Struct Ibf 

pub struct Ibf { /* private fields */ }

A fixed-width Invertible Bloom Filter over u64 hash values.

k hash functions are simulated by rotating a seed before each cell selection. For PSync, set elements are hashes of NDN name strings.

Implementations

impl Ibf

pub fn new(size: usize, k: usize) -> Self

Create an IBF with size cells and k hash functions.

pub fn from_cells(cells: Vec<(u64, u64, i64)>) -> Self

Create an IBF from raw cell data (xor_sum, hash_sum, count).

Uses k = 3 hash functions (the PSync default). The number of cells is inferred from the length of cells.

pub fn cells(&self) -> Vec<(u64, u64, i64)>

Export cells as (xor_sum, hash_sum, count) tuples for wire encoding.

pub fn insert(&mut self, value: u64)

Insert a hash value into the IBF.

pub fn remove(&mut self, value: u64)

Remove a hash value from the IBF.

pub fn subtract(&self, other: &Ibf) -> Ibf

Subtract other from self (XOR fields, subtract counts).

The result encodes the symmetric difference of the two sets.

pub fn decode(&self) -> Option<(HashSet<u64>, HashSet<u64>)>

Attempt to decode the symmetric difference from a subtracted IBF.

Returns Some((in_self_not_other, in_other_not_self)) on success, or None if the difference is too large for the IBF to decode.

Trait Implementations

impl Clone for Ibf

fn clone(&self) -> Ibf

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Ibf

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

Formats the value using the given formatter.