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.hadoop.fs; import static org.apache.hadoop.fs.FileContextTestHelper.createFile; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.concurrent.Callable; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.fs.FileSystem.Statistics; import org.apache.hadoop.test.GenericTestUtils; import org.junit.Assert; import org.junit.Test; import com.google.common.base.Supplier; import com.google.common.util.concurrent.Uninterruptibles; /** * <p> * Base class to test {@link FileContext} Statistics. * </p> */ public abstract class FCStatisticsBaseTest { private static final Log LOG = LogFactory.getLog(FCStatisticsBaseTest.class); static protected int blockSize = 512; static protected int numBlocks = 1; protected final FileContextTestHelper fileContextTestHelper = new FileContextTestHelper(); //fc should be set appropriately by the deriving test. protected static FileContext fc = null; @Test(timeout = 60000) public void testStatisticsOperations() throws Exception { final Statistics stats = new Statistics("file"); Assert.assertEquals(0L, stats.getBytesRead()); Assert.assertEquals(0L, stats.getBytesWritten()); Assert.assertEquals(0, stats.getWriteOps()); stats.incrementBytesWritten(1000); Assert.assertEquals(1000L, stats.getBytesWritten()); Assert.assertEquals(0, stats.getWriteOps()); stats.incrementWriteOps(123); Assert.assertEquals(123, stats.getWriteOps()); Thread thread = new Thread() { @Override public void run() { stats.incrementWriteOps(1); } }; thread.start(); Uninterruptibles.joinUninterruptibly(thread); Assert.assertEquals(124, stats.getWriteOps()); // Test copy constructor and reset function Statistics stats2 = new Statistics(stats); stats.reset(); Assert.assertEquals(0, stats.getWriteOps()); Assert.assertEquals(0L, stats.getBytesWritten()); Assert.assertEquals(0L, stats.getBytesRead()); Assert.assertEquals(124, stats2.getWriteOps()); Assert.assertEquals(1000L, stats2.getBytesWritten()); Assert.assertEquals(0L, stats2.getBytesRead()); } @Test public void testStatistics() throws IOException, URISyntaxException { URI fsUri = getFsUri(); Statistics stats = FileContext.getStatistics(fsUri); Assert.assertEquals(0, stats.getBytesRead()); Path filePath = fileContextTestHelper.getTestRootPath(fc, "file1"); createFile(fc, filePath, numBlocks, blockSize); Assert.assertEquals(0, stats.getBytesRead()); verifyWrittenBytes(stats); FSDataInputStream fstr = fc.open(filePath); byte[] buf = new byte[blockSize]; int bytesRead = fstr.read(buf, 0, blockSize); fstr.read(0, buf, 0, blockSize); Assert.assertEquals(blockSize, bytesRead); verifyReadBytes(stats); verifyWrittenBytes(stats); verifyReadBytes(FileContext.getStatistics(getFsUri())); Map<URI, Statistics> statsMap = FileContext.getAllStatistics(); URI exactUri = getSchemeAuthorityUri(); verifyWrittenBytes(statsMap.get(exactUri)); fc.delete(filePath, true); } @Test(timeout = 70000) public void testStatisticsThreadLocalDataCleanUp() throws Exception { final Statistics stats = new Statistics("test"); // create a small thread pool to test the statistics final int size = 2; ExecutorService es = Executors.newFixedThreadPool(size); List<Callable<Boolean>> tasks = new ArrayList<Callable<Boolean>>(size); for (int i = 0; i < size; i++) { tasks.add(new Callable<Boolean>() { public Boolean call() { // this populates the data set in statistics stats.incrementReadOps(1); return true; } }); } // run the threads es.invokeAll(tasks); // assert that the data size is exactly the number of threads final AtomicInteger allDataSize = new AtomicInteger(0); allDataSize.set(stats.getAllThreadLocalDataSize()); Assert.assertEquals(size, allDataSize.get()); Assert.assertEquals(size, stats.getReadOps()); // force the GC to collect the threads by shutting down the thread pool es.shutdownNow(); es.awaitTermination(1, TimeUnit.MINUTES); es = null; System.gc(); // force GC to garbage collect threads // wait for up to 60 seconds GenericTestUtils.waitFor(new Supplier<Boolean>() { @Override public Boolean get() { int size = stats.getAllThreadLocalDataSize(); allDataSize.set(size); if (size == 0) { return true; } LOG.warn( "not all references have been cleaned up; still " + allDataSize.get() + " references left"); LOG.warn("triggering another GC"); System.gc(); return false; } }, 500, 60 * 1000); Assert.assertEquals(0, allDataSize.get()); Assert.assertEquals(size, stats.getReadOps()); } /** * Bytes read may be different for different file systems. This method should * throw assertion error if bytes read are incorrect. * * @param stats */ protected abstract void verifyReadBytes(Statistics stats); /** * Bytes written may be different for different file systems. This method should * throw assertion error if bytes written are incorrect. * * @param stats */ protected abstract void verifyWrittenBytes(Statistics stats); /** * Returns the filesystem uri. Should be set * @return URI */ protected abstract URI getFsUri(); protected URI getSchemeAuthorityUri() { URI uri = getFsUri(); String SchemeAuthString = uri.getScheme() + "://"; if (uri.getAuthority() == null) { SchemeAuthString += "/"; } else { SchemeAuthString += uri.getAuthority(); } return URI.create(SchemeAuthString); } }