Java tutorial
/** * 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.hama.bsp.message; import java.io.File; import java.math.BigInteger; import java.security.SecureRandom; import junit.framework.TestCase; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.Writable; import org.apache.hama.HamaConfiguration; import org.apache.hama.bsp.TaskAttemptID; import org.apache.hama.bsp.TaskID; import org.apache.hama.bsp.message.queue.SpillingQueue; public class TestSpillingQueue extends TestCase { /** * Test the spilling queue where the message class is specified. * * @throws Exception */ public void testTextSpillingQueue() throws Exception { String msg = "Testing the spillage of spilling buffer"; Text text = new Text(msg); TaskAttemptID id = new TaskAttemptID(new TaskID("123", 1, 2), 0); SpillingQueue<Text> queue = new SpillingQueue<Text>(); Configuration conf = new HamaConfiguration(); String fileName = System.getProperty("java.io.tmpdir") + File.separatorChar + new BigInteger(128, new SecureRandom()).toString(32); File file = new File(fileName); conf.set(SpillingQueue.SPILLBUFFER_FILENAME, fileName); conf.setClass(SpillingQueue.SPILLBUFFER_MSGCLASS, Text.class, Writable.class); queue.init(conf, id); queue.prepareWrite(); for (int i = 0; i < 1000; ++i) { queue.add(text); } assertEquals(queue.size(), 1000); queue.prepareRead(); Text t; while ((t = queue.poll()) != null) { assertTrue(msg.equals(t.toString())); } assertEquals(queue.size(), 0); assertTrue(queue.poll() == null); assertTrue(file.exists()); queue.close(); assertFalse(file.exists()); } /** * Test the spilling queue where the message class is not specified and the * queue uses ObjectWritable to store messages. * * @throws Exception */ public void testObjectWritableSpillingQueue() throws Exception { String msg = "Testing the spillage of spilling buffer"; Text text = new Text(msg); TaskAttemptID id = new TaskAttemptID(new TaskID("123", 1, 2), 0); SpillingQueue<Text> queue = new SpillingQueue<Text>(); Configuration conf = new HamaConfiguration(); String fileName = System.getProperty("java.io.tmpdir") + File.separatorChar + new BigInteger(128, new SecureRandom()).toString(32); File file = new File(fileName); conf.set(SpillingQueue.SPILLBUFFER_FILENAME, fileName); queue.init(conf, id); queue.prepareWrite(); for (int i = 0; i < 1000; ++i) { queue.add(text); } queue.prepareRead(); for (Text t : queue) { assertTrue(msg.equals(t.toString())); text.clear(); } assertTrue(queue.poll() == null); assertTrue(file.exists()); queue.close(); assertFalse(file.exists()); } }