1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.hadoop.chukwa.datacollection.writer;
19
20 import java.util.List;
21 import org.apache.hadoop.chukwa.Chunk;
22 import org.apache.hadoop.conf.Configuration;
23 import org.apache.log4j.Logger;
24 import org.apache.hadoop.chukwa.util.ExceptionUtil;
25
26 /**
27 * Minimal writer; does nothing with data.
28 *
29 * Useful primarily as an end-of-pipeline stage, if stuff in the middle
30 * is accomplishing something useful.
31 *
32 */
33 public class NullWriter implements ChukwaWriter {
34 private static final Logger log = Logger.getLogger(NullWriter.class);
35
36 //in kb per sec
37 int maxDataRate = Integer.MAX_VALUE;
38 public static final String RATE_OPT_NAME = "nullWriter.dataRate";
39 @Override
40 public CommitStatus add(List<Chunk> chunks) throws WriterException {
41 try {
42 int dataBytes =0;
43 for(Chunk c: chunks)
44 dataBytes +=c.getData().length;
45 if(maxDataRate > 0)
46 Thread.sleep(dataBytes / maxDataRate);
47 } catch(Exception e) {
48 log.debug(ExceptionUtil.getStackTrace(e));
49 }
50 return COMMIT_OK;
51 }
52
53 @Override
54 public void close() throws WriterException {
55 }
56
57 @Override
58 public void init(Configuration c) throws WriterException {
59 maxDataRate = c.getInt(RATE_OPT_NAME, 0);
60 }
61
62 }