Struct scuttlebutt::bloomfilter::BloomFilter

pub struct BloomFilter { /* private fields */ }

Simple implementation of a Bloom Filter. Which is guaranteed to return 1 if an element is in the set, but returns 1 with probability p (settable) if an item is not in the set. Does not reveal what is in the set.

Implementations

impl BloomFilter

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

Create a new BloomFilter with size entries, using nhashes hash functions.

pub fn compute_expansion(p: f64) -> f64

Compute required expansion for false positive probability p.

That is - if you plan to insert n items into the BloomFilter, and want a false positive probability of p, then you should set the BloomFilter size to compute_expansion(p) * n.

pub fn compute_nhashes(p: f64) -> usize

Compute required number of hash functions for false positive probability p.

pub fn with_false_positive_prob(p: f64, n: usize) -> Self

Create a new BloomFilter with false positive probability p which can support up to n insertions.

pub fn len(&self) -> usize

Get the number of bins in this BloomFilter.

pub fn nhashes(&self) -> usize

Get the number of hash functions in this BloomFilter.

pub fn bins(&self) -> &[bool]

Get bloom filter bins.

pub fn as_bytes(&self) -> Vec<u8>

Get bloom filter bins packed in bytes.

pub fn from_bytes(bytes: &[u8], size: usize, nhashes: usize) -> Self

Create bloom filter from bytes.

pub fn bin<V: AsRef<[u8]>>(value: &V, hash_index: usize) -> usize

Compute the bin that this value would go to in a BloomFilter.

Result must be modded by the actual size of the bloom filter to avoid out of bounds errors.

pub fn insert<V: AsRef<[u8]>>(&mut self, value: &V)

Insert an item into the BloomFilter.

pub fn contains<V: AsRef<[u8]>>(&mut self, value: &V) -> bool

Check whether an item exists in the BloomFilter.

Trait Implementations

impl Debug for BloomFilter

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

Formats the value using the given formatter.

impl PartialEq<BloomFilter> for BloomFilter

fn eq(&self, other: &BloomFilter) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<BloomFilter> for BloomFilter

fn partial_cmp(&self, other: &BloomFilter) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for BloomFilter