001/*
002 * (C) Copyright 2016 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 */
017package org.nuxeo.lib.stream.pattern.consumer;
018
019import org.nuxeo.lib.stream.pattern.Message;
020
021/**
022 * A consumer consumes {@link Message} by batch.
023 *
024 * @since 9.1
025 */
026public interface Consumer<M extends Message> extends AutoCloseable {
027
028    /**
029     * Begin a batch of messages.
030     */
031    void begin();
032
033    /**
034     * Consume a message.
035     */
036    void accept(M message);
037
038    /**
039     * End of the batch message.
040     */
041    void commit();
042
043    /**
044     * Called when there is an exception during {@link #accept(Message)} or {@link #commit()}.
045     */
046    void rollback();
047
048}