Struct BloomFilter 

pub struct BloomFilter { /* private fields */ }

Probabilistic set membership test for string terms.

Optimized for the BM25 file-pruning use case: insert all tokenized terms from a data file at write time; at search time, check whether any query term may be present. False positives keep the file (safe); false negatives are impossible.

Implementations

impl BloomFilter

pub fn with_capacity(capacity: usize, fpr: f64) -> Self

Construct a Bloom filter sized for capacity items at fpr false-positive rate.

Formula: m = -n * ln(p) / ln(2)², rounded up to the next 64-bit boundary. A capacity=10_000, fpr=0.01 filter uses ~12 KB of bit storage.

pub fn insert(&mut self, term: &str)

pub fn may_contain(&self, term: &str) -> bool

Returns true if term might be in the set (false positives possible). Returns false only when the term is definitely absent.

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

Serialize to bytes: u64_le(num_bits) || u64_le(word_0) || ... || u64_le(word_N).

pub fn from_bytes(bytes: &[u8]) -> Option<Self>

Deserialize from bytes produced by to_bytes. Returns None on malformed input.

pub fn num_bits(&self) -> usize

Trait Implementations

impl Clone for BloomFilter

fn clone(&self) -> BloomFilter

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.