1   /**
2    * Copyright 2011 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.monitoring;
21  
22  import static org.junit.Assert.*;
23  
24  import java.io.PrintWriter;
25  import java.io.StringWriter;
26  
27  import org.junit.Test;
28  
29  /**
30   * Test case for the MemoryBoundedLogMessageBuffer utility.
31   * Ensures that it uses no more memory than it's supposed to,
32   * and that it properly deals with multibyte encodings.
33   */
34  public class TestMemoryBoundedLogMessageBuffer {
35  
36    private static final long TEN_KB = 10 * 1024;
37    private static final String JP_TEXT = "こんにちは";
38    
39    @Test
40    public void testBuffer() {
41      MemoryBoundedLogMessageBuffer buf =
42        new MemoryBoundedLogMessageBuffer(TEN_KB);
43      
44      for (int i = 0; i < 1000; i++) {
45        buf.add("hello " + i);
46      }
47      assertTrue("Usage too big: " + buf.estimateHeapUsage(),
48          buf.estimateHeapUsage() < TEN_KB);
49      assertTrue("Too many retained: " + buf.getMessages().size(),
50          buf.getMessages().size() < 100);
51      StringWriter sw = new StringWriter();
52      buf.dumpTo(new PrintWriter(sw));
53      String dump = sw.toString();
54      assertFalse("The early log messages should be evicted",
55          dump.contains("hello 1\n"));
56      assertTrue("The late log messages should be retained",
57          dump.contains("hello 999\n"));
58    }
59    
60    @Test
61    public void testNonAsciiEncoding() {
62      MemoryBoundedLogMessageBuffer buf =
63        new MemoryBoundedLogMessageBuffer(TEN_KB);
64      
65      buf.add(JP_TEXT);
66      StringWriter sw = new StringWriter();
67      buf.dumpTo(new PrintWriter(sw));
68      String dump = sw.toString();
69      assertTrue(dump.contains(JP_TEXT));
70    }
71  }