CavalliumDBEngine/src/main/java/it/cavallium/dbengine/lucene/comparators/DoubleComparator.java

120 lines
3.9 KiB
Java

/*
* 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 it.cavallium.dbengine.lucene.comparators;
import it.cavallium.dbengine.database.disk.LLTempLMDBEnv;
import it.cavallium.dbengine.lucene.DoubleCodec;
import it.cavallium.dbengine.lucene.IArray;
import it.cavallium.dbengine.lucene.LMDBArray;
import it.cavallium.dbengine.lucene.SortFieldCodec;
import java.io.IOException;
import org.apache.lucene.document.DoublePoint;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.LeafFieldComparator;
/**
* Comparator based on {@link Double#compare} for {@code numHits}. This comparator provides a
* skipping functionality - an iterator that can skip over non-competitive documents.
*/
public class DoubleComparator extends NumericComparator<Double> {
private final IArray<Double> values;
protected double topValue;
protected double bottom;
public DoubleComparator(LLTempLMDBEnv env,
int numHits, String field, Double missingValue, boolean reverse, int sortPos) {
super(field, missingValue != null ? missingValue : 0.0, reverse, sortPos, Double.BYTES);
values = new LMDBArray<>(env, new DoubleCodec(), numHits, 0d);
}
@Override
public int compare(int slot1, int slot2) {
return Double.compare(values.getOrDefault(slot1, 0d), values.getOrDefault(slot2, 0d));
}
@Override
public void setTopValue(Double value) {
super.setTopValue(value);
topValue = value;
}
@Override
public Double value(int slot) {
return values.getOrDefault(slot, 0d);
}
@Override
public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws IOException {
return new DoubleLeafComparator(context);
}
/** Leaf comparator for {@link DoubleComparator} that provides skipping functionality */
public class DoubleLeafComparator extends NumericLeafComparator {
public DoubleLeafComparator(LeafReaderContext context) throws IOException {
super(context);
}
private double getValueForDoc(int doc) throws IOException {
if (docValues.advanceExact(doc)) {
return Double.longBitsToDouble(docValues.longValue());
} else {
return missingValue;
}
}
@Override
public void setBottom(int slot) throws IOException {
bottom = values.getOrDefault(slot, 0d);
super.setBottom(slot);
}
@Override
public int compareBottom(int doc) throws IOException {
return Double.compare(bottom, getValueForDoc(doc));
}
@Override
public int compareTop(int doc) throws IOException {
return Double.compare(topValue, getValueForDoc(doc));
}
@Override
public void copy(int slot, int doc) throws IOException {
values.set(slot, getValueForDoc(doc));
super.copy(slot, doc);
}
@Override
protected boolean isMissingValueCompetitive() {
int result = Double.compare(missingValue, bottom);
return reverse ? (result >= 0) : (result <= 0);
}
@Override
protected void encodeBottom(byte[] packedValue) {
DoublePoint.encodeDimension(bottom, packedValue, 0);
}
@Override
protected void encodeTop(byte[] packedValue) {
DoublePoint.encodeDimension(topValue, packedValue, 0);
}
}
}