/**
 * 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.mapreduce.lib.input;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.io.IOException;
import java.net.URL;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl;
import org.junit.Test;

public class TestLineRecordReader {

  private void testSplitRecords(String testFileName, long firstSplitLength)
      throws IOException {
    URL testFileUrl = getClass().getClassLoader().getResource(testFileName);
    assertNotNull("Cannot find " + testFileName, testFileUrl);
    File testFile = new File(testFileUrl.getFile());
    long testFileSize = testFile.length();
    Path testFilePath = new Path(testFile.getAbsolutePath());
    Configuration conf = new Configuration();
    conf.setInt(org.apache.hadoop.mapreduce.lib.input.
        LineRecordReader.MAX_LINE_LENGTH, Integer.MAX_VALUE);
    assertTrue("unexpected test data at " + testFile,
        testFileSize > firstSplitLength);

    TaskAttemptContext context = new TaskAttemptContextImpl(conf, new TaskAttemptID());

    // read the data without splitting to count the records
    FileSplit split = new FileSplit(testFilePath, 0, testFileSize,
        (String[])null);
    LineRecordReader reader = new LineRecordReader();
    reader.initialize(split, context);
    int numRecordsNoSplits = 0;
    while (reader.nextKeyValue()) {
      ++numRecordsNoSplits;
    }
    reader.close();

    // count the records in the first split
    split = new FileSplit(testFilePath, 0, firstSplitLength, (String[])null);
    reader = new LineRecordReader();
    reader.initialize(split, context);
    int numRecordsFirstSplit = 0;
    while (reader.nextKeyValue()) {
      ++numRecordsFirstSplit;
    }
    reader.close();

    // count the records in the second split
    split = new FileSplit(testFilePath, firstSplitLength,
        testFileSize - firstSplitLength, (String[])null);
    reader = new LineRecordReader();
    reader.initialize(split, context);
    int numRecordsRemainingSplits = 0;
    while (reader.nextKeyValue()) {
      ++numRecordsRemainingSplits;
    }
    reader.close();

    assertEquals("Unexpected number of records in bzip2 compressed split",
        numRecordsNoSplits, numRecordsFirstSplit + numRecordsRemainingSplits);
  }

  @Test
  public void testBzip2SplitEndsAtCR() throws IOException {
    // the test data contains a carriage-return at the end of the first
    // split which ends at compressed offset 136498 and the next
    // character is not a linefeed
    testSplitRecords("blockEndingInCR.txt.bz2", 136498);
  }

  @Test
  public void testBzip2SplitEndsAtCRThenLF() throws IOException {
    // the test data contains a carriage-return at the end of the first
    // split which ends at compressed offset 136498 and the next
    // character is a linefeed
    testSplitRecords("blockEndingInCRThenLF.txt.bz2", 136498);
  }
}