arrow::array

Struct MapArray

pub struct MapArray {
    data_type: DataType,
    nulls: Option<NullBuffer>,
    entries: StructArray,
    value_offsets: OffsetBuffer<i32>,
}
Expand description

An array of key-value maps

Keys should always be non-null, but values can be null.

MapArray is physically a ListArray of key values pairs stored as an entries StructArray with 2 child fields.

See MapBuilder for how to construct a MapArray

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§data_type: DataType§nulls: Option<NullBuffer>§entries: StructArray§value_offsets: OffsetBuffer<i32>

Implementations§

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impl MapArray

pub fn try_new( field: Arc<Field>, offsets: OffsetBuffer<i32>, entries: StructArray, nulls: Option<NullBuffer>, ordered: bool, ) -> Result<MapArray, ArrowError>

Create a new MapArray from the provided parts

See MapBuilder for a higher-level interface to construct a MapArray

§Errors

Errors if

  • offsets.len() - 1 != nulls.len()
  • offsets.last() > entries.len()
  • field.is_nullable()
  • entries.null_count() != 0
  • entries.columns().len() != 2
  • field.data_type() != entries.data_type()

pub fn new( field: Arc<Field>, offsets: OffsetBuffer<i32>, entries: StructArray, nulls: Option<NullBuffer>, ordered: bool, ) -> MapArray

Create a new MapArray from the provided parts

See MapBuilder for a higher-level interface to construct a MapArray

§Panics

Panics if Self::try_new returns an error

pub fn into_parts( self, ) -> (Arc<Field>, OffsetBuffer<i32>, StructArray, Option<NullBuffer>, bool)

Deconstruct this array into its constituent parts

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) -> &Arc<dyn Array>

Returns a reference to the keys of this map

pub fn values(&self) -> &Arc<dyn Array>

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) -> MapArray

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

pub fn iter(&self) -> ArrayIter<&MapArray>

constructs a new iterator

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impl MapArray

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

Creates map array from provided keys, values and entry_offsets.

Trait Implementations§

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impl Array for MapArray

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fn as_any(&self) -> &(dyn Any + 'static)

Returns the array as Any so that it can be downcasted to a specific implementation. Read more
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fn to_data(&self) -> ArrayData

Returns the underlying data of this array
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fn into_data(self) -> ArrayData

Returns the underlying data of this array Read more
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fn data_type(&self) -> &DataType

Returns a reference to the DataType of this array. Read more
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fn slice(&self, offset: usize, length: usize) -> Arc<dyn Array>

Returns a zero-copy slice of this array with the indicated offset and length. Read more
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fn len(&self) -> usize

Returns the length (i.e., number of elements) of this array. Read more
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fn is_empty(&self) -> bool

Returns whether this array is empty. Read more
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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. Read more
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fn nulls(&self) -> Option<&NullBuffer>

Returns the null buffer of this array if any. Read more
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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.
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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.
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fn logical_nulls(&self) -> Option<NullBuffer>

Returns a potentially computed NullBuffer that represents the logical null values of this array, if any. Read more
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fn is_null(&self, index: usize) -> bool

Returns whether the element at index is null according to Array::nulls Read more
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fn is_valid(&self, index: usize) -> bool

Returns whether the element at index is not null, the opposite of Self::is_null. Read more
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fn null_count(&self) -> usize

Returns the total number of physical null values in this array. Read more
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fn is_nullable(&self) -> bool

Returns false if the array is guaranteed to not contain any logical nulls Read more
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impl<'a> ArrayAccessor for &'a MapArray

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type Item = StructArray

The Arrow type of the element being accessed.
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fn value(&self, index: usize) -> <&'a MapArray as ArrayAccessor>::Item

Returns the element at index i Read more
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unsafe fn value_unchecked( &self, index: usize, ) -> <&'a MapArray as ArrayAccessor>::Item

Returns the element at index i Read more
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impl Clone for MapArray

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fn clone(&self) -> MapArray

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
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impl Debug for MapArray

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

Formats the value using the given formatter. Read more
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impl From<ArrayData> for MapArray

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fn from(data: ArrayData) -> MapArray

Converts to this type from the input type.
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impl From<MapArray> for ArrayData

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fn from(array: MapArray) -> ArrayData

Converts to this type from the input type.
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impl From<MapArray> for GenericListArray<i32>

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fn from(value: MapArray) -> GenericListArray<i32>

Converts to this type from the input type.
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impl PartialEq for MapArray

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

Tests for self and other values to be equal, and is used by ==.
1.0.0 · source§

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

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

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🔬This is a nightly-only experimental API. (clone_to_uninit)
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