Struct ethcore_bloom_journal::Bloom

pub struct Bloom { /* fields omitted */ }

Bloom filter structure

Methods

impl Bloom

pub 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.

pub fn from_parts(parts: &[u64], k_num: u32) -> Bloom

Initializes bloom filter from saved state

pub 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[

pub 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.

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

Records the presence of an item.

pub 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.

pub fn number_of_bits(&self) -> u64

Return the number of bits in the filter

pub fn number_of_hash_functions(&self) -> u32

Return the number of hash functions used for check and set

pub fn drain_journal(&mut self) -> BloomJournal

Drains the bloom journal returning the updated bloom part

pub fn saturation(&self) -> f64

Returns the ratio of set bits in the bloom filter to the total bits