| /** |
| * 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.kafka.streams.kstream.internals; |
| |
| import org.apache.kafka.common.utils.Utils; |
| import org.apache.kafka.streams.kstream.Windowed; |
| import org.apache.kafka.streams.processor.StreamPartitioner; |
| |
| public class WindowedStreamPartitioner<K, V> implements StreamPartitioner<Windowed<K>, V> { |
| |
| private final WindowedSerializer<K> serializer; |
| |
| public WindowedStreamPartitioner(WindowedSerializer<K> serializer) { |
| this.serializer = serializer; |
| } |
| |
| /** |
| * WindowedStreamPartitioner determines the partition number for a record with the given windowed key and value |
| * and the current number of partitions. The partition number id determined by the original key of the windowed key |
| * using the same logic as DefaultPartitioner so that the topic is partitioned by the original key. |
| * |
| * @param windowedKey the key of the record |
| * @param value the value of the record |
| * @param numPartitions the total number of partitions |
| * @return an integer between 0 and {@code numPartitions-1}, or {@code null} if the default partitioning logic should be used |
| */ |
| public Integer partition(Windowed<K> windowedKey, V value, int numPartitions) { |
| byte[] keyBytes = serializer.serializeBaseKey(null, windowedKey); |
| |
| // hash the keyBytes to choose a partition |
| return toPositive(Utils.murmur2(keyBytes)) % numPartitions; |
| } |
| |
| private static int toPositive(int number) { |
| return number & 0x7fffffff; |
| } |
| |
| } |