| /** |
| * Copyright (C) 2015 DataTorrent, Inc. |
| * |
| * Licensed 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 com.datatorrent.api; |
| |
| import java.lang.reflect.Array; |
| |
| /** |
| * Abstraction for the processing logic or consumption of a data tuple. |
| * Implemented by concrete data ports for their processing behavior or by streams. |
| * |
| * @param <T> |
| * @since 0.3.2 |
| */ |
| public interface Sink<T> |
| { |
| /** |
| * Constant |
| * <code>NO_SINKS</code> |
| * |
| * Use this constant if you need array of size 0 of sinks. Typically it's needed to confirm with |
| * the code logic that expects a non null array of sinks to be passed in where you would ideally |
| * pass null otherwise. |
| */ |
| @SuppressWarnings("unchecked") |
| public static final Sink<Object>[] NO_SINKS = (Sink<Object>[])Array.newInstance(Sink.class, 0); |
| /** |
| * Constant |
| * <code>BLACKHOLE</code> |
| * |
| * This sink discards anything that's put into it silently. Use this sink if you need a sink that |
| * discards everything with super low cost. |
| */ |
| public static final Sink<Object> BLACKHOLE = new Sink<Object>() |
| { |
| @Override |
| public void put(Object tuple) |
| { |
| } |
| |
| @Override |
| public int getCount(boolean reset) |
| { |
| return 0; |
| } |
| |
| }; |
| |
| /** |
| * Process the payload which can either be user defined object or Tuple. |
| * |
| * @param tuple payload to be processed by this sink. |
| */ |
| public void put(T tuple); |
| |
| /** |
| * Give the count of the tuples processed since the last reset. |
| * |
| * @param reset reset the count if true. |
| * @return the count of tuples processed since the last reset. |
| */ |
| public int getCount(boolean reset); |
| |
| } |