// BSD License (http://www.galagosearch.org/license)

 package org.galagosearch.core.retrieval.structured;

 import java.util.ArrayList;

 import java.util.PriorityQueue;

 import org.galagosearch.tupleflow.Parameters;

 /**

  *

  * @author trevor

  */

 public class SynonymIterator extends ExtentDisjunctionIterator {

     public SynonymIterator(Parameters parameters, ExtentIterator[] iterators) {

         super(iterators);

         loadExtents();

     }

     public void loadExtents() {

         ExtentIterator iter = iterators.poll();

         document = iter.document();

         // get all the iteators that point to this document

         ArrayList<ExtentIterator> useable = new ArrayList<ExtentIterator>();

         while (iterators.size() > 0 && iterators.peek().document() == document) {

             useable.add(iterators.poll());

         }

         useable.add(iter);

         // make a priority queue of these ExtentArrayIterators

         PriorityQueue<ExtentArrayIterator> arrayIterators = new PriorityQueue<ExtentArrayIterator>();

         for (ExtentIterator iterator : useable) {

             arrayIterators.offer(new ExtentArrayIterator(iterator.extents()));

         }

         while (arrayIterators.size() > 0) {

             ExtentArrayIterator top = arrayIterators.poll();

             extents.add(top.current());

             if (top.next()) {

                 arrayIterators.offer(top);

             }

         }

         // put back the ones we used

         for (ExtentIterator i : useable) {

             if (!i.isDone()) {

                 iterators.offer(i);

             }

         }

     }

 }