Struct BloomFilter 

pub struct BloomFilter {
    pub size: u16,
    pub num_hashes: u8,
    pub bits: Vec<u8>,
}

Per-file bloom filter for fast trigram membership testing.

Uses a 256-byte bitset with 5 independent hashes, yielding a false-positive rate of ~0.7% for up to 200 trigrams.

Fields

size: u16

Size of the bit array in bytes.

num_hashes: u8

Number of hash functions (k).

bits: Vec<u8>

The bit array backing the filter.

Implementations

impl BloomFilter

pub fn new(size: usize, num_hashes: u8) -> Self

Create a new bloom filter with the given size and number of hash functions.

pub fn insert(&mut self, trigram: Trigram)

Insert a trigram into the bloom filter.

pub fn contains(&self, trigram: Trigram) -> bool

Check if a trigram may be present in the filter.

Returns true if the trigram might be present (could be a false positive). Returns false only if the trigram is definitely not present.

pub fn serialize<W: Write>(&self, w: W) -> Result<()>

Serialize the bloom filter to a writer.

Errors

Returns an I/O error if the writer fails.

pub fn from_slice(data: &[u8]) -> Option<(&[u8], usize)>

Load from a slice (borrowed).

pub fn slice_contains(bits: &[u8], num_hashes: u8, trigram: Trigram) -> bool

Check if a slice (from mmap) contains a trigram.

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.