hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/util/hash/TestHash.java

/**
 * 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.hadoop.util.hash;

import static org.junit.Assert.*;
import org.apache.hadoop.conf.Configuration;
import org.junit.Test;

public class TestHash {
  static final String LINE = "34563@45kjkksdf/ljfdb9d8fbusd*89uggjsk<dfgjsdfh@sddc2q3esc";

  @Test
  public void testHash() {
    int iterations = 30;
    assertTrue("testHash jenkins error !!!",
        Hash.JENKINS_HASH == Hash.parseHashType("jenkins"));
    assertTrue("testHash murmur error !!!",
        Hash.MURMUR_HASH == Hash.parseHashType("murmur"));
    assertTrue("testHash undefined",
        Hash.INVALID_HASH == Hash.parseHashType("undefined"));

    Configuration cfg = new Configuration();
    cfg.set("hadoop.util.hash.type", "murmur");
    assertTrue("testHash", MurmurHash.getInstance() == Hash.getInstance(cfg));

    cfg = new Configuration();
    cfg.set("hadoop.util.hash.type", "jenkins");
    assertTrue("testHash jenkins configuration error !!!",
        JenkinsHash.getInstance() == Hash.getInstance(cfg));

    cfg = new Configuration();
    assertTrue("testHash undefine configuration error !!!",
        MurmurHash.getInstance() == Hash.getInstance(cfg));

    assertTrue("testHash error jenkin getInstance !!!",
        JenkinsHash.getInstance() == Hash.getInstance(Hash.JENKINS_HASH));
    assertTrue("testHash error murmur getInstance !!!",
        MurmurHash.getInstance() == Hash.getInstance(Hash.MURMUR_HASH));

    assertNull("testHash error invalid getInstance !!!",
        Hash.getInstance(Hash.INVALID_HASH));

    int murmurHash = Hash.getInstance(Hash.MURMUR_HASH).hash(LINE.getBytes());
    for (int i = 0; i < iterations; i++) {
      assertTrue("multiple evaluation murmur hash error !!!",
          murmurHash == Hash.getInstance(Hash.MURMUR_HASH)
              .hash(LINE.getBytes()));
    }

    murmurHash = Hash.getInstance(Hash.MURMUR_HASH).hash(LINE.getBytes(), 67);
    for (int i = 0; i < iterations; i++) {
      assertTrue(
          "multiple evaluation murmur hash error !!!",
          murmurHash == Hash.getInstance(Hash.MURMUR_HASH).hash(
              LINE.getBytes(), 67));
    }

    int jenkinsHash = Hash.getInstance(Hash.JENKINS_HASH).hash(LINE.getBytes());
    for (int i = 0; i < iterations; i++) {
      assertTrue(
          "multiple evaluation jenkins hash error !!!",
          jenkinsHash == Hash.getInstance(Hash.JENKINS_HASH).hash(
              LINE.getBytes()));
    }

    jenkinsHash = Hash.getInstance(Hash.JENKINS_HASH).hash(LINE.getBytes(), 67);
    for (int i = 0; i < iterations; i++) {
      assertTrue(
          "multiple evaluation jenkins hash error !!!",
          jenkinsHash == Hash.getInstance(Hash.JENKINS_HASH).hash(
              LINE.getBytes(), 67));
    }   
  } 
}