| /** |
| * 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.atlas.notification; |
| |
| /** |
| * Atlas notification consumer. This consumer blocks until a notification can be read. |
| * |
| * @param <T> the class type of notifications returned by this consumer |
| */ |
| public interface NotificationConsumer<T> { |
| /** |
| * Returns true when the consumer has more notifications. Blocks until a notification becomes available. |
| * |
| * @return true when the consumer has notifications to be read |
| */ |
| boolean hasNext(); |
| |
| /** |
| * Returns the next notification. |
| * |
| * @return the next notification |
| */ |
| T next(); |
| |
| /** |
| * Returns the next notification without advancing. |
| * |
| * @return the next notification |
| */ |
| T peek(); |
| |
| /** |
| * Commit the offset of messages that have been successfully processed. |
| * |
| * This API should be called when messages read with {@link #next()} have been successfully processed and |
| * the consumer is ready to handle the next message, which could happen even after a normal or an abnormal |
| * restart. |
| */ |
| void commit(); |
| |
| void close(); |
| } |