Struct HnswIndex 

pub struct HnswIndex { /* private fields */ }

HNSW Index for approximate nearest neighbor search

Implementations

impl HnswIndex

pub fn new(config: HnswConfig) -> Self

Create a new HNSW index

pub fn build(&mut self, embeddings: &HashMap<String, Vec<f32>>) -> Result<()>

Build HNSW index from embeddings

pub fn search(&self, query: &[f32], k: usize) -> Result<Vec<SearchResult>>

Search for K nearest neighbors

pub fn batch_search( &self, queries: &[Vec<f32>], k: usize, ) -> Result<Vec<Vec<SearchResult>>>

Batch search for multiple queries

pub fn add(&mut self, entity_id: &str, vector: &[f32]) -> Result<()>

Add a new vector to the index (incremental update)

pub fn get_stats(&self) -> HnswStats

Get index statistics

pub fn set_ef_search(&mut self, ef: usize)

Set ef_search parameter (trade-off between speed and recall)

pub fn remove(&mut self, entity_id: &str) -> bool

Remove a vector from the index (lazy deletion with tombstone)

The vector is marked as deleted and will be excluded from search results. The actual data is not removed until compact() is called.

pub fn is_deleted(&self, entity_id: &str) -> bool

Check if a vector is deleted

pub fn deleted_count(&self) -> usize

Get the number of deleted vectors (tombstones)

pub fn active_count(&self) -> usize

Get the number of active (non-deleted) vectors

pub fn set_metadata(&mut self, entity_id: &str, metadata: Metadata)

Set metadata for an entity

pub fn set_metadata_batch(&mut self, metadata_map: HashMap<String, Metadata>)

Set metadata for multiple entities

pub fn get_metadata(&self, entity_id: &str) -> Option<&Metadata>

Get metadata for an entity

pub fn filtered_search( &self, query: &[f32], k: usize, filter: &Filter, ) -> Result<Vec<SearchResult>>

Search with metadata filtering (post-filtering)

Searches with HNSW, then filters results by metadata. Efficient when most results pass the filter.

pub fn prefiltered_search( &self, query: &[f32], k: usize, filter: &Filter, ) -> Result<Vec<SearchResult>>

Search with pre-filtering (filter candidates during search)

More accurate when filters are very selective, but may be slower. Uses brute-force search on filtered candidates.

pub fn optimize_graph(&mut self) -> Result<()>

Optimize the HNSW graph structure

This method performs periodic maintenance on the graph to improve search quality:

• Removes references to deleted nodes from neighbor lists
• Trims neighbor lists to respect the M parameter
• Rebuilds connections for isolated nodes

Call this method periodically after many deletions or additions to maintain optimal search performance.

pub fn compact(&mut self) -> Result<()>

Compact the index by removing tombstones

This method rebuilds the index without deleted vectors, freeing memory and improving cache efficiency. Use this after many deletions.

WARNING: This operation is expensive as it rebuilds the entire index.

Trait Implementations

impl Clone for HnswIndex

fn clone(&self) -> HnswIndex

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HnswIndex

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for HnswIndex

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for HnswIndex

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

where __S: Serializer,

Serialize this value into the given Serde serializer.