Directory.Exists(_path + fullFileName + @"\"))
{
Directory.CreateDirectory(_path + fullFileName + @"\");
}
download.Send();
if (!currentPeer.IsOnline())
{
DiskHelper.ConsoleWrite("The peer requested went offline.");
continue;
}
DiskHelper.ConsoleWrite("FileReceiver opened");
if (!Downloader(fullFileName, receiverPort))
{
return(false);
}
_ports.Release(download.port);
break;
}
else if (download.statusCode == StatusCode.FILE_NOT_FOUND)
{
Console.WriteLine("File not found at peer.");
chunk.peers.Remove(download.fromUuid);
}
}
}
}
if (File.Exists(_path + fullFileName + @"\" + _hash))
{
if (CheckDownloadHash(_path + fullFileName + @"\" + _hash, _hash))
{
DiskHelper.ConsoleWrite(@"Chunk done downloading");
return(true);
}
}
return(false);
}
