/*
* This file or a portion of this file is licensed under the terms of
* the Globus Toolkit Public License, found in file GTPL, or at
* http://www.globus.org/toolkit/download/license.html. This notice must
* appear in redistributions of this file, with or without modification.
*
* Redistributions of this Software, with or without modification, must
* reproduce the GTPL in: (1) the Software, or (2) the Documentation or
* some other similar material which is provided with the Software (if
* any).
*
* Copyright 1999-2004 University of Chicago and The University of
* Southern California. All rights reserved.
*/
package org.griphyn.vdl.router;
import java.util.*;
import org.griphyn.vdl.classes.Definition;
import org.griphyn.vdl.classes.Derivation;
/**
* This interface defines an arbitration. If multiple derivations
* produce the same output file, one derivation must be chosen over
* all others. There is not yet any mean to declare that none will
* do.
*
* @author Jens-S. Vöckler
* @author Yong Zhao
* @version $Revision $
*/
public interface Arbiter
{
/**
* The lone method of the arbitrarion receives some environmental
* information about the position in the call stack. Currently,
* this information is of limited nature. Furthermore, it receives
* the list of candidates. From this list, one candidate must be
* chosen, and returned to as the chosen one.<p>
*
* The environmental description currently contains the following entries:
* <table border="0">
* <tr><th>key</th><th>type</th><th>meaning</th></tr>
* <tr><td>lfn</td><td>String</td><td>Output filename produced by all.</td></tr>
* <tr><td>cwns</td><td>String</td><td>Current working namespace,
* may be null.</td></tr>
* <tr><td>level</td><td>Integer</td><td>Current recursion depth.</td></tr>
* </table>
*
* @param dvlist is a set of candidates
* @param environment is a map describing the environment.
* @return the chosen candidate from the input set
*/
public Derivation arbit( java.util.Collection dvlist,
java.util.Map environment );
}