| /* |
| * 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.spatial.util; |
| |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.search.DoubleValues; |
| import org.apache.lucene.search.DoubleValuesSource; |
| import org.apache.lucene.search.Explanation; |
| import org.apache.lucene.search.IndexSearcher; |
| |
| /** |
| * Caches the doubleVal of another value source in a HashMap |
| * so that it is computed only once. |
| * @lucene.internal |
| */ |
| public class CachingDoubleValueSource extends DoubleValuesSource { |
| |
| final DoubleValuesSource source; |
| final Map<Integer, Double> cache; |
| |
| public CachingDoubleValueSource(DoubleValuesSource source) { |
| this.source = source; |
| cache = new HashMap<>(); |
| } |
| |
| @Override |
| public String toString() { |
| return "Cached["+source.toString()+"]"; |
| } |
| |
| @Override |
| public DoubleValues getValues(LeafReaderContext readerContext, DoubleValues scores) throws IOException { |
| final int base = readerContext.docBase; |
| final DoubleValues vals = source.getValues(readerContext, scores); |
| return new DoubleValues() { |
| |
| @Override |
| public double doubleValue() throws IOException { |
| int key = base + doc; |
| Double v = cache.get(key); |
| if (v == null) { |
| v = vals.doubleValue(); |
| cache.put(key, v); |
| } |
| return v; |
| } |
| |
| @Override |
| public boolean advanceExact(int doc) throws IOException { |
| this.doc = doc; |
| return vals.advanceExact(doc); |
| } |
| |
| int doc = -1; |
| |
| }; |
| } |
| |
| @Override |
| public boolean needsScores() { |
| return false; |
| } |
| |
| @Override |
| public boolean isCacheable(LeafReaderContext ctx) { |
| return source.isCacheable(ctx); |
| } |
| |
| @Override |
| public Explanation explain(LeafReaderContext ctx, int docId, Explanation scoreExplanation) throws IOException { |
| return source.explain(ctx, docId, scoreExplanation); |
| } |
| |
| @Override |
| public DoubleValuesSource rewrite(IndexSearcher searcher) throws IOException { |
| return new CachingDoubleValueSource(source.rewrite(searcher)); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) return true; |
| if (o == null || getClass() != o.getClass()) return false; |
| |
| CachingDoubleValueSource that = (CachingDoubleValueSource) o; |
| |
| if (source != null ? !source.equals(that.source) : that.source != null) return false; |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| return source != null ? source.hashCode() : 0; |
| } |
| } |