mapreduce/src/contrib/streaming/src/test/org/apache/hadoop/streaming/TestDumpTypedBytes.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.streaming;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.OutputStreamWriter;
import java.io.PrintStream;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.streaming.DumpTypedBytes;
import org.apache.hadoop.typedbytes.TypedBytesInput;

import org.junit.Test;
import static org.junit.Assert.*;

public class TestDumpTypedBytes {

  @Test
  public void testDumping() throws Exception {
    Configuration conf = new Configuration();
    MiniDFSCluster cluster = new MiniDFSCluster(conf, 2, true, null);
    FileSystem fs = cluster.getFileSystem();
    PrintStream psBackup = System.out;
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    PrintStream psOut = new PrintStream(out);
    System.setOut(psOut);
    DumpTypedBytes dumptb = new DumpTypedBytes(conf);

    try {
      Path root = new Path("/typedbytestest");
      assertTrue(fs.mkdirs(root));
      assertTrue(fs.exists(root));
      OutputStreamWriter writer = new OutputStreamWriter(fs.create(new Path(
        root, "test.txt")));
      try {
        for (int i = 0; i < 100; i++) {
          writer.write("" + (10 * i) + "\n");
        }
      } finally {
        writer.close();
      }

      String[] args = new String[1];
      args[0] = "/typedbytestest";
      int ret = dumptb.run(args);
      assertEquals("Return value != 0.", 0, ret);

      ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
      TypedBytesInput tbinput = new TypedBytesInput(new DataInputStream(in));
      int counter = 0;
      Object key = tbinput.read();
      while (key != null) {
        assertEquals(Long.class, key.getClass()); // offset
        Object value = tbinput.read();
        assertEquals(String.class, value.getClass());
        assertTrue("Invalid output.",
          Integer.parseInt(value.toString()) % 10 == 0);
        counter++;
        key = tbinput.read();
      }
      assertEquals("Wrong number of outputs.", 100, counter);
    } finally {
      try {
        fs.close();
      } catch (Exception e) {
      }
      System.setOut(psBackup);
      cluster.shutdown();
    }
  }

}