Struct arrow::array::NullArray

pub struct NullArray { /* fields omitted */ }

An Array where all elements are nulls

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_eq!(array.len(), 10);
assert_eq!(array.null_count(), 10);

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.

Trait Implementations

impl Array for NullArray

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

Returns whether the element at index is null. All elements of a NullArray are always null.

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

Returns whether the element at index is valid. All elements of a NullArray are always invalid.

fn null_count(&self) -> usize

Returns the total number of null values in this array. The null count of a NullArray always equals its length.

fn as_any(&self) -> &dyn Any

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

fn data(&self) -> &ArrayData

Returns a reference to the underlying data of this array.

fn data_ref(&self) -> &ArrayData

Returns a reference-counted pointer to 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 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.

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 to_raw(&self) -> Result<(*const FFI_ArrowArray, *const FFI_ArrowSchema)>

returns two pointers that represent this array in the C Data Interface (FFI)

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

Performs the conversion.

impl JsonEqual for NullArray

fn equals_json(&self, json: &[&Value]) -> bool

Checks whether arrow array equals to json array.

fn equals_json_values(&self, json: &[Value]) -> bool

Checks whether arrow array equals to json array.

impl PartialEq<NullArray> for NullArray

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialEq<NullArray> for Value

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialEq<Value> for NullArray

fn eq(&self, json: &Value) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.