Struct bloomfilter::Bloom

pub struct Bloom { /* fields omitted */ }

Bloom filter structure

Methods

impl Bloom

fn new(bitmap_size: usize, items_count: usize) -> Bloom

Create a new bloom filter structure. bitmap_size is the size in bytes (not bits) that will be allocated in memory items_count is an estimation of the maximum number of items to store.

fn new_for_fp_rate(items_count: usize, fp_p: f64) -> Bloom

Create a new bloom filter structure. items_count is an estimation of the maximum number of items to store. fp_p is the wanted rate of false positives, in ]0.0, 1.0[

fn from_existing(
    bitmap: &[u8],
    bitmap_bits: u64,
    k_num: u32,
    sip_keys: [(u64, u64); 2]
) -> Bloom

Create a bloom filter structure with an existing state. The state is assumed to be retrieved from an existing bloom filter.

fn compute_bitmap_size(items_count: usize, fp_p: f64) -> usize

Compute a recommended bitmap size for items_count items and a fp_p rate of false positives. fp_p obviously has to be within the ]0.0, 1.0[ range.

fn set<T>(&mut self, item: T) where
    T: Hash, 

Record the presence of an item.

fn check<T>(&self, item: T) -> bool where
    T: Hash, 

Check if an item is present in the set. There can be false positives, but no false negatives.

fn check_and_set<T>(&mut self, item: T) -> bool where
    T: Hash, 

Record the presence of an item in the set, and return the previous state of this item.

fn bitmap(&self) -> Vec<u8>

Return the bitmap as a vector of bytes

fn number_of_bits(&self) -> u64

Return the number of bits in the filter

fn number_of_hash_functions(&self) -> u32

Return the number of hash functions used for check and set

fn sip_keys(&self) -> [(u64, u64); 2]

Return the keys used by the sip hasher

fn clear(&mut self)

Clear all of the bits in the filter, removing all keys from the set