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1   /**
2    *
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19  
20  package org.apache.hadoop.hbase.io;
21  
22  import junit.framework.TestCase;
23  
24  import org.apache.hadoop.hbase.SmallTests;
25  import org.apache.hadoop.hbase.util.Bytes;
26  import org.junit.experimental.categories.Category;
27  
28  import java.io.ByteArrayOutputStream;
29  import java.io.DataOutputStream;
30  import java.io.IOException;
31  
32  @Category(SmallTests.class)
33  public class TestImmutableBytesWritable extends TestCase {
34    public void testHash() throws Exception {
35      assertEquals(
36        new ImmutableBytesWritable(Bytes.toBytes("xxabc"), 2, 3).hashCode(),
37        new ImmutableBytesWritable(Bytes.toBytes("abc")).hashCode());
38      assertEquals(
39        new ImmutableBytesWritable(Bytes.toBytes("xxabcd"), 2, 3).hashCode(),
40        new ImmutableBytesWritable(Bytes.toBytes("abc")).hashCode());
41      assertNotSame(
42        new ImmutableBytesWritable(Bytes.toBytes("xxabc"), 2, 3).hashCode(),
43        new ImmutableBytesWritable(Bytes.toBytes("xxabc"), 2, 2).hashCode());
44    }
45  
46    public void testSpecificCompare() {
47      ImmutableBytesWritable ibw1 = new ImmutableBytesWritable(new byte[]{0x0f});
48      ImmutableBytesWritable ibw2 = new ImmutableBytesWritable(new byte[]{0x00, 0x00});
49      ImmutableBytesWritable.Comparator c = new ImmutableBytesWritable.Comparator();
50      assertFalse("ibw1 < ibw2", c.compare( ibw1, ibw2 ) < 0 );
51    }
52  
53    public void testComparison() throws Exception {
54      runTests("aa", "b", -1);
55      runTests("aa", "aa", 0);
56      runTests("aa", "ab", -1);
57      runTests("aa", "aaa", -1);
58      runTests("", "", 0);
59      runTests("", "a", -1);
60    }
61  
62    private void runTests(String aStr, String bStr, int signum)
63      throws Exception {
64      ImmutableBytesWritable a = new ImmutableBytesWritable(
65        Bytes.toBytes(aStr));
66      ImmutableBytesWritable b = new ImmutableBytesWritable(
67        Bytes.toBytes(bStr));
68  
69      doComparisonsOnObjects(a, b, signum);
70      doComparisonsOnRaw(a, b, signum);
71  
72      // Tests for when the offset is non-zero
73      a = new ImmutableBytesWritable(Bytes.toBytes("xxx" + aStr),
74                                     3, aStr.length());
75      b = new ImmutableBytesWritable(Bytes.toBytes("yy" + bStr),
76                                     2, bStr.length());
77      doComparisonsOnObjects(a, b, signum);
78      doComparisonsOnRaw(a, b, signum);
79  
80      // Tests for when offset is nonzero and length doesn't extend to end
81      a = new ImmutableBytesWritable(Bytes.toBytes("xxx" + aStr + "zzz"),
82                                     3, aStr.length());
83      b = new ImmutableBytesWritable(Bytes.toBytes("yy" + bStr + "aaa"),
84                                     2, bStr.length());
85      doComparisonsOnObjects(a, b, signum);
86      doComparisonsOnRaw(a, b, signum);
87    }
88  
89  
90    private int signum(int i) {
91      if (i > 0) return 1;
92      if (i == 0) return 0;
93      return -1;
94    }
95  
96    private void doComparisonsOnRaw(ImmutableBytesWritable a,
97                                    ImmutableBytesWritable b,
98                                    int expectedSignum)
99      throws IOException {
100     ImmutableBytesWritable.Comparator comparator =
101       new ImmutableBytesWritable.Comparator();
102 
103     ByteArrayOutputStream baosA = new ByteArrayOutputStream();
104     ByteArrayOutputStream baosB = new ByteArrayOutputStream();
105 
106     a.write(new DataOutputStream(baosA));
107     b.write(new DataOutputStream(baosB));
108 
109     assertEquals(
110       "Comparing " + a + " and " + b + " as raw",
111       signum(comparator.compare(baosA.toByteArray(), 0, baosA.size(),
112                                 baosB.toByteArray(), 0, baosB.size())),
113       expectedSignum);
114 
115     assertEquals(
116       "Comparing " + a + " and " + b + " as raw (inverse)",
117       -signum(comparator.compare(baosB.toByteArray(), 0, baosB.size(),
118                                  baosA.toByteArray(), 0, baosA.size())),
119       expectedSignum);
120   }
121 
122   private void doComparisonsOnObjects(ImmutableBytesWritable a,
123                                       ImmutableBytesWritable b,
124                                       int expectedSignum) {
125     ImmutableBytesWritable.Comparator comparator =
126       new ImmutableBytesWritable.Comparator();
127     assertEquals(
128       "Comparing " + a + " and " + b + " as objects",
129       signum(comparator.compare(a, b)), expectedSignum);
130     assertEquals(
131       "Comparing " + a + " and " + b + " as objects (inverse)",
132       -signum(comparator.compare(b, a)), expectedSignum);
133   }
134 
135 }
136