Struct BloomFilter 

pub struct BloomFilter { /* private fields */ }

Bit-set Bloom filter with num_hashes independent bit positions per key, derived from one FNV-1a hash + one SplitMix64-scrambled secondary (Kirsch–Mitzenmacher double-hashing). Tunable via the constructor’s (num_items, fp_rate) target.

Implementations

impl BloomFilter

pub fn with_target_fp_rate(num_items: usize, fp_rate: f64) -> Self

Build a Bloom sized to keep the false-positive rate at or below fp_rate when populated with num_items distinct keys. Sizes are derived from the standard formulas

m = -(n × ln(p)) / (ln 2)^2
k =  ⌈m / n × ln 2⌉

rounded so num_bits is a multiple of 64 (one u64 word per bit-pack unit) and num_hashes is clamped to [1, NUM_HASHES_MAX].

Constructor panics on num_items == 0 or fp_rate ∉ (0, 1) — both indicate caller misuse, not a recoverable runtime condition. v5 internal call sites always supply sane numbers (segment row count + a configured target).

pub fn insert(&mut self, key: &[u8])

Insert one key. Idempotent (re-inserting flips no bits).

pub fn contains(&self, key: &[u8]) -> bool

Probe one key. Returns true if every bit position derived from the key is set — i.e. the key might be present; false is a hard absence (no FP on negative).

pub const fn num_bits(&self) -> u64

Bit-count introspection — used by segment writer to size the envelope and by tests to assert FP-rate calculations.

pub const fn num_hashes(&self) -> u32

Hash-count introspection.

pub fn encoded_len(&self) -> usize

Encoded byte length without actually building the buffer. Header (4+8+4+4 = 20) + (num_bits / 8) body bytes.

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

Serialise to the v1 file format. Used by the segment writer to embed the bloom into a sidecar section of the segment envelope.

pub fn from_bytes(input: &[u8]) -> Result<Self, BloomError>

Parse from the v1 file format. Validates magic, shape, num_hashes range, and CRC over the body before constructing the value — any of those failing returns BloomError rather than panicking.

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.

impl Debug for BloomFilter

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

Formats the value using the given formatter.