edu.jhuapl.tinkerpop.mapreduce.MapReduceElement.java Source code

Introduction

Here is the source code for edu.jhuapl.tinkerpop.mapreduce.MapReduceElement.java

Source

/* Copyright 2014 The Johns Hopkins University Applied Physics Laboratory
 *
 * 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.jhuapl.tinkerpop.mapreduce;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.Serializable;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.hadoop.io.WritableComparable;

import com.google.common.collect.Sets;
import com.tinkerpop.blueprints.Element;
import com.tinkerpop.blueprints.Graph;

import edu.jhuapl.tinkerpop.AccumuloByteSerializer;
import edu.jhuapl.tinkerpop.AccumuloGraph;

public abstract class MapReduceElement implements Serializable, Element, WritableComparable<MapReduceElement> {

    protected String id;

    protected Map<String, Object> properties;

    protected Map<String, Object> newProperties;

    transient AccumuloGraph parent;

    MapReduceElement(AccumuloGraph parent) {
        this();
        this.parent = parent;
    }

    MapReduceElement() {
        properties = new HashMap<String, Object>();
        newProperties = new HashMap<String, Object>();
    }

    void prepareId(String id) {
        this.id = id;
    }

    void prepareProperty(String key, Object property) {
        properties.put(key, property);
    }

    Map<String, Object> getNewProperties() {
        return newProperties;
    }

    @Override
    public Object getId() {
        return id;
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> T getProperty(String key) {

        Object newProp = newProperties.get(key);
        if (newProp != null)
            return (T) newProp;
        return (T) properties.get(key);
    }

    @Override
    public Set<String> getPropertyKeys() {
        return Sets.union(new HashSet<String>(properties.keySet()), new HashSet<String>(newProperties.keySet()));
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException("You cannot remove an element during a MapReduce job.");
    }

    @Override
    public <T> T removeProperty(String key) {
        throw new UnsupportedOperationException("You cannot modify an element during a MapReduce job.");
    }

    @Override
    public void setProperty(String key, Object value) {
        newProperties.put(key, value);
    }

    protected Graph getParent() {
        return parent;
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        prepareId(in.readUTF());

        properties.clear();
        int count = in.readInt();
        for (int i = 0; i < count; i++) {
            String key = in.readUTF();
            byte[] data = new byte[in.readInt()];
            in.readFully(data);
            Object val = AccumuloByteSerializer.deserialize(data);
            properties.put(key, val);
        }

        count = in.readInt();
        for (int i = 0; i < count; i++) {
            String key = in.readUTF();
            byte[] data = new byte[in.readInt()];
            in.readFully(data);
            Object val = AccumuloByteSerializer.deserialize(data);
            newProperties.put(key, val);
        }

    }

    @Override
    public void write(DataOutput out) throws IOException {
        out.writeUTF(id);
        out.writeInt(properties.size());
        for (String key : properties.keySet()) {
            out.writeUTF(key);
            byte[] data = AccumuloByteSerializer.serialize(properties.get(key));
            out.writeInt(data.length);
            out.write(data);
        }

        for (String key : newProperties.keySet()) {
            out.writeUTF(key);
            byte[] data = AccumuloByteSerializer.serialize(newProperties.get(key));
            out.writeInt(data.length);
            out.write(data);
        }
    }

    @Override
    public int compareTo(MapReduceElement other) {
        int val = this.id.compareTo(other.id);
        if (val != 0) {
            return val;
        }
        return getClass().getSimpleName().compareTo(other.getClass().getSimpleName());
    }

    public boolean equals(Object object) {
        if (object == this) {
            return true;
        } else if (object == null) {
            return false;
        } else if (!object.getClass().equals(getClass())) {
            return false;
        } else {
            Element element = (Element) object;
            if (id == null) {
                return element.getId() == null;
            } else {
                return id.equals(element.getId());
            }
        }
    }

    public int hashCode() {
        int hash = 31 * getClass().hashCode();
        if (id != null) {
            hash ^= id.hashCode();
        }
        return hash;
    }

}