Struct MappedFile 

pub struct MappedFile { /* private fields */ }

A file’s bytes in array storage: on a Mac with a GPU, the file is memory-mapped and wrapped as GPU-visible memory without a copy, so arrays made from it are views whose pages are read when first touched (by the CPU or the GPU). Elsewhere the file is read into memory. The mapping lives as long as any array made from it.

use nuvec_core::{DType, MappedFile};

let path = std::env::temp_dir().join("nuvec-mapped-file-doc.bin");
let bytes: Vec<u8> = [1.0f32, 2.0, 3.0, 4.0].iter().flat_map(|v| v.to_le_bytes()).collect();
std::fs::write(&path, &bytes).unwrap();
let file = MappedFile::open(&path)?;
let a = file.array(4, DType::F32, &[3])?; // bytes 4..16, no copy
assert_eq!(a.to_vec::<f32>()?, vec![2.0, 3.0, 4.0]);

Implementations

impl MappedFile

pub fn open(path: impl AsRef<Path>) -> Result<Self>

Maps (or reads) the file at path.

pub fn len(&self) -> usize

The file’s size in bytes.

pub fn is_empty(&self) -> bool

Whether the file is empty.

pub fn bytes(&self) -> &[u8]

The file’s bytes.

pub fn section(&self, offset: usize, len: usize) -> Result<Self>

Bytes offset..offset + len as storage of their own: one copy into an aligned buffer, for files whose arrays are not aligned to their element sizes (safetensors written without header padding, as MLX writes them). Arrays made from the copy are views of it, and the file’s mapping is not kept.

pub fn array( &self, offset: usize, dtype: DType, shape: &[usize], ) -> Result<Array>

A row-major array of dtype and shape stored at byte offset: a view of the file if offset is a multiple of the element size, otherwise a copy.

Trait Implementations

impl Clone for MappedFile

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MappedFile

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

Formats the value using the given formatter.