PageRankNodeExtended.java Source code

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Here is the source code for PageRankNodeExtended.java

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/*
 * Cloud9: A Hadoop toolkit for working with big data
 *
 * 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.
 */

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.ArrayListOfFloatsWritable;
import edu.umd.cloud9.io.array.ArrayListOfIntsWritable;

/**
 * Representation of a graph node for PageRank. 
 *
 * @author Jimmy Lin
 * @author Michael Schatz
 */
public class PageRankNodeExtended implements Writable {
    public static enum Type {
        Complete((byte) 0), // PageRank mass and adjacency list.
        Mass((byte) 1), // PageRank mass 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.Mass, Type.Structure };

    private Type type;
    private int nodeid;
    private ArrayListOfFloatsWritable pageranks;
    private ArrayListOfIntsWritable adjacenyList;

    public PageRankNodeExtended() {
        pageranks = new ArrayListOfFloatsWritable();
    }

    public ArrayListOfFloatsWritable getPageRankArray() {
        return pageranks;
    }

    public void setPageRankArray(ArrayListOfFloatsWritable list) {
        this.pageranks = list;
    }

    public void setPageRank(int position, float value) {
        if (position >= 0 && position < pageranks.size()) {
            pageranks.set(position, value);
        } else {
            throw new ArrayIndexOutOfBoundsException("Can't set pagerank at invalid position: " + position);
        }
    }

    public float getPageRank(int position) {
        if (position >= 0 && position < pageranks.size()) {
            return pageranks.get(position);

        } else {
            throw new ArrayIndexOutOfBoundsException("Can't get pagerank at invalid position:" + position);
        }
    }

    public int getNodeId() {
        return nodeid;
    }

    public void setNodeId(int n) {
        this.nodeid = n;
    }

    public ArrayListOfIntsWritable getAdjacenyList() {
        return adjacenyList;
    }

    public void setAdjacencyList(ArrayListOfIntsWritable list) {
        this.adjacenyList = list;
    }

    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 {
        int b = in.readByte();
        type = mapping[b];
        nodeid = in.readInt();

        pageranks = new ArrayListOfFloatsWritable();
        pageranks.readFields(in);

        if (type.equals(Type.Mass)) {
            return;
        }

        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);
        pageranks.write(out);

        if (type.equals(Type.Mass)) {
            return;
        }

        adjacenyList.write(out);
    }

    @Override
    public String toString() {
        return String.format("{%d %s %s}", nodeid, (pageranks == null ? "[]" : pageranks.toString(10)),
                (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 PageRankNodeExtended create(DataInput in) throws IOException {
        PageRankNodeExtended m = new PageRankNodeExtended();
        m.readFields(in);

        return m;
    }

    /**
     * Creates object from a byte array.
     *
     * @param bytes raw serialized representation
     * @return newly-created object
     * @throws IOException
     */
    public static PageRankNodeExtended create(byte[] bytes) throws IOException {
        return create(new DataInputStream(new ByteArrayInputStream(bytes)));
    }
}