Package org.apache.hadoop.io

Class InputBuffer

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.hadoop.io.InputBuffer

All Implemented Interfaces:

Closeable, AutoCloseable

@LimitedPrivate({"HDFS","MapReduce"})
@Unstable
public class InputBuffer
extends FilterInputStream

A reusable InputStream implementation that reads from an in-memory buffer.

This saves memory over creating a new InputStream and ByteArrayInputStream each time data is read.

Typical usage is something like the following:

 InputBuffer buffer = new InputBuffer();
 while (... loop condition ...) {
   byte[] data = ... get data ...;
   int dataLength = ... get data length ...;
   buffer.reset(data, dataLength);
   ... read buffer using InputStream methods ...
 }
 

See Also:

• DataInputBuffer
• DataOutput

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
InputBuffer()	Constructs a new empty buffer.

Method Summary

Modifier and Type	Method	Description
int	getLength()	Returns the length of the input.
int	getPosition()	Returns the current position in the input.
void	reset(byte[] input, int length)	Resets the data that the buffer reads.
void	reset(byte[] input, int start, int length)	Resets the data that the buffer reads.

Methods inherited from class java.io.FilterInputStream

available, close, mark, markSupported, read, read, read, reset, skip

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Constructor Details

InputBuffer

public InputBuffer()

Constructs a new empty buffer.

Method Details

reset

public void reset(byte[] input,
 int length)

Resets the data that the buffer reads.

Parameters:

input - input.

length - length.

reset

public void reset(byte[] input,
 int start,
 int length)

Resets the data that the buffer reads.

Parameters:

input - input.

start - start.

length - length.

getPosition

public int getPosition()

Returns the current position in the input.

Returns:

the current position in the input.

getLength

public int getLength()

Returns the length of the input.

Returns:

length of the input.