| /** |
| * 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.hdfs.util; |
| |
| import static org.junit.Assert.*; |
| |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| |
| import org.apache.hadoop.hdfs.DFSTestUtil; |
| import org.aspectj.util.FileUtil; |
| import org.junit.Before; |
| import org.junit.Test; |
| |
| import com.google.common.base.Joiner; |
| |
| public class TestAtomicFileOutputStream { |
| |
| private static final String TEST_STRING = "hello world"; |
| private static final String TEST_STRING_2 = "goodbye world"; |
| |
| private static File BASE_DIR = new File( |
| System.getProperty("test.build.data", "build/test/data")); |
| private static File TEST_DIR = new File(BASE_DIR, |
| TestAtomicFileOutputStream.class.getName()); |
| |
| private static File DST_FILE = new File(TEST_DIR, "test.txt"); |
| |
| @Before |
| public void cleanupTestDir() throws IOException { |
| assertTrue(TEST_DIR.exists() || TEST_DIR.mkdirs()); |
| FileUtil.deleteContents(TEST_DIR); |
| } |
| |
| /** |
| * Test case where there is no existing file |
| */ |
| @Test |
| public void testWriteNewFile() throws IOException { |
| OutputStream fos = new AtomicFileOutputStream(DST_FILE); |
| assertFalse(DST_FILE.exists()); |
| fos.write(TEST_STRING.getBytes()); |
| fos.flush(); |
| assertFalse(DST_FILE.exists()); |
| fos.close(); |
| assertTrue(DST_FILE.exists()); |
| |
| String readBackData = DFSTestUtil.readFile(DST_FILE); |
| assertEquals(TEST_STRING, readBackData); |
| } |
| |
| /** |
| * Test case where there is no existing file |
| */ |
| @Test |
| public void testOverwriteFile() throws IOException { |
| assertTrue("Creating empty dst file", DST_FILE.createNewFile()); |
| |
| OutputStream fos = new AtomicFileOutputStream(DST_FILE); |
| |
| assertTrue("Empty file still exists", DST_FILE.exists()); |
| fos.write(TEST_STRING.getBytes()); |
| fos.flush(); |
| |
| // Original contents still in place |
| assertEquals("", DFSTestUtil.readFile(DST_FILE)); |
| |
| fos.close(); |
| |
| // New contents replace original file |
| String readBackData = DFSTestUtil.readFile(DST_FILE); |
| assertEquals(TEST_STRING, readBackData); |
| } |
| |
| /** |
| * Test case where the flush() fails at close time - make sure |
| * that we clean up after ourselves and don't touch any |
| * existing file at the destination |
| */ |
| @Test |
| public void testFailToFlush() throws IOException { |
| // Create a file at destination |
| FileOutputStream fos = new FileOutputStream(DST_FILE); |
| fos.write(TEST_STRING_2.getBytes()); |
| fos.close(); |
| |
| OutputStream failingStream = createFailingStream(); |
| failingStream.write(TEST_STRING.getBytes()); |
| try { |
| failingStream.close(); |
| fail("Close didn't throw exception"); |
| } catch (IOException ioe) { |
| // expected |
| } |
| |
| // Should not have touched original file |
| assertEquals(TEST_STRING_2, DFSTestUtil.readFile(DST_FILE)); |
| |
| assertEquals("Temporary file should have been cleaned up", |
| DST_FILE.getName(), Joiner.on(",").join(TEST_DIR.list())); |
| } |
| |
| /** |
| * Create a stream that fails to flush at close time |
| */ |
| private OutputStream createFailingStream() throws FileNotFoundException { |
| return new AtomicFileOutputStream(DST_FILE) { |
| @Override |
| public void flush() throws IOException { |
| throw new IOException("injected failure"); |
| } |
| }; |
| } |
| } |