| /* |
| * 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.query; |
| |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.List; |
| |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| import org.jetbrains.annotations.NotNull; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Lists; |
| |
| /** |
| * This {@code QueryIndexProvider} aggregates a list of query index providers |
| * into a single query index provider. |
| */ |
| public class CompositeQueryIndexProvider implements QueryIndexProvider { |
| |
| private final List<QueryIndexProvider> providers; |
| |
| private CompositeQueryIndexProvider(List<QueryIndexProvider> providers) { |
| this.providers = providers; |
| } |
| |
| public CompositeQueryIndexProvider(QueryIndexProvider... providers) { |
| this(Arrays.asList(providers)); |
| } |
| |
| @NotNull |
| public static QueryIndexProvider compose( |
| @NotNull Collection<QueryIndexProvider> providers) { |
| if (providers.isEmpty()) { |
| return new QueryIndexProvider() { |
| @Override |
| public List<QueryIndex> getQueryIndexes(NodeState nodeState) { |
| return ImmutableList.of(); |
| } |
| }; |
| } else if (providers.size() == 1) { |
| return providers.iterator().next(); |
| } else { |
| return new CompositeQueryIndexProvider( |
| ImmutableList.copyOf(providers)); |
| } |
| } |
| |
| @Override @NotNull |
| public List<? extends QueryIndex> getQueryIndexes(NodeState nodeState) { |
| List<QueryIndex> indexes = Lists.newArrayList(); |
| for (QueryIndexProvider provider : providers) { |
| indexes.addAll(provider.getQueryIndexes(nodeState)); |
| } |
| return indexes; |
| } |
| |
| @Override |
| public String toString() { |
| return getClass().getName() + ": " + providers.toString(); |
| } |
| |
| } |