public static bool ReceiveFileFrom(byte[] metadataAsBytes, UdpClient sender)
{
FileMetadata meta = new FileMetadata(metadataAsBytes);
byte[] receivedBytes = null;
IPEndPoint remoteIPEndPoint = null;
int currentPacket = 0;
if (File.Exists(Encoding.Default.GetString(meta.filename))) {
bool success = false;
while (!success) {
try {
File.Delete(Encoding.Default.GetString(meta.filename));
success = true;
}
catch (IOException ex) {
return false;
}
catch (Exception ex) {
return false;
}
}
}
while (currentPacket < meta.totalPackets) {
receivedBytes = sender.Receive(ref remoteIPEndPoint);
if (Utils.VerifyChecksum(receivedBytes)) {
if (receivedBytes[Constants.FIELD_TYPE] == Constants.TYPE_FILE_DELIVERY) {
SendAckTo(-1, sender);
return false;
}
Data datapack = new Data(receivedBytes);
if (datapack.id < meta.totalPackets - 1 && datapack.id == currentPacket) {
bool success = false;
while (!success) {
try {
File.AppendAllText(Encoding.Default.GetString(meta.filename), Encoding.Default.GetString(datapack.payload), Encoding.Default);
success = true;
}
catch (Exception e) {
Console.WriteLine(e.Message);
}
}
currentPacket++;
SendAckTo(datapack.id, sender);
}
else if (datapack.id == meta.totalPackets - 1 && datapack.id == currentPacket) {
int remainder = (meta.fileLength % Constants.PAYLOAD_SIZE);
byte[] finalBytes = new byte[remainder];
for (int i = 0; i < remainder; i++) {
finalBytes[i] = receivedBytes[i + Constants.FIELD_PAYLOAD];
}
File.AppendAllText(Encoding.Default.GetString(meta.filename), Encoding.Default.GetString(finalBytes), Encoding.Default);
currentPacket++;
SendAckTo(datapack.id, sender);
}
else if (datapack.id < currentPacket) {
SendAckTo(datapack.id, sender);
}
}
}
return true;
}
public static bool ReceiveAllDirectoryPackets(byte[] first, DirMetadata meta, UdpClient target)
{
IPEndPoint remoteIPEndPoint = null;
if (first == null) { return false; }
Data data = new Data(first);
if (meta.dirLength < Constants.PAYLOAD_SIZE)
Console.WriteLine(Encoding.Default.GetString(data.payload,0,meta.dirLength));
else
Console.WriteLine(Encoding.Default.GetString(data.payload));
SendAckTo(data.id, target);
int currentPacket = 1;
while (currentPacket < meta.totalPackets) {
byte[] recBytes = target.Receive(ref remoteIPEndPoint);
if (!Utils.VerifyChecksum(recBytes)) {
continue;
}
data = new Data(recBytes);
if (data.id < currentPacket) {
SendAckTo(data.id, target);
}
else if (data.id == currentPacket && currentPacket != meta.totalPackets - 1) {
Console.WriteLine(Encoding.Default.GetString(data.payload));
SendAckTo(data.id, target);
currentPacket++;
}
else if (data.id == currentPacket && currentPacket == meta.totalPackets - 1) {
byte[] finalBytes = new byte[(meta.dirLength % Constants.PAYLOAD_SIZE)];
for (int i = 0; i < finalBytes.Length; i++) {
finalBytes[i] = data.payload[i + Constants.FIELD_PAYLOAD];
}
Console.WriteLine(Encoding.Default.GetString(finalBytes));
currentPacket++;
SendAckTo(data.id, target);
}
}
return true;
}
