Struct HnswBackend 

pub struct HnswBackend { /* private fields */ }

HNSW vector backend wrapping HnswService.

Implementations

impl HnswBackend

pub fn new(config: HnswServiceConfig) -> Self

Create a new HNSW backend with the given configuration.

pub fn with_defaults() -> Self

Create with default configuration.

pub fn with_max_vectors(config: HnswServiceConfig, limit: usize) -> Self

Create with a capacity limit.

pub fn inner(&self) -> &HnswService

Access the underlying HnswService for legacy code paths.

pub fn save_to_file(&self, path: &Path) -> VectorResult<()>

Persist backend state (vectors, id map, tombstones, epoch, capacity).

Soft-deleted entries remain in the vector list but are recorded in the tombstones section so they stay excluded after [load_from_file]. See module docs for the compaction story.

pub fn load_from_file(path: &Path) -> VectorResult<Self>

Load a backend from a snapshot written by [save_to_file].

Backward compatible: files produced by plain HnswStore / HnswService save (entries + ef params only) load successfully with empty id_map, empty tombstones, epoch 0, and no capacity limit.

Trait Implementations

impl Debug for HnswBackend

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

Formats the value using the given formatter.

impl VectorBackend for HnswBackend

fn insert( &self, id: u64, key: &str, vector: &[f32], metadata: Value, ) -> VectorResult<()>

Insert a vector with the given numeric ID, string key, and metadata.

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

Search for the k nearest vectors to query.

fn len(&self) -> usize

Return the number of vectors currently stored.

fn contains(&self, id: u64) -> bool

Check whether a vector with the given ID exists.

fn remove(&self, id: u64) -> bool

Remove a vector by ID. Returns true if it was present.

fn flush(&self) -> VectorResult<()>

Persist any in-memory state to durable storage.

fn backend_name(&self) -> &str

Return a human-readable name for this backend (e.g. “hnsw”, “diskann”, “hybrid”).

fn current_epoch(&self) -> u64

Return the current monotonic epoch.

fn insert_with_epoch( &self, id: u64, key: &str, vector: &[f32], metadata: Value, parent_epoch: u64, ) -> VectorResult<()>

Insert a vector only if the store’s current epoch matches parent_epoch. If the epoch has advanced past parent_epoch, the call is rejected with VectorError::EpochConflict.

fn soft_delete(&self, id: u64) -> bool

Mark a vector as tombstoned instead of physically removing it.

fn compact(&self, older_than_epoch: u64) -> usize

Physically remove tombstones whose deletion epoch is older than older_than_epoch. Returns the number of entries purged.

fn tombstone_count(&self) -> usize

Return the number of tombstoned (soft-deleted) entries.

fn max_vectors(&self) -> Option<usize>

Return the configured maximum number of vectors, or None if unbounded.

fn set_max_vectors(&self, limit: Option<usize>)

Set the maximum number of vectors. Pass None for unbounded.

fn is_empty(&self) -> bool

Return true if the store contains no vectors.