| /* |
| * 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.samza.container.grouper.stream; |
| |
| import org.apache.samza.system.SystemStreamPartition; |
| |
| /** |
| * Input streams of a samza job can be either expanded or contracted by the user. |
| * This abstraction determines the previous {@link SystemStreamPartition} for a {@link SystemStreamPartition} |
| * of a input stream after the stream expansion or contraction. |
| */ |
| public interface SystemStreamPartitionMapper { |
| |
| /** |
| * Determines the previous {@link SystemStreamPartition} for a {@link SystemStreamPartition} |
| * of a input stream after the stream expansion or contraction. |
| * @param currentSystemStreamPartition denotes the current partition after the stream partition count change. |
| * @param previousPartitionCount the partition count of the stream before the stream partition count change. |
| * @param currentPartitionCount the partition count of the stream after the stream partition count change. |
| * @return the mapped {@link SystemStreamPartition}. |
| */ |
| SystemStreamPartition getPreviousSSP(SystemStreamPartition currentSystemStreamPartition, |
| int previousPartitionCount, int currentPartitionCount); |
| } |