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package pl.edu.mimuw.cloudatlas.agent.modules;
import pl.edu.mimuw.cloudatlas.agent.messages.UDUPMessage;
import javax.xml.crypto.Data;
import java.io.IOException;
import java.net.*;
import java.nio.ByteBuffer;
public class UDUPClient {
private UDUP udp;
private UDUPSerializer serializer;
private int serverPort;
private DatagramSocket socket;
private int bufsize;
private int lastTransmission;
UDUPClient(UDUP udp, int serverPort, int bufferSize) throws SocketException {
this.udp = udp;
this.serverPort = serverPort;
this.socket = new DatagramSocket();
this.bufsize = bufferSize;
this.serializer = new UDUPSerializer();
this.lastTransmission = 0;
}
private void logSending(DatagramPacket packet, int packetNo, byte[] buf) {
System.out.print("UDP sends packet no " + packetNo +
" with real bufsize " + (bufsize - 8) +
" out of data buffer with size " + buf.length +
" to " + packet.getAddress() + ": ");
for (byte b : packet.getData()) {
System.out.print(b);
}
System.out.println();
}
byte[] toByteArray(int val) {
return ByteBuffer.allocate(4).putInt(val).array();
}
private byte[] packSendBuffer(int transmissionNo, int packetNo, byte[] buf) {
byte[] sendBuf;
int sendBufSize = bufsize - 8;
if (packetNo*sendBufSize >= buf.length) {
int copyLength = buf.length - (packetNo-1)*sendBufSize;
sendBuf = new byte[copyLength + 8];
System.arraycopy(buf, (packetNo-1)*sendBufSize, sendBuf, 8, copyLength);
} else {
sendBuf = new byte[bufsize];
System.arraycopy(buf, (packetNo-1)*sendBufSize, sendBuf, 8, sendBufSize);
}
System.arraycopy(toByteArray(transmissionNo), 0, sendBuf, 0, 4);
System.arraycopy(toByteArray(packetNo), 0, sendBuf, 4, 4);
return sendBuf;
}
boolean checkEndOfTransmission(int packetNo, int dataBufSize) {
int sendBufSize = bufsize - 8;
int dataSentSoFar = (packetNo - 1) * sendBufSize;
return dataSentSoFar >= dataBufSize;
}
public void sendMessage(UDUPMessage msg) throws IOException {
int packetNo = 1;
byte[] sendBuf;
byte[] dataBuf = this.serializer.serialize(msg);
this.lastTransmission++;
do {
sendBuf = packSendBuffer(this.lastTransmission, packetNo, dataBuf);
DatagramPacket packet = new DatagramPacket(sendBuf, 0, sendBuf.length, msg.getContact().getAddress(), this.serverPort);
this.socket.send(packet);
logSending(packet, packetNo, dataBuf);
packetNo++;
} while (!checkEndOfTransmission(packetNo, dataBuf.length));
}
void close() {
this.socket.close();
}
}
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