| /* |
| * 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.BlockReader; |
| import org.apache.lucene.codecs.uniformsplit.FieldMetadata; |
| import org.apache.lucene.codecs.uniformsplit.IndexDictionary; |
| import org.apache.lucene.index.FieldInfos; |
| import org.apache.lucene.store.IndexInput; |
| import org.apache.lucene.util.BytesRef; |
| |
| /** |
| * Reads terms blocks with the Shared Terms format. |
| * |
| * @see STBlockWriter |
| * @lucene.experimental |
| */ |
| public class STBlockReader extends BlockReader { |
| |
| protected final FieldInfos fieldInfos; |
| |
| public STBlockReader( |
| IndexDictionary.BrowserSupplier dictionaryBrowserSupplier, |
| IndexInput blockInput, |
| PostingsReaderBase postingsReader, |
| FieldMetadata fieldMetadata, |
| BlockDecoder blockDecoder, |
| FieldInfos fieldInfos) |
| throws IOException { |
| super(dictionaryBrowserSupplier, blockInput, postingsReader, fieldMetadata, blockDecoder); |
| this.fieldInfos = fieldInfos; |
| } |
| |
| @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; |
| } |
| |
| /** |
| * Moves to the next term line and reads it, whichever are the corresponding fields. The term |
| * details are not read yet. They will be read only when needed with {@link |
| * #readTermStateIfNotRead()}. |
| * |
| * @return The read term bytes. |
| */ |
| @Override |
| protected BytesRef nextTerm() throws IOException { |
| BytesRef nextTerm = super.nextTerm(); |
| if (nextTerm != null && super.isBeyondLastTerm(nextTerm, blockStartFP)) { |
| return null; |
| } |
| return nextTerm; |
| } |
| |
| @Override |
| public SeekStatus seekCeil(BytesRef searchedTerm) throws IOException { |
| SeekStatus seekStatus = seekCeilIgnoreField(searchedTerm); |
| if (seekStatus != SeekStatus.END) { |
| if (!termOccursInField()) { |
| // The term does not occur for the field. |
| // We have to move the iterator to the next valid term for the field. |
| BytesRef nextTerm = next(); |
| seekStatus = nextTerm == null ? SeekStatus.END : SeekStatus.NOT_FOUND; |
| } |
| } |
| return seekStatus; |
| } |
| |
| // Visible for testing. |
| SeekStatus seekCeilIgnoreField(BytesRef searchedTerm) throws IOException { |
| return super.seekCeil(searchedTerm); |
| } |
| |
| @Override |
| public boolean seekExact(BytesRef searchedTerm) throws IOException { |
| if (super.seekExact(searchedTerm)) { |
| return termOccursInField(); |
| } |
| return false; |
| } |
| |
| @Override |
| protected boolean isBeyondLastTerm(BytesRef searchedTerm, long blockStartFP) { |
| return blockStartFP > fieldMetadata.getLastBlockStartFP() |
| || super.isBeyondLastTerm(searchedTerm, blockStartFP); |
| } |
| |
| @Override |
| protected STBlockLine.Serializer createBlockLineSerializer() { |
| return new STBlockLine.Serializer(); |
| } |
| |
| /** |
| * Reads the {@link BlockTermState} on the current line for this reader's field. |
| * |
| * @return The {@link BlockTermState}; or null if the term does not occur for the field. |
| */ |
| @Override |
| protected BlockTermState readTermState() throws IOException { |
| termStatesReadBuffer.setPosition( |
| blockFirstLineStart |
| + blockHeader.getTermStatesBaseOffset() |
| + blockLine.getTermStateRelativeOffset()); |
| return termState = |
| ((STBlockLine.Serializer) blockLineReader) |
| .readTermStateForField( |
| fieldMetadata.getFieldInfo().number, |
| termStatesReadBuffer, |
| termStateSerializer, |
| blockHeader, |
| fieldInfos, |
| scratchTermState); |
| } |
| } |