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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.facet;
import java.io.IOException;
import java.util.Objects;
import java.util.function.LongToDoubleFunction;
import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.SortedNumericDocValues;
import org.apache.lucene.search.DoubleValues;
import org.apache.lucene.search.DoubleValuesSource;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.SegmentCacheable;
/**
* Base class for producing {@link MultiDoubleValues}. See also {@link DoubleValuesSource} for a
* single-valued version.
*
* MultiDoubleValuesSource objects for NumericDocValues/SortedNumericDocValues fields can be
* obtained by calling {@link #fromFloatField(String)}, {@link #fromDoubleField(String)}, {@link
* #fromIntField(String)}, or {@link #fromLongField(String)}. If custom long-to-double logic is
* required, {@link #fromField(String, LongToDoubleFunction)} can be used. This is valid for both
* multi-valued and single-valued fields.
*
*
To obtain a MultiDoubleValuesSource from an existing {@link DoubleValuesSource}, see {@link
* #fromSingleValued(DoubleValuesSource)}. Instances created in this way can be "unwrapped" using
* {@link #unwrapSingleton(MultiDoubleValuesSource)} if necessary. Note that scores are never
* provided to the underlying {@code DoubleValuesSource}. {@link
* DoubleValuesSource#rewrite(IndexSearcher)} will also never be called. The user should be aware of
* this if using a {@code DoubleValuesSource} that relies on rewriting or scores. The faceting
* use-cases don't call rewrite or provide scores, which is why this simplification was made.
*
*
Currently meant only for use within the faceting module. Could be further generalized and made
* available for more use-cases outside faceting if there is a desire to do so.
*
* @lucene.experimental
*/
public abstract class MultiDoubleValuesSource implements SegmentCacheable {
/** Instantiates a new MultiDoubleValuesSource */
public MultiDoubleValuesSource() {}
/** Returns a {@link MultiDoubleValues} instance for the passed-in LeafReaderContext */
public abstract MultiDoubleValues getValues(LeafReaderContext ctx) throws IOException;
@Override
public abstract int hashCode();
@Override
public abstract boolean equals(Object o);
@Override
public abstract String toString();
/**
* Creates a MultiDoubleValuesSource that wraps a generic NumericDocValues/SortedNumericDocValues
* field. Uses the long-to-double decoding logic specified in {@code decoder} for converting the
* stored value to a double.
*/
public static MultiDoubleValuesSource fromField(String field, LongToDoubleFunction decoder) {
return new FieldMultiValuedSource(field, decoder);
}
/** Creates a MultiDoubleValuesSource that wraps a double-valued field */
public static MultiDoubleValuesSource fromDoubleField(String field) {
return fromField(field, Double::longBitsToDouble);
}
/** Creates a MultiDoubleValuesSource that wraps a float-valued field */
public static MultiDoubleValuesSource fromFloatField(String field) {
return fromField(field, v -> (double) Float.intBitsToFloat((int) v));
}
/** Creates a MultiDoubleValuesSource that wraps a long-valued field */
public static MultiDoubleValuesSource fromLongField(String field) {
return fromField(field, v -> (double) v);
}
/** Creates a MultiDoubleValuesSource that wraps an int-valued field */
public static MultiDoubleValuesSource fromIntField(String field) {
return fromLongField(field);
}
/** Creates a MultiDoubleValuesSource that wraps a single-valued {@code DoubleValuesSource} */
public static MultiDoubleValuesSource fromSingleValued(DoubleValuesSource singleValued) {
return new SingleValuedAsMultiValued(singleValued);
}
/**
* Returns a single-valued view of the {@code MultiDoubleValuesSource} if it was previously
* wrapped with {@link #fromSingleValued(DoubleValuesSource)}, or null.
*/
public static DoubleValuesSource unwrapSingleton(MultiDoubleValuesSource in) {
if (in instanceof SingleValuedAsMultiValued) {
return ((SingleValuedAsMultiValued) in).in;
} else {
return null;
}
}
/** Convert to a MultiLongValuesSource by casting the double values to longs */
public final MultiLongValuesSource toMultiLongValuesSource() {
return new LongDoubleValuesSource(this);
}
private static class FieldMultiValuedSource extends MultiDoubleValuesSource {
private final String field;
private final LongToDoubleFunction decoder;
FieldMultiValuedSource(String field, LongToDoubleFunction decoder) {
this.field = field;
this.decoder = decoder;
}
@Override
public MultiDoubleValues getValues(LeafReaderContext ctx) throws IOException {
final SortedNumericDocValues docValues = DocValues.getSortedNumeric(ctx.reader(), field);
return new MultiDoubleValues() {
@Override
public long getValueCount() {
return docValues.docValueCount();
}
@Override
public double nextValue() throws IOException {
return decoder.applyAsDouble(docValues.nextValue());
}
@Override
public boolean advanceExact(int doc) throws IOException {
return docValues.advanceExact(doc);
}
};
}
@Override
public boolean isCacheable(LeafReaderContext ctx) {
return DocValues.isCacheable(ctx, field);
}
@Override
public int hashCode() {
return Objects.hash(field, decoder);
}
@Override
public boolean equals(Object o) {
if (o == this) return true;
if (o == null || getClass() != o.getClass()) return false;
FieldMultiValuedSource that = (FieldMultiValuedSource) o;
return Objects.equals(field, that.field) && Objects.equals(decoder, that.decoder);
}
@Override
public String toString() {
return "multi-double(" + field + ")";
}
}
private static class SingleValuedAsMultiValued extends MultiDoubleValuesSource {
private final DoubleValuesSource in;
SingleValuedAsMultiValued(DoubleValuesSource in) {
this.in = in;
}
@Override
public MultiDoubleValues getValues(LeafReaderContext ctx) throws IOException {
final DoubleValues singleValues = in.getValues(ctx, null);
return new MultiDoubleValues() {
@Override
public long getValueCount() {
return 1;
}
@Override
public double nextValue() throws IOException {
return singleValues.doubleValue();
}
@Override
public boolean advanceExact(int doc) throws IOException {
return singleValues.advanceExact(doc);
}
};
}
@Override
public boolean isCacheable(LeafReaderContext ctx) {
return in.isCacheable(ctx);
}
@Override
public int hashCode() {
return Objects.hash(in);
}
@Override
public boolean equals(Object o) {
if (o == this) return true;
if (o == null || getClass() != o.getClass()) return false;
SingleValuedAsMultiValued that = (SingleValuedAsMultiValued) o;
return Objects.equals(in, that.in);
}
@Override
public String toString() {
return "multi-double(" + in + ")";
}
}
private static class LongDoubleValuesSource extends MultiLongValuesSource {
private final MultiDoubleValuesSource in;
LongDoubleValuesSource(MultiDoubleValuesSource in) {
this.in = in;
}
@Override
public MultiLongValues getValues(LeafReaderContext ctx) throws IOException {
final MultiDoubleValues doubleValues = in.getValues(ctx);
return new MultiLongValues() {
@Override
public long getValueCount() {
return doubleValues.getValueCount();
}
@Override
public long nextValue() throws IOException {
return (long) doubleValues.nextValue();
}
@Override
public boolean advanceExact(int doc) throws IOException {
return doubleValues.advanceExact(doc);
}
};
}
@Override
public boolean isCacheable(LeafReaderContext ctx) {
return in.isCacheable(ctx);
}
@Override
public int hashCode() {
return Objects.hash(in);
}
@Override
public boolean equals(Object o) {
if (o == this) return true;
if (o == null || getClass() != o.getClass()) return false;
LongDoubleValuesSource that = (LongDoubleValuesSource) o;
return Objects.equals(in, that.in);
}
@Override
public String toString() {
return "multi-double(" + in + ")";
}
}
}