package org.lcsim.lcio;
   
   import hep.io.sio.SIOInputStream;
   import hep.io.sio.SIOOutputStream;
   import hep.io.sio.SIORef;
   
   import java.io.IOException;
   import org.lcsim.event.LCRelation;
   
  /**
   * SIO-based I/O implementation of the LCRelation interface
   *
   * @author Guilherme Lima
   * @version $Id: SIOLCRelation.java,v 1.4 2007/10/17 02:06:23 tonyj Exp $
   */
  class SIOLCRelation implements LCRelation
  {
     protected SIORef from;
     protected SIORef to;
     protected float weight;
     
     protected SIOLCRelation() {      
     }
  
      /** Constructor for reading objects from file
       */
      SIOLCRelation(SIOInputStream in, int flags, int version) throws IOException
      {
         from = in.readPntr();
         to = in.readPntr();
         if (LCIOUtil.bitTest(flags,LCIOConstants.LCREL_WEIGHTED)) weight = in.readFloat();
      }
  
      /** Returns the 'from' object
       */
      public Object getFrom() {
         return from.getObject();
      }
      /** Returns the 'to' object
       */
      public Object getTo() {
  	return to.getObject();
      }
  
      /** Returns the weight of the relation
       */
      public float getWeight() {
  	return weight;
      }
  
      /** Weight should be between zero and one
       */
      public void setWeight(float weight) {
  	this.weight = weight;
      }
  
      /** Writes relations out to LCIO stream
       */
     static void write(LCRelation rel, SIOOutputStream out, int flags) throws IOException
     {
        out.writePntr( rel.getFrom() );
        out.writePntr( rel.getTo() );
        if (LCIOUtil.bitTest(flags,LCIOConstants.LCREL_WEIGHTED)) out.writeFloat( rel.getWeight() );
     }
  }