AccidentNotification.java

/*
 * #!
 * %
 * Copyright (C) 2014 - 2016 Humboldt-Universität zu Berlin
 * %
 * 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 de.hub.cs.dbis.lrb.types;

import backtype.storm.tuple.Fields;
import de.hub.cs.dbis.lrb.queries.utils.TopologyControl;





/**
 * An {@link AccidentNotification} represent an alert that must be sent to vehicle approaching an accident.
 * 
 * Accident notifications do have the following attributes: TYPE=1, TIME, EMIT, SEG, VID<br />
 * (the VID attribute is not part of the LRB specification; we need to add it to know the consumer of the notification)
 * <ul>
 * <li>TYPE: the tuple type ID</li>
 * <li>TIME: the timestamp of the {@link PositionReport} that triggered the accident notification to be generated (in
 * LRB seconds)</li>
 * <li>EMIT: 'the time the notification is emitted' (in LRB seconds)</li>
 * <li>SEG: 'the segment where the accident occured'</li>
 * <li>VID: the vehicle that is notified about an accident, ie, the consumer of this message</li>
 * </ul>
 * 
 * @author mjsax
 */
public class AccidentNotification extends AbstractOutputTuple {
	private static final long serialVersionUID = -2731071679224249483L;
	
	// attribute indexes
	/** The index of the segment attribute. */
	public final static int SEG_IDX = 3;
	/**
	 * The index of the VID attribute. (Not part of LRB specification but necessary for "mimic" message delivery to
	 * correct car.)
	 */
	public final static int VID_IDX = 4;
	
	
	
	public AccidentNotification() {
		super();
	}
	
	/**
	 * Instantiates a new accident notification for the given attributes.
	 * 
	 * @param time
	 *            the time or the position record triggering this notification
	 * @param emit
	 *            the emit time of the notification
	 * @param segment
	 *            the accident segment
	 * @param vid
	 *            the vehicle ID this notification has to be delivered to
	 */
	public AccidentNotification(Short time, Short emit, Short segment, Integer vid) {
		super(AbstractLRBTuple.ACCIDENT_NOTIFICATION, time, emit);
		
		assert (segment != null);
		
		super.add(SEG_IDX, segment);
		super.add(VID_IDX, vid);
		
		assert (super.size() == 5);
	}
	
	
	
	/**
	 * Returns the segment of this {@link AccidentNotification}.
	 * 
	 * @return the SEG of the accident
	 */
	public final Short getSegment() {
		return (Short)super.get(SEG_IDX);
	}
	
	/**
	 * Returns the vehicle ID of this {@link AccidentNotification}.
	 * 
	 * @return the VID of this tuple
	 */
	public final Integer getVid() {
		return (Integer)super.get(VID_IDX);
	}
	
	/**
	 * Returns the schema of an {@link AccidentNotification}.
	 * 
	 * @return the schema of an {@link AccidentNotification}
	 */
	public static Fields getSchema() {
		return new Fields(TopologyControl.TYPE_FIELD_NAME, TopologyControl.TIMESTAMP_FIELD_NAME,
			TopologyControl.EMIT_FIELD_NAME, TopologyControl.SEGMENT_FIELD_NAME, TopologyControl.VEHICLE_ID_FIELD_NAME);
	}
	
	/**
	 * Compares the specified object with this {@link AccidentNotification} object for equality. Returns true if and
	 * only if the specified object is also a {@link AccidentNotification} and their TIME, SEGMENT, and VID attributes
	 * are equals. The EMIT attribute is not considered. Furthermore, TYPE is known to be equal if the specified object
	 * is of type {@link AccidentNotification}.
	 */
	@Override
	public boolean equals(Object obj) {
		if(this == obj) {
			return true;
		}
		if(obj == null) {
			return false;
		}
		if(this.getClass() != obj.getClass()) {
			return false;
		}
		AccidentNotification other = (AccidentNotification)obj;
		assert (this.getType().equals(other.getType()));
		
		if(this.getTime() == null) {
			if(other.getTime() != null) {
				return false;
			}
		} else if(!this.getTime().equals(other.getTime())) {
			return false;
		}
		
		if(this.getSegment() == null) {
			if(other.getSegment() != null) {
				return false;
			}
		} else if(!this.getSegment().equals(other.getSegment())) {
			return false;
		}
		
		if(this.getVid() == null) {
			if(other.getVid() != null) {
				return false;
			}
		} else if(!this.getVid().equals(other.getVid())) {
			return false;
		}
		
		return true;
	}
}