| /* |
| * 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.ignite.cdc; |
| |
| import java.util.Iterator; |
| import org.apache.ignite.IgniteLogger; |
| import org.apache.ignite.cache.CacheEntryVersion; |
| import org.apache.ignite.internal.cdc.CdcMain; |
| import org.apache.ignite.lang.IgniteExperimental; |
| import org.apache.ignite.resources.LoggerResource; |
| |
| /** |
| * Consumer of WAL data change events. |
| * This consumer will receive data change events during {@link CdcMain} application invocation. |
| * The lifecycle of the consumer is the following: |
| * <ul> |
| * <li>Start of the consumer {@link #start()}.</li> |
| * <li>Notification of the consumer by the {@link #onEvents(Iterator)} call.</li> |
| * <li>Stop of the consumer {@link #stop()}.</li> |
| * </ul> |
| * |
| * In case consumer implementation wants to user {@link IgniteLogger}, please, use, {@link LoggerResource} annotation: |
| * <pre> |
| * public class ChangeDataCaptureConsumer implements ChangeDataCaptureConsumer { |
| * @LoggerResource |
| * private IgniteLogger log; |
| * |
| * ... |
| * } |
| * </pre> |
| * |
| * Note, consumption of the {@link CdcEvent} will be started from the last saved offset. |
| * The offset of consumptions is saved on the disk every time {@link #onEvents(Iterator)} returns {@code true}. |
| * |
| * @see CdcMain |
| * @see CdcEvent |
| * @see CacheEntryVersion |
| */ |
| @IgniteExperimental |
| public interface CdcConsumer { |
| /** |
| * Starts the consumer. |
| */ |
| public void start(); |
| |
| /** |
| * Handles entry changes events. |
| * If this method return {@code true} then current offset will be stored |
| * and ongoing notifications after CDC application fail/restart will be started from it. |
| * |
| * @param events Entry change events. |
| * @return {@code True} if current offset should be saved on the disk |
| * to continue from it in case any failures or restart. |
| */ |
| public boolean onEvents(Iterator<CdcEvent> events); |
| |
| /** |
| * Stops the consumer. |
| * This methods can be invoked only after {@link #start()}. |
| */ |
| public void stop(); |
| } |