org.apache.hawq.pxf.plugins.hdfs

Class ChunkReader

java.lang.Object

org.apache.hawq.pxf.plugins.hdfs.ChunkReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class ChunkReader
extends java.lang.Object
implements java.io.Closeable

A class that provides a line reader from an input stream. Lines are terminated by '\n' (LF) EOF also terminates an otherwise unterminated line.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_BUFFER_SIZE

Constructor Summary

Constructors

Constructor and Description
ChunkReader(java.io.InputStream in) Constructs a ChunkReader instance

Method Summary

Modifier and Type	Method and Description
void	close() Closes the underlying stream.
int	readChunk(org.apache.hadoop.io.Writable str, int maxBytesToConsume) Reads data in chunks of DEFAULT_CHUNK_SIZE, until we reach maxBytesToConsume.
int	readLine(org.apache.hadoop.io.Writable str, int maxBytesToConsume) Reads a line terminated by LF.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_BUFFER_SIZE

public static final int DEFAULT_BUFFER_SIZE

See Also:

Constant Field Values

Constructor Detail

ChunkReader

public ChunkReader(java.io.InputStream in)

Constructs a ChunkReader instance

Parameters:

in - input stream

Method Detail

close

public void close()
           throws java.io.IOException

Closes the underlying stream.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException

readChunk

public int readChunk(org.apache.hadoop.io.Writable str,
                     int maxBytesToConsume)
              throws java.io.IOException

Reads data in chunks of DEFAULT_CHUNK_SIZE, until we reach maxBytesToConsume.

Parameters:

str - - output parameter, will contain the read chunk byte array

maxBytesToConsume - - requested chunk size

Returns:

actual chunk size

Throws:

java.io.IOException - if the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.

readLine

public int readLine(org.apache.hadoop.io.Writable str,
                    int maxBytesToConsume)
             throws java.io.IOException

Reads a line terminated by LF.

Parameters:

str - - output parameter, will contain the read record

maxBytesToConsume - - the line mustn't exceed this value

Returns:

length of the line read

Throws:

java.io.IOException - if the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.