Struct arrow::ffi::ArrowArray

pub struct ArrowArray { /* fields omitted */ }

Struct used to move an Array from and to the C Data Interface. Its main responsibility is to expose functionality that requires both FFI_ArrowArray and FFI_ArrowSchema.

This struct has two main paths:

Import from the C Data Interface

• ArrowArray::empty to allocate memory to be filled by an external call
• ArrowArray::try_from_raw to consume two non-null allocated pointers

Export to the C Data Interface

• ArrowArray::try_new to create a new ArrowArray from Rust-specific information
• ArrowArray::into_raw to expose two pointers for FFI_ArrowArray and FFI_ArrowSchema.

Safety

Whoever creates this struct is responsible for releasing their resources. Specifically, consumers must call ArrowArray::into_raw and take ownership of the individual pointers, calling FFI_ArrowArray::release and FFI_ArrowSchema::release accordingly.

Furthermore, this struct assumes that the incoming data agrees with the C data interface.

Implementations

impl ArrowArray

pub unsafe fn try_new(
    data_type: &DataType,
    len: usize,
    null_count: usize,
    null_buffer: Option<Buffer>,
    offset: usize,
    buffers: Vec<Buffer>,
    child_data: Vec<ArrowArray>,
    nullable: bool
) -> Result<Self>

creates a new ArrowArray. This is used to export to the C Data Interface.

Safety

See safety of ArrowArray

pub unsafe fn try_from_raw(
    array: *const FFI_ArrowArray,
    schema: *const FFI_ArrowSchema
) -> Result<Self>

creates a new ArrowArray from two pointers. Used to import from the C Data Interface.

Safety

See safety of ArrowArray

Error

Errors if any of the pointers is null

pub unsafe fn empty() -> Self

creates a new empty ArrowArray. Used to import from the C Data Interface.

Safety

See safety of ArrowArray

pub fn into_raw(
    this: ArrowArray
) -> (*const FFI_ArrowArray, *const FFI_ArrowSchema)

exports ArrowArray to the C Data Interface

pub fn null_bit_buffer(&self) -> Option<Buffer>

returns the null bit buffer. Rust implementation uses a buffer that is not part of the array of buffers. The C Data interface’s null buffer is part of the array of buffers.

pub fn buffers(&self) -> Result<Vec<Buffer>>

returns all buffers, as organized by Rust (i.e. null buffer is skipped)

pub fn children(&self) -> Result<Vec<ArrayData>>

returns the child data of this array

pub fn len(&self) -> usize

the length of the array

pub fn is_empty(&self) -> bool

whether the array is empty

pub fn offset(&self) -> usize

the offset of the array

pub fn null_count(&self) -> usize

the null count of the array

pub fn data_type(&self, child_type: Option<DataType>) -> Result<DataType>

the data_type as declared in the schema

Trait Implementations

impl Debug for ArrowArray

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

Formats the value using the given formatter.

impl TryFrom<ArrayData> for ArrowArray

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(value: ArrayData) -> Result<Self>

Performs the conversion.

impl TryFrom<ArrowArray> for ArrayData

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(value: ArrowArray) -> Result<Self>

Performs the conversion.