org.apache.jackrabbit.oak.remote.RemoteTree 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.jackrabbit.oak.remote;
import java.util.Map;
/**
* This interface is a recursive data structure representing a view on a
* repository tree.
*
* The purpose of the remote tree is not to represent exactly the content as
* stored in the repository, but to provide a view on that content fulfilling
* the filtering options provided by the client when the tree was accessed.
*/
public interface RemoteTree {
/**
* Read the properties associated to the root of this remote tree. The root
* of this remote tree is represented by the instance of {@code RemoteTree}
* this method is invoked on.
*
* @return the properties associated to the root of this remote tree.
*/
Map getProperties();
/**
* Read the children associated to the root of this remote tree. The root of
* this remote tree is represented by the instance of {@code RemoteTree}
* this method is invoked on. The children of this remote tree are
* themselves remote trees.
*
* The remote tree may be truncated at some point (e.g. to avoid very deep
* remote trees to be returned), and this is the reason why the values of
* this {@code Map} can be {@code null}. When a {@code null} value is met,
* the consumer of this interface must assume that there is another subtree
* rooted under the corresponding key, but it is not returned to fulfill the
* filtering options provided when this tree was read.
*
* @return The children associated to the root of this remote tree.
*/
Map getChildren();
/**
* Return a flag to indicate that this remote tree actually has more
* children than the one returned by {@link #getChildren()}.
*
* This flag is important when the repository tree is read using very strict
* filtering options regarding the maximum number of children to return. If
* this method returns {@code true}, a consumer of this interface must
* assume that there are more children than the one attached to the root of
* this tree. They could be retrieved by varying the relevant filtering
* options and performing another read for this subtree.
*
* @return {@code true} if this remote tree is not exposing the full set of
* children as stored in the repository, {@code false} otherwise.
*/
boolean hasMoreChildren();
}