Struct galois_2p8::field::PrimitivePolynomialField

pub struct PrimitivePolynomialField { /* private fields */ }

Implements field arithmetic compatible with primitive 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 exponentiation and logarithm tables, and is only compatible with primitive IrreducablePolynomials. For an implementation compatible with all IrreducablePolynomials, see GeneralField.

Note that this implementation may also use multiplication and division tables for its vectorized operations. See the Field documentation for more details.

Implementations

impl PrimitivePolynomialField

pub fn new(poly: IrreducablePolynomial) -> Option<Self>

Constructs a new PrimitivePolynomialField with all tables initialized.

If the given poly argument is not primitive, this function returns None; otherwise it returns Some(f: PrimitivePolynomialField). In situations where the use of Option<PrimitivePolynomialField> is less ideal than incurring a panic, consider new_might_panic.

pub fn new_might_panic(poly: IrreducablePolynomial) -> Self

Constructs a new PrimitivePolynomialField with all tables initialized.

If the given poly argument is not primitive, this function panics. The contents of the resulting error message are not defined. In situations where incurring a panic is less ideal than the use of Option<PrimitivePolynomialField>, consider new.

Trait Implementations

impl Field for PrimitivePolynomialField

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 PrimitivePolynomialField