com.bigdata.io

Class ShortPacker

java.lang.Object

com.bigdata.io.ShortPacker

public class ShortPacker
extends Object

Packing utility for non-negative short values.

Version:

$Id$

Author:

Bryan Thompson

Constructor Summary

Constructors

Constructor and Description
ShortPacker()

Method Summary

Methods

Modifier and Type	Method and Description
static int	getNBytes(byte firstByte) Returns the #of bytes into which a short value was packed based on the first byte.
static int	packShort(DataOutput os, short v) Packs a non-negative short value into one or two bytes and writes them on os .
static short	unpackShort(DataInput is) Unpack a non-negative short value from the input stream.
static short	unpackShort(InputStream is) Unpack a non-negative short value from the input stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

ShortPacker

public ShortPacker()

Method Detail

packShort

public static int packShort(DataOutput os,
            short v)
                     throws IOException

Packs a non-negative short value into one or two bytes and writes them on os . A short in [0:127] is packed into one byte. Larger values are packed into two bytes. The high bit of the first byte is set if the value was packed into two bytes. If the bit is set, clear the high bit, read the next byte, and interpret the two bytes as a short value. Otherwise interpret the byte as a short value.

Returns:

The #of bytes into which the value was packed.

Throws:

IOException

unpackShort

public static short unpackShort(DataInput is)
                         throws IOException

Unpack a non-negative short value from the input stream.

Parameters:

is - The input stream.

Returns:

The short value.

Throws:

IOException

unpackShort

public static short unpackShort(InputStream is)
                         throws IOException

Unpack a non-negative short value from the input stream.

Parameters:

is - The input stream.

Returns:

The short value.

Throws:

IOException

getNBytes

public static int getNBytes(byte firstByte)

Returns the #of bytes into which a short value was packed based on the first byte.

Parameters:

firstByte - The first byte.

Returns:

The #of bytes (either one (1) or two (2)).