org.apache.solr.search.function.OrdFieldSource Maven / Gradle / Ivy
/**
* 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.solr.search.function.DocValues;
import org.apache.solr.search.function.ValueSource;
import java.io.IOException;
import java.util.Map;
/**
* Obtains the ordinal of the field value from the default Lucene {@link org.apache.lucene.search.FieldCache} using getStringIndex().
*
* The native lucene index order is used to assign an ordinal value for each field value.
*
Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1.
*
* Example:
* If there were only three field values: "apple","banana","pear"
*
then ord("apple")=1, ord("banana")=2, ord("pear")=3
*
* WARNING: ord() depends on the position in an index and can thus change when other documents are inserted or deleted,
* or if a MultiSearcher is used.
*
WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use since they must use a FieldCache entry
* at the top level reader, while sorting and function queries now use entries at the segment level. Hence sorting
* or using a different function query, in addition to ord()/rord() will double memory use.
* @version $Id: OrdFieldSource.java 826531 2009-10-18 21:41:54Z yonik $
*/
public class OrdFieldSource extends ValueSource {
protected String field;
public OrdFieldSource(String field) {
this.field = field;
}
public String description() {
return "ord(" + field + ')';
}
public DocValues getValues(Map context, IndexReader reader) throws IOException {
return new StringIndexDocValues(this, reader, field) {
protected String toTerm(String readableValue) {
return readableValue;
}
public float floatVal(int doc) {
return (float)order[doc];
}
public int intVal(int doc) {
return order[doc];
}
public long longVal(int doc) {
return (long)order[doc];
}
public double doubleVal(int doc) {
return (double)order[doc];
}
public String strVal(int doc) {
// the string value of the ordinal, not the string itself
return Integer.toString(order[doc]);
}
public String toString(int doc) {
return description() + '=' + intVal(doc);
}
};
}
public boolean equals(Object o) {
return o.getClass() == OrdFieldSource.class && this.field.equals(((OrdFieldSource)o).field);
}
private static final int hcode = OrdFieldSource.class.hashCode();
public int hashCode() {
return hcode + field.hashCode();
};
}