Struct QueryDb 

pub struct QueryDb { /* private fields */ }

The central incremental computation database.

QueryDb owns the sharded query cache, file-level input store, and global revision counters. All derived queries are evaluated and cached through QueryDb::get.

Concurrency

QueryDb is Send + Sync. The sharded cache uses parking_lot::RwLock per shard (64 shards) for high-concurrency reads. Global revision counters use AtomicU64 with Ordering::Acquire / Ordering::Release semantics.

Implementations

impl QueryDb

pub fn new(snapshot: Arc<GraphSnapshot>, config: QueryDbConfig) -> Self

Creates a new QueryDb backed by the given graph snapshot.

Every built-in DerivedQuery is pre-registered so callers of the planner executor and the relation / cycle / unused queries never have to hand-register them. Extra query types can still be added via Self::register.

pub fn register<Q: DerivedQuery>(&mut self)

Registers a derived query type for cache routing.

Must be called once per query type before the first get call. Panics (in debug builds) if the query type is already registered.

pub fn get<Q: DerivedQuery>(&self, key: &Q::Key) -> Q::Value

Evaluates a derived query, returning the cached result if valid or recomputing and caching on miss/invalidation.

Cache validation

A cached result is returned only if ALL applicable tiers pass:

1. Every (FileId, revision) pair in the cached deps matches the current file revision in FileInputStore.
2. If Q::TRACKS_EDGE_REVISION, the cached edge_revision matches the current global counter.
3. If Q::TRACKS_METADATA_REVISION, the cached metadata_revision matches the current global counter.

pub fn snapshot(&self) -> &GraphSnapshot

Returns the current graph snapshot.

pub fn snapshot_arc(&self) -> Arc<GraphSnapshot>

Returns the current graph snapshot as an Arc.

pub fn set_snapshot(&mut self, snapshot: Arc<GraphSnapshot>)

Replaces the current snapshot with a new one.

This does NOT invalidate the cache. Use [bump_edge_revision] and/or [bump_metadata_revision] after updating to trigger invalidation on next access.

pub fn inputs(&self) -> &FileInputStore

Returns a reference to the file input store.

pub fn inputs_mut(&mut self) -> &mut FileInputStore

Returns a mutable reference to the file input store.

pub fn edge_revision(&self) -> u64

Returns the current global edge revision counter.

pub fn bump_edge_revision(&self) -> u64

Atomically increments the global edge revision counter and returns the new value.

pub fn metadata_revision(&self) -> u64

Returns the current global metadata revision counter.

pub fn bump_metadata_revision(&self) -> u64

Atomically increments the global metadata revision counter and returns the new value.

pub fn config(&self) -> &QueryDbConfig

Returns the database configuration.

pub fn metrics(&self) -> QueryDbMetrics

Returns a snapshot of the cache-usage counters.

The returned QueryDbMetrics is a coherent read of the hit and miss counters (modulo the usual memory-ordering semantics of two separate atomic reads). The counters are monotonic and never reset — callers interested in deltas should take a baseline, run the work, and diff.

Used by Phase 3C DB21 Proof 3 to assert “zero recomputation” after a cache warm-up, and by production telemetry to emit cache hit rates.

pub fn invalidate_all(&self)

Invalidates all cached results unconditionally.

This is a heavy operation used for full rebuilds.

pub fn cold_load_allowed(&self) -> bool

Returns true if a cold-load is still permitted for this QueryDb.

true at construction. Transitions to false after a successful persistence::load_derived call. Once false, subsequent load_derived calls return persistence::LoadError::AlreadyLoaded without reading the file.

Trait Implementations

impl Send for QueryDb

impl Sync for QueryDb