org.apache.jackrabbit.oak.spi.state.NodeStateDiff Maven / Gradle / Ivy
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* 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.spi.state;
import org.apache.jackrabbit.oak.api.PropertyState;
/**
* Handler of node state differences. The
* {@link NodeState#compareAgainstBaseState(NodeState, NodeStateDiff)}
* method reports detected node state differences by calling methods of
* a handler instance that implements this interface.
*
* The compare method goes through all properties and child nodes of the
* two states, calling the relevant added, changed or deleted methods
* where appropriate. Differences in the ordering of properties or child
* nodes do not affect the comparison, and the order in which such
* differences are reported is unspecified.
*
* The methods in this interface all return a boolean value to signify
* whether the comparison should continue. If a method returns {@code false},
* then the comparison is immediately stopped. Otherwise it continues until
* all changes have been reported.
*
* Note that the
* {@link NodeState#compareAgainstBaseState(NodeState, NodeStateDiff)}
* method only compares the given states without recursing to the subtrees
* below. An implementation of this interface should recursively call that
* method for the relevant child node entries to find out all the changes
* across the entire subtree below the given node.
*/
public interface NodeStateDiff {
/**
* Called for all added properties.
*
* @param after property state after the change
* @return {@code true} to continue the comparison, {@code false} to stop
*/
boolean propertyAdded(PropertyState after);
/**
* Called for all changed properties. The names of the given two
* property states are guaranteed to be the same.
*
* @param before property state before the change
* @param after property state after the change
* @return {@code true} to continue the comparison, {@code false} to stop
*/
boolean propertyChanged(PropertyState before, PropertyState after);
/**
* Called for all deleted properties.
*
* @param before property state before the change
* @return {@code true} to continue the comparison, {@code false} to stop
*/
boolean propertyDeleted(PropertyState before);
/**
* Called for all added child nodes.
*
* @param name name of the added child node
* @param after child node state after the change
* @return {@code true} to continue the comparison, {@code false} to stop
*/
boolean childNodeAdded(String name, NodeState after);
/**
* Called for all child nodes that may contain changes between the before
* and after states. The comparison implementation is expected to make an
* effort to avoid calling this method on child nodes under which nothing
* has changed.
*
* @param name name of the changed child node
* @param before child node state before the change
* @param after child node state after the change
* @return {@code true} to continue the comparison, {@code false} to stop
*/
boolean childNodeChanged(String name, NodeState before, NodeState after);
/**
* Called for all deleted child nodes.
*
* @param name name of the deleted child node
* @param before child node state before the change
* @return {@code true} to continue the comparison, {@code false} to stop
*/
boolean childNodeDeleted(String name, NodeState before);
}