org.apache.arrow.vector

Class BitVectorHelper

java.lang.Object

org.apache.arrow.vector.BitVectorHelper

public class BitVectorHelper
extends Object

Helper class for performing generic operations on a bit vector buffer. External use of this class is not recommended.

Constructor Summary

Constructors

Constructor and Description
BitVectorHelper()

Method Summary

Modifier and Type	Method and Description
static int	bitIndex(int absoluteBitIndex) Get the relative index of bit within the byte in validity buffer
static int	byteIndex(int absoluteBitIndex) Get the index of byte corresponding to bit index in validity buffer
static int	get(ArrowBuf buffer, int index) Check if a bit at a given index is set or not.
static byte	getBitsFromCurrentByte(ArrowBuf data, int index, int offset)
static byte	getBitsFromNextByte(ArrowBuf data, int index, int offset)
static int	getNullCount(ArrowBuf validityBuffer, int valueCount) Given a validity buffer, find the number of bits that are not set.
static int	getValidityBufferSize(int valueCount) Compute the size of validity buffer required to manage a given number of elements in a vector.
static ArrowBuf	loadValidityBuffer(ArrowFieldNode fieldNode, ArrowBuf sourceValidityBuffer, BufferAllocator allocator)
static ArrowBuf	setValidityBit(ArrowBuf validityBuffer, BufferAllocator allocator, int valueCount, int index, int value) Set the bit at a given index to provided value (1 or 0).
static void	setValidityBit(ArrowBuf validityBuffer, int index, int value) Set the bit at a given index to provided value (1 or 0)
static void	setValidityBitToOne(ArrowBuf validityBuffer, int index) Set the bit at provided index to 1.

Methods inherited from class java.lang.Object

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

Constructor Detail

BitVectorHelper

public BitVectorHelper()

Method Detail

byteIndex

public static int byteIndex(int absoluteBitIndex)

Get the index of byte corresponding to bit index in validity buffer

bitIndex

public static int bitIndex(int absoluteBitIndex)

Get the relative index of bit within the byte in validity buffer

setValidityBitToOne

public static void setValidityBitToOne(ArrowBuf validityBuffer,
                                       int index)

Set the bit at provided index to 1.

Parameters:

validityBuffer -

index -

setValidityBit

public static void setValidityBit(ArrowBuf validityBuffer,
                                  int index,
                                  int value)

Set the bit at a given index to provided value (1 or 0)

Parameters:

validityBuffer -

index -

value -

setValidityBit

public static ArrowBuf setValidityBit(ArrowBuf validityBuffer,
                                      BufferAllocator allocator,
                                      int valueCount,
                                      int index,
                                      int value)

Set the bit at a given index to provided value (1 or 0). Internally takes care of allocating the buffer if the caller didn't do so.

Parameters:

validityBuffer -

allocator -

valueCount -

index -

value -

Returns:

ArrowBuf

get

public static int get(ArrowBuf buffer,
                      int index)

Check if a bit at a given index is set or not.

Parameters:

buffer -

index -

Returns:

1 if bit is set, 0 otherwise.

getValidityBufferSize

public static int getValidityBufferSize(int valueCount)

Compute the size of validity buffer required to manage a given number of elements in a vector.

Parameters:

valueCount -

Returns:

buffer size

getNullCount

public static int getNullCount(ArrowBuf validityBuffer,
                               int valueCount)

Given a validity buffer, find the number of bits that are not set. This is used to compute the number of null elements in a nullable vector.

Parameters:

validityBuffer -

valueCount -

Returns:

number of bits not set.

getBitsFromCurrentByte

public static byte getBitsFromCurrentByte(ArrowBuf data,
                                          int index,
                                          int offset)

getBitsFromNextByte

public static byte getBitsFromNextByte(ArrowBuf data,
                                       int index,
                                       int offset)

loadValidityBuffer

public static ArrowBuf loadValidityBuffer(ArrowFieldNode fieldNode,
                                          ArrowBuf sourceValidityBuffer,
                                          BufferAllocator allocator)