| /* |
| * 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.codecs.uniformsplit.sharedterms; |
| |
| import java.io.IOException; |
| import org.apache.lucene.codecs.BlockTermState; |
| import org.apache.lucene.codecs.PostingsReaderBase; |
| import org.apache.lucene.codecs.uniformsplit.BlockDecoder; |
| import org.apache.lucene.codecs.uniformsplit.FieldMetadata; |
| import org.apache.lucene.codecs.uniformsplit.IndexDictionary; |
| import org.apache.lucene.codecs.uniformsplit.IntersectBlockReader; |
| import org.apache.lucene.index.FieldInfos; |
| import org.apache.lucene.store.IndexInput; |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.lucene.util.automaton.CompiledAutomaton; |
| |
| /** |
| * The "intersect" {@link org.apache.lucene.index.TermsEnum} response to {@link |
| * STUniformSplitTerms#intersect(CompiledAutomaton, BytesRef)}, intersecting the terms with an |
| * automaton. |
| * |
| * @lucene.experimental |
| */ |
| public class STIntersectBlockReader extends IntersectBlockReader { |
| |
| protected final FieldInfos fieldInfos; |
| |
| public STIntersectBlockReader( |
| CompiledAutomaton compiled, |
| BytesRef startTerm, |
| IndexDictionary.BrowserSupplier dictionaryBrowserSupplier, |
| IndexInput blockInput, |
| PostingsReaderBase postingsReader, |
| FieldMetadata fieldMetadata, |
| BlockDecoder blockDecoder, |
| FieldInfos fieldInfos) |
| throws IOException { |
| super( |
| compiled, |
| startTerm, |
| dictionaryBrowserSupplier, |
| blockInput, |
| postingsReader, |
| fieldMetadata, |
| blockDecoder); |
| this.fieldInfos = fieldInfos; |
| } |
| |
| // --------------------------------------------- |
| // The methods below are duplicate from STBlockReader. |
| // |
| // This class inherits code from both IntersectBlockReader and STBlockReader. |
| // We choose to extend IntersectBlockReader because this is the one that |
| // runs the next(), reads the block lines and keeps the reader state. |
| // But we still need the STBlockReader logic to skip terms that do not occur |
| // in this TermsEnum field. |
| // So we end up having a couple of methods directly duplicate from STBlockReader. |
| // We tried various different approaches to avoid duplicating the code, but |
| // actually this becomes difficult to read and to understand. This is simpler |
| // to duplicate and explain it here. |
| // --------------------------------------------- |
| |
| @Override |
| public BytesRef next() throws IOException { |
| BytesRef next; |
| do { |
| next = super.next(); |
| if (next == null) { |
| // No more terms. |
| return null; |
| } |
| // Check if the term occurs for the searched field. |
| } while (!termOccursInField()); |
| // The term occurs for the searched field. |
| return next; |
| } |
| |
| private boolean termOccursInField() throws IOException { |
| readTermStateIfNotRead(); |
| return termState != null; |
| } |
| |
| @Override |
| protected STBlockLine.Serializer createBlockLineSerializer() { |
| return new STBlockLine.Serializer(); |
| } |
| |
| /** |
| * Reads the {@link BlockTermState} on the current line for the specific field corresponding to |
| * this reader. Returns null if the term does not occur for the field. |
| */ |
| @Override |
| protected BlockTermState readTermState() throws IOException { |
| termStatesReadBuffer.setPosition( |
| blockFirstLineStart |
| + blockHeader.getTermStatesBaseOffset() |
| + blockLine.getTermStateRelativeOffset()); |
| return ((STBlockLine.Serializer) blockLineReader) |
| .readTermStateForField( |
| fieldMetadata.getFieldInfo().number, |
| termStatesReadBuffer, |
| termStateSerializer, |
| blockHeader, |
| fieldInfos, |
| scratchTermState); |
| } |
| } |