Struct VGraph 

pub struct VGraph { /* private fields */ }

Implementations

impl VGraph

pub fn dim(&self) -> usize

Dimension of the indexed vectors.

pub fn metric(&self) -> Metric

The metric the index orders by.

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

Writes the index for VGraph::open: to a temporary file next to path, synced, then renamed over it, so a reader never sees a partial file. Little-endian targets only (the arrays are written as they lie in memory).

pub fn open(path: &Path, residency: Residency) -> Result<Self>

Opens an index written by VGraph::save with its arrays where residency puts them. The search reads the arrays in place, so its results are those of the saved index.

A mapped index (the default, prefaulted) must not be modified or truncated while it is open: the mapping would change under the index, and a truncated page faults with SIGBUS. Replace the file by renaming a new one over it, as VGraph::save does.

impl VGraph

pub fn from_graph(g: &Graph, residual: bool) -> Result<Self, HmsError>

Encodes a built graph with the 8-bit residual code used by rerank (or none), unaligned rows and the build’s vertex order.

pub fn from_graph_with( g: &Graph, bits: u8, residual_bits: u8, align: bool, reorder: bool, id_bytes: u8, screen: bool, ) -> Result<Self, HmsError>

Encodes a built graph. bits (8 or 4) sizes the traversal code and residual_bits (0, 4 or 8) the re-rank code of its residual; align keeps every code row inside as few 128-byte lines as its size allows; reorder renumbers the vertices in breadth-first order (search still returns the original ids); id_bytes 3 stores neighbour ids in three bytes (graphs below 2^24 - 1 vertices) instead of 4, and 0 stores each list sorted and delta-coded as varints (sizes vary; reorder makes the deltas small); screen adds a 1-bit sign code of the rotated centred vector per vertex (RaBitQ-style, with a per-vertex factor) that the search consults before paying for the 8-bit estimate.

pub fn with_blocks(self, g: &Graph, bits: u8) -> Result<Self, HmsError>

Adds neighbour-block codes: every vertex stores, next to its neighbour list, a bits-per-coordinate code of each neighbour’s rotated centred vector in the fast-scan layout (32 codes per block), so one streamed read and one table scan estimate all neighbours of an expanded vertex instead of one random row fetch per neighbour (SymphonyQG’s layout; Gou et al., SIGMOD 2025). bits is 1, 2 or 4.

pub fn has_blocks(&self) -> bool

True if the index carries neighbour-block codes.

pub fn block_bytes(&self) -> usize

Bytes of the neighbour-block codes and scales.

pub fn has_screen(&self) -> bool

True if the index carries the 1-bit screen.

pub fn screen_bytes(&self) -> usize

Bytes of the screen rows.

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn has_residual(&self) -> bool

pub fn index_bytes(&self) -> usize

Bytes held by the index, residual and id map included.

pub fn residual_bytes(&self) -> usize

Bytes of the residual codes and their scales, which only rerank reads.

pub fn searcher(&self) -> VSearcher<'_>

A searcher with the knobs of the environment (SearchKnobs::from_env).

pub fn searcher_with(&self, knobs: SearchKnobs) -> VSearcher<'_>

A searcher with explicit SearchKnobs.