/*
* 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.jackrabbit.core.query.lucene.join;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;
import org.apache.jackrabbit.core.query.lucene.ScoreNode;
/**
* <code>ScoreNodeMap</code> implements a simple mapping of an arbitrary key
* to an array of <code>ScoreNode[]</code>.
*/
public final class ScoreNodeMap {
/**
* The internal map.
*/
private final Map<Object, Object> map = new HashMap<Object, Object>();
/**
* Adds <code>scoreNodes</code> to this map under the given <code>key</code>.
* If there already exists a mapping with the given <code>key</code> the
* <code>scoreNodes</code> are added to the existing mapping. The add
* operation works as follows:
* <ul>
* <li>If the existing value for <code>key</code> is a <code>ScoreNode[]</code>,
* then the value is turned into a <code>List</code> and the existing value
* as well as the new value are added to the <code>List</code>. Finally
* the <code>List</code> is uses as the new value for the mapping.
* </li>
* <li>If the existing value for <code>key</code> is a <code>List</code> the
* <code>scoreNodes</code> are simply added to the <code>List</code>.
* </li>
* </ul>
*
* @param key the lookup key.
* @param nodes the score nodes.
*/
public void addScoreNodes(Object key, ScoreNode[] nodes) {
Object existing = map.get(key);
if (existing == null) {
existing = nodes;
map.put(key, existing);
} else if (existing instanceof List) {
@SuppressWarnings("unchecked")
List<ScoreNode[]> existingNodes = (List<ScoreNode[]>) existing;
existingNodes.add(nodes);
} else {
// ScoreNode[]
List<ScoreNode[]> tmp = new ArrayList<ScoreNode[]>();
tmp.add((ScoreNode[]) existing);
tmp.add(nodes);
existing = tmp;
map.put(key, existing);
}
}
/**
* Returns an array of <code>ScoreNode[]</code> for the given
* <code>key</code>.
*
* @param key the key.
* @return an array of <code>ScoreNode[]</code> that match the given
* <code>key</code> or <code>null</code> if there is none.
*/
public ScoreNode[][] getScoreNodes(Object key) {
Object sn = map.get(key);
if (sn == null) {
return null;
} else if (sn instanceof List) {
@SuppressWarnings("unchecked")
List<ScoreNode[]> list = (List<ScoreNode[]>) sn;
return list.toArray(new ScoreNode[list.size()][]);
} else {
// ScoreNode[]
return new ScoreNode[][]{(ScoreNode[]) sn};
}
}
}