org.apache.hadoop.mapred
Class LineRecordReader

java.lang.Object
  org.apache.hadoop.mapred.LineRecordReader

All Implemented Interfaces:

RecordReader

Direct Known Subclasses:

KeyValueLineRecordReader

public class LineRecordReader
extends Object
implements RecordReader

Treats keys as offset in file and value as line.

Author:

sanjaydahiya

Constructor Summary

LineRecordReader(Configuration job, FileSplit split)

LineRecordReader(InputStream in, long offset, long endOffset)

Method Summary

void	close() Close this to future operations.
WritableComparable	createKey() Create an object of the appropriate type to be used as a key.
Writable	createValue() Create an object of the appropriate type to be used as the value.
long	getPos() Returns the current position in the input.
float	getProgress() Get the progress within the split
boolean	next(Writable key, Writable value) Read a line.
protected long	readLine()
static long	readLine(InputStream in, OutputStream out)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LineRecordReader

public LineRecordReader(Configuration job,
                        FileSplit split)
                 throws IOException

Throws:

IOException

LineRecordReader

public LineRecordReader(InputStream in,
                        long offset,
                        long endOffset)
                 throws IOException

Throws:

IOException

Method Detail

createKey

public WritableComparable createKey()

Description copied from interface: RecordReader

Create an object of the appropriate type to be used as a key.

Specified by:

createKey in interface RecordReader

Returns:

a new key object

createValue

public Writable createValue()

Description copied from interface: RecordReader

Create an object of the appropriate type to be used as the value.

Specified by:

createValue in interface RecordReader

Returns:

a new value object

next

public boolean next(Writable key,
                    Writable value)
             throws IOException

Read a line.

Specified by:

next in interface RecordReader

Parameters:

key - the key to read data into

value - the value to read data into

Returns:

true iff a key/value was read, false if at EOF

Throws:

IOException

See Also:

Writable.readFields(DataInput)

readLine

protected long readLine()
                 throws IOException

Throws:

IOException

readLine

public static long readLine(InputStream in,
                            OutputStream out)
                     throws IOException

Throws:

IOException

getProgress

public float getProgress()

Get the progress within the split

Specified by:

getProgress in interface RecordReader

Returns:

progress from 0.0 to 1.0

getPos

public long getPos()
            throws IOException

Description copied from interface: RecordReader

Returns the current position in the input.

Specified by:

getPos in interface RecordReader

Throws:

IOException

close

public void close()
           throws IOException

Description copied from interface: RecordReader

Close this to future operations.

Specified by:

close in interface RecordReader

Throws:

IOException