/*
* 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.search;
import java.io.IOException;
import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.NumericDocValues;
import org.apache.lucene.index.SortedNumericDocValues;
/**
* SortField for {@link SortedNumericDocValues}.
* <p>
* A SortedNumericDocValues contains multiple values for a field, so sorting with
* this technique "selects" a value as the representative sort value for the document.
* <p>
* By default, the minimum value in the list is selected as the sort value, but
* this can be customized.
* <p>
* Like sorting by string, this also supports sorting missing values as first or last,
* via {@link #setMissingValue(Object)}.
* @see SortedNumericSelector
*/
public class SortedNumericSortField extends SortField {
private final SortedNumericSelector.Type selector;
private final SortField.Type type;
/**
* Creates a sort, by the minimum value in the set
* for the document.
* @param field Name of field to sort by. Must not be null.
* @param type Type of values
*/
public SortedNumericSortField(String field, SortField.Type type) {
this(field, type, false);
}
/**
* Creates a sort, possibly in reverse, by the minimum value in the set
* for the document.
* @param field Name of field to sort by. Must not be null.
* @param type Type of values
* @param reverse True if natural order should be reversed.
*/
public SortedNumericSortField(String field, SortField.Type type, boolean reverse) {
this(field, type, reverse, SortedNumericSelector.Type.MIN);
}
/**
* Creates a sort, possibly in reverse, specifying how the sort value from
* the document's set is selected.
* @param field Name of field to sort by. Must not be null.
* @param type Type of values
* @param reverse True if natural order should be reversed.
* @param selector custom selector type for choosing the sort value from the set.
*/
public SortedNumericSortField(String field, SortField.Type type, boolean reverse, SortedNumericSelector.Type selector) {
super(field, SortField.Type.CUSTOM, reverse);
if (selector == null) {
throw new NullPointerException();
}
if (type == null) {
throw new NullPointerException();
}
this.selector = selector;
this.type = type;
}
/** Returns the numeric type in use for this sort */
public SortField.Type getNumericType() {
return type;
}
/** Returns the selector in use for this sort */
public SortedNumericSelector.Type getSelector() {
return selector;
}
@Override
public int hashCode() {
final int prime = 31;
int result = super.hashCode();
result = prime * result + selector.hashCode();
result = prime * result + type.hashCode();
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (!super.equals(obj)) return false;
if (getClass() != obj.getClass()) return false;
SortedNumericSortField other = (SortedNumericSortField) obj;
if (selector != other.selector) return false;
if (type != other.type) return false;
return true;
}
@Override
public String toString() {
StringBuilder buffer = new StringBuilder();
buffer.append("<sortednumeric" + ": \"").append(getField()).append("\">");
if (getReverse()) buffer.append('!');
if (missingValue != null) {
buffer.append(" missingValue=");
buffer.append(missingValue);
}
buffer.append(" selector=");
buffer.append(selector);
buffer.append(" type=");
buffer.append(type);
return buffer.toString();
}
@Override
public void setMissingValue(Object missingValue) {
this.missingValue = missingValue;
}
@Override
public FieldComparator<?> getComparator(int numHits, int sortPos) {
switch(type) {
case INT:
return new FieldComparator.IntComparator(numHits, getField(), (Integer) missingValue) {
@Override
protected NumericDocValues getNumericDocValues(LeafReaderContext context, String field) throws IOException {
return SortedNumericSelector.wrap(DocValues.getSortedNumeric(context.reader(), field), selector, type);
}
};
case FLOAT:
return new FieldComparator.FloatComparator(numHits, getField(), (Float) missingValue) {
@Override
protected NumericDocValues getNumericDocValues(LeafReaderContext context, String field) throws IOException {
return SortedNumericSelector.wrap(DocValues.getSortedNumeric(context.reader(), field), selector, type);
}
};
case LONG:
return new FieldComparator.LongComparator(numHits, getField(), (Long) missingValue) {
@Override
protected NumericDocValues getNumericDocValues(LeafReaderContext context, String field) throws IOException {
return SortedNumericSelector.wrap(DocValues.getSortedNumeric(context.reader(), field), selector, type);
}
};
case DOUBLE:
return new FieldComparator.DoubleComparator(numHits, getField(), (Double) missingValue) {
@Override
protected NumericDocValues getNumericDocValues(LeafReaderContext context, String field) throws IOException {
return SortedNumericSelector.wrap(DocValues.getSortedNumeric(context.reader(), field), selector, type);
}
};
default:
throw new AssertionError();
}
}
}