Struct bitar::chunker::FilterBits

pub struct FilterBits(pub u32);

Helper type for creating a bit mask to use while scanning for chunk boundaries.

The bit mask given from the filter is used to match against the rolling hash sum. When sum | filter_mask == sum then we have found a chunk boundary. That is, with a mask set to 0b1 a chunk will be found every 2nd byte on average. With a mask set to 0b11 a chunk will be found every 4th byte on average.

Tuple Fields

0: u32

Implementations

impl FilterBits

pub fn from_size(size: u32) -> Self

Create new filter mask with an average target size of the given value.

The actual target size will be the given size rounded down to the closest power of 2 value.

pub fn from_bits(bits: u32) -> Self

Create new filter mask from a number of bits.

Eg 1 => 0b1, 2 => 0b11, 3 => 0b111 etc.

pub fn mask(self) -> u32

Get the bit mask value of the filter.

pub fn chunk_target_average(self) -> u32

Get the average target size from the filter.

pub fn bits(self) -> u32

Get number of bits set in the filter.

Trait Implementations

impl Clone for FilterBits

fn clone(&self) -> FilterBits

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FilterBits

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

Formats the value using the given formatter.

impl Hash for FilterBits

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for FilterBits

fn eq(&self, other: &FilterBits) -> bool

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

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for FilterBits

impl Eq for FilterBits

impl StructuralPartialEq for FilterBits