Struct VariantBloomFilter 

pub struct VariantBloomFilter { /* private fields */ }

A variant bloom filter, the best choice for bigger data set. In this structure, k hash functions all has it’s own slice of bitmap, whose max size is u64::MAX. Usage:

use roaring_bloom_filter::*;

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

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

bf.contains(&12);

Variant Bloom Filter(VBF)

Every hash function has it’s own slice instead of sharing the whole bitmap. This introduce the possibility of concurrency of manipulating multiply hash function at the same time.

Implementations

impl VariantBloomFilter

pub fn from_scratch( slices_length: u32, slice_size: u64, target_false_positive_rate: f64, ) -> VariantBloomFilter

Create an empty variant 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
• 0 < f < 1

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

Create an empty bloom filter with max element’s size and false positive rate. The crate would calculate the best buckets length and bucket size.

Trait Implementations

impl BloomFilter for VariantBloomFilter

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 is_full(&self) -> bool

If this bloom filter is full.

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 VariantBloomFilter

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

Formats the value using the given formatter.