Struct HnswIndex 

pub struct HnswIndex {
    pub m: usize,
    pub m_max0: usize,
    pub ef_construction: usize,
    pub entry_point: u32,
    pub max_level: u32,
    pub ef_search: usize,
    /* private fields */
}

A built HNSW index. Reads borrow from the on-disk payload at open time; the graph is owned (small relative to embeddings).

Fields

m: usize

m_max0: usize

ef_construction: usize

entry_point: u32

max_level: u32

ef_search: usize

the search beam floor, ef_construction at decode time: a caller’s ef widens the beam above it (max(ef, ef_search)) and never narrows it, so the recall measured at build stays the floor too.

Implementations

impl HnswIndex

pub fn build( vectors: Vec<f32>, n: usize, dim: usize, m: usize, ef_construction: usize, seed: u64, ) -> Self

Build an HNSW index from f32 vectors. Deterministic given the same seed. vectors is row-major n*dim.

pub fn build_from_int8( view: &Int8EmbeddingsView<'_>, m: usize, ef: usize, seed: u64, ) -> Self

Build from int8 quantized embeddings. Dequantizes once (lossy) and hands off to build. Recall ends up bounded by quantization noise; in practice still well above 0.95 @ k=10 for real corpora.

pub fn build_from_f16( bytes: &[u8], n: usize, dim: usize, m: usize, ef: usize, seed: u64, ) -> Self

Build from float16 LE bytes. Decodes once into f32 and builds.

pub fn build_from_f32( bytes: &[u8], n: usize, dim: usize, m: usize, ef: usize, seed: u64, ) -> Self

Build from raw f32 LE bytes. Copies into an owned buffer.

impl HnswIndex

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

Encode the index to bytes for embedding in section 0x07 (v2).

pub fn from_bytes( bytes: &[u8], n: usize, dim: usize, ) -> Result<Self, RuntimeError>

Parse an HNSW payload (v1 or v2). The vectors are reconstructed from the embeddings section by the caller; this constructor is for the on-disk graph only. Call attach_vectors before search.

impl HnswIndex

pub fn attach_vectors(&mut self, vectors: Vec<f32>)

Attach f32 vectors as the search store. Kept for callers that already hold an f32 buffer (build, tests); the runtime open path uses attach_store to avoid an f32 expansion.

pub fn level0_neighbors(&self, i: usize) -> &[u32]

Level-0 (densest layer) out-neighbors of node i, or an empty slice if i is out of range. Read-only accessor the graph build path uses to derive top-m semantic edges from the already-built hnsw graph without re-running an O(n^2) exact knn. The neighbor SET is the build-order hnsw adjacency; the graph builder sorts canonically before writing.

pub fn search(&self, q: &[f32], ef: usize) -> Vec<usize>

Search for the ef closest candidates to q. Returns ids only - the runtime reranks with the exact dot product to produce the final cosine score. the beam is max(ef, self.ef_search): ef widens the search above the file’s floor and never narrows it.