Event.java

/*******************************************************************************
 * Copyright (c) 2011 The Board of Trustees of the Leland Stanford Junior University
 * as Operator of the SLAC National Accelerator Laboratory.
 * Copyright (c) 2011 Brookhaven National Laboratory.
 * EPICS archiver appliance is distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution.
 *******************************************************************************/
package org.epics.archiverappliance;

import java.sql.Timestamp;

import org.epics.archiverappliance.config.ArchDBRTypes;
import org.epics.archiverappliance.data.SampleValue;



/**
 * An event represents an archiver sample. 
 * An actual sample has much more info; this interface outlines the minimum needed for the archiver appliance server side code.
 * Additional information can be gathered by using one of the other event related interfaces in org.epics.archiverappliance.data.
 * All the implementations of Event so far also implement DBRTimeEvent; this may change in the future.
 * @author mshankar
 *  
 */
public interface Event {
	/**
	 * Get java epoch seconds of the timestamp of this event.
	 * Note that we are skipping nanos. 
	 * To get to the nanos use the getEventTimeStamp method.
	 * @return The java epoch seconds of this event.
	 */
	public long getEpochSeconds();
	
	/**
	 * Get the epoch seconds and the nanos..
	 * We use java.sql.Timestamp as the main timestamp class.
	 * See TimeUtils for more time related utilities.
	 * @return The java epoch seconds and the nanos of this event
	 */
	public Timestamp getEventTimeStamp();

	
	/**
	 * Return a serialized form of this event in the internal currency of the archiver appliance. For now, this is Google's Protocol Buffers
	 * Note that the raw form is always escaped according to the archiver specification. 
	 * This is to have a minimum of conversion overhead when streaming data out to servers.
	 * @return A serialization of this event in the internal currency of the archiver appliance. 
	 */
	public ByteArray getRawForm();
	
	/**
	 * Get this event's value. The value for an EPICS sample is a complex thing and can be scalars and vectors of numbers and strings.
	 * With EPICS v4, this can get even more complicated. 
	 * @return The valus of this event
	 */
	public SampleValue getSampleValue(); 
	
	
	/**
	 * Make a clone of this event free from the confines of its containing stream.
	 * @return A clone of this event
	 */
	public Event makeClone();
	
	
	public ArchDBRTypes getDBRType();
}