Struct NullArray

pub struct NullArray {
    len: usize,
}

An array of null values

A NullArray is a simplified array where all values are null.

Example: Create an array

use arrow_array::{Array, NullArray};

let array = NullArray::new(10);

assert!(array.is_nullable());
assert_eq!(array.len(), 10);
assert_eq!(array.null_count(), 0);
assert_eq!(array.logical_null_count(), 10);
assert_eq!(array.logical_nulls().unwrap().null_count(), 10);

Fields

len: usize

Implementations

impl NullArray

pub fn new(length: usize) -> Self

Create a new NullArray of the specified length

Note: Use crate::array::new_null_array if you need an array of some other [DataType].

pub fn slice(&self, offset: usize, len: usize) -> Self

Returns a zero-copy slice of this array with the indicated offset and length.

pub fn builder(_capacity: usize) -> NullBuilder

Returns a new null array builder

Note that the capacity parameter to this function is deprecated. It now does nothing, and will be removed in a future version.

Trait Implementations

impl Array for NullArray

fn as_any(&self) -> &dyn Any

Returns the array as Any so that it can be downcasted to a specific implementation.

fn to_data(&self) -> ArrayData

Returns the underlying data of this array

fn into_data(self) -> ArrayData

Returns the underlying data of this array

fn data_type(&self) -> &DataType

Returns a reference to the [DataType] of this array.

fn slice(&self, offset: usize, length: usize) -> ArrayRef

Returns a zero-copy slice of this array with the indicated offset and length.

fn len(&self) -> usize

Returns the length (i.e., number of elements) of this array.

fn is_empty(&self) -> bool

Returns whether this array is empty.

fn offset(&self) -> usize

Returns the offset into the underlying data used by this array(-slice). Note that the underlying data can be shared by many arrays. This defaults to 0.

fn nulls(&self) -> Option<&NullBuffer>

Returns the null buffer of this array if any.

fn logical_nulls(&self) -> Option<NullBuffer>

Returns a potentially computed [NullBuffer] that represents the logical null values of this array, if any.

fn is_nullable(&self) -> bool

Returns false if the array is guaranteed to not contain any logical nulls

fn logical_null_count(&self) -> usize

Returns the total number of logical null values in this array.

fn get_buffer_memory_size(&self) -> usize

Returns the total number of bytes of memory pointed to by this array. The buffers store bytes in the Arrow memory format, and include the data as well as the validity map. Note that this does not always correspond to the exact memory usage of an array, since multiple arrays can share the same buffers or slices thereof.

fn get_array_memory_size(&self) -> usize

Returns the total number of bytes of memory occupied physically by this array. This value will always be greater than returned by get_buffer_memory_size() and includes the overhead of the data structures that contain the pointers to the various buffers.

fn shrink_to_fit(&mut self)

Shrinks the capacity of any exclusively owned buffer as much as possible

fn is_null(&self, index: usize) -> bool

Returns whether the element at index is null according to Array::nulls

fn is_valid(&self, index: usize) -> bool

Returns whether the element at index is not null, the opposite of Self::is_null.

fn null_count(&self) -> usize

Returns the total number of physical null values in this array.

impl Clone for NullArray

fn clone(&self) -> NullArray

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NullArray

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<ArrayData> for NullArray

fn from(data: ArrayData) -> Self

Converts to this type from the input type.

impl From<NullArray> for ArrayData

fn from(array: NullArray) -> Self

Converts to this type from the input type.

impl PartialEq for NullArray

fn eq(&self, other: &NullArray) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.