| /* |
| * 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.streams.api.entity; |
| |
| import static java.util.Objects.requireNonNull; |
| |
| import java.util.UUID; |
| |
| import org.apache.rya.streams.api.exception.RyaStreamsException; |
| |
| import edu.umd.cs.findbugs.annotations.DefaultAnnotation; |
| import edu.umd.cs.findbugs.annotations.NonNull; |
| |
| /** |
| * An infinite stream of values that are the results of a query within Rya Streams. |
| * |
| * @param <V> - The query results' value type. |
| */ |
| @DefaultAnnotation(NonNull.class) |
| public abstract class QueryResultStream<V> implements AutoCloseable { |
| |
| private final UUID queryId; |
| |
| /** |
| * Constructs an instance of {@link QueryResultStream}. |
| * |
| * @param queryId - The query whose results this stream iterates over. (not null) |
| */ |
| public QueryResultStream(final UUID queryId) { |
| this.queryId = requireNonNull(queryId); |
| } |
| |
| |
| /** |
| * @return Identifies which query in Rya Streams this result stream is over. |
| */ |
| public UUID getQueryId() { |
| return queryId; |
| } |
| |
| /** |
| * Wait at most {@code timeoutMs} milliseconds for the next collection of results. |
| * |
| * @param timeoutMs - The number of milliseconds to at most wait for the next collection of results. (not null) |
| * @return The next collection of values that are the result of the query. Empty if there where no new results |
| * within the timeout period. |
| * @throws IllegalStateException If the stream has been closed. |
| * @throws RyaStreamsException Could not fetch the next set of results. |
| */ |
| public abstract Iterable<V> poll(long timeoutMs) throws IllegalStateException, RyaStreamsException; |
| } |