Struct PQCodebook 

pub struct PQCodebook {
    pub config: PQConfig,
    pub rotation_matrix: Option<Vec<f32>>,
    pub centroids: Vec<f32>,
    pub version: u64,
    pub centroid_norms: Option<Vec<f32>>,
}

Learned codebook for Product Quantization with OPQ rotation

Trained once, shared across all segments (like CoarseCentroids).

Fields

config: PQConfig

Configuration

rotation_matrix: Option<Vec<f32>>

OPQ rotation matrix (dim × dim), stored row-major

centroids: Vec<f32>

Centroids: M subspaces × K centroids × subspace_dim

version: u64

Version for merge compatibility checking

centroid_norms: Option<Vec<f32>>

Precomputed centroid norms for faster distance computation

Implementations

impl PQCodebook

pub fn train(config: PQConfig, vectors: &[Vec<f32>], max_iters: usize) -> Self

Train codebook with OPQ rotation and anisotropic loss

pub fn encode(&self, vector: &[f32], centroid: Option<&[f32]>) -> PQVector

Encode a vector to PQ codes

pub fn decode(&self, codes: &[u8]) -> Vec<f32>

Decode PQ codes back to approximate vector

pub fn get_centroid(&self, subspace_idx: usize, code: u8) -> &[f32]

Get centroid for a specific subspace and code

pub fn rotate_query(&self, query: &[f32]) -> Vec<f32>

Rotate a query vector

pub fn save(&self, path: &Path) -> Result<()>

Save to binary file

pub fn write_to<W: Write>(&self, writer: &mut W) -> Result<()>

Write to any writer

pub fn load(path: &Path) -> Result<Self>

Load from binary file

pub fn read_from<R: Read>(reader: &mut R) -> Result<Self>

Read from any reader

pub fn size_bytes(&self) -> usize

Memory usage in bytes

Trait Implementations

impl Clone for PQCodebook

fn clone(&self) -> PQCodebook

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PQCodebook

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for PQCodebook

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Quantizer for PQCodebook

type Code = PQVector

The quantized code type

type Config = PQConfig

Configuration type

type QueryData = DistanceTable

Query-specific precomputed data for fast distance computation

fn encode(&self, vector: &[f32], centroid: Option<&[f32]>) -> Self::Code

Encode a vector (optionally relative to a centroid)

fn prepare_query( &self, query: &[f32], centroid: Option<&[f32]>, ) -> Self::QueryData

Prepare query-specific data for fast distance computation

fn compute_distance( &self, query_data: &Self::QueryData, code: &Self::Code, ) -> f32

Compute approximate distance using precomputed query data

fn decode(&self, code: &Self::Code) -> Option<Vec<f32>>

Decode a code back to approximate vector (if supported)

fn size_bytes(&self) -> usize

Memory usage of the quantizer itself (codebooks, etc.)

impl Serialize for PQCodebook

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

where __S: Serializer,

Serialize this value into the given Serde serializer.