| /* |
| * 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.plugins.observation; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import org.apache.jackrabbit.oak.spi.commit.CommitInfo; |
| import org.apache.jackrabbit.oak.spi.commit.Observer; |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| import org.jetbrains.annotations.NotNull; |
| |
| /** |
| * Part of the FilteringObserver: the FilteringDispatcher is used |
| * to implement the skipping (filtering) of content changes |
| * which the FilteringDispatcher flags as NOOP_CHANGE. |
| * When the FilteringDispatcher notices a NOOP_CHANGE it does |
| * not forward the change but only updates the before NodeState. |
| */ |
| public class FilteringDispatcher implements Observer { |
| |
| private final FilteringAwareObserver observer; |
| |
| private NodeState before; |
| |
| public FilteringDispatcher(FilteringAwareObserver observer) { |
| this.observer = checkNotNull(observer); |
| } |
| |
| @Override |
| public void contentChanged(@NotNull NodeState root, |
| @NotNull CommitInfo info) { |
| if (before != null) { |
| // avoid null being passed as before to observer |
| // before == null happens only at startup |
| if (info != FilteringObserver.NOOP_CHANGE) { |
| observer.contentChanged(before, root, info); |
| } |
| } |
| before = root; |
| } |
| } |