/*
* Cloud9: A MapReduce Library for Hadoop
*
* Licensed under the Apache License, Version 2.0 (the "License"); you
* may not use this file except in compliance with the License. You may
* obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package edu.umd.cloud9.example.bfs;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.hadoop.io.Writable;
import edu.umd.cloud9.io.array.ArrayListOfIntsWritable;
/**
* Representation of a graph node for parallel breadth-first search.
*
* @author Jimmy Lin
*/
public class BfsNode implements Writable {
public static enum Type {
Complete((byte) 0), // Complete structure.
Distance((byte) 1), // Distance only.
Structure((byte) 2); // Adjacency list only.
public byte val;
private Type(byte v) {
this.val = v;
}
};
private static final Type[] mapping = new Type[] { Type.Complete, Type.Distance, Type.Structure };
private Type type;
private int nodeid;
private int distance;
private ArrayListOfIntsWritable adjacenyList;
public BfsNode() {}
public int getDistance() {
return distance;
}
public void setDistance(int d) {
distance = d;
}
public int getNodeId() {
return nodeid;
}
public void setNodeId(int n) {
nodeid = n;
}
public ArrayListOfIntsWritable getAdjacenyList() {
return adjacenyList;
}
public void setAdjacencyList(ArrayListOfIntsWritable l) {
adjacenyList = l;
}
public Type getType() {
return type;
}
public void setType(Type type) {
this.type = type;
}
/**
* Deserializes this object.
*
* @param in source for raw byte representation
*/
@Override
public void readFields(DataInput in) throws IOException {
type = mapping[in.readByte()];
nodeid = in.readInt();
if (type.equals(Type.Distance)) {
distance = in.readInt();
return;
}
if (type.equals(Type.Complete)) {
distance = in.readInt();
}
adjacenyList = new ArrayListOfIntsWritable();
adjacenyList.readFields(in);
}
/**
* Serializes this object.
*
* @param out where to write the raw byte representation
*/
@Override
public void write(DataOutput out) throws IOException {
out.writeByte(type.val);
out.writeInt(nodeid);
if (type.equals(Type.Distance)) {
out.writeInt(distance);
return;
}
if (type.equals(Type.Complete)) {
out.writeInt(distance);
}
adjacenyList.write(out);
}
@Override
public String toString() {
return String.format("{%d %d %s}",
nodeid, distance, (adjacenyList == null ? "[]" : adjacenyList.toString(10)));
}
/**
* Returns the serialized representation of this object as a byte array.
*
* @return byte array representing the serialized representation of this object
* @throws IOException
*/
public byte[] serialize() throws IOException {
ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
DataOutputStream dataOut = new DataOutputStream(bytesOut);
write(dataOut);
return bytesOut.toByteArray();
}
/**
* Creates object from a <code>DataInput</code>.
*
* @param in source for reading the serialized representation
* @return newly-created object
* @throws IOException
*/
public static BfsNode create(DataInput in) throws IOException {
BfsNode m = new BfsNode();
m.readFields(in);
return m;
}
/**
* Creates object from a byte array.
*
* @param bytes raw serialized representation
* @return newly-created object
* @throws IOException
*/
public static BfsNode create(byte[] bytes) throws IOException {
return create(new DataInputStream(new ByteArrayInputStream(bytes)));
}
}