| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.solr.search.facet; |
| |
| import java.io.IOException; |
| import org.apache.lucene.search.DocIdSetIterator; |
| import org.apache.solr.search.DocIterator; |
| import org.apache.lucene.util.PriorityQueue; |
| |
| final class UnionDocIterator extends SweepDocIterator { |
| |
| private final int maxIdx; |
| private final SubIterStruct baseSub; |
| private boolean collectBase; |
| private final PriorityQueue<SubIterStruct> queue; |
| private SubIterStruct top; |
| private int docId = -1; |
| |
| private static final class SubIterStruct { |
| private final DocIterator sub; |
| private final int index; |
| private int docId; |
| public SubIterStruct(DocIterator sub, int index) throws IOException { |
| this.sub = sub; |
| this.index = index; |
| nextDoc(); |
| } |
| public void nextDoc() { |
| docId = sub.hasNext() ? sub.nextDoc() : DocIdSetIterator.NO_MORE_DOCS; |
| } |
| } |
| UnionDocIterator(DocIterator[] subIterators, int baseIdx) throws IOException { |
| super(subIterators.length); |
| this.maxIdx = size - 1; |
| queue = new PriorityQueue<SubIterStruct>(size) { |
| @Override |
| protected boolean lessThan(SubIterStruct a, SubIterStruct b) { |
| return a.docId < b.docId; |
| } |
| }; |
| SubIterStruct tmpBase = null; |
| int i = maxIdx; |
| do { |
| SubIterStruct subIterStruct = new SubIterStruct(subIterators[i], i); |
| queue.add(subIterStruct); |
| if (i == baseIdx) { |
| tmpBase = subIterStruct; |
| } |
| } while (i-- > 0); |
| this.baseSub = tmpBase; |
| top = queue.top(); |
| } |
| |
| @Override |
| public int nextDoc() { |
| if (top.docId == docId) { |
| do { |
| top.nextDoc(); |
| } while ((top = queue.updateTop()).docId == docId); |
| } |
| collectBase = false; |
| return docId = top.docId; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (top.docId == docId) { |
| do { |
| top.nextDoc(); |
| } while ((top = queue.updateTop()).docId == docId); |
| } |
| return top.docId != DocIdSetIterator.NO_MORE_DOCS; |
| } |
| |
| @Override |
| public boolean collectBase() { |
| assert top.docId != docId : "must call registerCounts() before collectBase()"; |
| return collectBase; |
| } |
| |
| @Override |
| public int registerCounts(SegCounter segCounts) { |
| int i = -1; |
| do { |
| if (!collectBase && top == baseSub) { |
| collectBase = true; |
| } |
| segCounts.map(top.index, ++i); |
| top.nextDoc(); |
| } while ((top = queue.updateTop()).docId == docId); |
| return i; |
| } |
| } |