org.apache.parquet.column.values.bitpacking

Class BytePacker

java.lang.Object

org.apache.parquet.column.values.bitpacking.BytePacker

public abstract class BytePacker
extends Object

Packs and unpacks into bytes packing unpacking treats: - n values at a time (with n % 8 == 0) - bitWidth * (n/8) bytes at a time.

Author:

Julien Le Dem

Method Summary

Methods

Modifier and Type	Method and Description
int	getBitWidth()
abstract void	pack32Values(int[] input, int inPos, byte[] output, int outPos) pack 32 values from input at inPos into bitWidth * 4 bytes in output at outPos.
abstract void	pack8Values(int[] input, int inPos, byte[] output, int outPos) pack 8 values from input at inPos into bitWidth bytes in output at outPos.
abstract void	unpack32Values(byte[] input, int inPos, int[] output, int outPos) unpack bitWidth * 4 bytes from input at inPos into 32 values in output at outPos.
abstract void	unpack8Values(byte[] input, int inPos, int[] output, int outPos) unpack bitWidth bytes from input at inPos into 8 values in output at outPos.

Methods inherited from class java.lang.Object

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

Method Detail

getBitWidth

public final int getBitWidth()

Returns:

the width in bits used for encoding, also how many bytes are packed/unpacked at a time by pack8Values/unpack8Values

pack8Values

public abstract void pack8Values(int[] input,
               int inPos,
               byte[] output,
               int outPos)

pack 8 values from input at inPos into bitWidth bytes in output at outPos. nextPosition: inPos += 8; outPos += getBitWidth()

Parameters:

input - the input values

inPos - where to read from in input

output - the output bytes

outPos - where to write to in output

pack32Values

public abstract void pack32Values(int[] input,
                int inPos,
                byte[] output,
                int outPos)

pack 32 values from input at inPos into bitWidth * 4 bytes in output at outPos. nextPosition: inPos += 32; outPos += getBitWidth() * 4

Parameters:

input - the input values

inPos - where to read from in input

output - the output bytes

outPos - where to write to in output

unpack8Values

public abstract void unpack8Values(byte[] input,
                 int inPos,
                 int[] output,
                 int outPos)

unpack bitWidth bytes from input at inPos into 8 values in output at outPos. nextPosition: inPos += getBitWidth(); outPos += 8

Parameters:

input - the input bytes

inPos - where to read from in input

output - the output values

outPos - where to write to in output

unpack32Values

public abstract void unpack32Values(byte[] input,
                  int inPos,
                  int[] output,
                  int outPos)

unpack bitWidth * 4 bytes from input at inPos into 32 values in output at outPos. nextPosition: inPos += getBitWidth() * 4; outPos += 32

Parameters:

input - the input bytes

inPos - where to read from in input

output - the output values

outPos - where to write to in output