package org.apache.lucene.queryparser.flexible.aqp.processors;
/*
* 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.
*/
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.lucene.queryparser.flexible.aqp.config.AqpAdsabsQueryConfigHandler;
import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
import org.apache.lucene.queryparser.flexible.core.config.QueryConfigHandler;
import org.apache.lucene.queryparser.flexible.core.nodes.BooleanQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.BoostQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.FieldableNode;
import org.apache.lucene.queryparser.flexible.core.nodes.GroupQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.OrQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode;
import org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessorImpl;
import org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler.ConfigurationKeys;
/**
*
* A modified copy of the MultiFieldQueryNodeProcessor - ADS is using it
* to provide virtual fields that map into real indexes, eg.
*
* <p>
*
* 'full' is a virtual field for 'body', 'title', 'abstract'
*
* <p>
*
* This processor is used to expand terms so the query looks for the same term
* in different fields. It also boosts a query based on its field.
* <p>
* This processor looks for every {@link FieldableNode} contained in the query
* node tree. If a {@link FieldableNode} is found, it checks if there is a
* {@link ConfigurationKeys#MULTI_FIELDS} defined in the {@link QueryConfigHandler}. If
* there is, the {@link FieldableNode} is cloned N times and the clones are
* added to a {@link BooleanQueryNode} together with the original node. N is
* defined by the number of fields that it will be expanded to. The
* {@link BooleanQueryNode} is returned.
*
* @see ConfigurationKeys#MULTI_FIELDS
*/
public class AqpVirtualFieldsQueryNodeProcessor extends QueryNodeProcessorImpl {
private boolean processChildren = true;
public AqpVirtualFieldsQueryNodeProcessor() {
// empty constructor
}
@Override
protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
return node;
}
@Override
protected void processChildren(QueryNode queryTree) throws QueryNodeException {
if (this.processChildren) {
super.processChildren(queryTree);
} else {
this.processChildren = true;
}
}
@Override
protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
if (node instanceof FieldableNode) {
this.processChildren = false;
FieldableNode fieldNode = (FieldableNode) node;
Map<String, Map<String, Float>> fields = getQueryConfigHandler().get(AqpAdsabsQueryConfigHandler.ConfigurationKeys.VIRTUAL_FIELDS);
if (fields == null) {
throw new IllegalArgumentException(
"AqpAdsabsQueryConfigHandler.ConfigurationKeys.VIRTUAL_FIELDS should be set on the QueryConfigHandler");
}
if (fieldNode.getField() != null && fields.containsKey(fieldNode.getField())) {
Map<String, Float> realFields = fields.get(fieldNode.getField());
if (realFields != null && realFields.size() > 0) {
if (fields.size() == 1) {
for (Entry<String, Float> en: realFields.entrySet()) {
fieldNode.setField(en.getKey());
if (en.getValue() != null && en.getValue() != 1.0f) {
return new BoostQueryNode(fieldNode, en.getValue());
}
else {
return fieldNode;
}
}
} else {
LinkedList<QueryNode> children = new LinkedList<QueryNode>();
for (Entry<String, Float> en: realFields.entrySet()) {
try {
FieldableNode newNode = (FieldableNode) fieldNode.cloneTree();
newNode.setField(en.getKey());
if (en.getValue() != null && en.getValue() != 1.0f) {
children.add(new BoostQueryNode(newNode, en.getValue()));
}
else {
children.add(newNode);
}
} catch (CloneNotSupportedException e) {
// should never happen
}
}
return new GroupQueryNode(new OrQueryNode(children));
}
}
}
}
return node;
}
@Override
protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
throws QueryNodeException {
return children;
}
}