Struct galois_2p8::field::GeneralField

pub struct GeneralField { /* private fields */ }

Implements field arithmetic compatible with all IrreducablePolynomials.

Recall that there are two strategies for optimizing field arithmetic in GF(2^8): accessing direct multiplication and division tables, and manipulating logarithms and exponentials. The latter method requires fewer operations, but is only possible if the given IrreducablePolynomial is primitive.

This struct uses direct multiplication and division tables for its operations, and is compatible with all IrreducablePolynomials, including primitive ones. Operations are expected to be less performant than those implemented by PrimitivePolynomialField, with the exception of vector operations, which may be accelerated in both using multiplication and division tables. See the Field documentation for more details regarding vector operations.

Implementations

impl GeneralField

pub fn new(poly: IrreducablePolynomial) -> Self

Constructs a new GeneralField with all tables initialized.

Trait Implementations

impl Field for GeneralField

fn polynomial(&self) -> IrreducablePolynomial

Returns the polynomial modulo which all operations are performed.

fn mult(&self, src: u8, scale: u8) -> u8

Returns the result of src * scale in this field.

fn div(&self, src: u8, scale: u8) -> u8

Returns the result of src / scale in this field.

fn two_pow(&self, x: u8) -> u8

Returns the result of 2^x in this field.

fn mult_two_pow(&self, scale: u8, x: u8) -> u8

Returns the result of scale * 2^x in this field.

unsafe fn add_ptr_scaled_len(
    &self,
    dst: *mut u8,
    src: *const u8,
    scale: u8,
    len: usize
)

Adds scale * src[0..len] into dst[0..len] in place.

unsafe fn mult_ptr_len(&self, dst: *mut u8, scale: u8, len: usize)

Multiplies dst[0..len] by scale in place.

unsafe fn div_ptr_len(&self, dst: *mut u8, scale: u8, len: usize)

Divides dst[0..len] by scale in place.

fn add(&self, left: u8, right: u8) -> u8

Adds left and right, returning their sum.

fn sub(&self, left: u8, right: u8) -> u8

Subtracts right from left, returning the difference.

unsafe fn add_ptr_len(&self, dst: *mut u8, src: *const u8, len: usize)

Adds src[0..len] into dst[0..len].

fn add_multiword(&self, dst: &mut [u8], src: &[u8])

Adds src into dst in place, over the smallest common length.

fn add_multiword_len(&self, dst: &mut [u8], src: &[u8], len: usize)

Adds src[0..len] into dst[0..len].

fn add_scaled_multiword(&self, dst: &mut [u8], src: &[u8], scale: u8)

Adds src * scale into dst in place, over the smallest common length.

fn add_scaled_multiword_len(
    &self,
    dst: &mut [u8],
    src: &[u8],
    scale: u8,
    len: usize
)

Adds src[0..len] * scale into dst[0..len].

unsafe fn sub_ptr_len(&self, dst: *mut u8, src: *const u8, len: usize)

Subtracts src[0..len] from dst[0..len] in place.

unsafe fn sub_ptr_scaled_len(
    &self,
    dst: *mut u8,
    src: *const u8,
    scale: u8,
    len: usize
)

Subracts scale * src[0..len] from dst[0..len] in place.

fn sub_multiword(&self, dst: &mut [u8], src: &[u8])

Subtracts src from dst in place, over the smallest common length.

fn sub_multiword_len(&self, dst: &mut [u8], src: &[u8], len: usize)

Subtracts src[0..len] from dst[0..len] in place.

fn sub_scaled_multiword(&self, dst: &mut [u8], src: &[u8], scale: u8)

Subtracts scale * src from dst in place, over the smallest common length.

fn sub_scaled_multiword_len(
    &self,
    dst: &mut [u8],
    src: &[u8],
    scale: u8,
    len: usize
)

Subtracts scale * src[0..len] from dst[0..len] in place.

fn mult_multiword(&self, dst: &mut [u8], scale: u8)

Multiplies dst by scale in place.

fn div_multiword(&self, dst: &mut [u8], scale: u8)

Divides dst by scale in place.

impl Sync for GeneralField