/**
 * 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.mapred;

import java.io.*;
import java.net.URI;

import junit.framework.TestCase;

import org.apache.hadoop.fs.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapred.JobContextImpl;
import org.apache.hadoop.mapred.TaskAttemptContextImpl;
import org.apache.hadoop.mapreduce.JobStatus;

public class TestFileOutputCommitter extends TestCase {
  private static Path outDir = new Path(
     System.getProperty("test.build.data", "/tmp"), "output");

  // A random task attempt id for testing.
  private static String attempt = "attempt_200707121733_0001_m_000000_0";
  private static TaskAttemptID taskID = TaskAttemptID.forName(attempt);
  private Text key1 = new Text("key1");
  private Text key2 = new Text("key2");
  private Text val1 = new Text("val1");
  private Text val2 = new Text("val2");
  
  @SuppressWarnings("unchecked")
  private void writeOutput(RecordWriter theRecordWriter, Reporter reporter)
      throws IOException {
    NullWritable nullWritable = NullWritable.get();

    try {
      theRecordWriter.write(key1, val1);
      theRecordWriter.write(null, nullWritable);
      theRecordWriter.write(null, val1);
      theRecordWriter.write(nullWritable, val2);
      theRecordWriter.write(key2, nullWritable);
      theRecordWriter.write(key1, null);
      theRecordWriter.write(null, null);
      theRecordWriter.write(key2, val2);
    } finally {
      theRecordWriter.close(reporter);
    }
  }
  
  private void setConfForFileOutputCommitter(JobConf job) {
    job.set(JobContext.TASK_ATTEMPT_ID, attempt);
    job.setOutputCommitter(FileOutputCommitter.class);
    FileOutputFormat.setOutputPath(job, outDir);
  }

  @SuppressWarnings("unchecked")
  public void testCommitter() throws Exception {
    JobConf job = new JobConf();
    setConfForFileOutputCommitter(job);
    JobContext jContext = new JobContextImpl(job, taskID.getJobID());
    TaskAttemptContext tContext = new TaskAttemptContextImpl(job, taskID);
    FileOutputCommitter committer = new FileOutputCommitter();
    FileOutputFormat.setWorkOutputPath(job, 
      committer.getTaskAttemptPath(tContext));

    committer.setupJob(jContext);
    committer.setupTask(tContext);
    String file = "test.txt";

    // A reporter that does nothing
    Reporter reporter = Reporter.NULL;
    // write output
    FileSystem localFs = FileSystem.getLocal(job);
    TextOutputFormat theOutputFormat = new TextOutputFormat();
    RecordWriter theRecordWriter =
      theOutputFormat.getRecordWriter(localFs, job, file, reporter);
    writeOutput(theRecordWriter, reporter);

    // do commit
    committer.commitTask(tContext);
    committer.commitJob(jContext);
    
    // validate output
    File expectedFile = new File(new Path(outDir, file).toString());
    StringBuffer expectedOutput = new StringBuffer();
    expectedOutput.append(key1).append('\t').append(val1).append("\n");
    expectedOutput.append(val1).append("\n");
    expectedOutput.append(val2).append("\n");
    expectedOutput.append(key2).append("\n");
    expectedOutput.append(key1).append("\n");
    expectedOutput.append(key2).append('\t').append(val2).append("\n");
    String output = UtilsForTests.slurp(expectedFile);
    assertEquals(output, expectedOutput.toString());

    FileUtil.fullyDelete(new File(outDir.toString()));
  }

  public void testAbort() throws IOException {
    JobConf job = new JobConf();
    setConfForFileOutputCommitter(job);
    JobContext jContext = new JobContextImpl(job, taskID.getJobID());
    TaskAttemptContext tContext = new TaskAttemptContextImpl(job, taskID);
    FileOutputCommitter committer = new FileOutputCommitter();
    FileOutputFormat.setWorkOutputPath(job, committer
        .getTaskAttemptPath(tContext));

    // do setup
    committer.setupJob(jContext);
    committer.setupTask(tContext);
    String file = "test.txt";

    // A reporter that does nothing
    Reporter reporter = Reporter.NULL;
    // write output
    FileSystem localFs = FileSystem.getLocal(job);
    TextOutputFormat theOutputFormat = new TextOutputFormat();
    RecordWriter theRecordWriter = theOutputFormat.getRecordWriter(localFs,
        job, file, reporter);
    writeOutput(theRecordWriter, reporter);

    // do abort
    committer.abortTask(tContext);
    File expectedFile = new File(new Path(committer
        .getTaskAttemptPath(tContext), file).toString());
    assertFalse("task temp dir still exists", expectedFile.exists());

    committer.abortJob(jContext, JobStatus.State.FAILED);
    expectedFile = new File(new Path(outDir, FileOutputCommitter.TEMP_DIR_NAME)
        .toString());
    assertFalse("job temp dir "+expectedFile+" still exists", expectedFile.exists());
    assertEquals("Output directory not empty", 0, new File(outDir.toString())
        .listFiles().length);
    FileUtil.fullyDelete(new File(outDir.toString()));
  }

  public static class FakeFileSystem extends RawLocalFileSystem {
    public FakeFileSystem() {
      super();
    }

    public URI getUri() {
      return URI.create("faildel:///");
    }

    @Override
    public boolean delete(Path p, boolean recursive) throws IOException {
      throw new IOException("fake delete failed");
    }
  }

  public void testFailAbort() throws IOException {
    JobConf job = new JobConf();
    job.set(FileSystem.FS_DEFAULT_NAME_KEY, "faildel:///");
    job.setClass("fs.faildel.impl", FakeFileSystem.class, FileSystem.class);
    setConfForFileOutputCommitter(job);
    JobContext jContext = new JobContextImpl(job, taskID.getJobID());
    TaskAttemptContext tContext = new TaskAttemptContextImpl(job, taskID);
    FileOutputCommitter committer = new FileOutputCommitter();
    FileOutputFormat.setWorkOutputPath(job, committer
        .getTaskAttemptPath(tContext));

    // do setup
    committer.setupJob(jContext);
    committer.setupTask(tContext);
    
    String file = "test.txt";
    File jobTmpDir = new File(committer.getJobAttemptPath(jContext).toUri().getPath());
    File taskTmpDir = new File(committer.getTaskAttemptPath(tContext).toUri().getPath());
    File expectedFile = new File(taskTmpDir, file);

    // A reporter that does nothing
    Reporter reporter = Reporter.NULL;
    // write output
    FileSystem localFs = new FakeFileSystem();
    TextOutputFormat theOutputFormat = new TextOutputFormat();
    RecordWriter theRecordWriter = theOutputFormat.getRecordWriter(localFs,
        job, expectedFile.getAbsolutePath(), reporter);
    writeOutput(theRecordWriter, reporter);

    // do abort
    Throwable th = null;
    try {
      committer.abortTask(tContext);
    } catch (IOException ie) {
      th = ie;
    }
    assertNotNull(th);
    assertTrue(th instanceof IOException);
    assertTrue(th.getMessage().contains("fake delete failed"));
    assertTrue(expectedFile + " does not exists", expectedFile.exists());

    th = null;
    try {
      committer.abortJob(jContext, JobStatus.State.FAILED);
    } catch (IOException ie) {
      th = ie;
    }
    assertNotNull(th);
    assertTrue(th instanceof IOException);
    assertTrue(th.getMessage().contains("fake delete failed"));
    assertTrue("job temp dir does not exists", jobTmpDir.exists());
  }
}