| /** |
| * 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.storm.streams; |
| |
| import org.apache.storm.tuple.Tuple; |
| |
| /** |
| * Provides reference counting of tuples. Used when operations that operate on a batch of tuples are involved (e.g. aggregation, join etc). |
| * The input tuples are acked once the result is emitted downstream. |
| */ |
| public class RefCountedTuple { |
| private final Tuple tuple; |
| private int count = 0; |
| private boolean acked; |
| |
| RefCountedTuple(Tuple tuple) { |
| this.tuple = tuple; |
| this.acked = false; |
| } |
| |
| public boolean shouldAck() { |
| return count == 0 && !acked; |
| } |
| |
| public void increment() { |
| ++count; |
| } |
| |
| public void decrement() { |
| --count; |
| } |
| |
| public Tuple tuple() { |
| return tuple; |
| } |
| |
| public void setAcked() { |
| acked = true; |
| } |
| |
| @Override |
| public String toString() { |
| return "RefCountedTuple{" |
| + "count=" + count |
| + ", tuple=" + tuple |
| + '}'; |
| } |
| } |