/*
* 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.spi;
/**
* <code>ItemInfoCache</code> instances are responsible for caching
* {@link ItemInfo}s along with an opaque generation counter. Implementations
* are free on the particular caching policy. That is, how long (if at all) item
* infos are cached.
*
* An <code>ItemInfoCache</code> is supplied per session from the {@link RepositoryService}. It is used
* to cache <code>ItemInfo</code>s read from the <code>RepositoryService</code>.
*
* @see RepositoryService#getItemInfos(SessionInfo, ItemId)
*/
public interface ItemInfoCache {
/**
* This class represents a cache entry.
* @param <T> Either a {@link NodeInfo} or a {@link PropertyInfo}.
*/
class Entry<T extends ItemInfo> {
/**
* The {@link ItemInfo}
*/
public final T info;
/**
* The generation
*/
public final long generation;
/**
* Create a new cache entry containing <code>info</code> with a given <code>generation</code>.
* @param info
* @param generation
*/
public Entry(T info, long generation) {
this.info = info;
this.generation = generation;
}
@Override
public int hashCode() {
return info.hashCode() + (int) generation;
}
@Override
public boolean equals(Object that) {
if (that == null) {
return false;
}
if (that == this) {
return true;
}
if (that instanceof ItemInfoCache.Entry) {
ItemInfoCache.Entry other = (ItemInfoCache.Entry) that;
return generation == other.generation && info.equals(other.info);
}
return false;
}
}
/**
* Retrieve a cache entry for the given <code>nodeId</code> or <code>null</code>
* if no such entry is in the cache.
*
* @param nodeId id of the entry to lookup.
* @return a <code>Entry<NodeInfo></code> instance or <code>null</code>
* if not found.
*/
ItemInfoCache.Entry<NodeInfo> getNodeInfo(NodeId nodeId);
/**
* Retrieve a cache entry for the given <code>propertyId</code> or <code>null</code>
* if no such entry is in the cache.
*
* @param propertyId id of the entry to lookup.
* @return a <code>Entry<PropertyInfo></code> instance or
* <code>null</code> if not found.
*/
ItemInfoCache.Entry<PropertyInfo> getPropertyInfo(PropertyId propertyId);
/**
* Create a {@link Entry} for <code>info</code> and <code>generation</code> and put it into
* the cache.
* @param info
* @param generation
*/
void put(ItemInfo info, long generation);
/**
* Clear the cache and dispose all entries.
*/
void dispose();
}