org.apache.arrow.vector

Class NullVector

java.lang.Object

org.apache.arrow.vector.NullVector

All Implemented Interfaces:

Closeable, AutoCloseable, Iterable<ValueVector>, FieldVector, ValueVector

Direct Known Subclasses:

ZeroVector

public class NullVector
extends Object
implements FieldVector

A null type vector.

Field Summary

Fields

Modifier and Type	Field and Description
protected Field	field

Constructor Summary

Constructors

Constructor and Description
NullVector() Deprecated.
NullVector(Field field) Instantiate a NullVector.
NullVector(Field field, int valueCount) Instantiate a NullVector with the given number of values.
NullVector(String name) Instantiate a NullVector.
NullVector(String name, FieldType fieldType) Instantiate a NullVector.
NullVector(String name, int valueCount) Instantiate a NullVector with the given number of values.

Method Summary

Modifier and Type	Method and Description
<OUT,IN> OUT	accept(VectorVisitor<OUT,IN> visitor, IN value) Accept a generic VectorVisitor and return the result.
void	allocateNew() Allocate new buffers.
boolean	allocateNewSafe() Allocates new buffers.
void	clear() Release any owned ArrowBuf and reset the ValueVector to the initial state.
void	close() Alternative to clear().
void	copyFrom(int fromIndex, int thisIndex, ValueVector from) Copy a cell value from a particular index in source vector to a particular position in this vector.
void	copyFromSafe(int fromIndex, int thisIndex, ValueVector from) Same as ValueVector.copyFrom(int, int, ValueVector) except that it handles the case when the capacity of the vector needs to be expanded before copy.
BufferAllocator	getAllocator()
ArrowBuf[]	getBuffers(boolean clear) Return the underlying buffers associated with this vector.
int	getBufferSize() Get the number of bytes used by this vector.
int	getBufferSizeFor(int valueCount) Returns the number of bytes that is used by this vector if it holds the given number of values.
List<FieldVector>	getChildrenFromFields() The returned list is the same size as the list passed to initializeChildrenFromFields.
ArrowBuf	getDataBuffer() Gets the underlying buffer associated with data vector.
long	getDataBufferAddress() Gets the starting address of the underlying buffer associated with data vector.
Field	getField() Get information about how this field is materialized.
List<ArrowBuf>	getFieldBuffers() Get the buffers of the fields, (same size as getFieldVectors() since it is their content).
List<BufferBacked>	getFieldInnerVectors() Deprecated. This API will be removed as the current implementations no longer support inner vectors.
Types.MinorType	getMinorType()
String	getName() Gets the name of the vector.
int	getNullCount() Returns number of null elements in the vector.
Object	getObject(int index) Get friendly type object from the vector.
ArrowBuf	getOffsetBuffer() Gets the underlying buffer associated with offset vector.
long	getOffsetBufferAddress() Gets the starting address of the underlying buffer associated with offset vector.
FieldReader	getReader() Get a reader for this vector.
TransferPair	getTransferPair(BufferAllocator allocator) To transfer quota responsibility.
TransferPair	getTransferPair(Field field, BufferAllocator allocator) To transfer quota responsibility.
TransferPair	getTransferPair(Field field, BufferAllocator allocator, CallBack callBack) To transfer quota responsibility.
TransferPair	getTransferPair(String ref, BufferAllocator allocator) To transfer quota responsibility.
TransferPair	getTransferPair(String ref, BufferAllocator allocator, CallBack callBack) To transfer quota responsibility.
ArrowBuf	getValidityBuffer() Gets the underlying buffer associated with validity vector.
long	getValidityBufferAddress() Gets the starting address of the underlying buffer associated with validity vector.
int	getValueCapacity() Returns the maximum number of values that can be stored in this vector instance.
int	getValueCount() Gets the number of values.
int	hashCode(int index) Returns hashCode of element in index with the default hasher.
int	hashCode(int index, ArrowBufHasher hasher) Returns hashCode of element in index with the given hasher.
void	initializeChildrenFromFields(List<Field> children) Initializes the child vectors to be later loaded with loadBuffers.
boolean	isNull(int index) Check whether an element in the vector is null.
Iterator<ValueVector>	iterator()
void	loadFieldBuffers(ArrowFieldNode fieldNode, List<ArrowBuf> ownBuffers) Loads data in the vectors.
TransferPair	makeTransferPair(ValueVector target) Makes a new transfer pair used to transfer underlying buffers.
void	reAlloc() Allocate new buffer with double capacity, and copy data into the new buffer.
void	reset() Reset the ValueVector to the initial state without releasing any owned ArrowBuf.
void	setInitialCapacity(int numRecords) Set the initial record capacity.
void	setNull(int index) Set the element at the given index to null.
void	setValueCount(int valueCount) Set number of values in the vector.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.arrow.vector.FieldVector

exportBuffer, exportCDataBuffers

Methods inherited from interface org.apache.arrow.vector.ValueVector

validate, validateFull

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

field

protected Field field

Constructor Detail

NullVector

public NullVector(String name)

Instantiate a NullVector.

Parameters:

name - name of the vector

NullVector

public NullVector(String name,
                  int valueCount)

Instantiate a NullVector with the given number of values.

Parameters:

name - name of the vector

valueCount - number of values (i.e., nulls) in this vector.

NullVector

public NullVector(String name,
                  FieldType fieldType)

Instantiate a NullVector.

Parameters:

name - name of the vector

fieldType - type of Field materialized by this vector.

NullVector

public NullVector(Field field)

Instantiate a NullVector.

Parameters:

field - field materialized by this vector.

NullVector

public NullVector(Field field,
                  int valueCount)

Instantiate a NullVector with the given number of values.

Parameters:

field - field materialized by this vector.

valueCount - number of values (i.e., nulls) in this vector.

NullVector

@Deprecated
public NullVector()

Deprecated.

Method Detail

close

public void close()

Description copied from interface: ValueVector

Alternative to clear(). Allows use as an AutoCloseable in try-with-resources.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ValueVector

clear

public void clear()

Description copied from interface: ValueVector

Release any owned ArrowBuf and reset the ValueVector to the initial state. If the vector has any child vectors, they will also be cleared.

Specified by:

clear in interface ValueVector

reset

public void reset()

Description copied from interface: ValueVector

Reset the ValueVector to the initial state without releasing any owned ArrowBuf. Buffer capacities will remain unchanged and any previous data will be zeroed out. This includes buffers for data, validity, offset, etc. If the vector has any child vectors, they will also be reset.

Specified by:

reset in interface ValueVector

getField

public Field getField()

Description copied from interface: ValueVector

Get information about how this field is materialized.

Specified by:

getField in interface ValueVector

Returns:

the field corresponding to this vector

getMinorType

public Types.MinorType getMinorType()

Specified by:

getMinorType in interface ValueVector

getTransferPair

public TransferPair getTransferPair(BufferAllocator allocator)

Description copied from interface: ValueVector

To transfer quota responsibility.

Specified by:

getTransferPair in interface ValueVector

Parameters:

allocator - the target allocator

Returns:

a transfer pair, creating a new target vector of the same type.

iterator

public Iterator<ValueVector> iterator()

Specified by:

iterator in interface Iterable<ValueVector>

getBufferSize

public int getBufferSize()

Description copied from interface: ValueVector

Get the number of bytes used by this vector.

Specified by:

getBufferSize in interface ValueVector

Returns:

the number of bytes that is used by this vector instance.

getBufferSizeFor

public int getBufferSizeFor(int valueCount)

Description copied from interface: ValueVector

Returns the number of bytes that is used by this vector if it holds the given number of values. The result will be the same as if setValueCount() were called, followed by calling getBufferSize(), but without any of the closing side-effects that setValueCount() implies wrt finishing off the population of a vector. Some operations might wish to use this to determine how much memory has been used by a vector so far, even though it is not finished being populated.

Specified by:

getBufferSizeFor in interface ValueVector

Parameters:

valueCount - the number of values to assume this vector contains

Returns:

the buffer size if this vector is holding valueCount values

getBuffers

public ArrowBuf[] getBuffers(boolean clear)

Description copied from interface: ValueVector

Return the underlying buffers associated with this vector. Note that this doesn't impact the reference counts for this buffer so it only should be used for in-context access. Also note that this buffer changes regularly thus external classes shouldn't hold a reference to it (unless they change it).

Specified by:

getBuffers in interface ValueVector

Parameters:

clear - Whether to clear vector before returning; the buffers will still be refcounted; but the returned array will be the only reference to them

Returns:

The underlying buffers that is used by this vector instance.

allocateNew

public void allocateNew()
                 throws OutOfMemoryException

Description copied from interface: ValueVector

Allocate new buffers. ValueVector implements logic to determine how much to allocate.

Specified by:

allocateNew in interface ValueVector

Throws:

OutOfMemoryException - Thrown if no memory can be allocated.

allocateNewSafe

public boolean allocateNewSafe()

Description copied from interface: ValueVector

Allocates new buffers. ValueVector implements logic to determine how much to allocate.

Specified by:

allocateNewSafe in interface ValueVector

Returns:

Returns true if allocation was successful.

reAlloc

public void reAlloc()

Description copied from interface: ValueVector

Allocate new buffer with double capacity, and copy data into the new buffer. Replace vector's buffer with new buffer, and release old one

Specified by:

reAlloc in interface ValueVector

getAllocator

public BufferAllocator getAllocator()

Specified by:

getAllocator in interface ValueVector

setInitialCapacity

public void setInitialCapacity(int numRecords)

Description copied from interface: ValueVector

Set the initial record capacity.

Specified by:

setInitialCapacity in interface ValueVector

Parameters:

numRecords - the initial record capacity.

getValueCapacity

public int getValueCapacity()

Description copied from interface: ValueVector

Returns the maximum number of values that can be stored in this vector instance.

Specified by:

getValueCapacity in interface ValueVector

Returns:

the maximum number of values that can be stored in this vector instance.

getTransferPair

public TransferPair getTransferPair(String ref,
                                    BufferAllocator allocator)

Description copied from interface: ValueVector

To transfer quota responsibility.

Specified by:

getTransferPair in interface ValueVector

Parameters:

ref - the name of the vector

allocator - the target allocator

Returns:

a transfer pair, creating a new target vector of the same type.

getTransferPair

public TransferPair getTransferPair(Field field,
                                    BufferAllocator allocator)

Description copied from interface: ValueVector

To transfer quota responsibility.

Specified by:

getTransferPair in interface ValueVector

Parameters:

field - the Field object used by the target vector

allocator - the target allocator

Returns:

a transfer pair, creating a new target vector of the same type.

getTransferPair

public TransferPair getTransferPair(String ref,
                                    BufferAllocator allocator,
                                    CallBack callBack)

Description copied from interface: ValueVector

To transfer quota responsibility.

Specified by:

getTransferPair in interface ValueVector

Parameters:

ref - the name of the vector

allocator - the target allocator

callBack - A schema change callback.

Returns:

a transfer pair, creating a new target vector of the same type.

getTransferPair

public TransferPair getTransferPair(Field field,
                                    BufferAllocator allocator,
                                    CallBack callBack)

Description copied from interface: ValueVector

To transfer quota responsibility.

Specified by:

getTransferPair in interface ValueVector

Parameters:

field - the Field object used by the target vector

allocator - the target allocator

callBack - A schema change callback.

Returns:

a transfer pair, creating a new target vector of the same type.

makeTransferPair

public TransferPair makeTransferPair(ValueVector target)

Description copied from interface: ValueVector

Makes a new transfer pair used to transfer underlying buffers.

Specified by:

makeTransferPair in interface ValueVector

Parameters:

target - the target for the transfer

Returns:

a new transfer pair that is used to transfer underlying buffers into the target vector.

getReader

public FieldReader getReader()

Description copied from interface: ValueVector

Get a reader for this vector.

Specified by:

getReader in interface ValueVector

Returns:

a field reader that supports reading values from this vector.

initializeChildrenFromFields

public void initializeChildrenFromFields(List<Field> children)

Description copied from interface: FieldVector

Initializes the child vectors to be later loaded with loadBuffers.

Specified by:

initializeChildrenFromFields in interface FieldVector

Parameters:

children - the schema

getChildrenFromFields

public List<FieldVector> getChildrenFromFields()

Description copied from interface: FieldVector

The returned list is the same size as the list passed to initializeChildrenFromFields.

Specified by:

getChildrenFromFields in interface FieldVector

Returns:

the children according to schema (empty for primitive types)

loadFieldBuffers

public void loadFieldBuffers(ArrowFieldNode fieldNode,
                             List<ArrowBuf> ownBuffers)

Description copied from interface: FieldVector

Loads data in the vectors. (ownBuffers must be the same size as getFieldVectors())

Specified by:

loadFieldBuffers in interface FieldVector

Parameters:

fieldNode - the fieldNode

ownBuffers - the buffers for this Field (own buffers only, children not included)

getFieldBuffers

public List<ArrowBuf> getFieldBuffers()

Description copied from interface: FieldVector

Get the buffers of the fields, (same size as getFieldVectors() since it is their content).

Specified by:

getFieldBuffers in interface FieldVector

Returns:

the buffers containing the data for this vector (ready for reading)

getFieldInnerVectors

@Deprecated
public List<BufferBacked> getFieldInnerVectors()

Deprecated. This API will be removed as the current implementations no longer support inner vectors.

Get the inner vectors.

Specified by:

getFieldInnerVectors in interface FieldVector

Returns:

the inner vectors for this field as defined by the TypeLayout

getValidityBufferAddress

public long getValidityBufferAddress()

Description copied from interface: FieldVector

Gets the starting address of the underlying buffer associated with validity vector.

Specified by:

getValidityBufferAddress in interface FieldVector

Returns:

buffer address

getDataBufferAddress

public long getDataBufferAddress()

Description copied from interface: FieldVector

Gets the starting address of the underlying buffer associated with data vector.

Specified by:

getDataBufferAddress in interface FieldVector

Returns:

buffer address

getOffsetBufferAddress

public long getOffsetBufferAddress()

Description copied from interface: FieldVector

Gets the starting address of the underlying buffer associated with offset vector.

Specified by:

getOffsetBufferAddress in interface FieldVector

Returns:

buffer address

getValidityBuffer

public ArrowBuf getValidityBuffer()

Description copied from interface: ValueVector

Gets the underlying buffer associated with validity vector.

Specified by:

getValidityBuffer in interface ValueVector

Returns:

buffer

getDataBuffer

public ArrowBuf getDataBuffer()

Description copied from interface: ValueVector

Gets the underlying buffer associated with data vector.

Specified by:

getDataBuffer in interface ValueVector

Returns:

buffer

getOffsetBuffer

public ArrowBuf getOffsetBuffer()

Description copied from interface: ValueVector

Gets the underlying buffer associated with offset vector.

Specified by:

getOffsetBuffer in interface ValueVector

Returns:

buffer

getValueCount

public int getValueCount()

Description copied from interface: ValueVector

Gets the number of values.

Specified by:

getValueCount in interface ValueVector

Returns:

number of values in the vector

setValueCount

public void setValueCount(int valueCount)

Description copied from interface: ValueVector

Set number of values in the vector.

Specified by:

setValueCount in interface ValueVector

getObject

public Object getObject(int index)

Description copied from interface: ValueVector

Get friendly type object from the vector.

Specified by:

getObject in interface ValueVector

Parameters:

index - index of object to get

Returns:

friendly type object

getNullCount

public int getNullCount()

Description copied from interface: ValueVector

Returns number of null elements in the vector.

Specified by:

getNullCount in interface ValueVector

Returns:

number of null elements

setNull

public void setNull(int index)

Set the element at the given index to null. In a NullVector, this is a no-op.

Specified by:

setNull in interface FieldVector

Parameters:

index - position of element

isNull

public boolean isNull(int index)

Description copied from interface: ValueVector

Check whether an element in the vector is null.

Specified by:

isNull in interface ValueVector

Parameters:

index - index to check for null

Returns:

true if element is null

hashCode

public int hashCode(int index)

Description copied from interface: ValueVector

Returns hashCode of element in index with the default hasher.

Specified by:

hashCode in interface ValueVector

hashCode

public int hashCode(int index,
                    ArrowBufHasher hasher)

Description copied from interface: ValueVector

Returns hashCode of element in index with the given hasher.

Specified by:

hashCode in interface ValueVector

accept

public <OUT,IN> OUT accept(VectorVisitor<OUT,IN> visitor,
                           IN value)

Description copied from interface: ValueVector

Accept a generic VectorVisitor and return the result.

Specified by:

accept in interface ValueVector

Type Parameters:

OUT - the output result type.

IN - the input data together with visitor.

copyFrom

public void copyFrom(int fromIndex,
                     int thisIndex,
                     ValueVector from)

Description copied from interface: ValueVector

Copy a cell value from a particular index in source vector to a particular position in this vector.

Specified by:

copyFrom in interface ValueVector

Parameters:

fromIndex - position to copy from in source vector

thisIndex - position to copy to in this vector

from - source vector

copyFromSafe

public void copyFromSafe(int fromIndex,
                         int thisIndex,
                         ValueVector from)

Description copied from interface: ValueVector

Same as ValueVector.copyFrom(int, int, ValueVector) except that it handles the case when the capacity of the vector needs to be expanded before copy.

Specified by:

copyFromSafe in interface ValueVector

Parameters:

fromIndex - position to copy from in source vector

thisIndex - position to copy to in this vector

from - source vector

getName

public String getName()

Description copied from interface: ValueVector

Gets the name of the vector.

Specified by:

getName in interface ValueVector

Returns:

the name of the vector.