| /* |
| * 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; |
| |
| /** |
| * A filtered LeafReader that only includes the terms that are also in a provided set of terms. |
| * Certain methods may be unimplemented or cause large operations on the underlying reader |
| * and be slow. |
| * |
| * @lucene.internal |
| */ |
| final class TermVectorFilteredLeafReader extends FilterLeafReader { |
| // NOTE: super ("in") is baseLeafReader |
| |
| private final Terms filterTerms; |
| private final String fieldFilter; |
| |
| /** |
| * <p>Construct a FilterLeafReader based on the specified base reader. |
| * <p>Note that base reader is closed if this FilterLeafReader is closed.</p> |
| * @param baseLeafReader full/original reader. |
| * @param filterTerms set of terms to filter by -- probably from a TermVector or MemoryIndex. |
| * @param fieldFilter the field to do this on |
| */ |
| TermVectorFilteredLeafReader(LeafReader baseLeafReader, Terms filterTerms, String fieldFilter) { |
| super(baseLeafReader); |
| this.filterTerms = filterTerms; |
| this.fieldFilter = fieldFilter; |
| } |
| |
| @Override |
| public Terms terms(String field) throws IOException { |
| if (!field.equals(fieldFilter)) { |
| return super.terms(field); // proceed like normal for fields we're not interested in |
| } |
| Terms terms = in.terms(field); |
| return terms==null ? null : new TermsFilteredTerms(terms, filterTerms); |
| } |
| |
| private static final class TermsFilteredTerms extends FilterLeafReader.FilterTerms { |
| // NOTE: super ("in") is the baseTerms |
| |
| private final Terms filterTerms; |
| |
| TermsFilteredTerms(Terms baseTerms, Terms filterTerms) { |
| super(baseTerms); |
| this.filterTerms = filterTerms; |
| } |
| |
| //TODO delegate size() ? |
| |
| //TODO delegate getMin, getMax to filterTerms |
| |
| @Override |
| public TermsEnum iterator() throws IOException { |
| return new TermVectorFilteredTermsEnum(in.iterator(), filterTerms.iterator()); |
| } |
| |
| @Override |
| public TermsEnum intersect(CompiledAutomaton compiled, BytesRef startTerm) throws IOException { |
| return new TermVectorFilteredTermsEnum(in.iterator(), filterTerms.intersect(compiled, startTerm)); |
| } |
| } |
| |
| private static final class TermVectorFilteredTermsEnum extends FilterLeafReader.FilterTermsEnum { |
| // NOTE: super ("in") is the filteredTermsEnum. This is different than wrappers above because we |
| // navigate the terms using the filter. |
| |
| //TODO: track the last term state from the term state method and do some potential optimizations |
| private final TermsEnum baseTermsEnum; |
| |
| TermVectorFilteredTermsEnum(TermsEnum baseTermsEnum, TermsEnum filteredTermsEnum) { |
| super(filteredTermsEnum); // note this is reversed from constructors above |
| this.baseTermsEnum = baseTermsEnum; |
| } |
| |
| //TODO delegate docFreq & ttf (moveToCurrentTerm() then call on full? |
| |
| @Override |
| public PostingsEnum postings(PostingsEnum reuse, int flags) throws IOException { |
| moveToCurrentTerm(); |
| return baseTermsEnum.postings(reuse, flags); |
| } |
| |
| void moveToCurrentTerm() throws IOException { |
| BytesRef currentTerm = in.term(); // from filteredTermsEnum |
| boolean termInBothTermsEnum = baseTermsEnum.seekExact(currentTerm); |
| |
| if (!termInBothTermsEnum) { |
| throw new IllegalStateException("Term vector term '" + currentTerm.utf8ToString() + "' does not appear in full index."); |
| } |
| } |
| |
| } |
| |
| @Override |
| public CacheHelper getCoreCacheHelper() { |
| return null; |
| } |
| |
| @Override |
| public CacheHelper getReaderCacheHelper() { |
| return null; |
| } |
| } |