| /* |
| * 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.document; |
| |
| import java.io.IOException; |
| import java.util.Objects; |
| |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.PostingsEnum; |
| import org.apache.lucene.index.Terms; |
| import org.apache.lucene.index.TermsEnum; |
| import org.apache.lucene.search.DoubleValues; |
| import org.apache.lucene.search.DoubleValuesSource; |
| import org.apache.lucene.search.IndexSearcher; |
| import org.apache.lucene.util.BytesRef; |
| |
| /** |
| * A {@link DoubleValuesSource} instance which can be used to read the values of a feature from a |
| * {@link FeatureField} for documents. |
| */ |
| class FeatureDoubleValuesSource extends DoubleValuesSource { |
| |
| private final BytesRef featureName; |
| private final String field; |
| |
| /** |
| * Creates a {@link DoubleValuesSource} instance which can be used to read the values of a feature from the a |
| * {@link FeatureField} for documents. |
| * |
| * @param field field name. Must not be null. |
| * @param featureName feature name. Must not be null. |
| * @throws NullPointerException if {@code field} or {@code featureName} is null. |
| */ |
| public FeatureDoubleValuesSource(String field, String featureName) { |
| this.field = Objects.requireNonNull(field); |
| this.featureName = new BytesRef(Objects.requireNonNull(featureName)); |
| } |
| |
| @Override |
| public boolean isCacheable(LeafReaderContext ctx) { |
| return true; |
| } |
| |
| @Override |
| public DoubleValues getValues(LeafReaderContext ctx, DoubleValues scores) throws IOException { |
| Terms terms = ctx.reader().terms(field); |
| if (terms == null) { |
| return DoubleValues.EMPTY; |
| } else { |
| TermsEnum termsEnum = terms.iterator(); |
| if (termsEnum.seekExact(featureName) == false) { |
| return DoubleValues.EMPTY; |
| } else { |
| PostingsEnum currentReaderPostingsValues = termsEnum.postings(null, PostingsEnum.FREQS); |
| return new FeatureDoubleValues(currentReaderPostingsValues); |
| } |
| } |
| } |
| |
| @Override |
| public boolean needsScores() { |
| return false; |
| } |
| |
| @Override |
| public DoubleValuesSource rewrite(IndexSearcher reader) throws IOException { |
| return this; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(field, featureName); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj == null) { |
| return false; |
| } |
| if (obj.getClass() != getClass()) { |
| return false; |
| } |
| FeatureDoubleValuesSource other = (FeatureDoubleValuesSource) obj; |
| return Objects.equals(field, other.field) && |
| Objects.equals(featureName, other.featureName); |
| } |
| |
| @Override |
| public String toString() { |
| return "FeatureDoubleValuesSource("+field+", "+featureName.utf8ToString()+")"; |
| } |
| |
| static class FeatureDoubleValues extends DoubleValues { |
| |
| private final PostingsEnum currentReaderPostingsValues; |
| |
| public FeatureDoubleValues(PostingsEnum currentReaderPostingsValues) throws IOException { |
| this.currentReaderPostingsValues = currentReaderPostingsValues; |
| } |
| |
| @Override |
| public double doubleValue() throws IOException { |
| return FeatureField.decodeFeatureValue(currentReaderPostingsValues.freq()); |
| } |
| |
| @Override |
| public boolean advanceExact(int doc) throws IOException { |
| if (doc >= currentReaderPostingsValues.docID() |
| && (currentReaderPostingsValues.docID() == doc || currentReaderPostingsValues.advance(doc) == doc)) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| } |
| |
| } |