org.apache.hadoop.io
Class DataInputBuffer

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          java.io.DataInputStream
              org.apache.hadoop.io.DataInputBuffer

All Implemented Interfaces:

Closeable, DataInput

public class DataInputBuffer
extends DataInputStream

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

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

Typical usage is something like the following:

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

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

DataInputBuffer()
Constructs a new empty buffer.

Method Summary

byte[]	getData()
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.DataInputStream

read, read, readBoolean, readByte, readChar, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedShort, readUTF, readUTF, skipBytes

Methods inherited from class java.io.FilterInputStream

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

Methods inherited from class java.lang.Object

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

Constructor Detail

DataInputBuffer

public DataInputBuffer()

Constructs a new empty buffer.

Method Detail

reset

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

Resets the data that the buffer reads.

reset

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

Resets the data that the buffer reads.

getData

public byte[] getData()

getPosition

public int getPosition()

Returns the current position in the input.

getLength

public int getLength()

Returns the length of the input.