Struct arrow2::buffer::Buffer

pub struct Buffer<T: NativeType> { /* fields omitted */ }

Buffer is a contiguous memory region that can be shared across thread boundaries. The easiest way to think about Buffer<T> is being equivalent to an immutable Vec<T>, with the following differences:

• T must be NativeType
• clone is O(1)
• memory is sharable across thread boundaries (it is under an Arc)
• it supports external allocated memory (FFI)

Implementations

impl<T: NativeType> Buffer<T>

pub fn new() -> Self

Creates an empty Buffer.

pub fn new_zeroed(length: usize) -> Self

Creates a new Buffer filled with zeros.

pub fn from_vec(data: Vec<T>) -> Self

This is supported on non-crate feature cache_aligned only.

Takes ownership of Vec.

Implementation

This function is O(1)

pub fn len(&self) -> usize

Returns the number of bytes in the buffer

pub fn is_empty(&self) -> bool

Returns whether the buffer is empty.

pub fn as_slice(&self) -> &[T]

Returns the byte slice stored in this buffer

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

Returns a new Buffer that is a slice of this buffer starting at offset. Doing so allows the same memory region to be shared between buffers.

Panics

Panics iff offset is larger than len.

pub unsafe fn slice_unchecked(self, offset: usize, length: usize) -> Self

Returns a new Buffer that is a slice of this buffer starting at offset. Doing so allows the same memory region to be shared between buffers.

Safety

The caller must ensure offset + length <= self.len()

pub fn as_ptr(&self) -> *const T

Returns a pointer to the start of this buffer.

impl<T: NativeType> Buffer<T>

pub fn from_trusted_len_iter<I: TrustedLen<Item = T>>(iterator: I) -> Self

Creates a Buffer from an Iterator with a trusted length. Prefer this to collect whenever possible, as it often enables auto-vectorization.

Example

let v = vec![1u32];
let iter = v.iter().map(|x| x * 2);
let buffer = unsafe { Buffer::from_trusted_len_iter(iter) };
assert_eq!(buffer.len(), 1)

pub fn try_from_trusted_len_iter<E, I: TrustedLen<Item = Result<T, E>>>(
    iterator: I
) -> Result<Self, E>

Safety

This method assumes that the iterator’s size is correct and is undefined behavior to use it on an iterator that reports an incorrect length.

pub unsafe fn from_trusted_len_iter_unchecked<I: Iterator<Item = T>>(
    iterator: I
) -> Self

Creates a Buffer from an Iterator with a trusted (upper) length.

Safety

This method assumes that the iterator’s size is correct and is undefined behavior to use it on an iterator that reports an incorrect length.

pub unsafe fn try_from_trusted_len_iter_unchecked<E, I: Iterator<Item = Result<T, E>>>(
    iterator: I
) -> Result<Self, E>

Safety

This method assumes that the iterator’s size is correct and is undefined behavior to use it on an iterator that reports an incorrect length.

Trait Implementations

impl<T: Clone + NativeType> Clone for Buffer<T>

fn clone(&self) -> Buffer<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: NativeType> Debug for Buffer<T>

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

Formats the value using the given formatter.

impl<T: NativeType> Default for Buffer<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: NativeType> Deref for Buffer<T>

type Target = [T]

The resulting type after dereferencing.

fn deref(&self) -> &[T]

Dereferences the value.

impl<T: NativeType> From<MutableBuffer<T>> for Buffer<T>

fn from(buffer: MutableBuffer<T>) -> Self

Performs the conversion.

impl<T: NativeType, U: AsRef<[T]>> From<U> for Buffer<T>

fn from(p: U) -> Self

Performs the conversion.

impl<T: NativeType> FromIterator<T> for Buffer<T>

fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self

Creates a value from an iterator.

impl<T: PartialEq + NativeType> PartialEq<Buffer<T>> for Buffer<T>

fn eq(&self, other: &Buffer<T>) -> bool

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

fn ne(&self, other: &Buffer<T>) -> bool

This method tests for !=.

impl<T: NativeType> StructuralPartialEq for Buffer<T>