Struct ScalableBloomFilter 

pub struct ScalableBloomFilter { /* private fields */ }

A scalable bloom filter implementation, based on VariantBloomFilter.

use roaring_bloom_filter::*;

let mut bf = ScalableBloomFilter::new(100, 0.001_f64);

bf.add(&10);
bf.add(&'a');
bf.add(&"a string");

bf.contains(&12);

Scalable Bloom Filter(SBF)

SBF is based on variant bloom filter, consists of one or more filter. When the first filter is full, a brand new filter with more k and smaller target false positive rate would be added, extending capacity of SBF while promising target false positive rate.

Implementations

impl ScalableBloomFilter

pub fn from_scratch( first_slices_length: u32, slice_size: u64, s: u8, r: f64, target_false_positive_rate: f64, ) -> ScalableBloomFilter

Create an empty scalable bloom filter from scratch.

Generally, user should not use this initializer directly. Promise the limitation on yourself:

• 0 < k <= u32::MAX
• 0 < m <= u32::MAX
• s = 2 or 4
• 0.8 <= r <= 0.9
• 0 < f < 1

pub fn new(first_max_size: u64, target_false_positive: f64) -> impl BloomFilter

Create an empty bloom filter with max element’s size for the first filter and false positive rate. The crate would calculate the best buckets length and bucket size, and make s = 4, r = 0.9.

Trait Implementations

impl BloomFilter for ScalableBloomFilter

fn is_full(&self) -> bool

Because this is scalable bloom filter, it never gets full

fn add<T>(&mut self, value: &T) -> bool

where T: Hash,

Add new element into the bloom filter. Return true when any key are inserted in a slice.

fn contains<T>(&self, value: &T) -> bool

where T: Hash,

Check if the bloom filter contains the specific key. Return true when all key are present in all slices, which may contains false positive situation.

fn target_false_positive_rate(&self) -> f64

Get target false positive rate.

fn current_false_positive_rate(&self) -> f64

Get current false positive rate.

fn is_empty(&self) -> bool

If this bloom filter is empty.

fn size(&self) -> u64

Get the number of inserted elements in this bloom filter.

fn len(&self) -> u64

Get the number of inserted bits in all slices.

impl Display for ScalableBloomFilter

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

Formats the value using the given formatter.