Struct RaBitQuantizer 

pub struct RaBitQuantizer { /* private fields */ }

RaBitQ 1-bit quantizer (32x compression, unbiased distance estimator).

Implementations

impl RaBitQuantizer

pub fn fit(training_vectors: &[Vec<f32>]) -> Self

Fit a quantizer from training vectors using the default rotation seed.

Computes the centroid as the per-dimension mean and generates a seeded random orthonormal rotation. Reproducible across runs.

Panics

Panics if training_vectors is empty or has inconsistent dimensions.

pub fn fit_with_seed(training_vectors: &[Vec<f32>], seed: u64) -> Self

Fit with an explicit rotation seed.

pub fn dim(&self) -> usize

Dimensionality.

pub fn encode(&self, vector: &[f32]) -> RaBitCode

Encode a vector into a RaBitQ code.

pub fn prepare_query(&self, query: &[f32]) -> PreparedQuery

Prepare a query once for repeated estimate_dist_sq calls.

pub fn estimate_dist_sq(&self, query: &PreparedQuery, code: &RaBitCode) -> f32

Estimate squared L2 distance between a prepared query and a code.

S = Σ (2bᵢ − 1) · rqᵢ, then ‖o−q‖² ≈ dtc² + ‖q−c‖² − 2·est_factor·S.

impl RaBitQuantizer

Inherent, not a trait impl.

These used to satisfy a Quantizer trait in vector::quantize, which had three implementors and was used polymorphically by nothing – no dyn Quantizer, no T: Quantizer bound anywhere in the workspace. The other two implementors (ScalarQuantizer, BinaryQuantizer) were a SECOND implementation of SQ8, which the index never called: hnsw.rs has its own SoA layout and its own AVX2 kernels in vector::simd. Two copies of one idea, one of them shipped and one of them merely benchmarked. That is the shape of every bug in the 1.0 audit, so the copy nobody ran was deleted and the abstraction over it went with it.

pub fn quantize(&self, vector: &[f32]) -> RaBitCode

Encode a vector to its 1-bit code. See Self::encode.

pub fn dequantize(&self, quantized: &RaBitCode) -> Vec<f32>

Reconstruct an approximate vector from its code. Lossy (sign-only) but directionally correct; used by [Self::distance_symmetric].

pub fn distance_quantized(&self, a: &RaBitCode, b: &RaBitCode) -> f32

Distance between two codes, with one side dequantized – RaBitQ’s estimator is asymmetric, so there is no honest code-to-code distance.

pub fn distance_asymmetric(&self, query: &[f32], quantized: &RaBitCode) -> f32

Distance from a full-precision query to a code. This is the estimator the index uses, though the hot path goes through simd::rabitq_asymmetric_l2_simd rather than here.

Trait Implementations

impl Clone for RaBitQuantizer

fn clone(&self) -> RaBitQuantizer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RaBitQuantizer

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for RaBitQuantizer

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for RaBitQuantizer

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.