Struct AdjacencyManager 

pub struct AdjacencyManager { /* private fields */ }

Unified adjacency manager for the dual-CSR architecture.

Orchestrates Main CSR (packed alive edges), L0-csr overlay (in-memory mutations), and Shadow CSR (deleted edges for time-travel). Data flush never invalidates or rebuilds the CSR.

Implementations

impl AdjacencyManager

pub fn new(max_bytes: usize) -> Self

Creates a new adjacency manager with the given memory budget.

pub fn get_neighbors( &self, vid: Vid, edge_type: u32, direction: Direction, ) -> Vec<(Vid, Eid)>

Returns neighbors for the current state (hot path, no version filtering).

Reads Main CSR + frozen segments + active overlay, minus tombstones. Tombstones from any layer remove edges from all lower layers.

pub fn get_neighbors_at_version( &self, vid: Vid, edge_type: u32, direction: Direction, version: u64, ) -> Vec<(Vid, Eid)>

Returns neighbors visible at a specific snapshot version.

Filters Main CSR entries by created_version, applies frozen/active overlay with version filtering, and resurrects Shadow CSR entries that were alive at the given version.

pub fn insert_edge( &self, src: Vid, dst: Vid, eid: Eid, edge_type: u32, version: u64, )

Records an edge insertion into the L0-csr overlay (both directions).

pub fn add_tombstone( &self, eid: Eid, src: Vid, dst: Vid, edge_type: u32, version: u64, )

Records a tombstone for a deleted edge in the L0-csr overlay.

pub fn set_main_csr(&self, edge_type: u32, direction: Direction, csr: MainCsr)

Sets the Main CSR for a specific edge type and direction.

Used by warm() to install a freshly built CSR from storage.

pub fn has_csr(&self, edge_type: u32, direction: Direction) -> bool

Checks whether a Main CSR exists for the given edge type and direction.

pub fn is_active_for(&self, edge_type: u32, direction: Direction) -> bool

Checks whether this manager has been activated for the given edge type.

Returns true if a Main CSR exists or the overlay has entries for this edge type and direction.

pub fn frozen_segment_count(&self) -> usize

Returns the number of frozen segments awaiting compaction.

pub fn should_compact(&self, threshold: usize) -> bool

Returns whether compaction should be triggered based on segment count.

pub fn compact(&self)

Compacts frozen overlay segments into the Main CSR.

Freezes the active overlay, merges all frozen segments with the existing Main CSR, moves tombstoned edges to Shadow CSR, and atomically swaps in the new Main CSR.

CRITICAL: Frozen segments remain readable until the new CSR is installed, eliminating the visibility gap where edges would be invisible.

pub async fn warm( &self, storage: &StorageManager, edge_type_id: u32, direction: Direction, version: Option<u64>, ) -> Result<()>

Warms the Main CSR from storage (L2 adjacency + L1 delta) for a specific edge type and direction.

Reads L2 adjacency datasets and L1 delta entries from Lance, builds a MainCsr with version metadata, and populates the ShadowCsr with L1 tombstones. Called once at startup or lazily on first access per edge type.

pub async fn warm_coalesced( &self, storage: &StorageManager, edge_type_id: u32, direction: Direction, version: Option<u64>, ) -> Result<()>

Coalesced warm() operation to prevent cache stampede (Issue #13).

Uses double-checked locking: fast-path checks if CSR already loaded, then acquires per-(edge_type, direction) lock to ensure only one concurrent warm() per adjacency key. Other readers wait for the first warm() to complete.

pub fn memory_usage(&self) -> usize

Returns the current approximate memory usage in bytes.

pub fn max_bytes(&self) -> usize

Returns the maximum memory budget in bytes.

pub fn shadow(&self) -> &ShadowCsr

Provides access to the shadow CSR for time-travel queries.

Trait Implementations

impl Debug for AdjacencyManager

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

Formats the value using the given formatter.