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.producer;
018
019import java.util.Iterator;
020
021import org.nuxeo.lib.stream.pattern.Message;
022
023/**
024 * A ProducerIterator returns {@link Message}. It also has the logic to return a partition index, that will be used to
025 * run concurrent consumers.
026 *
027 * @since 9.1
028 */
029public interface ProducerIterator<M extends Message> extends Iterator<M>, AutoCloseable {
030
031    /**
032     * The remove method is not needed.
033     */
034    @Override
035    default void remove() {
036        throw new UnsupportedOperationException();
037    }
038
039    /**
040     * Returns a partition associated with the {@link Message}. The value returned must be between 0 and lower than
041     * partitions.
042     *
043     * @param message the message to shard
044     * @param partitions the number of partitions
045     */
046    int getPartition(M message, int partitions);
047
048}