Example usage for org.apache.hadoop.mapreduce.lib.input LineRecordReader getCurrentKey

List of usage examples for org.apache.hadoop.mapreduce.lib.input LineRecordReader getCurrentKey

Introduction

In this page you can find the example usage for org.apache.hadoop.mapreduce.lib.input LineRecordReader getCurrentKey.

Prototype

@Override
    public LongWritable getCurrentKey() 

Source Link

Usage

From source file:example.TestLineRecordReader.java

License:Apache License

@Test
public void testUncompressedInputCustomDelimiterPosValue() throws Exception {
    Configuration conf = new Configuration();
    conf.setInt("io.file.buffer.size", 10);
    conf.setInt(org.apache.hadoop.mapreduce.lib.input.LineRecordReader.MAX_LINE_LENGTH, Integer.MAX_VALUE);
    String inputData = "abcdefghij++kl++mno";
    Path inputFile = createInputFile(conf, inputData);
    String delimiter = "++";
    byte[] recordDelimiterBytes = delimiter.getBytes(Charsets.UTF_8);
    int splitLength = 15;
    FileSplit split = new FileSplit(inputFile, 0, splitLength, (String[]) null);
    TaskAttemptContext context = new TaskAttemptContextImpl(conf, new TaskAttemptID());
    LineRecordReader reader = new LineRecordReader(recordDelimiterBytes);
    reader.initialize(split, context);// w  ww .j  a va2s. com
    // Get first record: "abcdefghij"
    assertTrue("Expected record got nothing", reader.nextKeyValue());
    LongWritable key = reader.getCurrentKey();
    Text value = reader.getCurrentValue();
    assertEquals("Wrong length for record value", 10, value.getLength());
    assertEquals("Wrong position after record read", 0, key.get());
    // Get second record: "kl"
    assertTrue("Expected record got nothing", reader.nextKeyValue());
    assertEquals("Wrong length for record value", 2, value.getLength());
    // Key should be 12 right after "abcdefghij++"
    assertEquals("Wrong position after record read", 12, key.get());
    // Get third record: "mno"
    assertTrue("Expected record got nothing", reader.nextKeyValue());
    assertEquals("Wrong length for record value", 3, value.getLength());
    // Key should be 16 right after "abcdefghij++kl++"
    assertEquals("Wrong position after record read", 16, key.get());
    assertFalse(reader.nextKeyValue());
    // Key should be 19 right after "abcdefghij++kl++mno"
    assertEquals("Wrong position after record read", 19, key.get());
    // after refresh should be empty
    key = reader.getCurrentKey();
    assertNull("Unexpected key returned", key);
    reader.close();
    split = new FileSplit(inputFile, splitLength, inputData.length() - splitLength, (String[]) null);
    reader = new LineRecordReader(recordDelimiterBytes);
    reader.initialize(split, context);
    // No record is in the second split because the second split dropped
    // the first record, which was already reported by the first split.
    assertFalse("Unexpected record returned", reader.nextKeyValue());
    key = reader.getCurrentKey();
    assertNull("Unexpected key returned", key);
    reader.close();

    // multi char delimiter with starting part of the delimiter in the data
    inputData = "abcd+efgh++ijk++mno";
    inputFile = createInputFile(conf, inputData);
    splitLength = 5;
    split = new FileSplit(inputFile, 0, splitLength, (String[]) null);
    reader = new LineRecordReader(recordDelimiterBytes);
    reader.initialize(split, context);
    // Get first record: "abcd+efgh"
    assertTrue("Expected record got nothing", reader.nextKeyValue());
    key = reader.getCurrentKey();
    value = reader.getCurrentValue();
    assertEquals("Wrong position after record read", 0, key.get());
    assertEquals("Wrong length for record value", 9, value.getLength());
    // should have jumped over the delimiter, no record
    assertFalse(reader.nextKeyValue());
    assertEquals("Wrong position after record read", 11, key.get());
    // after refresh should be empty
    key = reader.getCurrentKey();
    assertNull("Unexpected key returned", key);
    reader.close();
    // next split: check for duplicate or dropped records
    split = new FileSplit(inputFile, splitLength, inputData.length() - splitLength, (String[]) null);
    reader = new LineRecordReader(recordDelimiterBytes);
    reader.initialize(split, context);
    assertTrue("Expected record got nothing", reader.nextKeyValue());
    key = reader.getCurrentKey();
    value = reader.getCurrentValue();
    // Get second record: "ijk" first in this split
    assertEquals("Wrong position after record read", 11, key.get());
    assertEquals("Wrong length for record value", 3, value.getLength());
    // Get third record: "mno" second in this split
    assertTrue("Expected record got nothing", reader.nextKeyValue());
    assertEquals("Wrong position after record read", 16, key.get());
    assertEquals("Wrong length for record value", 3, value.getLength());
    // should be at the end of the input
    assertFalse(reader.nextKeyValue());
    assertEquals("Wrong position after record read", 19, key.get());
    reader.close();

    inputData = "abcd|efgh|+|ij|kl|+|mno|pqr";
    inputFile = createInputFile(conf, inputData);
    delimiter = "|+|";
    recordDelimiterBytes = delimiter.getBytes(Charsets.UTF_8);
    // walking over the buffer and split sizes checks for proper processing
    // of the ambiguous bytes of the delimiter
    for (int bufferSize = 1; bufferSize <= inputData.length(); bufferSize++) {
        for (int splitSize = 1; splitSize < inputData.length(); splitSize++) {
            // track where we are in the inputdata
            int keyPosition = 0;
            conf.setInt("io.file.buffer.size", bufferSize);
            split = new FileSplit(inputFile, 0, bufferSize, (String[]) null);
            reader = new LineRecordReader(recordDelimiterBytes);
            reader.initialize(split, context);
            // Get the first record: "abcd|efgh" always possible
            assertTrue("Expected record got nothing", reader.nextKeyValue());
            key = reader.getCurrentKey();
            value = reader.getCurrentValue();
            assertTrue("abcd|efgh".equals(value.toString()));
            // Position should be 0 right at the start
            assertEquals("Wrong position after record read", keyPosition, key.get());
            // Position should be 12 right after the first "|+|"
            keyPosition = 12;
            // get the next record: "ij|kl" if the split/buffer allows it
            if (reader.nextKeyValue()) {
                // check the record info: "ij|kl"
                assertTrue("ij|kl".equals(value.toString()));
                assertEquals("Wrong position after record read", keyPosition, key.get());
                // Position should be 20 after the second "|+|"
                keyPosition = 20;
            }
            // get the third record: "mno|pqr" if the split/buffer allows it
            if (reader.nextKeyValue()) {
                // check the record info: "mno|pqr"
                assertTrue("mno|pqr".equals(value.toString()));
                assertEquals("Wrong position after record read", keyPosition, key.get());
                // Position should be the end of the input
                keyPosition = inputData.length();
            }
            assertFalse("Unexpected record returned", reader.nextKeyValue());
            // no more records can be read we should be at the last position
            assertEquals("Wrong position after record read", keyPosition, key.get());
            // after refresh should be empty
            key = reader.getCurrentKey();
            assertNull("Unexpected key returned", key);
            reader.close();
        }
    }
}

From source file:example.TestLineRecordReader.java

License:Apache License

@Test
public void testUncompressedInputDefaultDelimiterPosValue() throws Exception {
    Configuration conf = new Configuration();
    String inputData = "1234567890\r\n12\r\n345";
    Path inputFile = createInputFile(conf, inputData);
    conf.setInt("io.file.buffer.size", 10);
    conf.setInt(org.apache.hadoop.mapreduce.lib.input.LineRecordReader.MAX_LINE_LENGTH, Integer.MAX_VALUE);
    FileSplit split = new FileSplit(inputFile, 0, 15, (String[]) null);
    TaskAttemptContext context = new TaskAttemptContextImpl(conf, new TaskAttemptID());
    LineRecordReader reader = new LineRecordReader(null);
    reader.initialize(split, context);//  w  w w .  ja v a2  s.  co m
    LongWritable key;
    Text value;
    reader.nextKeyValue();
    key = reader.getCurrentKey();
    value = reader.getCurrentValue();
    // Get first record:"1234567890"
    assertEquals(10, value.getLength());
    assertEquals(0, key.get());
    reader.nextKeyValue();
    // Get second record:"12"
    assertEquals(2, value.getLength());
    // Key should be 12 right after "1234567890\r\n"
    assertEquals(12, key.get());
    assertFalse(reader.nextKeyValue());
    // Key should be 16 right after "1234567890\r\n12\r\n"
    assertEquals(16, key.get());

    split = new FileSplit(inputFile, 15, 4, (String[]) null);
    reader = new LineRecordReader(null);
    reader.initialize(split, context);
    // The second split dropped the first record "\n"
    reader.nextKeyValue();
    key = reader.getCurrentKey();
    value = reader.getCurrentValue();
    // Get third record:"345"
    assertEquals(3, value.getLength());
    // Key should be 16 right after "1234567890\r\n12\r\n"
    assertEquals(16, key.get());
    assertFalse(reader.nextKeyValue());
    // Key should be 19 right after "1234567890\r\n12\r\n345"
    assertEquals(19, key.get());

    inputData = "123456789\r\r\n";
    inputFile = createInputFile(conf, inputData);
    split = new FileSplit(inputFile, 0, 12, (String[]) null);
    reader = new LineRecordReader(null);
    reader.initialize(split, context);
    reader.nextKeyValue();
    key = reader.getCurrentKey();
    value = reader.getCurrentValue();
    // Get first record:"123456789"
    assertEquals(9, value.getLength());
    assertEquals(0, key.get());
    reader.nextKeyValue();
    // Get second record:""
    assertEquals(0, value.getLength());
    // Key should be 10 right after "123456789\r"
    assertEquals(10, key.get());
    assertFalse(reader.nextKeyValue());
    // Key should be 12 right after "123456789\r\r\n"
    assertEquals(12, key.get());
}