| /* |
| * 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.lucene.search.uhighlight; |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.index.FilterLeafReader; |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.PostingsEnum; |
| import org.apache.lucene.index.Terms; |
| import org.apache.lucene.index.TermsEnum; |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.lucene.util.automaton.CompiledAutomaton; |
| |
| /** |
| * Overlays a 2nd LeafReader for the terms of one field, otherwise the primary reader is |
| * consulted. The 2nd reader is assumed to have one document of 0 and we remap it to a target doc ID. |
| * |
| * @lucene.internal |
| */ |
| public class OverlaySingleDocTermsLeafReader extends FilterLeafReader { |
| |
| private final LeafReader in2; |
| private final String in2Field; |
| private final int in2TargetDocId; |
| |
| public OverlaySingleDocTermsLeafReader(LeafReader in, LeafReader in2, String in2Field, int in2TargetDocId) { |
| super(in); |
| this.in2 = in2; |
| this.in2Field = in2Field; |
| this.in2TargetDocId = in2TargetDocId; |
| assert in2.maxDoc() == 1; |
| } |
| |
| @Override |
| public Terms terms(String field) throws IOException { |
| if (!in2Field.equals(field)) { |
| return in.terms(field); |
| } |
| |
| // Shifts leafReader in2 with only doc ID 0 to a target doc ID |
| final Terms terms = in2.terms(field); |
| if (terms == null) { |
| return null; |
| } |
| if (in2TargetDocId == 0) { // no doc ID remapping to do |
| return terms; |
| } |
| return new FilterTerms(terms) { |
| @Override |
| public TermsEnum iterator() throws IOException { |
| return filterTermsEnum(super.iterator()); |
| } |
| |
| @Override |
| public TermsEnum intersect(CompiledAutomaton compiled, BytesRef startTerm) throws IOException { |
| return filterTermsEnum(super.intersect(compiled, startTerm)); |
| } |
| |
| private TermsEnum filterTermsEnum(TermsEnum termsEnum) throws IOException { |
| return new FilterTermsEnum(termsEnum) { |
| @Override |
| public PostingsEnum postings(PostingsEnum reuse, int flags) throws IOException { |
| //TODO 'reuse' will always fail to reuse unless we unwrap it |
| return new FilterPostingsEnum(super.postings(reuse, flags)) { |
| @Override |
| public int nextDoc() throws IOException { |
| final int doc = super.nextDoc(); |
| return doc == 0 ? in2TargetDocId : doc; |
| } |
| |
| @Override |
| public int advance(int target) throws IOException { |
| return slowAdvance(target); |
| } |
| |
| @Override |
| public int docID() { |
| final int doc = super.docID(); |
| return doc == 0 ? in2TargetDocId : doc; |
| } |
| }; |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public CacheHelper getCoreCacheHelper() { |
| return null; |
| } |
| |
| @Override |
| public CacheHelper getReaderCacheHelper() { |
| return null; |
| } |
| } |