/**
* 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.solr.search.function;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.FieldComparator;
import org.apache.lucene.search.FieldComparatorSource;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.SortField;
import org.apache.lucene.util.Bits;
import org.apache.lucene.index.MultiFields;
import java.io.IOException;
import java.io.Serializable;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.Collections;
/**
* Instantiates {@link org.apache.solr.search.function.DocValues} for a particular reader.
* <br>
* Often used when creating a {@link FunctionQuery}.
*
* @version $Id: ValueSource.java 987961 2010-08-22 23:37:23Z mikemccand $
*/
public abstract class ValueSource implements Serializable {
@Deprecated
public DocValues getValues(IndexReader reader) throws IOException {
return getValues(null, reader);
}
/**
* Gets the values for this reader and the context that was previously
* passed to createWeight()
*/
public DocValues getValues(Map context, IndexReader reader) throws IOException {
return getValues(reader);
}
public abstract boolean equals(Object o);
public abstract int hashCode();
/**
* description of field, used in explain()
*/
public abstract String description();
public String toString() {
return description();
}
/**
* EXPERIMENTAL: This method is subject to change.
* <br>WARNING: Sorted function queries are not currently weighted.
* <p>
* Get the SortField for this ValueSource. Uses the {@link #getValues(java.util.Map, org.apache.lucene.index.IndexReader)}
* to populate the SortField.
*
* @param reverse true if this is a reverse sort.
* @return The {@link org.apache.lucene.search.SortField} for the ValueSource
* @throws IOException if there was a problem reading the values.
*/
public SortField getSortField(boolean reverse) throws IOException {
//should we pass in the description for the field name?
//Hmm, Lucene is going to intern whatever we pass in, not sure I like that
//and we can't pass in null, either, as that throws an illegal arg. exception
return new SortField(description(), new ValueSourceComparatorSource(), reverse);
}
/**
* 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, Searcher searcher) throws IOException {
}
/**
* Returns a new non-threadsafe context map.
*/
public static Map newContext() {
return new IdentityHashMap();
}
class ValueSourceComparatorSource extends FieldComparatorSource {
public ValueSourceComparatorSource() {
}
public FieldComparator newComparator(String fieldname, int numHits,
int sortPos, boolean reversed) throws IOException {
return new ValueSourceComparator(numHits);
}
}
/**
* Implement a {@link org.apache.lucene.search.FieldComparator} that works
* off of the {@link org.apache.solr.search.function.DocValues} for a ValueSource
* instead of the normal Lucene FieldComparator that works off of a FieldCache.
*/
class ValueSourceComparator extends FieldComparator {
private final double[] values;
private DocValues docVals;
private double bottom;
ValueSourceComparator(int numHits) {
values = new double[numHits];
}
public int compare(int slot1, int slot2) {
final double v1 = values[slot1];
final double v2 = values[slot2];
if (v1 > v2) {
return 1;
} else if (v1 < v2) {
return -1;
} else {
return 0;
}
}
public int compareBottom(int doc) {
final double v2 = docVals.doubleVal(doc);
if (bottom > v2) {
return 1;
} else if (bottom < v2) {
return -1;
} else {
return 0;
}
}
public void copy(int slot, int doc) {
values[slot] = docVals.doubleVal(doc);
}
public void setNextReader(IndexReader reader, int docBase) throws IOException {
docVals = getValues(Collections.emptyMap(), reader);
}
public void setBottom(final int bottom) {
this.bottom = values[bottom];
}
public Comparable value(int slot) {
return Double.valueOf(values[slot]);
}
}
}
class ValueSourceScorer extends Scorer {
protected IndexReader reader;
private int doc = -1;
protected final int maxDoc;
protected final DocValues values;
protected boolean checkDeletes;
private final Bits delDocs;
protected ValueSourceScorer(IndexReader reader, DocValues values) {
super(null);
this.reader = reader;
this.maxDoc = reader.maxDoc();
this.values = values;
setCheckDeletes(true);
this.delDocs = MultiFields.getDeletedDocs(reader);
}
public IndexReader getReader() {
return reader;
}
public void setCheckDeletes(boolean checkDeletes) {
this.checkDeletes = checkDeletes && reader.hasDeletions();
}
public boolean matches(int doc) {
return (!checkDeletes || !delDocs.get(doc)) && matchesValue(doc);
}
public boolean matchesValue(int doc) {
return true;
}
@Override
public int docID() {
return doc;
}
@Override
public int nextDoc() throws IOException {
for (; ;) {
doc++;
if (doc >= maxDoc) return doc = NO_MORE_DOCS;
if (matches(doc)) return doc;
}
}
@Override
public int advance(int target) throws IOException {
// also works fine when target==NO_MORE_DOCS
doc = target - 1;
return nextDoc();
}
public int doc() {
return doc;
}
public boolean next() {
for (; ;) {
doc++;
if (doc >= maxDoc) return false;
if (matches(doc)) return true;
}
}
public boolean skipTo(int target) {
doc = target - 1;
return next();
}
public float score() throws IOException {
return values.floatVal(doc);
}
public Explanation explain(int doc) throws IOException {
return values.explain(doc);
}
}