| /* |
| * 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.rya.api.function.aggregation; |
| |
| import java.util.Optional; |
| |
| import org.apache.rya.api.model.VisibilityBindingSet; |
| |
| import edu.umd.cs.findbugs.annotations.DefaultAnnotation; |
| import edu.umd.cs.findbugs.annotations.NonNull; |
| |
| /** |
| * Provides a mechanism for storing the updating {@link AggregationState} while using an {@link AggregationsEvaluator}. |
| */ |
| @DefaultAnnotation(NonNull.class) |
| public interface AggregationStateStore { |
| |
| /** |
| * Stores a state. If this value updates a previously stored state, then it will overwrite the old value |
| * with the new one. |
| * |
| * @param state - The state that will be stored. (not null) |
| */ |
| public void store(AggregationState state); |
| |
| /** |
| * Get the {@link AggregationState} that may be updatted using the provided binding set. |
| * |
| * @param bs - A binding set that defines which state to fetch. (not null) |
| * @return The {@link AggregationState} that is updated by the binding set, if one has been stored. |
| */ |
| public Optional<AggregationState> get(VisibilityBindingSet bs); |
| } |