| /* |
| * 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.suggest; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import org.apache.lucene.document.Document; |
| import org.apache.lucene.index.IndexReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.ReaderUtil; |
| import org.apache.lucene.search.LongValues; |
| import org.apache.lucene.search.LongValuesSource; |
| |
| |
| /** |
| * <p> |
| * Dictionary with terms and optionally payload and |
| * optionally contexts information |
| * taken from stored fields in a Lucene index. Similar to |
| * {@link DocumentDictionary}, except it obtains the weight |
| * of the terms in a document based on a {@link LongValuesSource}. |
| * </p> |
| * <b>NOTE:</b> |
| * <ul> |
| * <li> |
| * The term field has to be stored; if it is missing, the document is skipped. |
| * </li> |
| * <li> |
| * The payload and contexts field are optional and are not required to be stored. |
| * </li> |
| * </ul> |
| * <p> |
| * In practice the {@link LongValuesSource} will likely be obtained |
| * using the lucene expression module. The following example shows |
| * how to create a {@link LongValuesSource} from a simple addition of two |
| * fields: |
| * <code> |
| * Expression expression = JavascriptCompiler.compile("f1 + f2"); |
| * SimpleBindings bindings = new SimpleBindings(); |
| * bindings.add(new SortField("f1", SortField.Type.LONG)); |
| * bindings.add(new SortField("f2", SortField.Type.LONG)); |
| * LongValuesSource valueSource = expression.getDoubleValuesSource(bindings).toLongValuesSource(); |
| * </code> |
| * </p> |
| * |
| */ |
| public class DocumentValueSourceDictionary extends DocumentDictionary { |
| |
| private final LongValuesSource weightsValueSource; |
| |
| /** |
| * Creates a new dictionary with the contents of the fields named <code>field</code> |
| * for the terms, <code>payload</code> for the corresponding payloads, <code>contexts</code> |
| * for the associated contexts and uses the <code>weightsValueSource</code> supplied |
| * to determine the score. |
| */ |
| public DocumentValueSourceDictionary(IndexReader reader, String field, |
| LongValuesSource weightsValueSource, String payload, String contexts) { |
| super(reader, field, null, payload, contexts); |
| this.weightsValueSource = weightsValueSource; |
| } |
| |
| /** |
| * Creates a new dictionary with the contents of the fields named <code>field</code> |
| * for the terms, <code>payloadField</code> for the corresponding payloads |
| * and uses the <code>weightsValueSource</code> supplied to determine the |
| * score. |
| */ |
| public DocumentValueSourceDictionary(IndexReader reader, String field, |
| LongValuesSource weightsValueSource, String payload) { |
| super(reader, field, null, payload); |
| this.weightsValueSource = weightsValueSource; |
| } |
| |
| /** |
| * Creates a new dictionary with the contents of the fields named <code>field</code> |
| * for the terms and uses the <code>weightsValueSource</code> supplied to determine the |
| * score. |
| */ |
| public DocumentValueSourceDictionary(IndexReader reader, String field, |
| LongValuesSource weightsValueSource) { |
| super(reader, field, null, null); |
| this.weightsValueSource = weightsValueSource; |
| } |
| |
| @Override |
| public InputIterator getEntryIterator() throws IOException { |
| return new DocumentValueSourceInputIterator(payloadField!=null, contextsField!=null); |
| } |
| |
| final class DocumentValueSourceInputIterator extends DocumentDictionary.DocumentInputIterator { |
| |
| private LongValues currentWeightValues; |
| /** leaves of the reader */ |
| private final List<LeafReaderContext> leaves; |
| /** starting docIds of all the leaves */ |
| private final int[] starts; |
| /** current leave index */ |
| private int currentLeafIndex = 0; |
| |
| public DocumentValueSourceInputIterator(boolean hasPayloads, boolean hasContexts) |
| throws IOException { |
| super(hasPayloads, hasContexts); |
| leaves = reader.leaves(); |
| starts = new int[leaves.size() + 1]; |
| for (int i = 0; i < leaves.size(); i++) { |
| starts[i] = leaves.get(i).docBase; |
| } |
| starts[leaves.size()] = reader.maxDoc(); |
| currentWeightValues = (leaves.size() > 0) |
| ? weightsValueSource.getValues(leaves.get(currentLeafIndex), null) |
| : null; |
| } |
| |
| /** |
| * Returns the weight for the current <code>docId</code> as computed |
| * by the <code>weightsValueSource</code> |
| * */ |
| @Override |
| protected long getWeight(Document doc, int docId) throws IOException { |
| if (currentWeightValues == null) { |
| return 0; |
| } |
| int subIndex = ReaderUtil.subIndex(docId, starts); |
| if (subIndex != currentLeafIndex) { |
| currentLeafIndex = subIndex; |
| currentWeightValues = weightsValueSource.getValues(leaves.get(currentLeafIndex), null); |
| } |
| if (currentWeightValues.advanceExact(docId - starts[subIndex])) |
| return currentWeightValues.longValue(); |
| else |
| return 0; |
| |
| } |
| |
| } |
| } |