package eu.unicore.uftp.rsync;

 import java.io.DataInputStream;

 import java.io.DataOutputStream;

 import java.io.IOException;

 import java.net.Socket;

 import java.nio.ByteBuffer;

 import java.nio.channels.ByteChannel;

 import java.util.ArrayList;

 public class SocketMasterChannel implements MasterChannel{

         private final Socket socket;

         public SocketMasterChannel(Socket socket){

                 this.socket=socket;

         }

         @Override

         public ChecksumHolder receiveChecksums() throws IOException {

                 DataInputStream dis=new DataInputStream(socket.getInputStream());

                 ChecksumHolder res=new ChecksumHolder();

                 res.blocksize=dis.readInt();

                 int numBlocks=dis.readInt();

                 res.weakChecksums=new ArrayList<Long>();

                 res.strongChecksums=new ArrayList<byte[]>();

                 for(int i=0; i<numBlocks; i++){

                         res.weakChecksums.add(dis.readLong());

                         byte[]cs=new byte[16];

                         dis.readFully(cs);

                         res.strongChecksums.add(cs);

                 }

                 return res;

         }

         @Override

         public void sendData(long bytes, ByteChannel source, int index)

                         throws IOException {

                 DataOutputStream dos=new DataOutputStream(socket.getOutputStream());

                 // send index first

                 dos.writeInt(index);

                 dos.writeLong(bytes);

                 dos.flush();

                 if(source==null)return;

                 // send bytes

                 long remaining=bytes;

                 ByteBuffer buf=ByteBuffer.allocate(2048);

                 int len=0;

                 while(len>-1 && remaining>0){

                         if(remaining<buf.limit()){

                                 buf.limit((int)remaining);

                         }

                         len=source.read(buf);

                         if(len>0){

                                 buf.flip();

                                 socket.getOutputStream().write(buf.array(),0,len);

                                 buf.clear();

                                 remaining-=len;

                         }

                 }

                 socket.getOutputStream().flush();

         }

         @Override

         public void shutdown() throws IOException {

                 // of course we do NOT close any streams here

                 sendData(-1, null, -1);

         }

 }