| /* |
| * 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.index.diffindex; |
| |
| import static org.apache.jackrabbit.oak.commons.PathUtils.concat; |
| import static org.apache.jackrabbit.oak.plugins.memory.EmptyNodeState.EMPTY_NODE; |
| |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import org.apache.jackrabbit.oak.spi.query.Filter; |
| import org.apache.jackrabbit.oak.spi.state.DefaultNodeStateDiff; |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| import org.apache.jackrabbit.oak.spi.state.NodeStateUtils; |
| |
| public abstract class BaseDiffCollector implements DiffCollector { |
| |
| protected boolean init; |
| |
| private final NodeState before; |
| private final NodeState after; |
| |
| private Set<String> results; |
| |
| /** |
| * The filter that was used to generate the result. |
| */ |
| private Filter resultFilter; |
| |
| /** |
| * @param before initial state |
| * @param after after state |
| */ |
| public BaseDiffCollector(NodeState before, NodeState after) { |
| this.before = before; |
| this.after = after; |
| results = new HashSet<String>(); |
| } |
| |
| @Override |
| public Set<String> getResults(Filter filter) { |
| if (!init) { |
| collect(filter); |
| } |
| return results; |
| } |
| |
| @Override |
| public double getCost(Filter filter) { |
| if (!init || filter != resultFilter) { |
| collect(filter); |
| } |
| if (results.isEmpty()) { |
| return Double.POSITIVE_INFINITY; |
| } |
| // no read operations needed |
| return 0; |
| } |
| |
| public void collect(final Filter filter) { |
| DiffCollectorNodeStateDiff diff = new DiffCollectorNodeStateDiff(this, |
| filter); |
| after.compareAgainstBaseState(before, diff); |
| this.results = new HashSet<String>(diff.getResults()); |
| this.resultFilter = filter; |
| this.init = true; |
| } |
| |
| abstract boolean match(NodeState state, Filter filter); |
| |
| protected boolean isUnique() { |
| return false; |
| } |
| |
| private static class DiffCollectorNodeStateDiff extends DefaultNodeStateDiff { |
| |
| private final BaseDiffCollector collector; |
| private final Filter filter; |
| private final Set<String> results; |
| |
| private final String path; |
| |
| DiffCollectorNodeStateDiff(BaseDiffCollector collector, Filter filter) { |
| this(collector, filter, "", new HashSet<String>()); |
| } |
| |
| private DiffCollectorNodeStateDiff( |
| BaseDiffCollector collector, Filter filter, String path, |
| Set<String> results) { |
| this.collector = collector; |
| this.filter = filter; |
| this.path = path; |
| this.results = results; |
| } |
| |
| @Override |
| public boolean childNodeAdded(String name, NodeState after) { |
| return childNodeChanged(name, EMPTY_NODE, after); |
| } |
| |
| @Override |
| public boolean childNodeChanged(String name, NodeState before, |
| NodeState after) { |
| if (NodeStateUtils.isHidden(name)) { |
| return true; |
| } |
| return testNodeState(after, name) |
| && after.compareAgainstBaseState( |
| before, |
| new DiffCollectorNodeStateDiff( |
| collector, filter, |
| concat(path, name), results)); |
| } |
| |
| private boolean testNodeState(NodeState nodeState, String currentPath) { |
| if (collector.match(nodeState, filter)) { |
| results.add(concat(path, currentPath)); |
| if (collector.isUnique()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| Set<String> getResults() { |
| return results; |
| } |
| } |
| |
| } |