Crate sqry_db 

sqry-db: Salsa-style incremental computation engine for sqry.

This crate provides a demand-driven memoized query engine with file-level dependency tracking, three-tier cache invalidation, and incremental indexing support. All analysis queries (callers, callees, dependency impact, unused detection, etc.) are expressed as DerivedQuery implementations whose results are cached in a 64-shard ShardedCache and automatically invalidated when their input dependencies change.

Architecture

┌─────────────┐      ┌──────────────────┐      ┌──────────────���─┐
│  MCP / CLI   │─────▶│     QueryDb      │─────▶│  GraphSnapshot │
│  handlers    │      │  (ShardedCache)   │      │  (immutable)   │
└─────────────┘      └──────────────────┘      └────���───────────┘
                            │                          │
                      ┌─────┴──────┐           ┌──────┴───────┐
                      │ FileInput  │           │  NodeArena   │
                      │   Store    │           │  EdgeStore   │
                      └────────────┘           └──────────────┘

Three-Tier Invalidation

• Tier 1 — File-level deps: Every query records the FileId of every node it reads. Invalidated when any recorded file’s revision bumps.
• Tier 2 — Global edge revision: A single AtomicU64 that increments when any file’s edges change. Reverse queries (callers_of, is_node_in_cycle) set TRACKS_EDGE_REVISION = true.
• Tier 3 — Global metadata revision: A single AtomicU64 that increments when node metadata changes. find_unused sets TRACKS_METADATA_REVISION = true.

Usage

use sqry_db::{QueryDb, QueryDbConfig};

let config = QueryDbConfig::default();
let db = QueryDb::new(snapshot, config);
let result = db.get::<CallersQuery>(&node_id);

Re-exports

pub use cache::ShardedCache;

pub use comparative::ChangeType;

pub use comparative::ComparativeQueryDb;

pub use comparative::DiffOptions;

pub use comparative::DiffOutput;

pub use comparative::DiffSummary;

pub use comparative::NodeChange;

pub use comparative::NodeLocation;

pub use config::QueryDbConfig;

pub use dependency::DependencyRecorderGuard;

pub use input::FileInput;

pub use input::FileInputStore;

pub use persistence::DERIVED_FORMAT_VERSION;

pub use persistence::DERIVED_MAGIC;

pub use persistence::DerivedHeader;

pub use persistence::DerivedManifest;

pub use persistence::LoadError;

pub use persistence::LoadOutcome;

pub use persistence::PersistedEntry;

pub use persistence::QueryDeps;

pub use persistence::SkipReason;

pub use persistence::StagedEntry;

pub use persistence::load_derived;

pub use queries::dispatch::derived_path;

pub use queries::dispatch::load_derived_opportunistic;

pub use queries::dispatch::make_query_db_cold;

pub use query::DerivedQuery;

pub use query::QueryKey;

pub use query::QueryRegistry;

Modules

cache

64-shard query cache with three-tier invalidation.

compaction

Async background compaction for the graph arena.

comparative

ComparativeQueryDb for cross-snapshot operations.

config

Configuration for QueryDb.

dependency

Thread-local dependency recording with RAII cleanup.

input

File-level input storage with per-file revision counters.

persistence

Derived facts persistence to .sqry/graph/derived.sqry.

planner

Structural query planner for sqry-db.

queries

Derived queries: SCC, condensation, reachability, plus relation and analysis queries migrated from sqry-core::query::executor::graph_eval.

query

Derived query trait and TypeId-based query registry.

Structs

QueryDb

The central incremental computation database.

QueryDbMetrics

Lightweight snapshot of QueryDb cache-usage counters.