Struct arrow_array::array::MapArray

pub struct MapArray { /* private fields */ }

A nested array type where each record is a key-value map. Keys should always be non-null, but values can be null.

MapArray is physically a crate::array::ListArray that has a StructArray with 2 child fields.

Implementations

impl MapArray

pub fn offsets(&self) -> &OffsetBuffer<i32>

Returns a reference to the offsets of this map

Unlike Self::value_offsets this returns the OffsetBuffer allowing for zero-copy cloning

pub fn keys(&self) -> &ArrayRef

Returns a reference to the keys of this map

pub fn values(&self) -> &ArrayRef

Returns a reference to the values of this map

pub fn entries(&self) -> &StructArray

Returns a reference to the StructArray entries of this map

pub fn key_type(&self) -> &DataType

Returns the data type of the map’s keys.

pub fn value_type(&self) -> &DataType

Returns the data type of the map’s values.

pub unsafe fn value_unchecked(&self, i: usize) -> StructArray

Returns ith value of this map array.

Safety

Caller must ensure that the index is within the array bounds

pub fn value(&self, i: usize) -> StructArray

Returns ith value of this map array.

This is a StructArray containing two fields

pub fn value_offsets(&self) -> &[i32]

Returns the offset values in the offsets buffer

pub fn value_length(&self, i: usize) -> i32

Returns the length for value at index i.

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

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

impl MapArray

pub fn new_from_strings<'a>( keys: impl Iterator<Item = &'a str>, values: &dyn Array, entry_offsets: &[u32] ) -> Result<Self, ArrowError>

Creates map array from provided keys, values and entry_offsets.

Trait Implementations

impl Array for MapArray

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 buffers of this array if any

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

Returns whether the element at index is null. When using this function on a slice, the index is relative to the slice.

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

Returns whether the element at index is not null. When using this function on a slice, the index is relative to the slice.

fn null_count(&self) -> usize

Returns the total number of null values in this array.

impl Clone for MapArray

fn clone(&self) -> MapArray

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MapArray

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

Formats the value using the given formatter.

impl From<ArrayData> for MapArray

fn from(data: ArrayData) -> Self

Converts to this type from the input type.

impl From<MapArray> for ArrayData

fn from(array: MapArray) -> Self

Converts to this type from the input type.

impl From<MapArray> for ListArray

fn from(value: MapArray) -> Self

Converts to this type from the input type.

impl PartialEq<MapArray> for MapArray

fn eq(&self, other: &Self) -> 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 !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.