Transport.java

package com.mathpar.NAUKMA.examples;

import java.io.*;
import java.nio.ByteBuffer;
import java.util.logging.Level;
import java.util.logging.Logger;
import mpi.MPI;
import mpi.MPIException;
import mpi.Status;

public class Transport {

  public static void sendArrayOfObjects(Object[] a, int proc, int tag)
      throws MPIException, IOException {
    for (int i = 0; i < a.length; i++) {
      sendObject(a[i], proc, tag + i);
    }
  }

  public static Object[] recvArrayOfObjects(int proc, int tag)
      throws MPIException, IOException, ClassNotFoundException {

    Object[] o = new Object[4];
    for (int i = 0; i < 4; i++) {
      o[i] = recvObject(proc, tag + i);
    }
    return o;
  }

  public static void sendObject(Object a, int proc, int tag) throws MPIException, IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(bos);
    oos.writeObject(a);
    byte[] tmp = bos.toByteArray();
    MPI.COMM_WORLD.send(tmp, tmp.length, MPI.BYTE, proc, tag);
  }

  public static Object recvObject(int proc, int tag)
      throws MPIException, IOException, ClassNotFoundException {

    Status st = MPI.COMM_WORLD.probe(proc, tag);

    int size = st.getCount(MPI.BYTE);

    byte[] tmp = new byte[size];

    MPI.COMM_WORLD.recv(tmp, size, MPI.BYTE, proc, tag);
    Object res = null;
    ByteArrayInputStream bis = new ByteArrayInputStream(tmp);
    ObjectInputStream ois = new ObjectInputStream(bis);
    res = ois.readObject();

    return res;
  }

  public static void sendObjects(Object[] a, int proc, int tag) throws MPIException {
    ByteArrayOutputStream bos = null;
    try {
      bos = new ByteArrayOutputStream();
      ObjectOutputStream oos = new ObjectOutputStream(bos);
      for (int i = 0; i < a.length; i++) {
        oos.writeObject(a[i]);
      }
      bos.toByteArray();
    } catch (Exception ex) {
      Logger.getLogger(Transport.class.getName()).log(Level.SEVERE, null, ex);
    }
    byte[] temp = bos.toByteArray();
    ByteBuffer buf = MPI.newByteBuffer(temp.length);
    buf.put(temp);
    MPI.COMM_WORLD.iSend(buf, temp.length, MPI.BYTE, proc, tag);
  }

  public static Object[] recvObjects(int m, int proc, int tag) throws MPIException {
    Status s = MPI.COMM_WORLD.probe(proc, tag);
    int n = s.getCount(MPI.BYTE);
    byte[] arr = new byte[n];
    MPI.COMM_WORLD.recv(arr, n, MPI.BYTE, proc, tag);
    Object[] res = new Object[m];
    try {
      ByteArrayInputStream bis = new ByteArrayInputStream(arr);
      ObjectInputStream ois = new ObjectInputStream(bis);
      for (int i = 0; i < m; i++) {
        res[i] = ois.readObject();
      }
    } catch (Exception ex) {
      Logger.getLogger(Transport.class.getName()).log(Level.SEVERE, null, ex);
    }
    return res;
  }
}