Struct DeltaIndex 

pub struct DeltaIndex {
    pub dim: usize,
    /* private fields */
}

Secondary in-memory index that absorbs fresh inserts before they are patched into the main HNSW graph.

Fields

dim: usize

Implementations

impl DeltaIndex

pub fn new(dim: usize, max_fresh: usize) -> Self

Create a new delta index for vectors of dim dimensions.

max_fresh is the capacity threshold above which is_full() returns true, signalling that a compaction flush should be triggered.

pub fn insert(&mut self, id: u32, vector: Vec<f32>)

Stage a fresh insert. Does not deduplicate — callers must ensure IDs are unique across the delta and the main HNSW.

pub fn tombstone(&mut self, id: u32)

Mark id as tombstoned. It will be excluded from search results and from the patch applied to the main HNSW.

pub fn is_full(&self) -> bool

Returns true when the number of fresh vectors has reached max_fresh.

pub fn fresh_len(&self) -> usize

Number of un-drained fresh vectors.

pub fn search( &self, query: &[f32], k: usize, metric: DistanceMetric, ) -> Vec<(u32, f32)>

Brute-force scan over fresh vectors (excluding tombstones), returning the top-k results sorted ascending by distance.

pub fn drain_fresh(&mut self) -> Vec<(u32, Vec<f32>)>

Drain all staged fresh vectors for patching into the main HNSW. After this call fresh_len() returns 0.

pub fn drain_tombstones(&mut self) -> Vec<u32>

Drain the current tombstone set. After this call no IDs are considered tombstoned in this delta.

pub fn is_tombstoned(&self, id: u32) -> bool

Returns true if id is currently tombstoned in this delta.