org.apache.lucene.queries.function.ValueSource Maven / Gradle / Ivy
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* 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.queries.function;
import java.io.IOException;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.Objects;
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.FieldComparator;
import org.apache.lucene.search.FieldComparatorSource;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.LongValues;
import org.apache.lucene.search.LongValuesSource;
import org.apache.lucene.search.Pruning;
import org.apache.lucene.search.Scorable;
import org.apache.lucene.search.SimpleFieldComparator;
import org.apache.lucene.search.SortField;
/**
* Instantiates {@link FunctionValues} for a particular reader.
* Often used when creating a {@link FunctionQuery}.
*/
public abstract class ValueSource {
/**
* Gets the values for this reader and the context that was previously passed to createWeight().
* The values must be consumed in a forward docID manner, and you must call this method again to
* iterate through the values again.
*/
public abstract FunctionValues getValues(
Map context, LeafReaderContext readerContext) throws IOException;
@Override
public abstract boolean equals(Object o);
@Override
public abstract int hashCode();
/** description of field, used in explain() */
public abstract String description();
@Override
public String toString() {
return description();
}
/**
* Implementations should propagate createWeight to sub-ValueSources which can optionally store
* weight info in the context. The context object will be passed to getValues() where this info
* can be retrieved.
*/
public void createWeight(Map context, IndexSearcher searcher)
throws IOException {}
/** Returns a new non-threadsafe context map. */
public static Map newContext(IndexSearcher searcher) {
Map context = new IdentityHashMap<>();
context.put("searcher", searcher);
return context;
}
private static class ScorableView extends Scorable {
final DoubleValues scores;
int docId = -1;
int scoresDocId = -1;
float score = 0;
public ScorableView(int docId, float score) {
this(null);
this.docId = this.scoresDocId = docId;
this.score = score;
}
public ScorableView(DoubleValues scores) {
this.scores = scores == null ? DoubleValues.EMPTY : scores;
}
@Override
public int docID() {
return docId;
}
@Override
public float score() throws IOException {
// ensure we calculate the score at most once
if (scoresDocId != docId) {
scoresDocId = docId;
if (scores.advanceExact(docId)) {
score = (float) scores.doubleValue();
} else {
score = 0;
}
}
return score;
}
}
/** Expose this ValueSource as a LongValuesSource */
public LongValuesSource asLongValuesSource() {
return new WrappedLongValuesSource(this, null);
}
private static class WrappedLongValuesSource extends LongValuesSource {
private final ValueSource in;
private final IndexSearcher searcher;
private WrappedLongValuesSource(ValueSource in, IndexSearcher searcher) {
this.in = in;
this.searcher = searcher;
}
@Override
public LongValues getValues(LeafReaderContext ctx, DoubleValues scores) throws IOException {
Map context = newContext(searcher);
var scorer = new ScorableView(scores);
context.put("scorer", scorer);
FunctionValues fv = in.getValues(context, ctx);
return new LongValues() {
@Override
public long longValue() throws IOException {
return fv.longVal(scorer.docId);
}
@Override
public boolean advanceExact(int doc) throws IOException {
scorer.docId = doc;
return fv.exists(doc);
}
};
}
@Override
public boolean isCacheable(LeafReaderContext ctx) {
return false;
}
@Override
public boolean needsScores() {
return false;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
WrappedLongValuesSource that = (WrappedLongValuesSource) o;
return Objects.equals(in, that.in);
}
@Override
public int hashCode() {
return Objects.hash(in);
}
@Override
public String toString() {
return in.toString();
}
@Override
public LongValuesSource rewrite(IndexSearcher searcher) throws IOException {
return new WrappedLongValuesSource(in, searcher);
}
}
/** Expose this ValueSource as a DoubleValuesSource */
public DoubleValuesSource asDoubleValuesSource() {
return new WrappedDoubleValuesSource(this, null);
}
static class WrappedDoubleValuesSource extends DoubleValuesSource {
final ValueSource in;
final IndexSearcher searcher;
private WrappedDoubleValuesSource(ValueSource in, IndexSearcher searcher) {
this.in = in;
this.searcher = searcher;
}
@Override
public DoubleValues getValues(LeafReaderContext ctx, DoubleValues scores) throws IOException {
Map context = newContext(searcher);
var scorer = new ScorableView(scores);
context.put("scorer", scorer);
FunctionValues fv = in.getValues(context, ctx);
return new DoubleValues() {
@Override
public double doubleValue() throws IOException {
return fv.doubleVal(scorer.docId);
}
@Override
public boolean advanceExact(int doc) {
scorer.docId = doc;
// ValueSource will return values even if exists() is false, generally a default
// of some kind. To preserve this behaviour with the iterator, we need to always
// return 'true' here.
return true;
}
};
}
@Override
public boolean needsScores() {
return true; // be on the safe side
}
@Override
public boolean isCacheable(LeafReaderContext ctx) {
return false;
}
@Override
public Explanation explain(LeafReaderContext ctx, int docId, Explanation scoreExplanation)
throws IOException {
Map context = newContext(searcher);
context.put("scorer", new ScorableView(docId, scoreExplanation.getValue().floatValue()));
FunctionValues fv = in.getValues(context, ctx);
return fv.explain(docId);
}
@Override
public DoubleValuesSource rewrite(IndexSearcher searcher) throws IOException {
return new WrappedDoubleValuesSource(in, searcher);
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
WrappedDoubleValuesSource that = (WrappedDoubleValuesSource) o;
return Objects.equals(in, that.in);
}
@Override
public int hashCode() {
return Objects.hash(in);
}
@Override
public String toString() {
return in.toString();
}
}
public static ValueSource fromDoubleValuesSource(DoubleValuesSource in) {
return new FromDoubleValuesSource(in);
}
private static class FromDoubleValuesSource extends ValueSource {
final DoubleValuesSource in;
private FromDoubleValuesSource(DoubleValuesSource in) {
this.in = in;
}
@Override
public FunctionValues getValues(Map context, LeafReaderContext readerContext)
throws IOException {
Scorable scorer = (Scorable) context.get("scorer");
DoubleValues scores = scorer == null ? null : DoubleValuesSource.fromScorer(scorer);
IndexSearcher searcher = (IndexSearcher) context.get("searcher");
DoubleValues inner;
if (searcher != null) {
inner = in.rewrite(searcher).getValues(readerContext, scores);
} else {
inner = in.getValues(readerContext, scores);
}
return new FunctionValues() {
@Override
public String toString(int doc) throws IOException {
return in.toString();
}
@Override
public float floatVal(int doc) throws IOException {
if (inner.advanceExact(doc) == false) {
return 0;
}
return (float) inner.doubleValue();
}
@Override
public double doubleVal(int doc) throws IOException {
if (inner.advanceExact(doc) == false) {
return 0;
}
return inner.doubleValue();
}
@Override
public boolean exists(int doc) throws IOException {
return inner.advanceExact(doc);
}
};
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
FromDoubleValuesSource that = (FromDoubleValuesSource) o;
return Objects.equals(in, that.in);
}
@Override
public int hashCode() {
return Objects.hash(in);
}
@Override
public String description() {
return in.toString();
}
}
//
// Sorting by function
//
/**
* EXPERIMENTAL: This method is subject to change.
*
* Get the SortField for this ValueSource. Uses the {@link #getValues(java.util.Map,
* org.apache.lucene.index.LeafReaderContext)} to populate the SortField.
*
* @param reverse true if this is a reverse sort.
* @return The {@link org.apache.lucene.search.SortField} for the ValueSource
*/
public SortField getSortField(boolean reverse) {
return new ValueSourceSortField(reverse);
}
class ValueSourceSortField extends SortField {
public ValueSourceSortField(boolean reverse) {
super(description(), SortField.Type.REWRITEABLE, reverse);
}
@Override
public SortField rewrite(IndexSearcher searcher) throws IOException {
Map context = newContext(searcher);
createWeight(context, searcher);
return new SortField(getField(), new ValueSourceComparatorSource(context), getReverse());
}
}
class ValueSourceComparatorSource extends FieldComparatorSource {
private final Map context;
public ValueSourceComparatorSource(Map context) {
this.context = context;
}
@Override
public FieldComparator newComparator(
String fieldname, int numHits, Pruning pruning, boolean reversed) {
return new ValueSourceComparator(context, numHits);
}
}
/**
* Implement a {@link org.apache.lucene.search.FieldComparator} that works off of the {@link
* FunctionValues} for a ValueSource instead of the normal Lucene FieldComparator that works off
* of a FieldCache.
*/
class ValueSourceComparator extends SimpleFieldComparator {
private final double[] values;
private FunctionValues docVals;
private double bottom;
private final Map fcontext;
private double topValue;
ValueSourceComparator(Map fcontext, int numHits) {
this.fcontext = fcontext;
values = new double[numHits];
}
@Override
public int compare(int slot1, int slot2) {
return Double.compare(values[slot1], values[slot2]);
}
@Override
public int compareBottom(int doc) throws IOException {
return Double.compare(bottom, docVals.doubleVal(doc));
}
@Override
public void copy(int slot, int doc) throws IOException {
values[slot] = docVals.doubleVal(doc);
}
@Override
public void doSetNextReader(LeafReaderContext context) throws IOException {
docVals = getValues(fcontext, context);
}
@Override
public void setBottom(final int bottom) {
this.bottom = values[bottom];
}
@Override
public void setTopValue(final Double value) {
this.topValue = value;
}
@Override
public Double value(int slot) {
return values[slot];
}
@Override
public int compareTop(int doc) throws IOException {
final double docValue = docVals.doubleVal(doc);
return Double.compare(topValue, docValue);
}
}
}