/*
* 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;
import java.util.HashMap;
import java.util.Map;
/**
* A cache of arbitrarily typed values used during the execution of a
* single query.
*/
class PerQueryCache {
/**
* The internal map of this <code>PerQueryCache</code>.
*/
private final Map<Key, Object> map = new HashMap<Key, Object>();
/**
* Returns the value from the cache with the given <code>type</code> and
* <code>key</code>.
*
* @param type the query type.
* @param key the key object.
* @return the value assigned to <code>type</code> and <code>key</code> or
* <code>null</code> if it does not exist in the cache.
*/
Object get(Class<?> type, Object key) {
return map.get(new Key(type, key));
}
/**
* Puts the <code>value</code> into the cache and assigns it to
* <code>type</code> and <code>key</code>.
*
* @param type the query type.
* @param key the key object.
* @param value the value to cache.
* @return the existing value in the cache assigned to <code>type</code> and
* <code>key</code> or <code>null</code> if there was none.
*/
Object put(Class<?> type, Object key, Object value) {
return map.put(new Key(type, key), value);
}
/**
* Simple key class.
*/
private static final class Key {
/**
* The query type.
*/
private final Class<?> type;
/**
* The key object.
*/
private final Object key;
/**
* Creates a new internal <code>Key</code> object.
*
* @param type the query type.
* @param key the key object.
*/
private Key(Class<?> type, Object key) {
this.type = type;
this.key = key;
}
/**
* {@inheritDoc}
*/
public int hashCode() {
return type.hashCode() ^ key.hashCode();
}
/**
* {@inheritDoc}
*/
public boolean equals(Object obj) {
if (obj instanceof Key) {
Key other = (Key) obj;
return type == other.type && key.equals(other.key);
}
return false;
}
}
}